Effects of sodium L-lactate and sodium racemic lactate on intraoperative acid-base status. Lactated Ringer's solution is frequently used to avoid metabolic acidosis during fluid resuscitation. The standard lactated Ringer's solution contains racemic lactate, an equal mixture of the D- and L-stereoisomers. We investigated whether sodium L-lactate or sodium racemic lactate (DL-lactate) is more effective for increasing buffering capacity in body fluids. For the purpose of this comparison, Ringer's solutions containing no lactate, sodium L-lactate, or racemic lactate at a concentration of 84 mEq/L (three times more than the ordinary level) were infused in patients under general anesthesia during tympanoplasty. Although differences occurred among the three groups in blood concentrations of L-lactate, D-lactate, and the L-lactate/pyruvate ratio, no differences occurred between the two lactate groups in either bicarbonate ion concentration or base excess. The amount of buffering capacity increased significantly in both lactate groups, compared with preinfusion levels, and was more than the values in the nonlactated Ringer's solution group. We conclude that sodium racemic lactate is metabolized at nearly the same rate as that of sodium L-lactate.


A comparison of the effects of propofol and nitrous oxide on the electroencephalogram in epileptic patients during conscious sedation for dental procedures. The influence of sedative doses of propofol or nitrous oxide on the electroencephalogram was studied in 11 mentally handicapped patients with treated epilepsy undergoing dental procedures. At one session, propofol was titrated to achieve conscious sedation. The mean (+/- SD) dose requirements were 5.5 +/- 1.1 mg.kg-1.h-1. In six patients, the electroencephalogram was unchanged during propofol administration. In three patients, there was a decrease in epileptic activity, and in two patients, paroxysmal discharges disappeared. At another session, nitrous oxide was administered by nasal mask. The mean (+/- SD) concentration of nitrous oxide needed was 43.6% +/- 4.8%. The electroencephalogram did not change in nine patients, whereas in two patients epileptic activity decreased. There were no clinical epileptoid or other adverse manifestations during any treatment or up to 48 h thereafter. The results of the present study suggest that propofol or nitrous oxide can be administered in subanesthetic doses for conscious sedation in mentally handicapped patients with treated epilepsy.


Venous air embolism in prone dogs positioned with the abdomen hanging freely: percentage of gas retrieved and success rate of resuscitation. Based on reports of fatal venous air embolism (VAE) occurring during lumbar laminectomy and spinal fusion in prone patients positioned with the abdomen hanging freely, it has been recommended that monitoring for VAE should be used for such cases and that a multiorificed central venous catheter should be inserted for aspiration of VAE. The present study was designed to examine aspiration of VAE when prone dogs positioned with the abdomen hanging freely were given a fatal VAE via a femoral vein. Twenty-one dogs were anesthetized with halothane and nitrous oxide in oxygen and positioned with the abdomen ventral and hanging freely, the head fixed in a stereotaxic frame, the upper extremities resting on a surface approximately 10 cm below the level of the stereotaxic frame, and the lower extremities on a surface below the level of the upper extremities (to ensure that VAE entering the inferior vena cava would ascend toward the heart). In the control group (n = 7), a central catheter was placed but was not used to aspirate VAE. In a second group (n = 7), a Cook Bunegin-Albin multiorificed catheter was inserted; and in a third group (n = 7), an American Edwards 7F Swan-Ganz catheter was inserted. Dogs were then given a predetermined lethal dose of air (5 mL/kg) over 30 s via the femoral vein. In groups 2 and 3, attempts to aspirate VAE were begun with the first decrease in expired CO2. The amounts of gas retrieved (expressed as a percent of the injected air) and the incidence of successful resuscitation were compared.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of halothane, fentanyl, and ketamine on the threshold for transpulmonary passage of venous air emboli in dogs. We assumed that the capacity of the lungs to filter gas bubbles would vary as a function of anesthetic management. The effects of halothane (1% inspired concentration [group 1, n = 8]), fentanyl (100 micrograms/kg IV, followed by 1 micrograms.kg-1.min-1 [group 2, n = 7]), and ketamine (10 mg/kg IV, followed by 0.2 mg.kg-1.min-1 [group 3, n = 6]) on the passage of bolus injections of air across the pulmonary circulation were studied in dogs by using transesophageal echocardiography to detect air in the left atrium or the aorta, or both. The thresholds for bolus air detection during halothane, fentanyl, and ketamine administration were 0.05 mL/kg (range 0.01-0.1), 0.5 mL/kg (range 0.2-1.0), and 0.35 mL/kg (range 0.1-0.5), respectively. We conclude that the threshold during fentanyl- or ketamine-induced anesthesia was significantly higher than during halothane-induced anesthesia. Therefore, halothane interferes with the capacity of the lungs to filter air from the pulmonary circulation.


Isoflurane and nitrous oxide: comparative impact on cerebrospinal fluid pressure in patients with brain tumors. The relative effects on cerebrospinal fluid pressure (CSFP) of equipotent concentrations of isoflurane and N2O were compared in 20 patients with brain tumors who had lumbar subarachnoid catheters in place. Patients were randomly assigned to receive one of two anesthetic sequences: group 1, 0.7% end-tidal isoflurane in O2, which was changed to 70% N2O in O2; or group 2, 70% N2O in O2, which was changed to 0.7% end-tidal isoflurane in O2. End-tidal PCO2 and percent end-tidal N2O and isoflurane were monitored by mass spectrometry from just before changing anesthetics (time = 0 min) until the end of a 20-min observation period (time = 20 min). Ventilation was held constant at PaCO2 = 36 +/- 1 mm Hg (mean +/- SE). The patients in group 1 sustained an increase in CSFP that reached a maximum of 33% above the value at 0 min, despite a 3-mm Hg decrease in PaCO2 (P < 0.05). By contrast, CSFP remained unchanged in group 2. Although the absolute increase in CSFP after replacement of isoflurane/O2 by N2O/O2 anesthesia was relatively small (9 +/- 1 to 12 +/- 2 mm Hg; P < 0.05), the absence of a similar effect in patients where N2O was replaced by isoflurane suggests that replacement of isoflurane by an equipotent concentration of N2O is more likely to lead to an increase in CSFP in patients with altered intracranial dynamics than is replacement of N2O by isoflurane.


Effect of partial neuromuscular blockade on intraoperative electromyography in patients undergoing resection of acoustic neuromas. Intraoperative electromyographic monitoring of the facial nerve during acoustic neuroma excision provides early detection of nerve injury and improved outcome. To determine whether a useful level of peripheral neuromuscular blockade could be achieved without compromise of facial electromyographic monitoring, we studied 10 patients undergoing resection of acoustic neuroma. Facial nerve monitoring was accomplished by placement of wire electrodes in the orbicularis oris, orbicularis occuli, and mentalis muscles. Peripheral neuromuscular blockade was assessed by recording unprocessed hypothenar compound muscle action potentials (CMAPs). After induction of anesthesia, an infusion of atracurium (1.0 micrograms.kg-1.min-1) accompanied by a bolus dose of 50 micrograms/kg was administered. The infusion was then increased in increments of 0.5 micrograms.kg-1.min-1 until a 50% reduction in hypothenar single-twitch CMAP was obtained. Facial nerve function was continuously monitored by comparison of facial CMAPs produced by stimulation of the nerve proximal and distal to the tumor bed. The mean (+/- SD) infusion rate of atracurium was 2.55 +/- 0.75 micrograms.kg-1.min-1. Decrements in facial nerve CMAPs were detected in 6 of 10 patients, and all demonstrated moderate to severe facial nerve dysfunction. In no patient was an unexpected deficit present postoperatively. Moderate degrees of peripheral neuromuscular blockade can be achieved without compromising facial nerve electromyographic monitoring.


Comparison among intrathecal fentanyl, meperidine, and sufentanil for labor analgesia. This study compared the analgesic efficacy of intermittent injections of intrathecal fentanyl (10 micrograms), meperidine (10 mg), or sufentanil (5 micrograms) administered to 65 parturients during the first stage of labor. The groups did not differ in onset or duration of effective analgesia. The meperidine group, however, had significantly lower pain scores once cervical dilation progressed beyond 6 cm. Side effects included mild pruritus and nausea. After intrathecal drug injection, variable decelerations of the fetal heart rate increased in the fentanyl and meperidine groups. All neonates had a 5-min Apgar score of 7 or more. We conclude that intermittent intrathecal injections of fentanyl, meperidine, or sufentanil can provide adequate first-stage labor analgesia. Meperidine appears to provide more reliable analgesia as the first stage of labor progresses.


Nalbuphine is better than naloxone for treatment of side effects after epidural morphine. This study compared naloxone and nalbuphine when administered for treatment of side effects after epidural morphine, 5 mg, given for postcesarean analgesia. Patients requesting treatment for pruritus or nausea randomly received, in a double-blind fashion, up to three intravenous doses of either naloxone 0.2 mg (group 1; n = 20) or nalbuphine 5 mg (group 2; n = 20). The incidence of vomiting, the severity of nausea and pruritus, and the degree of sedation and pain were assessed before and 30 min after each dose. The first dose of nalbuphine decreased the incidence of vomiting (P < 0.005) and the severity of nausea and pruritus (P < 0.01), whereas naloxone caused no significant changes. Sedation scores increased after nalbuphine (P < 0.05) and remained unchanged after naloxone, whereas pain scores increased after naloxone (P < 0.01) and were unchanged after nalbuphine. Eighteen patients in group 1 and 12 in group 2 received a second dose, and 8 and 4 patients, respectively, a third dose. Other than decreased pruritus after the second dose with both drugs, no further changes occurred. We conclude that nalbuphine is superior to naloxone for the treatment of side effects after epidural morphine. However, persistent symptoms may require supplemental therapy, as repeated doses proved less effective than the initial dose.


Adverse effects of epidural 0.03% bupivacaine during analgesia after cesarean section. To develop a regimen that would provide good analgesia after cesarean section with minimal side effects in the setting of prolonged (> 24 h) epidural infusion, buprenorphine or fentanyl was combined with 0.03% bupivacaine in a double-blind study of 23 parturients. Patients were randomly assigned to two groups: group I (n = 12), patient-controlled analgesia by epidural infusion of buprenorphine (3 micrograms/mL) with 0.03% bupivacaine; group II (n = 11), patient-controlled analgesia by epidural infusion of fentanyl (2 micrograms/mL) with 0.03% bupivacaine. Plasma for determination of opioid concentrations was obtained at intermittent intervals. Pain relief was similar and satisfactory in both groups. The median overall satisfaction score was higher (10.0 vs 7.5; P < 0.03) for group II. Pruritus was mild in most patients. Nausea and vomiting, which were most disturbing to the patients, were seen only with buprenorphine. No patient had a respiratory rate of < 12 breaths/min. Mean plasma opioid concentrations did not exceed 1 ng/mL during the study. However, four patients (33%) in group I and six patients (55%) in group II experienced sensory loss in the lower extremities, which made ambulation difficult. One patient in each group developed extensive pressure blisters on both heels. These complications led us to terminate the study. We conclude that 0.03% bupivacaine used in combination with an opioid in prolonged epidural infusions produces a high incidence of sensory loss in the lower extremities and is unsuitable for situations in which early ambulation is desired.


Preoxygenation of pregnant and nonpregnant women in the head-up versus supine position. The influence of preoxygenation in the supine (n = 10) versus the 45 degrees head-up (n = 10) position on the duration of apnea leading to a decrease in arterial oxygen saturation to 95%, as monitored by pulse oximetry, was investigated in 20 women undergoing elective cesarean section at term of pregnancy. The results were compared with those obtained in a control group of 20 nonpregnant women. In the supine position, the average time to desaturation to 95% was significantly shorter in the pregnant group (173 +/- 4.8 s [mean +/- SD]) than in the control group of nonpregnant women (243 +/- 7.4 s). Using the head-up position resulted in an increase in the desaturation time in the nonpregnant group (331 +/- 7.2 s) but had no significant effect in the pregnant group (156 +/- 2.8 s). We conclude that pregnant women desaturate their arterial blood of oxygen more rapidly than do nonpregnant women. Furthermore, the head-up position extends the duration of apnea that can take place before desaturation occurs in nonpregnant patients.


Metoclopramide-enhanced analgesia for prostaglandin-induced termination of pregnancy. We previously determined that a single dose of metoclopramide could significantly reduce the patient-controlled analgesia (PCA) morphine requirements of women undergoing prostaglandin-induced termination of pregnancy. In the present study, we evaluated whether repeated doses of metoclopramide would further reduce pain and accelerate expulsion of the fetus. After intraamnionic injection of prostaglandin, patients were randomly allocated to receive either 10 mg of intravenous metoclopramide (n = 17) or saline (n = 15), concurrent with the initiation of PCA. A second, identical dose was administered 4 h later. Data included visual analogue scale scores for pain 45 min after each administration of metoclopramide or saline and visual analogue scale and sedation scores every 2 h for the first 10 h, amount of morphine delivered by PCA pump, time of fetal and placental passage, and hospital discharge. Metoclopramide-treated patients experienced significantly earlier fetal and placental passage (P < 0.05). This was associated with a 66% reduction in PCA morphine received by the time of fetal delivery (P < 0.05). In addition, patients in the metoclopramide group were discharged from the hospital significantly sooner (P < 0.05). This difference included fewer second-day hospital stays (P < 0.05). Visual analogue scale scores measured 45 min after each infusion of the study agent were reduced from baseline in the metoclopramide group only (P < 0.05). No significant intergroup differences were noted with respect to pain or interval morphine usage. We conclude that repeated doses of metoclopramide significantly reduce the duration of induced labor and therefore the total PCA morphine requirements.(ABSTRACT TRUNCATED AT 250 WORDS)


A comparison of methods for the detection of myocardial ischemia during noncardiac surgery: automated ST-segment analysis systems, electrocardiography, and transesophageal echocardiography. Clinicians often fail to detect intraoperative ischemic electrocardiographic (ECG) changes when viewing oscilloscopes. Automated ST-segment monitors promise to increase the detection of such ECG changes. We investigated the capacity of two commercially available ST-segment monitors to detect intraoperative myocardial ischemia in patients at high risk for developing intraoperative myocardial ischemia during vascular and other noncardiac procedures. The ST-segment monitors were compared with two reference monitors: (a) printed eight-lead ECGs, as interpreted by a cardiologist, and (b) the presence of segmental wall motion abnormalities and thickening abnormalities detected by transesophageal echocardiography (TEE). We also examined the capacity of the printed ECG to diagnose myocardial ischemia when compared with TEE. We studied 44 patients who underwent TEE, printed multilead ECG, oscilloscope monitoring of leads V5 and II, and measurement of ST-segment deviation from the baseline using an automated Hewlett Packard ST-segment device. The sensitivities for the Hewlett Packard system were 40% for TEE-diagnosed myocardial ischemia and 75% for ECG-diagnosed ischemia. Comparison of the printed ECG with TEE revealed that ST-segment changes in the printed ECG, as analyzed by a cardiologist, were 25% sensitive and 62% specific for the detection of TEE-diagnosed myocardial ischemia. When T-wave inversions were added to ST-segment depression as a criterion for the diagnosis of myocardial ischemia by the printed ECG, the sensitivity of ECG for the detection of intraoperative myocardial ischemia, as determined by TEE, was 40% and specificity was 58%. Twenty-three of the 44 patients were simultaneously monitored in leads I, II, and V5 with an automated Marquette ST-segment monitor.(ABSTRACT TRUNCATED AT 250 WORDS)


Lung traction causes an increase in plasma prostacyclin concentration and decrease in mean arterial blood pressure. The effects of lung traction on arterial blood pressure and plasma prostacyclin concentrations were studied in five patients undergoing partial pneumonectomy or lobectomy. After manual traction of a lung segment, mean arterial blood pressure decreased from 77 +/- 5 mm Hg (mean +/- SEM, before lung traction) to 59 +/- 5 mm Hg. The concentrations of 6-keto prostaglandin F1 alpha (a stable breakdown product of prostacyclin) increased significantly from 46 +/- 6 pg/mL (mean +/- SEM, before thoracotomy) to 593 +/- 91 pg/mL. Four of five patients showed facial flushing and palmar erythema. Arterial blood pressure returned to pretraction value, and both the facial flushing and palmar erythema disappeared within 30 min after lung traction. These results suggest that traction of the lung stimulates release and/or production of prostacyclin, which results in facial flushing, palmar erythema, and decrease in arterial blood pressure.


Comparison of two techniques to inflate the bronchial cuff of the Univent tube. The Univent tube is an endotracheal tube with a movable bronchial blocker. The blocker cuff reportedly exhibits high-pressure characteristics when inflated to seal any adult bronchus. This study was aimed at measuring the cuff volume that would seal the bronchus when two different techniques of cuff inflation were used. One technique is based on creating negative pressure and the other is based on creating positive pressure within the breathing system. In addition, we directly measured the compliance characteristics of the cuff. The study was performed in eight adult patients undergoing thoracotomy. The negative pressure technique of cuff inflation (NPT) was tested by applying -150 mm Hg of pressure to the blocker lumen, causing loss of volume in the breathing system as evidenced by deflation of the reservoir bag. The blocker cuff was then inflated until the bag ceased to deflate. In the positive pressure technique of cuff inflation (PPT), the blocker lumen was connected to a beaker of water while maintaining pressure of +30 mm Hg within the breathing system. The bronchial cuff was then inflated until air bubbles ceased to appear in the beaker. Direct measurement of compliance of the blocker cuff confirmed its high-pressure characteristics. Bronchial sealing volume ranged from 3 to 5 mL when measured with the NPT and from 4 to 6 mL when measured with the PPT.(ABSTRACT TRUNCATED AT 250 WORDS)


Tracheal intubation without the use of muscle relaxants: a technique using propofol and varying doses of alfentanil. We have noted that tracheal intubation can be accomplished in many patients after induction of anesthesia with propofol and alfentanil without the simultaneous use of muscle relaxants. This study was designed to evaluate airway and intubating conditions after administration of propofol and alfentanil in 75 ASA physical status I or II outpatients with Mallampati class I airways undergoing various surgical procedures. The patients were randomly assigned to one of five groups for induction of anesthesia. All patients received midazolam 1 mg IV before induction of anesthesia. Group I patients (n = 15) received d-tubocurarine 3 mg, thiamylal 4 mg/kg, and succinylcholine 1 mg/kg IV. Groups II-V patients (n = 15 each) received alfentanil 30, 40, 50, or 60 micrograms/kg followed by propofol 2 mg/kg IV. No muscle relaxants were given to patients in groups II-V. Airway management was performed by one of the authors who was blinded as to the dose of alfentanil administered. After loss of consciousness, patients' lungs were ventilated via face mask, and the ease of ventilation was recorded. Jaw mobility was also assessed. Ninety seconds after administration of the propofol or thiamylal, laryngoscopy was performed and exposure of the glottis and position of the vocal cords were noted. Intubation of the trachea was performed and patient response was noted. Heart rate and arterial blood pressure were also recorded before induction of anesthesia, after induction, and then again after intubation of the trachea. The lungs of all patients were easily ventilated via mask, and the jaw was judged to be relaxed in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)


Comparison of the anesthetic requirement for tolerance of laryngeal mask airway and endotracheal tube. We tested the hypothesis that the laryngeal mask airway (LMA) is tolerated at lighter levels of anesthesia than an endotracheal tube (ET). We studied 20 unpremedicated, nonsmoking ASA physical status I or II patients aged 18-40 yr whose surgery lasted > 1 h. Subjects were randomly assigned to receive either an ET or LMA. Anesthesia was induced with intravenous propofol and the LMA or ET was inserted. The ET-group patients received 1.5 mg/kg of succinylcholine, preceded by vecuronium (0.015 mg/kg IV). Maintenance of anesthesia was with only isoflurane and approximately 66% N2O in O2 by spontaneous ventilation. All gas concentrations were measured by a Raman spectrometer sampling from the breathing circuit end of the LMA or ET. Toward the end of the procedure, the end-tidal N2O and isoflurane concentrations were allowed to decrease to < 3 vol% and 0.8 +/- 0.05 vol%, respectively. The end-tidal isoflurane concentration was then decreased in 0.1% +/- 0.05% decrements, each stable value being held for 5 min. The patient was observed for signs of reaction to the presence of the LMA or ET. The mean (range) end-tidal isoflurane concentrations for reaction to ET and LMA were 0.55% (0.4-0.7) and 0.35% (0.2-0.51), respectively (P < 0.001). These data confirm the original hypothesis of the study.


A randomized, double-blind comparison of lumbar epidural and intravenous fentanyl infusions for postthoracotomy pain relief. Analgesic, pharmacokinetic, and respiratory effects. Although epidural opioids frequently are used to provide postoperative analgesia, several articles have suggested that the analgesia after epidural fentanyl is similar to that after an equal dose of fentanyl given intravenously. To address this issue further, 29 postthoracotomy patients were studied in a randomized, double-blinded trial comparing a lumbar epidural fentanyl infusion with an intravenous fentanyl infusion for analgesia, plasma fentanyl pharmacokinetics, and respiratory effects for 20 h postoperatively. In all patients in both groups, good analgesia was achieved (pain score less than 3, maximum 10) over a similar time course, although the patients receiving epidural infusion required a significantly larger fentanyl infusion dose than did the patients receiving intravenous infusion (group receiving epidural fentanyl infusion: 1.95 +/- 0.45 micrograms.kg-1.h-1; group receiving intravenous fentanyl infusion: 1.56 +/- 0.36 micrograms.kg-1.h-1; P = 0.0002). The time course for the plasma fentanyl concentrations was similar in the two groups, and plasma fentanyl concentrations were not significantly different at any sampling period (T7-T20; group receiving epidural fentanyl infusion: 1.8 +/- 0.5 ng/ml; group receiving intravenous fentanyl infusion: 1.6 +/- 0.6 ng/ml; P = 0.06). Similarly, calculated clearance values for the two groups were not significantly different (group receiving epidural fentanyl infusion: 0.95 +/- 0.26 l.kg-1.h-1; group receiving intravenous fentanyl infusion: 0.87 +/- 0.25 l.kg-1.h-1; P = 0.3). Both groups demonstrated a similar degree of mild to moderate respiratory depression postoperatively, which was assessed with continuous respiratory inductance plethysmography and sequential arterial blood gas analysis. Side effects (nausea, vomiting, pruritus) were mild and did not differ between groups.(ABSTRACT TRUNCATED AT 250 WORDS)


ST segment depression during labor and delivery. ECG changes suggestive of myocardial ischemia are common during cesarean delivery under regional anesthesia. To determine the time course, duration, and significance of these ECG changes, we monitored 111 parturients with continuous ambulatory ECG (Holter) during and after cesarean delivery. Twenty-two parturients undergoing vaginal delivery were similarly monitored. ST segment depression was present in 25% of patients undergoing cesarean delivery but was not found in those patients delivering vaginally. ST segment elevation was not detected in either group. The incidence of ST segment depression during cesarean delivery was similar with epidural (29%), spinal (17%), and general (18%) anesthesia, occurring most commonly in the 30 min following delivery (P less than 0.001). Transthoracic echocardiographic imaging was performed in 23 patients undergoing cesarean section. Five of the 23 patients had seven episodes of intraoperative ST segment depression. Regional wall motion abnormalities were not present in any patient. A decrease in ejection fraction area greater than 15% from baseline or from previous interval ejection fraction area was present during four episodes of ST change. Three episodes of ST depression were not associated with significant decreases in ejection fraction area. Precordial Doppler monitoring for detection of venous air embolism in 25 patients revealed no association between the occurrence of venous air embolism and ST segment depression. We conclude that although significant myocardial impairment during cesarean delivery does not occur, episodes of ST depression may not all be merely an artifact of parturition.


Elderly, conscious patients have an accentuated hypotensive response to nitroglycerin. There is no adequate explanation for the highly variable response of systemic blood pressure to nitroglycerin (glyceryl trinitrate [GTN]). Aging produces cardiovascular changes that should alter the effects of GTN, but elderly patients usually have been excluded from studies of GTN. Accordingly, the authors compared the effects of GTN on systemic blood pressure in elderly and younger patients. Fifty-three patients, aged 49-87 (with 30 patients older than 70), were studied. Before elective vascular surgery, 14 patients received an infusion of placebo; 26, a constant infusion of GTN; and 13, a stepwise increasing infusion of GTN. After a standardized anesthetic induction and the start of surgery, the identical infusion protocols were repeated in each group. Data on GTN infusion rate, arterial blood pressure, and GTN concentrations versus time, age, and other potentially influencing variables were pooled for analysis. Before anesthesia and surgery, GTN more commonly caused excessive hypotension in patients older than 70 yr than in younger patients, but none of the patients had complications. A repeated-measures model analysis indicated that age significantly influenced the effects of GTN on blood pressure. That is, patients who are in their 70s who receive 0.5 micrograms.kg-1.min-1 of GTN are predicted to experience a twofold greater decrease in systolic arterial pressure (approximately 33 mmHg) than patients in their 50s. However, no apparent effect of age on intraoperative GTN responsiveness was discernible nor was a predictable relationship found between the preoperative and intraoperative responsiveness or between arterial concentrations of GTN and blood pressure or age. Therefore, the authors conclude that, in the absence of the effects of anesthesia and surgery, elderly patients have a more pronounced blood pressure response to GTN than younger patients. Furthermore, the authors conclude that preoperative blood pressure responsiveness to GTN is not a reliable predictor of intraoperative responsiveness.


Kinetics of cerebral deoxygenation during deep hypothermic circulatory arrest in neonates. Brain injury associated with neonatal congenital heart operations performed during deep hypothermia and/or total circulatory arrest is often attributed to cerebral hypoxia. We studied the kinetic changes in cerebrovascular hemoglobin O2 saturation (HbO2%) and total hemoglobin concentration (Hbtotal) in 17 neonates undergoing cardiac surgery as they were cooled to 15 degrees C, underwent total circulatory arrest, and were rewarmed. HbO2% and Hbtotal in brain vasculature were monitored noninvasively by near-infrared spectroscopy. Neonates were cooled over 12 min and rewarmed over 15 min while being perfused using cardiopulmonary bypass (CPB). Total circulatory arrest lasted from 20 to 70 min. We found that HbO2% in brain vasculature increased during the initial 8 min of CPB as nasopharyngeal temperature decreased, and then remained constant until circulatory arrest. After the onset of circulatory arrest, cerebrovascular HbO2% decreased curvilinearly for 40 min; no further hemoglobin desaturation was observed from 40 to 70 min of arrest. The changes in cerebrovascular Hbtotal were quite different from those in HbO2%, as Hbtotal decreased during the initial minute of CPB and circulatory arrest and then remained constant until recirculation. Brain intravascular HbO2% and Hbtotal increased within 3 min after the onset of recirculation to prearrest levels, and during rewarming, HbO2% decreased to normothermic baseline values. The results demonstrate that cerebral oxygenation increased during CPB cooling; O2 was consumed by the neonatal brain during the initial 40 min of deep hypothermic circulatory arrest; and cerebral oxygenation was restored on recirculation. These observations may be important in identifying the etiologies of brain injury during neonatal congenital heart surgery.


Spectral analysis of heart rate variability during isoflurane anesthesia. The autonomic nervous system is an important neural control system for maintaining cardiovascular stability in humans. Analysis of heart rate variations may provide important clinical information on the influence of anesthesia on the autonomic nervous system and the central nervous system. Therefore, the effects of 1.0, 1.5, and 2.0 minimum alveolar concentrations of isoflurane anesthesia on beat-to-beat heart rate variations were studied in ten patients (ASA Physical Status 1). Spectral analysis was used to determine the intensity of the variations. For each power spectrum, the frequency components were identified as follows: 1) the parasympathetically mediated respiratory component (0.15-0.4 Hz) and 2) both parasympathetically and sympathetically mediated components (0.04-0.15 Hz). The latter was subdivided into the low-frequency component (0.04-0.09 Hz) of vasomotor origin and the mid-frequency component (0.09-0.15 Hz) of baroreceptor origin. Marked reductions in the power of heart rate variations, at all frequencies, were found during isoflurane anesthesia, indicating isoflurane decreased total autonomic nervous system activity. Isoflurane decreased the high-frequency and mid-frequency components in a concentration-dependent manner. The low-frequency component increased transiently at 1.5 minimum alveolar concentrations concomitant with the burst suppression in the electroencephalogram. The ratio of mid-frequency to high-frequency components did not change significantly during isoflurane anesthesia compared with the awake period. These frequency characteristics of heart rate variations during isoflurane anesthesia suggest there are dose-related decreases in autonomic nervous system activity in both the vagus and the cardiac sympathetic nerves.


Comparison of postoperative respiratory function after laparoscopy or open laparotomy for cholecystectomy. Cholecystectomy performed via laparotomy is associated with reduction of lung volumes including functional residual capacity that may lead to postoperative hypoxia and atelectasis. Laparoscopic cholecystectomy is associated with faster recovery compared to open laparotomy and cholecystectomy. To determine whether laparoscopic cholecystectomy was associated with less pulmonary dysfunction, 20 patients (ASA Physical Status I) undergoing elective cholecystectomy were randomly assigned to surgical teams performing either laparoscopy or open laparotomy for cholecystectomy. Patients in whom one or the other surgical technique had to be performed for medical or psychologic indications were excluded from the study. A standardized anesthetic technique and postoperative analgesic regimen were used. Forced vital capacity and forced expiratory volume in 1 s; functional residual capacity determined by a closed-circuit, constant volume helium dilution technique; and arterial O2 and CO2 tensions were measured preoperatively and at 6, 24, and 72 h postcholecystectomy. Forced vital capacity and forced expiratory volume in 1 s were significantly greater (P less than 0.05) in the laparoscopy compared to the laparotomy group at 6, 24, and 72 h postoperatively. Forced vital capacity relative to preoperative values was significantly (P less than 0.05) greater in patients with laparoscopy (24 h, 70 +/- 14%; 72 h, 91 +/- 6%) compared to open laparotomy (24 h, 57 +/- 23%; 72 h, 77 +/- 14%). Similarly, forced expiratory volumes in 1 s relative to preoperative values were significantly (P less than 0.05) greater in patients with laparoscopy (24 h, 85 +/- 13%; 72 h, 92 +/- 9%) compared to open laparotomy (24 h, 54 +/- 22%; 72 h, 77 +/- 11%).(ABSTRACT TRUNCATED AT 250 WORDS)


Monitoring of brainstem function during vertebral basilar aneurysm surgery. The use of spontaneous ventilation. Monitoring of cardiovascular, respiratory, and evoked potential parameters has been advocated during posterior fossa surgery to detect brainstem ischemia that may result from surgical manipulations. We report here our retrospective and smaller prospective experience of spontaneous ventilation as a monitor in patients undergoing vascular surgical procedures in the posterior fossa. Forty patients' charts were reviewed retrospectively, and 10 patients were studied prospectively. Respiratory changes in the retrospectively studied group occurred in 9 patients. Four patients developed apnea during temporary occlusion of the vertebral artery. These respiratory changes were associated with simultaneous cardiovascular changes in only 2 patients, and of the 13 patients monitored with evoked potentials, only 2 had simultaneous evoked potential changes. In the prospectively studied group, respiratory changes occurred in 4 patients. Three patients (2 with apnea during temporary occlusion) had a simultaneous change in evoked potentials but no cardiovascular changes. One patient had a change in all three parameters. Allowing our patients to breathe spontaneously provided an early and rapid indication of brainstem ischemia, especially during the temporary occlusion of the vertebral basilar artery system.


Pancuronium increases the duration of electroencephalogram burst suppression in dogs anesthetized with isoflurane. Earlier studies have demonstrated both a decrease as well as no effect on halothane MAC after administration of nondepolarizing neuromuscular relaxants. To clarify further the relationship between neuromuscular blocking agents and anesthetic potency, the authors studied the effect of pancuronium on steady-state electroencephalogram (EEG) burst suppression produced by isoflurane in dogs. Anesthesia was induced using isoflurane and oxygen via mask without the administration of other drugs. The trachea was intubated, and isoflurane was administered at a concentration sufficient to produce EEG burst suppression. Thereafter, end-tidal isoflurane concentration, temperature, and end-tidal PCO2 were meticulously maintained at constant values. Dogs in group 1 (n = 6) received pancuronium 0.1 mg.kg-1. The percent of the EEG that was isoelectric increased from 21 +/- 9% (mean +/- SD) to 35 +/- 11% (P less than 0.01). After the return of single-twitch response to train-of-four stimulation, neostigmine 0.05 mg.kg-1 and glycopyrrolate 0.01 mg.kg-1 were administered. This resulted in a reduction in EEG isoelectricity to 19 +/- 8% (P less than 0.01), similar to the value before pancuronium administration. In group 2 dogs (n = 6), the percent isoelectricity of the EEG prior to pancuronium was 25 +/- 10%. After administration of pancuronium 0.02, 0.04, and 0.2 mg.kg-1 sequentially, the percent isoelectricity of the EEG was 29 +/- 11, 37 +/- 15, and 43 +/- 9%, respectively. This represents a dose-related increase in isoelectricity for the 0.04- and 0.2-mg.kg-1 doses (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Positive end-expiratory pressure reduces renal excretion without hormonal activation after volume expansion in dogs. Controlled mechanical ventilation (CMV) with positive end-expiratory airway pressure decreases urine output and renal sodium excretion. This study investigates--independent of surgical stress, general anesthesia, and sedation--the influences of antidiuretic hormone, atrial natriuretic peptide, plasma renin activity, and aldosterone on decreased urine output and renal sodium excretion during CMV with positive end-expiratory airway pressure. Hemodynamic, renal, and hormonal parameters were measured over a 4-h period in six trained, nonanesthetized, chronically tracheotomized dogs under two conditions: 1) control: hours 1-4, spontaneous breathing at continuous positive airway pressure of 4 cmH2O; and 2) CMV 20: hour 1, continuous positive airway pressure of 4 cmH2O; hours 2 and 3, CMV with a mean airway pressure of 20 cmH2O; and hour 4, continuous positive airway pressure of 4 cmH2O. Throughout the experiments, 0.5 ml.kg body weight-1.min-1 balanced electrolyte solution was administered intravenously. During the 2nd and 3rd h of CMV 20, urine volume decreased by 43% and sodium excretion decreased by 44% when compared with control values (P less than 0.05). The glomerular filtration rate decreased from 4.4 +/- 0.1 to 3.9 +/- 0.1 ml.kg-1.min-1 (P less than 0.05) during the 2nd h and from 4.4 +/- 0.1 to 4.1 +/- 0.1 ml.kg-1.min-1 (P less than 0.05) during the 3rd h of CMV 20. Fractional sodium excretion decreased from 4.7 +/- 0.3% to 2.9 +/- 0.2% (P less than 0.05) during the 2nd h and from 7.5 +/- 0.3% to 4.6 +/- 0.2% (P less than 0.05) during the 3rd h of CMV 20, compared with values during the control period.(ABSTRACT TRUNCATED AT 250 WORDS)


The inhibitory effect of halothane on mesenteric venoconstriction and related reflex responses during acute graded hypoxia in rabbits. Systemic hypoxia is a common abnormality encountered frequently in the clinical setting that produces compensatory cardiopulmonary changes affecting heart rate, blood pressure, peripheral vascular resistance, and respiratory drive. These changes are known to be inhibited or reversed by inhaled anesthetics. More recently, chemoreflex-mediated constriction of capacitance veins has been identified as a mechanism that contributes significantly to the hemodynamic adjustments during hypoxia. However, the effects of anesthetics on this response have not been clarified. The current study was designed to quantify sympathetically mediated mesenteric venoconstriction as well as heart rate and blood pressure responses to acute graded hypoxia; to identify the inhibitory effects of inhaled halothane on these responses; and to estimate the contribution of the peripheral chemoreceptors in mediating these changes. Changes in mesenteric vein diameter were measured in alpha-chloralose anesthetized rabbits in situ with simultaneous changes in heart rate and blood pressure during 40-s periods of 10%, 5%, 2.5%, and 0% inspired O2 administered sequentially before, during, and after 1% or 1.25% inhaled halothane. Sympathetic efferent nerve activity also was measured, and, in a separate group of animals, measurements were preceded by carotid chemoreceptor denervation. Hypoxia-mediated venoconstriction, bradycardia, and hypertension were attenuated almost equally by both 1% and 1.25% inhaled halothane (the higher dose produced only slightly greater inhibition). These responses were inhibited significantly in chemoreceptor-denervated animals, and the subsequent 1% inhaled halothane added only minimal additional attenuation. Increases in chemoreflex-mediated sympathetic efferent nerve activity also were reduced significantly by (1.25%) inhaled halothane. These results indicate that halothane impairs capacitance vein responses and other hemodynamic adjustments during hypoxia. Inhibition of these compensatory changes appears to be mediated, at least in part, via attenuation of peripheral chemoreflex responses and suppression of the resultant reflex increases in sympathetic efferent nerve activity.


Glutathione depletion enhances subanesthetic halothane hepatotoxicity in guinea pigs. Reduced glutathione has a potential role in protecting the liver against the reactive acyl acid chloride intermediate generated during the oxidative biotransformation of halothane. Glutathione is also important in maintaining the integrity of an injured cell. Thus, the effect of decreased hepatic glutathione concentrations on covalent binding of halothane metabolic intermediates to hepatic protein and lipid and the resultant hepatic injury were investigated in male, outbred Hartley guinea pigs. The animals were injected with either 1.6 g.kg-1 dl-buthionine-S,R-sulfoximine to deplete hepatic glutathione or vehicle-control solution 24 h before exposure to 0.1% (subanesthetic) halothane for 4 h (fractional inspired oxygen tension = 0.40). Buthionine sulfoximine pretreatment depleted liver glutathione concentrations by 85% at the time of halothane exposure, without affecting the degree of halothane biotransformation or causing hepatic injury. Glutathione depletion caused a significant increase in the level of organic fluorine covalently bound to hepatic protein but not lipid after halothane exposure. Glutathione-depleted animals also exhibited a significant enhancement of hepatotoxicity after halothane exposure; plasma isocitrate dehydrogenase activity was 25-fold greater than the increase observed 48 h after exposure in animals treated with vehicle plus halothane, and the incidence and severity of hepatic injury were significantly greater, as observed by light microscopic examination of tissue 96 h after exposure. These findings are in agreement with a previously proposed mechanism of halothane-associated hepatotoxicity in guinea pigs and indicate that hepatic glutathione status may play an important role in the susceptibility of patients to halothane-induced liver injury.


Cerebral extracellular glucose and lactate concentrations during and after moderate hypoxia in glucose- and saline-infused rats. To assess the effect of a glucose infusion on brain extracellular fluid (ECF) during systemic hypoxia, changes in glucose and lactate concentrations in cerebral ECF during and after moderate hypoxic hypoxia were measured in adult, conscious, unrestrained rats, with a microdialysis probe in the posterior hippocampus. The rats were given either saline (n = 6) or 50% glucose solution (n = 6) for 3 h, starting 60 min before the onset of hypoxia. Hypoxia was produced by circulating 7% O2 gas in a plastic chamber for 90 min. In saline-infused animals, brain ECF glucose concentrations decreased slightly during hypoxia, although blood glucose concentrations did not change. Blood lactate concentrations increased to 6.28 +/- 0.91 mM, at 60 min after the onset of hypoxia (P less than 0.05). Brain ECF lactate concentrations increased to 3.53 +/- 0.20 mM and remained constant during 60 min of steady-state hypoxia (P less than 0.05) and decreased to the basal level within 60 min after the end of hypoxia. When sodium lactate solution was infused intravenously for 90 min (n = 4), blood lactate concentrations increased to a level as high as those found during hypoxia. However, the brain ECF lactate concentration increased only to 1.86 +/- 0.09 mM. In glucose-infused animals, the blood glucose concentration reached 339.1 +/- 32.3 mg/dl at the end of the glucose infusion, and the brain ECF glucose concentration increased to 54.7 +/- 7.3 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of progesterone on the cardiac electrophysiologic alterations produced by ropivacaine and bupivacaine. Bupivacaine-induced cardiotoxicity is enhanced in pregnant laboratory animals and in progesterone-pretreated isolated cardiac tissues. Ropivacaine is a new local anesthetic chemically related to bupivacaine. Although clinically equipotent with bupivacaine, ropivacaine is less cardiodepressant. Progesterone levels are elevated during pregnancy, and exogenously increasing progesterone levels in rabbits has increased bupivacaine's depressive effects on excitability. In neural tissues, bupivacaine's increased onset of block and depression of compound action potentials in tissues from progesterone-treated animals was similar to its effect in nerves from pregnant animals. This study determined whether exogenously increased progesterone levels can increase myocardial sensitivity to ropivacaine. Female ovariectomized rabbits were pretreated with progesterone for 4 days. After killing, the hearts were removed and Purkinje fibers (PFs) and ventricular muscle (VM) action potential parameters recorded. Tissues from animals receiving either progesterone or placebo were exposed to either ropivacaine or bupivacaine at concentrations ranging from 3.5 to 18.7 microM. Preparations were routinely paced at 2 Hz except where rate-dependent effects on the maximal rate of depolarization of phase zero (Vmax) were determined. Progesterone increased depression of myocardial Vmax only to bupivacaine (P less than 0.05). Ropivacaine was generally 3-5 times less potent in depressing cardiac electrophysiologic parameters. Bupivacaine demonstrated rate-dependent depression of Vmax that at higher frequencies was greater than ropivacaine's effects (P less than 0.05). Ropivacaine is less cardiodepressant than bupivacaine in this isolated PF-VM preparation. Exogenously increasing progesterone levels in vivo does not increase ropivacaine's depression of myocardial Vmax in isolated PF-VM tissues as it does to bupivacaine.(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of glucose infusion on cerebral cortical glucose and lactate concentrations during endotoxemia in rats. Hypoglycemia has been observed in several species before death from endotoxemia. Although several studies have emphasized the importance of maintaining brain glucose at normal concentration during endotoxemia, the effect of glucose infusion on cerebral glucose metabolism has not been studied. Accordingly, the effects of glucose infusion on interstitial glucose and lactate concentrations in the cerebral cortex during endotoxemia were studied in 22 Wistar rats. Cerebral glucose and lactate were measured at 30-min intervals for 4 h using microdialysis. Animals were divided into four groups: 1) saline-infused control (n = 5); 2) saline-infused endotoxemia (n = 7); 3) glucose-infused control (n = 5); and 4) glucose-infused endotoxemia (n = 5). In groups 2 and 4, endotoxemia was induced by intravenous injection with E. coli lipopolysaccharide B (5 mg.100 g-1). One hour after endotoxin administration, saline or 50% glucose was infused at a flow rate of 0.5 ml.100 g-1.h-1 for 3 h. Endotoxin induced a significant increase (P less than 0.05) in blood glucose in the saline-infused rats, which survived for 4 h (n = 5), from 91.6 +/- 15.4 mg.100 ml-1 at baseline to 136.3 +/- 23.3 mg.100 ml-1 (149%) at 1 h, followed by a gradual decrease (to 63% of the basal concentration at 4 h). Similar changes were observed in brain glucose (14.9 +/- 1.9 mg.100 ml-1 baseline, 175% of baseline at 2 h, and 57% of baseline at 4 h).(ABSTRACT TRUNCATED AT 250 WORDS)


Physical and chemical properties of drug molecules governing their diffusion through the spinal meninges. Drugs administered into the epidural space for selective spinal analgesia must diffuse through the spinal meninges to gain access to their sites of action in the spinal cord. Therefore, knowledge of the physical and chemical properties of drug molecules that govern their diffusion through the meninges is important for understanding the pharmacokinetics of epidural analgesia. To determine the physicochemical properties of drug molecules that govern the rate at which drugs diffuse through the spinal meninges, the authors measured the permeability coefficient of eight different drug molecules through the spinal meninges of the monkey using a previously established in vitro model. We previously reported permeability measurements for four of the molecules used in this study; the other four molecules' permeability measurements are new. The measured permeability coefficient was then correlated with the drugs' molecular weight, molecular surface area, molecular volume, length of the major molecular axis, and octanol:buffer distribution coefficient. We found no relationship between the drugs' permeability coefficients and any measure of drug mass, molecular shape, or molecular size. There was, however, a biphasic relationship between the octanol: buffer distribution coefficient and the drugs' measured permeability coefficients. Drugs that were either very hydrophilic or very hydrophobic had permeability coefficients that were significantly less than drugs of intermediate hydrophobicity. These data suggest that it should be possible to design novel analgesics for which meningeal permeability is maximal.


Comparison of the antinociceptive effects of pre- and posttreatment with intrathecal morphine and MK801, an NMDA antagonist, on the formalin test in the rat. Current thinking emphasizes that protracted small afferent input can evoke mechanisms that mediate a significant potentiation of spinal nociceptive processing and that this facilitory component has a unique pharmacology. To investigate the behavioral parallels of this spinal facilitation, we evaluated the effects of pre- and post-treatment of intrathecal morphine (mu agonist) and MK801 (N-methyl-D-aspartate [NMDA] antagonist) on the formalin test. Intraplantar formalin resulted in a biphasic appearance of flinching behavior (phase 1 = 0-5 min; phase 2 = 10-60 min). Morphine and MK801 were administered intrathecally 15 min before formalin injection in the pretreatment study and 9 min after formalin injection in the posttreatment study. Pretreatment with intrathecal morphine produced comparable dose-dependent suppressions of the phase 1 and phase 2 behaviors (ED50 = 0.5 micrograms [95% CI = 0.3-0.9] and 0.3 micrograms [95% CI = 0.1-0.7], respectively). Posttreatment with morphine also resulted in comparable suppression of the phase 2 response (ED50 = 0.2 micrograms [95% CI = 0.1-0.3]). At the highest dose of intrathecal morphine (10 micrograms), an almost complete suppression of formalin-evoked behavior was observed. Pretreatment with MK801 inhibited the second-phase response more strongly than the first-phase response (ED50 = 1.6 micrograms [95% CI = 0.5-5.7] vs. 0.1 microgram [95% CI = 0.3 - 0.4], respectively). In contrast, posttreatment with the highest dose of MK801 had no effect on the phase 2 response.(ABSTRACT TRUNCATED AT 250 WORDS)


The role of neutrophils, oxidants, and proteases in the pathogenesis of acid pulmonary injury. We recently reported a biphasic injury pattern of nonlethal acid aspiration pneumonitis in rats. The first phase consisted of the immediate effects of the direct tissue injury, and the second phase was associated with a neutrophilic inflammatory response. Using this model, the present report examines the possible role of neutrophils, oxidants, and proteases in the pathogenesis of the second phase of this lung injury. Acid aspiration injury was induced by instillation of saline/HCl, pH = 1.25, into the trachea of rats. Lung injury was assessed by measuring the degree of alveolar capillary permeability to 125I-labeled albumin (permeability index [PI]). Rats made neutropenic with polyclonal antineutrophil antibody had a lower PI (0.44 +/- 0.07, P less than 0.05) 6 h after acid aspiration than similarly injured animals with normal whole blood neutrophil counts (PI = 0.85 +/- 0.03). Even though neutrophils appeared necessary for the full development of the lung injury in this model, the administration of different intravenous and/or intratracheal concentrations of either deferoxamine or catalase offered no protection against injury. This suggests that neutrophil oxidants were minimally involved in the injury. Large increases in leukocyte-free serine protease activity (1,477 +/- 438 u/ml, P less than 0.05) were detected in the bronchoalveolar lavage fluid from the saline/HCl, pH = 1.25, injured rats at 6 h postinjury, as compared to saline/HCl, pH = 5.3, treated control animals (2.7 +/- 0.2 u/ml). This study supports the hypothesis that neutrophils are necessary for the full expression of acid-induced lung injury and that the generation of leukocyte-derived oxidants does not appear to be the primary mechanism involved in this injury.(ABSTRACT TRUNCATED AT 250 WORDS)


Controlled substance dispensing and accountability in United States anesthesiology residency programs. Controlled substance dependence (CSD) among anesthesiology personnel, particularly residents, has become a matter of increasing concern. Opinions vary as to the effectiveness of controlled substances (CS) accountability in deterring, identifying, or confirming CSD. A survey of program directors of American anesthesiology training programs was conducted in the summer of 1990 to determine the level of CS dispensing and accountability within their programs. The survey demonstrated that CS dispensing and accountability varied considerably among programs, among hospitals associated with individual programs, and within geographically distinct anesthesia delivery areas within the separate hospitals. Nevertheless, most institutions were moving toward improved methods of CS dispensing and providing more and better CS accountability. The presence of significant CSD, particularly among anesthesiology residents, was reconfirmed. We were unable to correlate the level of accountability of CS with the incidence of CSD. It remains to be seen to what extent CS accountability will continue to develop and whether CSD prevalence will then be changed.


Michael Faraday and his contribution to anesthesia. Michael Faraday (1791-1867) was a protégé of Humphry Davy. He became one of Davy's successors as Professor of Chemistry at the Royal Institution of Great Britain. Of Faraday's many brilliant discoveries in chemistry and physics, probably the best remembered today is his work on electromagnetic induction. Faraday's contribution to introduction of anesthesia was his published announcement in 1818 that inhalation of the vapor of ether produced the same effects on mentation and consciousness as the breathing of nitrous oxide. He most likely became familiar with the central nervous system effects of nitrous oxide through his association with Davy, an avid user of the gas. Sulfuric ether was a common, convenient, cheap, and easily available substance, in contrast to nitrous oxide, which required expensive, cumbersome, and probably not widely available apparatus for its production and administration. The capability for inhaling intoxicating vapors eventually became commonly available with the use of ether instead of the gas. The first surgical anesthetics were a consequence of the resulting student "ether frolics." The 1818 announcement on breathing ether vapor was published anonymously; however, notations in Faraday's handwriting in some of his personal books clearly establish Michael Faraday as the author of this brief communication.


[The effect of indomethacin and leukinferon on the level of blood plasma thromboxane B2, platelet aggregation and the immune system of patients with endometrial cancer in the perioperative period]. The perioperative influence of leukinferon, indomethacin and their combination on the blood plasma level of thromboxane B2 (TxB2), platelet aggregation ability and humoral and cellular immunity has been assessed in 40 endometrial cancer patients. It has been found that the perioperative use of indomethacin diminishes the blood plasma level of TxB2 and platelet aggregation ability. Leukinferon did not affect substantially the parameters. However, the combination of leukinferon with indomethacin causes a more stable reduction in platelet aggregation and TxB2 level than the use of indomethacin alone. The use of these drugs and their combination prevented postoperative immune suppression in the endometrial cancer patients. However, leukinferon alone or its combination with indomethacin were more effective than the use of indomethacin alone. Possible mechanisms of indomethacin and leukinferon effect on tumor cell metabolism of arachidonic acid and possible role of eicosanoids in the pathogenetic mechanisms of tumor growth and metastasis dissemination are discussed.


[The effect of droperidol on heart function]. The effect of droperidol (3.3 x 10(-6) M) on the functional capacities of the isolated heart has been studied. The drug inhibited myocardial contractility. The effect manifested directly after the introduction of droperidol into perfusate (prompt phase). Afterwards the progress of the drug inhibitory effect was slow (slow phase). It is assumed that the difficulties in the use of droperidol in the critical cardiosurgical patients are associated with the attenuation in the realization of the regulatory effects of the central nervous system.


[Characteristics of the metabolic disorders during prolonged craniofacial surgery]. Brain and liver metabolism has been studied by selective probing of vessels collecting blood from the brain and liver, in 95 patients with various surgical craniofacial pathology. Prolonged general anesthesia in craniofacial traumas has a negative effect on brain metabolism. Changes in indispensible amino acid formulas and hypoxia may cause the loss of brain circulation autoregulation and damages in central mechanisms regulating metabolic processes. A complex scheme of metabolism correction during prolonged anesthesia in craniofacial surgery is suggested.


[Clinical aspects of the use of nubain, tramal and moradol in patients in the early postoperative period]. Opioid analgesics were used in 282 patients on the first-third day after heart, lung and abdominal surgery. The main indication for their use was pain syndrome. Adequate analgesia with tramal, nubain and moradol was noted in 73, 76 and 81% of cases. In marked pain syndrome after thoracotomy the most effective agents were moradol and morphine. Computer monitoring of the respiratory function in tramal analgesia has shown a decrease in lung ventilation, esophageal pressure, inhalation volume, O2 production. Tramal, nubain and moradol in analgesic doses did not inhibit respiration. In adequate analgesia there was a decrease in lung ventilation which was not accompanied by shifts in acid-base balance of the arterial blood. The above analgesics had no considerable effect on systemic hemodynamics, though the use of tramal decreased systemic blood pressure and the use of moradol decreased systemic blood pressure and total peripheral vascular resistance. Tramal was most effective for synchronization of spontaneous respiration with a lung ventilation device in prolonged ventilation, as well as for the arrest of muscular tremor in the postoperative period. Tramal was effective in 95% of patients in the early post-anesthesia and postoperative period.


[The effect of tramal and acupuncture analgesia on labor pain and the psychoemotional status of the parturient]. The intensity and structure of pain during delivery as well as changes in psychoemotional status have been studied in 65 women with reference to the use of concomitant correcting therapy during various types of analgesia. 44 women comprised a control group. It has been found that acupunctural analgesia was optimal during delivery without any correcting therapy, while tramal (at a dose of 1.43 +/- 0.06 mg/kg) was optimal during "programmed" delivery.


[Changes in the concentration of beta-endorphin in the cerebrospinal fluid due to morphine analgesia in incurable oncologic patients]. Thirty cancer patients, clinical group IV, have been examined. It has been established that a persistent pain syndrome leads to lowering in beta-endorphin liquor level. Morphine analgesia is followed by beta-endorphin level elevation which directly depends on pain intensity and analgesia efficacy. Determination of changes in beta-endorphin liquor level may serve as a criterion of analgesia efficacy.


[Immunologic indices in patients with sepsis and their changes in response to complex intensive therapy]. Immune status has been studied in the course of intensive care in 48 patients. It has been established that hemosorption may enhance already existing changes in immune homeostasis in patients with sepsis. Therefore, immunostimulating therapy with tactivin and group B vitamins (B1, B6, B12) or ultraviolet (UV) blood irradiation in combination with group B vitamins administration have been included into therapy. Simultaneous use of tactivin, group B vitamins and UV blood irradiation was not advisable due to reduction of immunostimulating effect. Consecutive use of the immunity-stimulating methods seems expedient.


[The effect of infusion therapy on the ventilation-gas exchange function of the lung during acute destructive pneumonia in young children]. It has been established that respiratory failure in young children with destructive acute pneumonia was enhanced upon intravenous correction of homeostasis disturbances with daily physiological volume repletion. Combined enteral-parenteral correction of homeostasis disturbances was an alternative technique.


[The immunoprotective effect of ceruloplasmin in the acute period of patients in critical conditions of different origin]. Cellular immunity and opsono-phagocytic system have been studied in acute period in 23 critically ill patient. The immunoprotective effect of an antioxidant ceruloplasmin (800-1000 mg/day) has been assessed. It has been found that along with correction of antioxidant potential, ceruloplasmin promoted the retention of opsono-phagocytic system activity. Direct immunoprotective effect of ceruloplasmin was confirmed in vitro.


[The functional status of the sinoatrial node and the atrioventricular conductivity in patients with acute klofelin poisoning]. Using diagnostic transesophageal electrical cardiostimulation, sinus node function, sinoatrial and atrioventricular conductivity have been studied in 30 patients with acute clophelin poisoning. The results of pharmacological tests with atropine and alupent are presented. Control examinations have been performed on discharge. The results of pharmacological tests have shown that clophelin effect could be realized via imbalance of autonomous heart innervation. The technique of diagnostic transesophageal electrical cardiostimulation is recommended for wider use in clinical toxicology.


[The contractility of the lower portion of the esophagus as a criterion of the adequacy of anesthesia]. It has been found that narcotic analgesics (morphine, fentanyl and dipidolor), inhalation anesthetics (phthorothan and frilen) and an intravenous anesthetic calypsol suppress lower esophageal contractility. Comparison of lower esophageal contractility with hemodynamic parameters and ACTH and cortisol blood plasma content have revealed a direct correlation. It is concluded that the method of dynamic control over lower esophageal contractility may be an objective test controlling the adequacy of anesthesia during various surgical interventions.


[Anesthesia in emergency surgery on the organs of the hepato-pancreato-duodenal area in elderly and aged patients]. One hundred and two male and female patients, aged 65-85 years, have been examined. All of them had been subjected to urgent surgery for acute surgical pathology of the organs of hepatopancreatoduodenal area. Surgery was performed under one of the following anesthesia techniques: neuroleptanalgesia, epidural anesthesia (EA), combination of EA and endotracheal anesthesia. Changes in central hemodynamics, acid-base balance and oxygen balance parameters have been studied in the preoperative, intraoperative and early postoperative period. The advantages of a combined technique which ensures optimal conditions for the maintenance of circulatory and oxygen homeostasis have been proved.


[Infusion-transfusion tactics in tubercular surgical patients in relation to the volume of surgical blood loss]. Infusion-transfusion tactics were studied in 71 patients with pulmonary tuberculosis during surgery and after it. Hemostasis parameters have been determined at different periods after surgery. Blood transfusion was not performed in patients with surgical blood loss below 500 g. When surgical blood loss was 500 to 1000 g hemotransfusion volume was 40-50% of blood loss. When surgical blood loss was 1000 g the volume of blood substituting solutions exceeded blood loss 2.4-4 times; in massive blood loss it was 1.5 times more. For the first 24 hours after surgery the volume of infusion-transfusion therapy was maintained at the same level, with its decrease 48 and 72 hours later. Such tactics promoted a favourable clinical course of the postoperative period and stabilization of basic homeostasis parameters.


[The pulmonary distress syndrome during acute arterial occlusion of the lower extremities]. After surgery for acute arterial occlusion in the lower extremities 59 patients have developed tachypnea, respiratory alkalosis and arterial hypoxemia. These symptoms persisted over the whole postoperative period. In 66% of dead patients pulmonary changes have been observed and only in 34% of patients who died suddenly the lungs were unaffected. Morphological changes in the lungs are most marked in long-standing ischemia and have the signs of the "shock lung" (adult respiratory distress syndrome). Pronounced changes in the respiratory function, acid-base balance, blood gas composition can account for a more severe course of the disease, deteriorate the prognosis, predetermine multiorgan failure in the early postoperative period.


Filariasis in Gongola State Nigeria. I: Clinical and parasitological studies in Mutum-Biyu District. A total of 2,552 persons living in 9 villages along the Benue river valley, Mutum Biyu district of Gongola State, Nigeria were examined between October and December 1989 for filariasis. It is the first time a filariasis survey will be carried out in this state. 276 (10.8%) had Wuchereria bancrofti, 50 (2.0%) had Loa loa, 281 (11.0%) were positive for Mansonella perstans while 12 (0.5%) were positive for Onchocerca volvulus. Villages located near the Benue river had higher prevalence rates than those further away. Dermatitis and hydrocoele were common and clinical manifestations were associated with parasite types. Clinical symptoms without microfilaremia and microfilaremia without clinical symptoms were also observed.


[Non-inhalation anesthesia with preservation of spontaneous breathing in emergency surgery in children]. A total of 320 patients with acute abdominal surgical pathology were examined after general anesthesia with combined intravenous injection of sodium hydroxybutyrate and calypsol, with spontaneous respiration preserved. The examinations were performed under clinical control and impedance plethysmography. The combination of the above anesthetics has a lot of advantages over calypsol mono-anesthesia and ensures adequate blockade of visceral innervation. A slight circulatory hyperdynamia has been observed. This type of analgesia is one of the optimal methods of general anesthesia in children.


Musculo-skeletal pain (MSP) in onchocerciasis: a potential in the rapid low cost epidemiological survey and in the assessment of impact of ivermectin treatment on a community. The diagnostic potential of musculo-skeletal pain (MSP) in the rapid assessment of onchocerciasis of morbidity and of the impact of ivermectin treatment in a community is brought to picture. The clinical impression is that MSP is a common, early, chronic important symptom of onchocerciasis. With a significant association with onchocerciasis, MSP has the potential of being an important operational diagnostic clue in the detection of onchocerciasis. It has the advantage of being easily recognizable, and therefore can be applied by primary health care workers. MPS is proved to cause the greatest morbidity, particularly among working farmers in areas where the forest strain of O. volvulus is predominant. Thus, onchocerciasis is contributing more than was perhaps realized to the reduced output of work from farmers. However, MPS, a parasitic rheumatism, is proved to be eminently susceptible to treatment by DEC.


[Awake tracheal intubation--a method of choice in patients at risk of aspiration of gastric contents]. The experience gained with awake tracheal intubation in 39 urgent surgical patients at risk of gastric contents aspiration is presented. After standard premedication fentanyl (4.5 micrograms/kg) was injected, local anesthesia of the root of the tongue, epiglottis and vocal cords was performed with 10% lidocaine spray, rohipnol (0.032 mg/kg) and muscular relaxants were administered and controlled lung ventilation was started. Four patients had vomiting, in 5 patients fentanyl caused muscular restraint. No failures have been observed. Indications for awake tracheal intubation and drawbacks of fentanyl injections are discussed. Awake tracheal intubation prevented effectively aspiration due to retention of coughing and guttural reflexes.


[The volume of circulating blood during surgery of the aorta performed under epidural anesthesia]. Various methods of circulating blood volume (CBV) determination have been compared. The calculation method based on anthropometric to hemodynamic parameter ratio was shown to be optimal during surgery on the aorta and major vessels. Epidural anesthesia in 15% CBV deficit in the preoperative period and anesthetic administration into the epidural space intraoperatively in 10% CBV deficit were contraindicated. Epidural anesthesia caused CBV reduction, with its maximum changes observed upon blood flow recovery in the vascular bed. 10-15 ml/kg, 15-20 ml/kg and 20-30 ml/kg blood loss was 2.5,3 and 3.5 times overcompensated, respectively.


Experimental Wuchereria bancrofti infection of Culex quinquefasciatus and Aedes aegypti. Laboratory-derived females of Culex quinquefasciatus and Aedes aegypti were experimentally infected with Wuchereria bancrofti by allowing the insects to feed on infected volunteers of known microfilariae density between 24.00 and 2.00 hours. Of the 240 mosquitoes used for the experiments only 67 (55.8%) of C. quinquefasciatus and 83 (69.2%) of the Ae.aegypti actually fed on the volunteers' blood. After 16 days post-infection period, 50 (74.62%) of the engorged C. quinquefasciatus harboured infective L3 larval stages of W. bancrofti, while 16 (23.9%) and 1 (1.49%) harboured L2 and L1 pre-infective larval stages, respectively. On the other hand, no development to the L3 infective stage was observed in the engorged Ae.aegypti though 34 (40.96%) harboured L1 pre-infective stages of the parasite. Our results suggest that C.quinquefasciatus could be actively involved in the transmission of urban bancroftian filariasis in Nigeria.


[Electroacupuncture stimulation in the treatment of postoperative disorders of the motor-evacuatory function of the stomach and intestines]. One hundred and eight patients with gastric ulcer subjected to planned and urgent surgery have been treated for postoperative gastric atonia and intestinal paresis using electroacupuncture stimulation (EAPS). The treatment was effective in 85% of cases, with the efficacy confirmed by clinical results and gastroenterologic findings. EAPS promoted a decrease in the initially high blood levels of cortisol, aldosterone and histamine, an increase in serotonin and a reduction in gastric juice histamine levels, which were indicative of the analgetic and antihistamine EAPS effect and attenuation of parasympathetic activity. EAPS introduction into a complex of postoperative rehabilitation procedures led to reduction of drug doses or total drug replacement, early activation of surgical patients and prompt recovery of normal gastrointestinal evacuation.


[Extent and course of excretion of larva in the milk of female dogs after infections of different severity with Ancylostoma caninum (Ancylostomatidae)]. It was investigated whether there is a linear correlation between the number of applied infective larvae of Ancylostoma caninum and the number of larvae excreted by bitches with the milk. The investigations were carried out with nine bitches that were infected percutaneously each with 5,000, 10,000 or 20,000 third stage larvae of Ancylostoma caninum at the day of conception. A clear linear correlation between the number of applied infective larvae of Ancylostoma caninum and the number of larvae excreted with the milk could be demonstrated only for the first week of lactation. Regarding the total investigated period of 28 days only a tendency towards such a correlation between infective dosage and excretion of larvae with the milk could be found.


[A case of successful treatment of a severe form of suppurative meningitis]. A patient with severe meningoencephalitis has been treated using a combination of generalized and local mechanisms of antibacterial drug delivery to the inflammation focus, detoxication and brain circulation improvement. The management results have been analysed. Positive neurological dynamics, homeostasis recovery and shorter period of the patient's stay in an intensive care unit proved the efficacy of management. It is assumed that the improvement of brain perfusion is an important pathophysiological mechanism.


[The interaction of moradol (butorphanol tartrate) and flormidal (midazolam) in the patient's body]. Twenty five female patients (3 groups) operated on for cholelithiasis without premedication have been examined. In patients of group F an effective flormidal dose (EFD) causing an unconscious state upon intravenous injection by a measuring device has been determined. Due to an insufficient sedative effect of moradol it was impossible to determine an effective moradol dose (EMD). In group M+F right after intravenous administration of a standard moradol dose (SMD) flormidal infusion was begun, as in patients of group F. EFD after moradol injection (EFMD) was determined. Making proportions with known EFD, EFMD and SMD values, EMD was calculated. Upon intravenous administration of the calculated EMD by a measuring device the sedative effect was superficial in all the patients of group M and it was impossible to achieve an unconscious state. The interaction of moradol (butorphanol tartrate) and flormidal (midazolam) in the patients' body is of synergic nature.


[Determination of parasite-specific antibodies during human schistosomiasis--diagnostic relevance]. Sera from patients with schistosomiasis (Schistosoma mansoni or S. haematobium) were examined for the presence of parasite specific antibodies (total antibodies), specific IgE and IgG4 antibodies by means fo ELISA technique using antigens prepared from adult worms of S. mansoni. Individuals from tropical countries who had no schistosomiasis and blood donors from Germany were studied for comparison. Significantly higher levels of specific antibodies were given by sera from patients with schistosomiasis than by controls in the tests for total antibodies, IgE and IgG4. The use of these results in diagnosis is compared and assessed with microscopic-parasitological methods.


[Hyperbaric oxygenation and antianginal preparations: the effect of a single combined use on the functional indices of the state of the heart in patients with angina pectoris]. Using electrocardiographic technique, the effect of a single hyperbaric oxygenation session (O2 pressure 1.5 atm, duration 40 min) in combination with antianginal drugs (nifedipine--20 mg, propranolol--40 mg, nitrong--6.5 mg, orally) on central hemodynamics and myocardial contractility has been studied in 35 patients with ischemic heart disease and angina pectoris of effort, NYHA functional class II-III. It has been shown that hyperbaric oxygenation reduced the degree of indirect hemodynamic effect of nifedipine, potentiated negative chronotropic and inotropic effects of propranolol and had no impact on the degree of hemodynamic effect of depot-glycerol trinitrate.


[The improvement of polyxenic cultivation of Entamoeba histolytica type HK 9]. The serological diagnosis of extraintestinal infections with E. histolytica by indirect immunofluorescence (IFAT) requires a corpuscular antigen. This is produced in our laboratory via polyxenic cultivation of E. histolytica strain HK 9 in a nutrient medium containing a simple salt mixture (Resembling the Ringer-mixture), calf serum and rice starch. It was the aim of the experiments described in this paper to search for a useful medium in which the amebae grow in high density but without substances disturbing the antigen production like debris or rice starch granules. It was shown that the cell culture media of EAGLE MEM and PARKER were easy to handle (contrary to the worldwide used DIAMOND medium TYI-S-33) and brought good results. After a period of 10 subcultures both media were suitable for the cultivation of E. histolytica for making an antigen reasonable for IFAT. As a side effect it was noticed that there was an adaptation phase during which the amebae grew slowly when the medium was changed to another which was completely different (from a cell culture medium to a Ringer-like solution).


[Short term cultivation of Plasmodium for the determination of chloroquine resistance]. The in-vivo-test of Plasmodium drug resistance is one of the essential basic controls, assisting therapeutic measures in tropical malaria. An initial in-vitro-check up of drugs provided for antimalarial therapy is another useful help to the clinician. Even when manufactured WHO test kits are not available, the analysis of drug resistance can be performed under simple working conditions. Its application is demonstrated in a patients history.


[The tick fauna of eastern Germany].

[The tick fauna of eastern Germany]. The occurrence of several tick species in selected areas of Eastern Germany is described. From May 1987 till December 1989 8,472 ticks from 430 places were examined. Ixodidae of the genus Ixodes, Dermacentor and Haemaphysalis as well as Argasidae of the genus Argas were identified. The most common species was Ixodes ricinus. Furthermore, an endemic area of Dermacentor reticulatus was detected in the Düben-Dahlen and Annaburg health. Two other species of ticks, which were found frequently and sometimes with a high intensity on the host were Ixodes hexagonus and Ixodes canisuga. On the other side the species Haemaphysalis concinna and Argas vespertilionis were present at only one respectively two places and with a low population density.


[Calf carotids in experimental vascular surgery]. Use of calf [correction of sheep] carotids maintained on 98% glycerol is described as a material of substitution of aorta and femoral arteries in the dog, in experimental surgery. Taking, maintenance and application technics of such heterografts are described. Also, histology after 24 months following the surgical procedure was studied in 10 cases of dog aortic grafts and its results are presented.


[The treatment of vasospastic disease by chronic spinal cord stimulation. A case report]. In 1976, by first time, Cook used the chronic medullar stimulation (CMS) for the treatment of chronic arteriopathies at the limbs in patients with distal ischemic ulcerations. Up to now, some studies about this procedure have been published. Results, poor at first, have presented an important improvement with the time and the better choosing of patients. In 1981, Neglio used by first time CMS as a treatment of vasospastic disease, with excellent results. With this procedure, pain and vasospastic crisis disappeared and re-epithelialization of ischemic ulcerations is found. In this article, we presented a case interesting because it show the different possibilities of this method as a symptomatic treatment of such kind of disease. Patient, with a Raynaud syndrome secondary to an sclerodermia treated previously by medical and surgical procedures, was treated, in different times, with CMS because of digital ischemic ulcerations in both hands. Results were positives and ulcerations healed.


[The arterial complications of closed injuries to the shoulder girdle]. After a period of time of 5 years, we made a review of all the patients registered at our Center. Eight cases of closed traumatism at the scapulohumeral belt, with vascular injury associated (0.2% of all closed traumatisms at this level registered in our center during this time) were reported. Six patients presented also an osteoarticular injury associated. Three different vascular injuries were showed: three cases of complete arterial section, two arterial contusions and a partial arterial section. From the two cases without osteoarticular injuries, one of them showed a complete section and the other presented an arterial contusion. Polytraumatic patients showed multiple osteoarticular injuries. We registered one fracture-luxation at the shoulder, 3 diafisaric humeral fractures, one humeral neck fracture, one clavicle fracture, one fracture-luxation at the cervical column and one simple luxation of the shoulder.


Estimated and true hinge axis: a comparison of condylar displacements. The purposes of the investigation were: i) to compare the condylar displacements from centric slides for 74 sets of casts mounted with an estimated versus a true hinge axis; ii) to determine the error in hinge axes location on the recording of condylar displacements from centric slides; and iii) to define the reproducibility of the Mandibular Position Indicator (MPI), a method of measuring condylar (in vitro) displacements from centric relation position. The findings revealed that routine use of the true hinge axis to obtain MPI readings for analysis of diagnostic casts is not warranted. The mean standard error of MPI double readings attributed to both hinge axes location was 0.4 mm for each component in the sagittal plane. Of the 0.4 mm of mean standard error, 0.2 mm was contributed by the lack of reproducibility of the MPI. The centric relation bite registration technique outlined in this study always captured a superior articulator position of the condylar mechanism. The condylar distractions and deflections from centric relation to maximum intercuspation were primarily in an inferior direction with a smaller posterior component.


Assessment of buccal separators in the relief of bruxist activity associated with myofascial pain-dysfunction. The purpose of this study was to evaluate the effectiveness of heavy (S2) Alastik separators in relieving bruxist activity as monitored through masseter muscle area EMG activity, muscle palpation, and self-reporting in 21 Caucasian subjects. The subjects, all of whom suffered from both bruxism and myofascial pain-dysfunction, were randomly assigned to one of three groups: experimental (separator group); placebo (separator placed and removed); and control groups (no separator). The findings from this study indicate that there were no observable differences in either subjective or objective responses to the pretreatment versus posttreatment questionnaire and clinical examination for tooth clenching or grinding, facial pain, and fatigue of the jaws. In addition, no statistical differences were found between pre and posttreatment data. The EMG data did not show any statistical differences between pretreatment and posttreatment evaluations or among the 3 groups.


Facial growth during adolescence in early, average and late maturers. The relative stage of maturity of a child may be determined by comparing the child's hand-wrist radiograph to known standards of skeletal development. Hand-wrist radiographs of 70 adolescents were used to categorize the individuals by skeletal maturation into early, average and late maturation groups using the Fishman SMA method of assessment. The rates of mandibular and maxillary growth relative to the last stages of the pubertal growth spurt were measured. Statistical evaluation of the data was performed using an analysis of variance. The magnitude of change in growth increments of the mandible was greater in the late maturers than in the early or average maturers. Incremental differences in growth between the maxilla and mandible during the last stages of puberty were noted, with the mandible growing significantly more than the maxilla.


[Reinterventions for the late failures of femoral-distal grafts]. In this retrospective study of 195 patients treated for late failure of a previous femoral-distal reconstruction, there were 178 men and 17 women ranging in age from 42 to 79 years. The graft material utilised for initial operation was an autogenous vein reversed saphenous vein (75), in situ (1), and arm veins (4) in 80, polytetrafluoroethylene in 51, Dacron in 46, Biografts in 12 and composite grafts in 6 patients. The previous site for distal anastomosis was above the knee in 79, and tibial or peroneal arteries in 18 cases. The most common cause of graft failure was late thrombosis (95), progression of the underlying disease (64), deterioration of the graft (15), pseudoaneurysms (8), and rarely perigraft reactions, hemodynamic insufficiency, late infection, etc. The aim of the reoperation was: graft extension for distal disease (68) desobstruction and patch angioplasty (21), thrombectomy (9) exchange of the graft (17), local repair of the graft (3). Seventeen patients required inflow procedures. Other reinterventions (sympathectomy, catheterisation and prostaglandin perfusion) were used in patients with no chance for reconstructive arterial surgery. Secondary reoperations were performed in 12, tertiary operations in 7 patients. Major amputations rate, operation mortality, wound morbidity and hemodynamic success rates with limb salvage in reoperated patients support usefulness of repeated revascularisation when femoro-distal bypass failure occurs.


[The use of the Gott shunt in the surgical repair of a dissecting aneurysm of the descending thoracic aorta]. A 49-years-old man was operated on of a descending thoracic dissecting aneurysm by means of a heparin-less external Gott shunt. A review of spinal irrigation, neurological deficits postclamping of the descending thoracic aorta and methods of spinal preservation in aortic surgery are presented.


Force generation by orthodontic samarium-cobalt magnets. The use of samarium-cobalt (Sm-Co) magnets for light force application is a relatively new concept in orthodontic tooth movement. This study reports on the forces generated by these magnets. Magnets were attached to aluminum rods mounted in a universal testing machine. The magnets were initially separated by 10 mm were moved toward each other at 2.5mm/min in repulsion or attraction, depending upon the magnetic pole orientation. The magnets were also positioned initially in contact and then moved apart at a rate of 2.5mm/min, again producing repulsion or attraction, depending upon the pole orientation. The Sm-Co magnets exhibit very large forces when in close approximation but forces decrease markedly at separations greater than 2mm. The force, P, generated between magnets is determined by their separation, d, and follows the relationship P = dn. At magnet separations of 0 to 2mm, the exponent n is equal to -0.4; at separations of 2mm to 7mm, exponent n equals -2.1 for both attraction and repulsion. Thus the classic Coulomb law of magnetic force was followed only at magnet separations of greater than 2mm. Force-separation behavior and the high cost of these magnets may not justify their routine clinical use.


[The past, present and future of lumbar sympathectomy]. The ischemic extremities treatment in a precarious phase has been standardized in the two last decades with a significance extremities savement. But the ischemia of the interdigital vessels and at the microcirculation is still a defiance. We expose the hiperemiant surgery past. We describe the experience of four years in Centre Hospitalari-Unitat Coronaria, Manresa, with 21 lumbar sympathetic ablation in patients without distal pulse, ankle/arm index by Doppler effect between 0 and 0.6 and angiographies without distal bed images, with 13 successes, 2 exitus by M.A.I., 3 amputations and a lung edema. We finish with a futuristic vision that suggest alternatives for the usage of the lumbar sympathectomy according to the medical advances in the coming time for available the ischemic extremities.


Force magnitude effects upon osteoprogenitor cells during premaxillary expansion in rats. To study the effects of force magnitude on osteoprogenitor cell activity during premaxillary expansion, stainless steel helical springs were attached to the maxillary central incisors of 45 3-month-old male rats. The animals were randomly divided into force levels (0, 50, 100, 150, 200 gm) and were injected intraperitoneally with tritiated thymidine (1.0 uc/g wt.) 1 hour prior to sacrifice which occurred at 27, 40, and 60 hours. In order to examine cell activity within different regions of the suture, each premaxilla was divided into three geographic areas. Quantitative results were obtained by comparing the percent of labeled cells observed at different force levels, geographic areas, and observation times. The greatest number of labeled cells at each force level was found at 27 hours. Increased forces were correlated with increased numbers of labeled cells up to 100 gm, with decreased cell numbers at higher forces. The numbers of labeled cells at 200 gm were not significantly different from the controls. Histological observations of early bone formation at 60 hours supported the quantitative labeling results at 27 hours. The results also demonstrate a significant correlation between the geographic location of the labeled cells and force magnitude, with maximal cell stimulation occurring more superiorly in the suture as forces increased. The results suggest that early bone formation within the expanded suture can be maximized by varying force magnitude and distance from the point of force application.


Childhood and pubertal growth changes of the human symphysis. Longitudinal growth changes of the human symphysis were evaluated for 75 children (37 males and 38 females) between 6 and 15 years old. Childhood growth was described by mean yearly rates of change between 6 and 10 years for females and between 7 and 11 years for males; pubertal changes pertain to growth between 10 and 14 for females and between 11 and 15 for males. Cephalometric tracings of the mandible were superimposed using stable reference structures. Vertical growth changes, particularly for landmarks located in the upper 20% of the symphysis, were most pronounced. Annual rates of vertical growth ranged between 0.9 mm/yr for the lingual incisor contact point to -0.2 mm/yr for gnathion. Males showed significantly greater rates of vertical growth than females, especially for the upper half of the symphysis. Vertical growth rates were also greater during puberty than during childhood. The horizontal growth changes indicated lingual movement of most symphyseal landmarks. Annual rates of growth were greatest for landmarks located in the upper half of the symphysis. B-point showed the greatest lingual drift. During puberty, the mandibular incisors in females moved lingually as the upper anterior half of the symphysis remodeled; in males, the incisors maintained their horizontal position as the labial sulcus developed.


Long-term orthodontic tooth movement response to short-term force in the rat. Both the amount of force applied and the duration of the application affect tooth movement. To study the effect of duration, adult male Sprague-Dawley rats were fitted with orthodontic appliances delivering a 40-gm initial mesial tipping force to the maxillary molars. The animals were divided into two longitudinal groups (I: 1 hour and II: 24 hours; N = 15). Sham-treated control (III) and 14 day (IV) continuous cross-sectional force tooth movement data were also included for comparison (72 rats per group). Extraoral cephalometric radiographs were obtained at appliance placement and at 1, 3, 5, 7, 10, & 14 days. Tooth movement was determined with respect to palatal implants. ANOVA indicated significant differences existed over time in each group (p = 0.0001). Continuous force applied for 14 days generated a classic three-part tooth movement curve. Short-term forces were characterized by initial mesial movement, a distal relapse period (d3-d5), and a late mesial movement period (d7-d14). The results suggest short-term forces of 1 and 24 hours initiate remodeling events, which result in tooth movement 7 to 14 days later and that the minimum effective duration of a 40-gm activation is less than 1 hour in this animal model.


Comparison of mandibular growth with other variables during puberty. The purpose of this investigation was to compare growth characteristics of the mandible during puberty with growth characteristics of the hyoid bone, cervical vertebrae, hand bones and standing height. Data were compiled from serial lateral cephalometric roentgenograms, hand-wrist roentgenograms and body height records of 33 Japanese girls between 9 and 14 years old. Records were updated annually. The mandibular growth rate differed from the other growth rates. The timing of maximum growth velocity of the mandible varied more widely than the timing of maximum growth velocity of the other parameters measured, and the total amount of mandibular growth did not correlate to any other measurement. The timing and magnitude of circumpubertal growth acceleration of various components of the body vary within a certain range of difference. However, the amount and timing of mandibular growth seems to be more variable than the other areas studied.


A functional rationale for routine maxillary bonded retention. A technique is presented for the lingual bonded retention of anterior teeth. Functional concepts to guide the goals of orthodontic treatment during finishing are reviewed. The importance of proper anterior guidance is emphasized as the protector of posterior teeth in eccentric jaw position. Clinical procedures for attaining optimum function are suggested, including the elimination of removable retainers.


Molecular cloning and sequence analysis of a chicken ornithine decarboxylase cDNA. A chicken embryo cDNA library was screened with a mouse probe for ornithine decarboxylase (ODC) and 14 positively hybridizing clones isolated. The longest of these (1.7 kb) was sub-cloned and sequenced. It is estimated that the clone comprises approximately 98% of the coding region for chicken ODC. The DNA sequence shows 78% identity with the human ODC cDNA sequence and the deduced amino acid sequence is almost 90% homologous to mouse and human. Both the peptide and cDNA sequences show interesting potential regulatory features which are discussed here.


Genetic linkage analysis between protein polymorphisms and the FecB major gene in sheep. A genetically linked marker locus is sought for the Booroola gene (FecB), a major gene which confers increased prolificacy in sheep. We examined 18 polymorphic proteins in sheep and found 10 to be informative in half-sib families where the Booroola gene was segregating. Recombination was observed between each of the protein loci and the Booroola gene. The loci and exclusion distance for each (calculated as the recombination fraction where the lod score was equal to -2.0) are as follows: NADH diaphorase, DIA1 (9.2 cM); arylesterase, EsA (11.9 cM); haemoglobin beta chain, HBB (17.5 cM); leucine amino peptidase, LAP (19.7 cM); malic enzyme, ME1 (14.8 cM); ovine plasminogen antigen, OPA (12.6 cM); alpha-1-protease inhibitor, PI2 (5.7 cM), erythrocyte 'X' protein, Prot-X (25.3 cM); post transferrin, PTF (2.2 cM); transferrin, TF (33.8 cM).


Temperature gradient gel electrophoresis: detection of a single base substitution in the cattle beta-lactoglobulin gene. An A in equilibrium with G transition in exon III is known to differentiate alleles A and B of the cattle beta-lactoglobulin (BLG) gene. A BLG exon III fragment containing the transition site was amplified by the polymerase chain reaction. Temperature gradient gel electrophoresis (TGGE) was then used to detect this transition and hence to genotype cattle: the AT base-pair in allele A was readily distinguished from the GC base-pair of allele B. TGGE can be used to detect any single base-pair substitution, and thus is a powerful method of detecting genetic variability.


Characterization of a porcine variable number tandem repeat sequence specific for the glucosephosphate isomerase locus. A variable number of tandem repeat from a porcine glucosephosphate isomerase intron has been isolated and sequenced. The repeat has a unit size of 39 bp, is highly conserved and is present in at least 14 copies. Flanking sequences show a sequence periodicity of 53-54 bp and some sequence homology to the 39 bp repeat. A considerable part of the genomic DNA has been lost during subcloning and is considered to be deletion prone or refractory to propagation in E. coli. The tandem repeat is locus specific and detects at least six alleles in BamHI digested porcine DNA. No homology to other tandem repeat sequences has been found.