Quantitative measurement of regional cerebral blood flow using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography. We have developed a quantitative method of measuring regional cerebral blood flow (rCBF) by using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography (SPECT). Twenty-five dynamic SPECT images (24 sec/scan) were collected immediately after tracer injection using a ring-type SPECT system and the accumulation curve (C(t)) was obtained. The time-activity curve corresponding to the arterial blood activity curve was used as B(t). The latter curve was calculated from the lung time-activity curve monitored during scanning and corrected by the actual activity obtained by one-point blood sampling 5 min after tracer injection. The octanol extraction ratio during scanning was considered to be constant and taken as the value measured 5 min after tracer injection (E). The uptake constant (K) per pixel was calculated by the least squares fitting method as the slope of the linear relationship in which C(t)/E x B(t) was plotted against E x integral of t(o)B(tau)d tau/E x B(t). Functional maps of rCBF values were obtained on a 64 x 64 matrix by calculating the uptake constant per pixel and the cross calibration factor (CF) between the SPECT system and a well counter (rCBF = K.CF x 100).


Radioimmunodetection of occult carcinoembryonic antigen-producing cancer. This study evaluates the ability of 111In-labeled anti-carcinoembryonic antigen (CEA) monoclonal antibody (Mab) ZCE-025 to detect sites of occult cancer in patients with elevated serum CEA who have negative or equivocal CT scans. One hundred forty patients suspected of having occult cancer were evaluated. Except for elevated CEA levels, all had negative work-ups, including negative or inconclusive CT scans. Eighty-two patients (59%) had positive scans and 58 (41%) had negative scans. Seventy-five of the 82 patients with positive scans had confirmation of at least one Mab-positive lesion (91% positive predictive value). Thirty-eight of the 58 patients with negative scans had negative follow-up (66% negative predictive value). The Mab scan correctly identified at least one site of tumor in 75 of the 95 patients with recurrent or metastatic disease (79% sensitivity) and correctly predicted the absence of disease in 38 of 45 patients (84% specificity).


Colon carcinoma immunoscintigraphy by monoclonal anti-CEA antibody labeled with gallium-67-aminooxyacetyldeferroxamine. Previous experimental results in nude mice showing that radiolabeling the monoclonal antibody anti-CEA 35 with 67Ga-aminooxyacetyldeferroxamine could give better tumor localization than radioiodination prompted us to initiate the present clinical study. The 67Ga-labeled antibody anti-CEA 35 (185 MBq, 0.7-1.7 mg) was injected preoperatively into 14 patients for colorectal carcinoma imaging. The same antibody labeled with 125I (3.7 MBq, 0.25 mg) was injected simultaneously to compare the 67Ga and 125I dose recoveries in surgical specimens. Twelve of 14 primary tumors gave a positive 67Ga scintigraph. The mean %ID/g recovered in all tumors 3-9 days after injection was significantly higher for 67Ga (0.019%) than for 125I (0.005%) (p < 0.001, paired t test). The tumor-to-normal tissue ratios were generally higher for 67Ga, with the exception of liver. We conclude that 67Ga-aminooxyacetyldeferroxamine improved immunoscintigraphy outside the liver, particularly in the pelvic region. We also show that deferroxamine infusion accelerates the excretion of 67Ga in eight patients and propose that this could lead to further improvement of immunoscintigraphy.


Local and systemic effects of radiation on bone metabolism measured by quantitative SPECT. Quantitative bone scintigraphy (QBS), which measures 99mTc-MDP uptake expressed as percent of injected dose per cc, indicates bone metabolism. It is measured in the bones of patients before and after radiation treatment and then compared to normal controls. QBS was performed in a group of 22 normal individuals and was measured twice, 2-10 mo (mean 4.9) apart. There was no significant difference between the two measurements. QBS was performed also in 28 patients before, immediately after and at certain time intervals after radiation therapy for cancer. Both the irradiated and the nonirradiated bones showed significant decreases in bone metabolism at 2-18 mo (mean 8.8) after irradiation. In addition, increases and decreases of 99mTc-MDP uptake were similar in the irradiated and in the nonirradiated bones, and there were significant correlations of the QBS values in the different bones of each individual patient. The etiology of the changes in bone metabolism in the nonirradiated bones is not yet fully understood, but it appears to be the result of a systemic effect of radiation.


Planar myocardial perfusion imaging with technetium-99m-teboroxime: comparison by vascular territory with thallium-201 and coronary angiography. Myocardial perfusion agents labeled with 99mTc offer improved physical imaging properties compared to 201TI. Teboroxime is a new 99mTc-labeled compound for myocardial perfusion imaging that shows a high myocardial extraction and rapid clearance. Sixty-seven patients underwent planar teboroxime imaging with a rapid acquisition protocol. Agreement of teboroxime and 201TI for the presence or absence of disease occurred in 56/65 patients (86%). There was agreement (normal or abnormal) between the two agents in 156/195 vessels (80%) and 457/585 segments (78%). When abnormal segments (ischemia or infarction) were compared, teboroxime showed significantly more ischemic segments (89/135, 66%) than did 201TI (73/135, 54%, p < 0.05). Teboroxime offers accuracy comparable to 201TI for the diagnosis of coronary artery disease and may improve the detection of ischemic or viable myocardium. In addition, its rapid myocardial clearance permits stress/rest imaging in 60-90 min.


Brain SPECT and the effect of cerebral angioplasty in delayed ischemia due to vasospasm. Cerebral vasospasm is a major determinant of outcome after subarachnoid hemorrhage (SAH). Brain SPECT with 99mTc-HMPAO was obtained before and after cerebral angioplasty in 10 patients with delayed ischemia due to vasospasm. Eight patients had clinically evident neurologic improvement after the procedure. Visual interpretation and an internal-reference (cerebellum), manual, semi-quantitative region of interest (ROI) analysis revealed improvement of regional cerebral blood flow (rCBF) in 9 out of 10. There were disagreements between the visual and ROI analysis in the two that did not improve clinically. For all 10, the average increase per anterior circulation vessel dilated (n = 17) was 8.8% by comparison of the corticocerebellar ratios. For the eight that improved, the average increase was 10.5%. Brain SPECT is valuable for evaluating delayed cerebral ischemia caused by vasospasm after SAH and is useful to document the changes in rCBF induced by angioplasty. It is possible that SPECT may be useful to detect critical reductions in perfusion before clinical deficits develop, thereby offering the potential to identify candidates for early treatment with angioplasty.


Localization of infection using streptavidin and biotin: an alternative to nonspecific polyclonal immunoglobulin. Since favorable images of infection are obtained with radio-labeled nonspecific IgG, streptavidin has been considered as an alternative protein in this investigation. The advantage of streptavidin is that once localized it may be targeted with radiolabeled biotin. Studies were conducted in a mouse model with an Escherichia coli infection in one thigh. Indium-111-labeled streptavidin showed equivalent localization to the infection as that obtained with 111In-labeled polyclonal nonspecific IgG, however blood levels with streptavidin were lower at all time points; consequently, target-to-blood ratios were improved. Pretargeting with unlabeled streptavidin followed 3 hr later with 111In-labeled biotin showed equivalent localization in the target and reduced activity in all organs sampled. As such, infected thigh-to-normal thigh ratios were improved 3-fold for pretargeting versus either labeled IgG or streptavidin. Improvements in infected thigh-to-liver and blood ratios were greater than 8-fold. Only in the case of kidneys was the ratio unimproved. In conclusion, we have shown that by preadministration of unlabeled streptavidin followed by labeled biotin, infectious lesions in a mouse model may be imaged earlier with lower background levels relative to the administration of labeled nonspecific IgG.


Comparison of regional blood-brain transport kinetics between glucose and fluorodeoxyglucose. The fluorodeoxyglucose (FDG) method for estimating regional cerebral glucose metabolic rate (LCMRglc) requires that a fixed relationship (the "lumped constant") exists between net FDG and glucose (GLC) extraction throughout the brain. In addition to the relative rate of metabolism between FDG and GLC, this assumed constant is affected by the relative rate of blood-to-brain FDG transport compared to that of glucose. However, little data is available regarding the regional stability of the FDG versus GLC transport-rate relationship. We therefore used high resolution, quantitative dual-tracer digital autoradiography to directly compare the blood-to-brain transport rate constants (K1) of radiolabeled GLC and FDG in normal and pharmacologically-stimulated rats. The rats were given 45 sec terminal intravenous infusions of a mixture of 18F-FDG and 14C-GLC. Autoradiograms of the brain representing the FDG and GLC tracer concentrations were produced, digitized, and converted into digital images of K1. We found that the global K1 values of FDG and GLC were not significantly different from each other. However, detailed analysis revealed that some structures in the normal animals, such as the hippocampus and cerebellum, had different quantitative patterns of FDG transport compared to GLC transport. Thus, our results indicate that the relationship between GLC and FDG transport is not uniform throughout the brain as has previously been assumed. This observation suggests that regional variations in the type and distribution of glucose transporters may exist and that the fluorodeoxyglucose "lumped constant" may vary somewhat among different brain regions.


A quantitative autoradiographic study of the heterogeneous activity distribution of different indium-111-labeled radiopharmaceuticals in rat tissues. In light of the increased interest in small scale dosimetry, this paper presents a quantitative autoradiographic method for evaluation of heterogeneous activity distribution in tissues. This was studied in rat tissues after administration of 111In-chloride, -oxine, -tropolone, 111In-labeled homologous blood cells and 111In-anti-CEA-F(ab')2, using quantitative whole-body autoradiography. Quantification was performed utilizing an image analyzing system designed for whole-body autoradiographs. Very heterogeneous activity distribution was found in several tissues including the liver, spleen, kidneys, bone marrow, lymph nodes and testes. Notable was the high 111In uptake in organs characterized as rapidly proliferating, and known to have numerous transferrin receptors. In the gastrointestinal tract, all activity was associated with the intestinal walls. The heterogeneous tissue distribution shown in this investigation accentuates the necessity for performing detailed studies of the tissue distribution of radiopharmaceuticals. This is especially important for the radiation dosimetry of radionuclides emitting beta-particles or low energy electrons. We suggest whole-body autoradiography as an excellent implement to determine local activity concentrations in organs and tissues necessary for accurate absorbed dose calculations.


Technetium-99m-N1-(2-mercapto-2-methylpropyl)-N2-(2-propargylthio-2- methylpropyl)-1,2-benzenediamine (T691): preclinical studies of a potential new tracer of regional cerebral perfusion. We report in vitro and in vivo preclinical studies of a new cerebral blood flow tracer, [99mTc]N1-(2-mercapto-2-methyl-propyl)-N2-(2- propargylthio-2-methylpropyl)-1,2-benzenediamine (T691). The tracer demonstrates excellent in vitro chemical stability and accumulates regionally in the brain in a pattern consistent with that of cerebral blood flow. First-pass cerebral extraction determined with the use of the brain uptake index method in the rat was 0.76. Bolus intracarotid injection in monkeys indicated a cerebral extraction of 68% and prolonged retention of 67% of the initially extracted activity. Autoradiographic studies in rats revealed a pattern characteristic of cerebral blood flow at both 1 and 60 min after systemic injection. Dynamic tomographic imaging following systemic injection in the monkey revealed peak brain activity 1 to 2 min postinjection, without significant decline over 60 min. Chromatographic studies of brain as long as 60 min following systemic injection of [99mTc]T691 showed no evidence of tracer metabolism to account for its retention. Overall, [99mTc]T691 demonstrates promise as a potential new clinical tracer of cerebral perfusion.


Major upward creep of the heart during exercise thallium-201 myocardial SPECT in a patient with chronic obstructive pulmonary disease. We report on a patient in whom we observed an unusually important upward creep of the heart on postexercise 201TI tomographic acquisition. When uncorrected, this led to reconstruction of grossly abnormal tomograms, which were normal after correction of upward creep of the heart. This phenomenon may be related to the patient's history of chronic obstructive pulmonary disease. Special attention should be given to upward creep artifact in such pulmonary diseases.


Pelvic radioiodine uptake in a rectal wall teratoma after thyroidectomy for papillary carcinoma. A 30-yr-old woman with previously resected papillary thyroid carcinoma was found to have a pelvic lesion which concentrated radioiodine. By performing simultaneous 131I whole-body and 99mTc-methylene diphosphonate bone scans, we found the lesion to be in soft tissue between the sacrum and bladder. Radioiodine therapy was postponed so that the lesion, a benign teratoma of the rectal wall, could be surgically removed. Prior to laparotomy, the patient received a second tracer dose of 131I so that the lesion could be located at surgery with a hand-held gamma detector. A postoperative whole-body 131I scan confirmed that the lesion had been removed, thus reducing the absorbed radiation that would have been received by the ovaries during radioiodine therapy. Although the lesion contained both thyroid and gastric epithelium, accumulated 131I was limited to the area with thyroid follicles.


Gallium-67-citrate scanning in patients with sarcoid uveitis. Gallium-67-citrate is useful for characterizing activity in patients with sarcoidosis. Gallium-67 uptake in bilateral symmetrical hilar lymphadenopathy and/or symmetrical salivary glands is typical of this clinical entity. Sarcoidosis is a systemic disease, and uveitis is considered the hallmark of ophthalmic sarcoidosis. We present two cases of ophthalmic sarcoidosis that shows uveal accumulation of 67Ga-citrate associated with clinical symptoms.


Thallium-201 accumulation by epidermoid inclusion cyst. An elderly male undergoing re-evaluation for coronary artery disease demonstrated an extra-cardiac focus of 201Tl accumulation during the performance of a planar myocardial perfusion scan. This corresponded to a subcutaneous lesion of the left posterior thorax found on a concurrent computerized axial tomographic (CAT) scan and upon surgical excision proved to be an "epidermoid inclusion cyst." A follow-up nuclear scan failed to reveal any residual extracardiac tracer localization. Confusing this lesion with metastatic deposits during 201Tl neoplastic evaluations can be avoided by examination of the adjacent integument.


Sensitivity, resolution and image quality with a multi-head SPECT camera. This investigation sought to determine which collimation factors were most important in providing superior image quality with a three-headed SPECT device. The relationship between sensitivity, resolution and SPECT image quality was studied. Two different sets of parallel-hole collimators were used. The ultrahigh-resolution collimators have higher spatial resolution (8.9 versus 11.0 mm), but only 55% of the sensitivity of the high-resolution collimators. A phantom with hot rods was imaged with both collimator sets. Observers compared images with the ultrahigh-resolution collimators to images of varying counts with the high-resolution collimators and determined which high-resolution images matched the ultrahigh-resolution images in image quality. Eleven patient studies were acquired with both collimator sets for equal time, and observers chose which image set they preferred. Transverse images of brain and liver studies were simulated with varying resolution and counts and subjectively compared. The phantom study indicated that the improvement in resolution led to image quality comparable to increasing the number of counts by a factor of 2.5 to 3.4. The clinical studies showed that the ultrahigh-resolution collimators were preferred in a large majority of the cases. These trends were also seen in the simulation study. These results confirm that higher resolution collimators should be used with multihead SPECT devices. The improvement in resolution more than compensates for the loss in sensitivity, leading to an overall improvement in image quality.


Fatty acid kinetics in aerobic myocardium: characteristics of tracer carbon entry and washout and influence of metabolic demand. These studies evaluated the kinetics of tracer uptake and washout after step-function labeling with 14C-palmitate. Washout and uptake function curve analysis for total radioactivity (TR) was derived according to the expressions: TR = Fx integral of 0 infinity C(t) x dt and TR = Fx integral of 0 infinity (Css - C(t)) x dt, respectively, with Vc = TR/Ca, where F = coronary flow; Css = steady-state concentration; C(t) = concentration with respect to time; Ca = arterial concentration; and Vc = distribution volumes within the fatty acid pathway. The only radioactive metabolites in venous effluent were fatty acids and 14CO2. The estimated Vc of fatty acids was small (1.2-1.7 ml/g dry wt or 0.4-0.5 mumol/g dry wt) and compatible with labeled substrate trapped in the blood volume. The Vc of 14CO2 was much larger (11.4-15.8 ml/g dry wt or 3.6-4.2 mumol/g dry wt) and correlated with counts contained in the aqueous soluble and fatty acid fractions in tissue. The counts in tissue were distributed between the aqueous soluble fraction (40%), which was rapidly depleted during washout, and a lipid fraction (60%) (triacylglycerols and phospholipids), which was resistant to washout. Distributions in tissue radioactivity between the aqueous soluble and lipid fractions support the notion of a dual pathway in fatty acid oxidation, one arm of which passes through the resident pool of triacylglycerols, which has a long time constant. The presence of this pool may impart an error in estimating fatty acid oxidation by external labeling techniques.


Correction for attenuation in technetium-99m-HMPAO SPECT brain imaging. We present a correction technique that uses the effective bone and tissue attenuation coefficients to compensate 99mTc-HMPAO brain SPECT projections for attenuation. Transverse images of a human skull filled with a uniform mixture of 99mTc and gelatin have a greater count density at the center with respect to the periphery when corrected for attenuation with the effective water/tissue coefficient of 0.12 cm-1. An attenuation coefficient of 0.09 cm-1 produces uniform images at the expense of a reduced count density. Additional experiments with phantoms wrapped with aluminum (to simulate bone) indicate that the greater count density at the image center is a result of increased attenuation at the edges of the projections where there is a greater path length through the aluminum (or bone). SPECT projections explicitly corrected for both bone and soft-tissue attenuation result in images of improved uniformity and increased count density.


Description of a prototype emission-transmission computed tomography imaging system. We have developed a prototype imaging system that can perform simultaneous x-ray transmission CT and SPECT phantom studies. This system employs a 23-element high-purity-germanium detector array. The detector array is coupled to a collimator with septa angled toward the focal spot of an x-ray tube. During image acquisition, the x-ray fan beam and the detector array move synchronously along an arc pivoted at the x-ray source. Multiple projections are obtained by rotating the object, which is mounted at the center of rotation of the system. The detector array and electronics can count up to 10(6) cps/element with sufficient energy-resolution to discriminate between x-rays at 100-120 kVp and gamma rays from 99mTc. We have used this device to acquire x-ray CT and SPECT images of a three-dimensional Hoffman brain phantom. The emission and transmission images may be superimposed in order to localize the emission image on the transmission map.


Predictive value of dipyridamole thallium imaging in a patient with myocardial bridging but without fixed obstructive coronary artery disease. Both dipyridamole and exercise-201Tl imaging are sensitive, specific and of prognostic value in patients with suspected coronary artery disease, following myocardial infarction, and undergoing major noncardiac surgery. Though reported sensitivities and specificities vary widely from 60% to 100%, the consensus is that both are between 80% and 90% for both dipyridamole and exercise studies (23). Moreover, when compared directly in the same study populations, the two have equal sensitivities and specificities (9,11,13,23). Transient thallium perfusion abnormalities are the most consistent predictors of adverse cardiac events and have more predictive power than clinical and angiographic parameters. Thallium reversibility may be a better predictor of adverse cardiac events than angiography since it represents more of a physiologic rather than a purely anatomic evaluation of the heart. It is difficult to make an exact comparison of some of the studies in the literature because they use different patient populations, sometimes define coronary stenosis in different ways, may have different cardiac endpoints and may not differentiate between reversible and fixed thallium perfusion defects. Exercise has the advantage of a graded examination and more experience historically and is of importance in a detailed study of cardiopulmonary hemodynamics, as in cardiac transplantation. Dipyridamole is more useful in patients who cannot achieve symptom-limited, submaximal exercise. It may also be more useful for patients who are bedridden or have peripheral vascular disease. Angina occurs less frequently with dipyridamole.(ABSTRACT TRUNCATED AT 250 WORDS)


Acupuncture and related treatment modalities. Part I: Theoretical background. An introduction to the therapeutic applications, history, and theory of acupuncture and several related treatment modalities is presented. The practices of acupuncture, moxibustion, acupressure, and shiatsu are described. The underlying concept of treatment of imbalances of ch'i, or life energy, is presented along with the flow of ch'i in meridians (pathways), and the theories of yin and yang, Five Elements, and Eight Principle Patterns.


The National Birth Center Study. Part I--Methodology and prenatal care and referrals. This is the first of three articles that will report on the complete findings from the National Birth Center Study (NBCS). This article describes the study methodology, compares the entire group of NBCS subjects with all women who gave birth in the United States in 1986, describes the prenatal care and prenatal referral practices of birth centers in the study, and describes the women who were admitted to the birth centers for intrapartum care with regard to characteristics known or thought to be associated with perinatal risk. Nearly 18,000 women were included in the study; two-thirds of them (n = 11,814) were admitted to the birth centers for intrapartum care. Although medical and obstetric complications were the most common reason for discontinuing birth center care, they accounted for less than half of the women who were not admitted to the birth centers for labor and delivery; many women left for a variety of other reasons. In addition to describing birth center clients, birth center care providers, and birth center care, the NBCS provides detailed information about the characteristics and experiences during pregnancy of a large population of essentially low-risk women receiving a low-intervention style of maternity care.


Prevalence of abuse among pregnant women choosing certified nurse-midwife or physician providers. Despite the fact that violence against women is a widespread problem in the United States, many providers do not routinely screen for it, particularly if the woman is not from a lower socioeconomic group. This was a secondary analysis of survey data from 940 antenatal women in private CNM and MD practices. Median annual income was $40,000 to $49,000 and mean schooling completed was 15 years. It was found that 91 (9.7%) had a history of previous abuse and eight (0.9%) were currently in an abusive relationship. Women with a previous history of abuse were found in the CNM caseloads at higher than expected levels. Annual income was predictive of women currently being abused, but not for women with past history. Abused women had on average less education than nonabused, with the most marked difference seen in women reporting current abuse. These results provide further evidence that the problem of abuse is not restricted to women of lower socioeconomic status. The finding that women with history of abuse were more likely to appear in CNM caseloads adds further support to the need for routine screening.


Evaluation of research studies. Part I: Randomized trials. Clinical practice is often based on the results of research. Critical evaluation of research studies is important if appropriate conclusions are to be drawn. In this series of columns, we review principles of research methodology and statistical analysis. Our intent is to assist certified nurse-midwives in understanding the relative merits of the research they read and use. This article, the first of the series, will review issues pertinent to randomized clinical trials.


Acupuncture and related treatment modalities. Part II: Applications to antepartal and intrapartal care. The application of acupuncture, moxibustion, acupressure, and shiatsu to antepartal and intrapartal care are discussed. Information on therapeutic interventions as described in textbooks is presented and compared with specific treatments evaluated in research studies. Specific clinical indications addressed include nausea during pregnancy, repositioning of the fetus in breech position, stimulation of contractions and true labor, and pain relief in labor. Qualifications for practitioners and recommendations for certified nurse-midwives caring for clients seeking referral for these services are discussed.


The National Birth Center Study. Part II--Intrapartum and immediate postpartum and neonatal care. Part II of a three-part report of the National Birth Center Study describes care provided to 11,814 women and their newborns during and after labor and delivery until they were transferred or discharged from the birth centers. There were few low birth weight or preterm or postterm births, but more macrosomic babies than among all U.S. births during the same time period. Certified nurse-midwives provided most of the intrapartum care, which is described in the context of medically recommended standards and data that describe care provided to low-risk women giving birth in U.S. hospitals. Birth center care deviated from typical hospital care in several ways. Birth center clients were much less likely to receive central nervous system depressants, anesthesia, continuous electronic fetal monitoring, induction and/or augmentation of labor, intravenous infusions, amniotomies, or episiotomies, and they had relatively few vaginal examinations. They were more likely to eat solid food during labor and to take showers and/or baths. Nulliparity was strongly associated with longer first stage labors and longer labor was associated with more frequent use of many kinds of interventions. Infant birth weight, mother's position during delivery, and forceps- or vacuum-assisted deliveries are examined in relation to episiotomies and lacerations and tears.


In-hospital care for low-risk childbirth. Comparison with results from the National Birth Center Study. The largest prospective study of freestanding birth centers was reported in 1989. This article reports on data from a comparison group of over 2,000 low-risk women who were admitted to hospital-care settings during the same period. The data on the hospitalized women were collected using the research methodology and data collection instruments developed for the birth center study. Consequently, these data offer the opportunity to observe differences that can be associated with birth site. Both groups of women experienced similar rates of serious antepartum and intrapartum health problems and maternal morbidity. However, even when controlling for complications and differences in sociodemographic characteristics, women in hospitals were more likely to receive an interventive style of labor and birth management. Neonatal outcomes were also similar, although the incidence of sustained fetal distress, prolapsed cord, and difficulty in establishing respirations were significantly greater in the hospital sample. Hospital care did not offer any advantage for women at lowest risk, and it was associated with increased intervention. The results of this study provide support for the National Birth Center Study's conclusion that birth centers offer a safe and acceptable alternative for selected pregnant women.


Nurse-midwifery care to vulnerable populations. Phase I: Demographic characteristics of the National CNM Sample. The purpose of this article is to describe the extent to which certified nurse-midwives (CNMs) provide care to vulnerable populations in the United States and the source of reimbursement for this care. The data were obtained from the first phase of a national study to address the characteristics of women served and cost of care provided by CNMs. Results were analyzed nationally and by American College of Nurse-Midwives regions. Certified nurse-midwives in all types of practices are providing care to women from populations that are vulnerable to poorer than average outcomes of childbirth because of age, socioeconomic status, refugee status, and ethnicity. Ninety-nine percent of CNMs report serving at least one group of vulnerable women, and CNMs in the inner city and rural practices serve several groups. The vast majority of CNMs are salaried; only 11% receive their primary income from fee-for-service. Fifty percent of the payment for CNM services is from Medicaid and government-subsidized sources whereas less than 20% comes from private insurance. Source of income varies by type of setting in which the CNM attends births. The results suggest that CNMs, as a group, make a major contribution to the care of vulnerable populations.


Occupational risks for nasopharyngeal cancer in Shanghai. To investigate occupational determinants of nasopharyngeal cancer (NPC) in the urban area of Shanghai, occupational information for 996 incident NPC patients diagnosed during 1980 to 1984 was compared with 1982 census data on employment. Standardized incidence ratios for NPC were estimated for broad and detailed occupational classifications. For the broadest level of classification, no excess risk was observed among craftmen and related manufacturing workers, but within this group significant excess risks were observed for specific occupations of textile weavers and knitters; metal smelting, converting, and refining furnacemen; boiler firemen; blacksmiths, hammersmiths, and forging-press operators; bakers, pastry cooks, and confectionery makers; welders and flame-cutters; and metal grinders, polishers, tool sharpeners, and machine-tool operators. Some of these findings are new; others are consistent with previous studies in other areas of the world. This study provides further evidence for the role of occupational factors in NPC.


Investigation of an occupational cancer cluster using a population-based tumor registry and the National Death Index. Occupational physicians investigate perceived cancer clusters to alleviate employee concerns and pursue etiologic hypotheses. We conducted a retrospective cohort analysis of all past and present employees of a metal fabrication plant and a comparison plant after employees recognized five cancer cases in 1987. We ascertained cases of all subjects who were employed at some time in the 8 years before 1987 through the Colorado Central Cancer Registry and determined vital status through the National Death Index. Cancer incidence at the index plant was almost identical to that of the population of the Denver metropolitan area (standardized incidence ratio [SIR] = 99, 95% confidence interval [CI] 59-165). Proportional incidence ratios revealed that no type of cancer occurred with significant excess in the index plant population during 1979 through 1986. Where population-based tumor registries exist, occupational physicians can employ this inexpensive and robust methodology to assess cancer incidence in exposed cohorts, pursue exposure-response relations, and evaluate clusters.


Factors affecting plasma aluminum concentrations in nonexposed workers. In this study, the distribution and determinants of plasma aluminum concentrations were examined in 71 office employees not occupationally exposed to aluminum. The samples were analyzed by Zeeman graphite furnace atomic absorption spectroscopy and were found to be log normally distributed. After using the International Federation of Clinical Chemistry (IFCC) recommended procedure for removal of likely aberrant values, the 95th percentile value was 198 nmol/L (90% CI:165-238); when those using antacids were also excluded, the 95th percentile value fell to 175 nmol/L (90% CI:147-208). Multiple regression analysis indicated that the factors most predictive of log plasma aluminum were the batch in which the sample was analyzed and the use of antacids containing aluminum. The statistical significance of the batch variable likely indicates the well-recognized problem of contamination in sampling and analyzing aluminum.


Computer-specific spectacle lens design preference of presbyopic operators. Twenty-nine presbyopic subjects who spent at least 20 hours a week at a video display terminal compared a progressive addition lens designed for this function, with another commonly prescribed task-specific lens. Each of the paired lens types was worn for 4 weeks and then compared directly for 1 week. A statistically significant (P < .05) portion of the subjects (76%) preferred the task-specific lenses overall. It also was preferred more frequently for each feature compared, although the difference was statistically significant (P < .05) only for utility of distance vision. Both of the task-specific designs contributed to symptomatic relief. The presence of a distance-clear zone and the absence of lens discontinuities most likely account for user preference for the task-specific lenses. That preference suggests improved performance for presbyopic computer users wearing task-specific progressive addition lenses.


Definition, sources, magnitude, effect modifiers, and strategies of reduction of the healthy worker effect. This article summarizes, compares, and contrasts the definition, sources, magnitude, effect modifiers, and strategies of reduction of the healthy worker effect (HWE), based on the opinion expressed in the papers of nine contributors who responded to the request of the Industrial Disease Standards Panel (IDSP), Ontario, Canada. It provides an insight into the complex issues relating to the HWE. In addition, the catalog of 15 strategies to reduce the HWE is deemed to be useful for investigators in occupational epidemiology.


IgG subclass antibody against trimellitic anhydride in workers with and without immunologic lung diseases. In a retrospective comparison of two worker cohorts with elevated total antibody against trimellitic anhydride (TMA) conjugated to human serum albumin (TM-HSA), IgG subclass antibodies against TMA were studied in 19 workers with and 12 workers without TMA-induced immunologic lung disease. The main outcome measures were ELISA index of IgG1, IgG2, IgG3, and IgG4 against TM-HSA. There were no statistically significant differences in levels of any IgG subclass between these two groups. Neither were there any statistically significant differences when workers without lung disease were compared with subgroups of workers with lung disease, such as late respiratory systemic syndrome (n = 8), asthma/rhinitis (n = 6), or both (n = 5). In TMA workers with elevated total antibody against TM-HSA, IgG subclasses against TM-HSA in workers with TMA-induced immunologic lung disease were not different from workers without disease.


Ethnographic explanations for the clustering of attendance, injury, and health problems in a heavy machinery assembly plant. We examine the clustering of attendance, illness, and accidental injury problems in a large unionized manufacturing plant using both quantitative and qualitative methods. We find that the distribution of workers into problem groups is related to 1) conflicts over seniority, 2) physical stressors and their influence on perceived desirability of certain kinds of jobs, and 3) organizational conditions and environments congenial to the development of distinct occupational "subcultures." We suggest that the case study approach we apply in this paper is critical to the design of programs of preventive intervention and complements the more commonly applied multiple-site and individually focused, survey approaches.


Achieving consensus on withdrawing or withholding care for critically ill patients. To examine the decision-making process to withhold or stop life support. Survey. Medical intensive care unit of a tertiary care center. Physicians and families of 15 critically ill patients; in seven cases patients also participated. Meetings between physicians and family members concerning a decision to withhold or stop treatment of a critically ill family member were tape-recorded. Transcriptions of the meetings were analyzed for 1) process: how the physician introduced the need for a decision, framed the likely outcomes of options, and closed on a decision; 2) what decision was made; and 3) the outcome; died, discharged home, or discharged to another institution. The concept of "patient's wishes" was a central orientation point for the negotiation of consensus regarding withholding or withdrawing therapy even when the patient was not a participant. Physicians tended to provide a direct and unambiguous introduction, give equal weights to options during decision framing, but narrow the options during decision closure to correspond to their judgments. Not every decision was consistent with the physician's judgment. Decision making to withhold or withdraw life-support therapy from critically ill persons involves complex, difficult processes. Successful management of the tension among life extension, quality of life, patient autonomy, and social justice requires better understanding of these processes.


Diagnosing sinusitis by X-ray: is a single Waters view adequate? To determine whether a single Waters view (occipito-mental) radiograph could be substituted for a four-view sinus series to diagnose sinusitis, and to determine the inter- and intraobserver variabilities for sinus radiography. Radiographs were interpreted by radiologists blinded to the clinical history, and results were recorded on a standardized form. Veterans Affairs Medical Center. Staff attending radiologists, an attending radiologist with special training in skull radiology, and a senior radiology resident. The agreement between the Waters view and the four-view sinus series was moderate to substantial (simple agreement = 75-84%, kappa = 0.5-0.68). However, agreement varied by sinus and, after correction for chance agreement, was substantial only for the maxillary sinuses (kappa = 0.72-0.87). Intraobserver agreement (kappa = 0.72-0.84) was superior to interobserver agreement (kappa = 0.49-0.59) for the four-view sinus series. Substituting a single Waters view for a four-view sinus series may be an acceptable strategy for diagnosing maxillary sinusitis.


Placing patients in the queue for coronary surgery: do age and work status alter Canadian specialists' decisions? To determine the effects of age and work status on whether and where cardiovascular specialists would place hypothetical patients in the queue for coronary surgery. Mailed survey presenting a set of clinical scenarios either to be rated on a scale with 7 time frames for urgency of need or to be designated as questionable/inappropriate for intervention. The basic scenario was a patient with mild-moderate stable angina, good left ventricular function, and limited coronary disease; operative risks and stress test results were varied. Three identifiers were used: "45-year-old civil servant gainfully employed"; "45-year-old laborer disabled by angina, faces job loss"; and "75-year-old retiree, angina limits golf." Cardiologists and cardiac surgeons practicing in five Ontario medical centers (n = 120). There was a 59% response rate (120 usable responses). Large shifts in willingness to intervene occurred in favor of the disabled laborer (p less than 0.0001) and against the retiree (p-value ranges from 0.04 to less than 0.0001, depending on operative risk and stress test results), but not for the employed civil servant. Striking effects (p less than 0.0001) were also evident in ratings of waiting time, with the order of priority being the disabled laborer first, the civil servant second, and the retiree last. The overall mean shift due to work status or age was equal to, or larger than, the mean shift due to clinical factors, such as stress test results, changes in severity of stable angina, and extent of coronary disease. Cardiovascular specialists may place considerable weight on age and work status in determining urgency and appropriateness of coronary revascularization. Risk-benefit concerns may partly explain shifting thresholds for intervention, but not differential waiting times. The influence of these factors should be sought in utilization audits and addressed from an ethical perspective.


Utilization of medical services for the treatment of acute low back pain: conformance with clinical guidelines. To assess the utilization of diagnostic and therapeutic medical services for the management of acute low back pain in a primary care setting, and to determine whether such utilization conforms to suggested guidelines for the management of this condition. A retrospective chart audit of consecutive cases of acute low back pain. Specific elements of the diagnostic and therapeutic approach were judged appropriate or inappropriate based on comparison with published recommendations supported by the medical literature. The primary care adult practice of a university-affiliated health maintenance organization. One hundred eighty-three patients presenting with acute low back pain of musculoskeletal origin. According to suggested guidelines for the care of acute low back pain, 26% of plain lumbar x-rays (10/38), 66% of computed tomography (CT) and magnetic resonance imaging (MRI) scans (12/18), and 82% (23/28) of subspecialty referrals were categorized as inappropriate. Among patients without indications for these services, 12% (10/85) had received lumbar x-rays, 7% (12/168) had received lumbar MRI or CT scans, and 14% (23/168) had received subspecialty referrals. Underutilization of these services had occurred in 71% (70/98) of patients with an indication for plain lumbar radiography, and 47% (7/15) of patients with potential indications for surgical referral or CT/MRI scanning. Neither overutilization nor underutilization had led to adverse outcomes or delays in diagnosis in this small sample. According to guidelines from the medical literature, the primary care physicians in this study both overutilized and underutilized diagnostic and referral services in cases of acute low back pain. It is necessary to determine whether underutilization of plain lumbar radiography adversely affects diagnostic accuracy and whether overutilization of other services improves important clinical outcomes, given the generally benign natural history of this condition.


How well do faculty evaluate the interviewing skills of medical students? To study the reliability and validity of using medical school faculty in the evaluation of the interviewing skills of medical students. All second-year University of North Carolina medical students (n = 159) were observed interviewing standardized patients for 5 minutes by one of eight experienced clinical faculty. Interview quality was assessed by a faculty checklist covering questioning style, facilitative behaviors, and specific content. Twenty-one randomly chosen students were videotaped and rated: by the original rater as well as four other raters; by two nationally recognized experts; and according to Roter's coding dimensions, which have been found to correlate strongly with patient compliance and satisfaction. Medical school at a state university in the southeastern United States. Faculty members who volunteered to evaluate second-year medical students during an annual Objective Structured Clinical Exam. Interrater reliability and intrarater reliability were tested using videotapes of medical students interviewing a standardized patient. Validity was tested by comparing the faculty judgment with both an analysis using the Roter Interactional Analysis System and an assessment made by expert interviewers. Faculty mean checklist score was 80% (range 41-100%). Intrarater reliability was poor for assessment of skills and behaviors as compared with that for content obtained. Interrater reliability was also poor as measured by intraclass correlation coefficients ranging from 0.11 to 0.37. When compared with the experts, faculty raters had a sensitivity of 80% but a specificity of 45% in identifying students with adequate skills. The predictive value of faculty assessment was 12%. Analysis using Roter's coding scheme suggests that faculty scored students on the basis of likability rather than specific behavioral skills, limiting their ability to provide behaviorally specific feedback. To accurately evaluate clinical interviewing skills we must enhance rater consistency, particularly in assessing those skills that both satisfy patients and yield crucial data.


Factors affecting the reliability of ratings of students' clinical skills in a medicine clerkship. To determine the overall reliability and factors that might affect the reliability of ratings of students' clinical skills in a medicine clerkship. A nine-item instrument was used to evaluate students' clinical skills. Raters were also asked to provide a grade of each student's overall clinical performance. Generalizability studies were performed to estimate the reliability of the ratings. The effects of rater experience and clerkship setting were investigated by regression analysis. Teaching hospitals and community-based sites in three Northwestern states. All students (328) who had completed the 12-week clerkship in internal medicine at one medical school during the academic years 1987-1989. Raters included attending physicians, chief residents, and other residents. Seven observations were needed to provide a reliable rating of the overall clinical grade. More observations were needed to obtain reliable ratings for individual items, ranging from seven observations needed for the rating of data gathering skills to 27 observations needed for the rating of interpersonal relationships with patients. Rater experience and clerkship setting (i.e., teaching hospitals vs. community-based clinics) were found, in general, not to affect significantly the ratings received by students. Reliable ratings of students' overall clinical skills, including overall clinical grades, can be achieved by collecting a minimum of seven observations. More observations are needed to measure reliably the interpersonal aspects of clinical performance. These findings support the use of performance ratings to evaluate clinical skills and knowledge of students in clerkship settings.


Home visits in a rural office practice: clinical spectrum and effect on utilization of health care services. To describe the clinical features of home visits and their role in continuity of care, costs, and benefits in a rural office practice. Prospective study of all home visits performed during a 26-month period. A general medicine teaching office practice located in rural Virginia. All persons to whom home visits were made during the study period. 138 home visits were made to 47 patients who had a mean age of 73.2 years. Home visits accounted for 1.4% of patient encounters in the practice, required a mean of 7.1 miles of one-way travel and a mean of 48 minutes, including travel time, to complete, and generated $36 in income per visit. Most patients (27 of 47) were not permanently homebound. Reasons for patients' being homebound were grouped into six categories (acute illness, frail elderly, terminal illness, advanced chronic disease, neurologic problem, and miscellaneous reasons). The reasons for visits were grouped into four categories (acute self-limited illness, exacerbation of chronic disease, routine follow-up of chronic disease, and psychosocial problem). Physicians judged that 80% of home visits represented appropriate use of their services. In addition, 46% of home visits made an emergency room visit unnecessary, and 9% made a hospital admission unnecessary. At the time of 75% of home visits, physicians reported personal benefits of making the visit. Home visits have an important role in the care of ambulatory as well as permanently homebound patients. While physicians judged most home visits to be appropriate and personally beneficial, these visits required more time and generated less revenue than did office visits for comparable problems. Because home visits generated as well as prevented the use of medical services, their impact on the overall cost of medical care in this setting is unclear.


Dietary counseling of hypercholesterolemic patients by internal medicine residents. To assess the knowledge, attitudes, and practices of internal medicine residents concerning dietary counseling for hypercholesterolemic patients. Cross-sectional, self-administered questionnaire survey. Survey conducted August 1989 in seven internal medicine residency programs in four southeastern and middle Atlantic states. All 130 internal medicine residents who were actively participating in outpatient continuity clinic. None. Only 32% of the residents felt prepared to provide effective dietary counseling, and only 25% felt successful in helping patients change their diets. Residents had good scientific knowledge, but the degree of practical knowledge about dietary facts varied. Residents reported giving dietary counseling to 58% of their hypercholesterolemic patients and educational materials to only 35%. Residents who felt more self-confident and prepared to counsel reported more frequent use of effective behavior modification techniques in counseling. Forty-three percent of residents had received no training in dietary counseling skills during medical school or residency. Internal medicine residents know much more about the rationale for treatment for hypercholesterolemia than about the practical aspects of dietary therapy, and they feel ineffective and ill-prepared to provide dietary counseling to patients.


Physician detection of drinking problems in patients attending a general medicine practice. To assess the patient and physician characteristics that influence physicians' detection of problem drinking in their medical patients. The outpatient medical clinic at an urban university teaching hospital staffed by interns and residents. Cross-sectional study of a randomly chosen subsample of consecutive patients. Univariate and multivariate analysis with calculated adjusted odds ratios of factors associated with physician detection of drinking problems. A problem was diagnosed according to the patient's results on the alcohol module of the Diagnostic Interview Schedule (DIS). Physicians detected 22% of 189 presumably inactive problems and 49% of 92 current problems, i.e., those that have occurred within the preceding year. Multivariate correlates of detection of active problems included male patient gender, presence of gastrointestinal complications of excessive drinking, number of concurrent medical disorders, and previous medical record reference to alcohol (p less than 0.05). Physician gender and year of training were not associated with detection. Our physicians appear to rely on specific patient characteristics as well as the patient's medical record to detect drinking problems in their ambulatory patients. Their reliance upon these factors may hinder their detection of drinking problems in women patients and less seriously impaired individuals.


Ambulatory opiate detoxification and primary care: a role for the primary care physician. To determine the feasibility of primary care-based ambulatory opiate detoxification (AOD) and an optimal regimen, the authors conducted a pilot study of AOD in a medical clinic comparing two regimens: clonidine and clonidine plus naltrexone. Sixty-two opiate addicts who had been referred for AOD had the following features: mean age was 34 years, 75% were male, 74% used cocaine, and 64% shared needles. Initially, 40 patients selected clonidine, 22 clonidine/naltrexone. The groups (clonidine and clonidine/naltrexone) were similar in baseline features, including: craving scores (44/100 vs. 42/100) and withdrawal scores (20/72 vs. 17/72). Overall, 61% (38/62) of initial AODs were successful, including 43% (17/40) of those using clonidine and 95% (21/22) of those using clonidine/naltrexone (p less than 0.0001). Of 45 patients who ultimately completed AOD, 78% (35/45) remained in treatment for at least one month.


Computer-generated mailed reminders for influenza immunization: a clinical trial. A randomized, single-blind, controlled trial was performed at a community health center to measure the impact of computer-generated reminders mailed to patients on the rate of influenza immunization. High-risk patients were randomized to one of three groups: 1) usual care, 2) one reminder letter, offering free influenza immunization without an appointment, or 3) two sequential reminder letters, offering the same. The reminders did not significantly affect rates of influenza immunization. Analysis of the combined groups indicates that an appointment with a primary care provider remains the most reliable method of immunizing high-risk patients at this health center.


Maternal blood donation for intrauterine transfusion. Pregnancy affected by erythrocyte alloimmunization often requires intrauterine transfusion for fetal survival. Because blood donated by a random donor has been associated with an increased risk of disease transmission, maternal blood donation has been advocated as an alternative blood source for intrauterine transfusion. Collaboration between medical, nursing, laboratory, and nutrition personnel optimizes the safety and success of the procedure. This article describes the collaborative care of the woman participating in maternal blood donation for intrauterine transfusion.


Nursing assessment and responsibilities in monitoring the preterm pregnancy. Evaluating women for pregnancy-related problems that may result in preterm birth frequently requires electronic fetal monitoring at early gestational ages. Caution is needed to interpret information correctly from the preterm fetal heart rate and uterine activity tracings. Interpreting fetal heart rate tracings from preterm fetuses requires knowledge of fetal physiologic development. Obtaining clear tracings of preterm uterine activity remains a challenge and heightens the importance of thorough nursing assessment, including inquiry about risk factors for pregnancy complications.


Dose optimization study of arterial changes associated with angiotensin converting enzyme inhibition in hypertension. In treating hypertension the optimal dose of angiotensin converting enzyme (ACE) inhibitor is derived from dose-response curves that relate the quantity of drug taken to the resulting fall in blood pressure; the blood pressure fall reflects a decrease in vascular resistance and hence, a degree of arteriolar vasodilation. However, ACE inhibition dilates not only the small arteries but also the larger calibre arteries, which increases compliance. Given the differences in structure and function of large and small arteries, the optimal drug dose for a given vessel may differ according to the size and structure of the vessel. DOSE-RESPONSE EFFECTS IN CLINICAL STUDIES: Clinical studies indicate that in the brachial artery territory, larger doses are required to obtain arterial dilation than to produce a decrease in vascular resistance. In the aorta, an improvement in arterial compliance and distensibility is governed both by the fall in blood pressure and the drug dose. Finally, for the femoral artery, the degree of arterial dilation is influenced markedly only by the drug dose. An understanding of the drug dose required to produce a given change in the hypertensive arterial system may have important implications for the control of blood pressure. For a given mean arterial pressure, systolic blood pressure is lower and diastolic blood pressure higher when aortic compliance is increased, a haemodynamic change commonly seen following ACE inhibition. Recent double-blind studies have shown that ACE inhibitors produced a more pronounced decrease in systolic than diastolic blood pressure. These findings indicate that the optimum doses required to improve the arterial wall in large arteries must be evaluated by long-term antihypertensive therapy.


Use of ultrasonic and microsphere techniques to evaluate regional aspects of vasodilator therapy in myocardial ischaemia, arterial hypertension and heart failure. To review regional aspects of vasodilator therapy in myocardial ischemia, arterial hypertension and heart failure. Results were obtained from experiments (1) performed either in experimental animals or in human volunteers or patients; (2) using either ultrasonic or microsphere techniques; (3) on the effects of different drug classes, including angiotensin converting enzyme inhibitors, calcium antagonists, potassium channel openers and nitrates; and (4) on the arterial and arteriolar vasodilating effects of different drug classes. The regional vasodilator effects, both arteriolar and arterial, of the major classes of drugs used in the treatment of coronary insufficiency, arterial hypertension and cardiac failure appear to be heterogenous. This heterogeneity is seen with a given drug in different vascular beds; within a class of drugs in a single vascular region; and between the regional vasodilator profiles of different classes of drugs. From the clinical point of view, the consequences of this heterogeneous vasodilation may be either positive (increase in flow, favourable redistribution of flow) or negative (steal phenomenon, opening of shunts).


Effectiveness of a pregnancy smoking cessation program. To evaluate two nursing approaches to promoting smoking cessation during initial antenatal visits. Experimental, with assignment to interventions using a random, alternate-day strategy and blind assessment of smoking at baseline, 1 month postintervention, 36 weeks' gestation, and 6 weeks postpartum. 224 daily smokers, fewer than 31 weeks gestation, during first prenatal visit, at a teaching hospital antenatal clinic. An evening class providing guidance on a self-help program for 2 hours on a group basis or 20 minutes on an individual basis during the prenatal appointment. Smoking cessation, confirmed by urinary cotinine levels. All women assigned to the referral intervention received a referral, but none attended the classes. In contrast, 93% assigned to the immediate intervention received the intervention. The group receiving immediate intervention had two to three times higher rates of cessation at all follow-up periods, with significant differences at the 1-month follow-up. There were certain similarities between the groups. Cessation interventions should be administered during the first prenatal visit.


The dose-response relationship with angiotensin converting enzyme inhibitors: effects on blood pressure and biochemical parameters. CURRENT USAGE: Plasma angiotensin converting enzyme (ACE) inhibition and dose-response relationships during blood pressure reductions were compared for several marketed ACE inhibitor compounds. Both peak and trough responses are considered and contrasted. The presently recommended antihypertensive doses of enalapril, lisinopril, perindopril and ramipril appear to lie within the linear range of the antihypertensive dose-response relationship. For benazepril and captopril, the recommended doses may be in the flat, upper part of the relationship. The recommended doses for initiating antihypertensive therapy may still be excessive in patients at risk of heightened pharmacodynamic responses. Further studies are required to clarify the dose-response relationship for all of these compounds.


Use of home apnea monitors.

Use of home apnea monitors. To examine the frequency of use of home apnea monitors, reasons for not using them, and factors associated with their use among families of infants for whom home monitoring had been prescribed. Cross-sectional study, including a telephone interview to collect demographic data and a mailed questionnaire to obtain data on monitor use. The apnea clinics in two tertiary-care centers. Ninety-three families (representing an 80.9% response rate) with infants considered at increased risk of sudden infant death syndrome and requiring home monitors. Infants with tracheostomies or bronchopulmonary dysplasia and families with monitored twins, a mother known to be drug addicted, or no home telephone were excluded. Of concern were that 23.1% of mothers reported using the monitor 12 or fewer hours per day and that 10.8% believed their infants did not need a monitor. Of 11 variables examined, only color change in the infant was associated with frequency of monitor use. Clear, consistent communication with families regarding the use of apnea monitors is essential to improve compliance with proper monitoring techniques.


Use of monitoring software to improve the measurement of carotid wall thickness by B-mode imaging. High-resolution B-mode imaging is a reliable, easily performed and non-invasive means of studying atherosclerosis in superficial blood vessels. Recently it has been used for in vivo studies on the thickness of the common carotid artery wall. It is very sensitive, although the results of practical investigations are highly dependent on both the operator and the direction and angle of ultrasound beams directed towards the vessel. We have assessed inter- and intra-observer reproducibility of the measurement of common carotid artery wall thickness in 13 subjects, using two procedures. The first was a standard echographical investigation. In the second procedure, the principal parameters recorded from the first investigation were used to reposition the beam with the same incident angle. Intra-observer variability (correlation coefficient, r = 0.61 for procedure 1 and r = 0.77 for procedure 2) and inter-observer variation (r = 0.58 for procedure 1 and r = 0.71 for procedure 2) were reduced when the second investigation was assisted by reproducibility software. The proposed method is a reliable and reproducible way of assessing combined intimal and medial wall thickness in the common carotid artery. It may be possible to improve reproducibility using specific software to aid the operator. Since the intimal and medial thickness of the common carotid artery appears to be a sensitive marker of vascular risk, the proposed standardized method of measuring these parameter may allow early detection and assessment of changes.


Arterial mechanics and wave reflection with antihypertensive therapy. To describe a logical therapy for hypertension, based on functional elements of structural changes. Structural changes to large blood vessels in hypertension include medial degenerative changes, which stiffen arteries and increase pulse wave velocity, and intimal atherosclerotic changes, which narrow arterial segments. The former cause early wave reflection with increased systolic pressure in central arteries and the left ventricle. The latter compromise blood flow to vital organs. Vasodilator drugs with arterial dilating properties are the most logical and effective therapy. These agents decrease wave reflection from peripheral sites and so reduce systolic pressure in the left ventricle and central arteries; this effect is achieved both by decreasing the stiffness of peripheral arteries and by a differential effect on arterial calibre at branching sites. Arterial vasodilators also tend to dilate stenoses and collateral vessels and thereby minimize vascular 'steal', whereas arterial vasodilators (such as dipyridamole, hydralazine, prazosin) have little or no significant effect on wave reflection, and so fail to reduce the ill-effects of early wave reflection on the left ventricle and central arteries. Furthermore, by dilating arterioles in normal tissue, arteriolar vasodilators can cause vascular 'steal' in the heart or brain. The most effective vasodilators are those with both arterial- and arteriolar-dilating properties. Differential effects of vasodilators on arteries and arterioles can explain some differing effects of antihypertensive agents in clinical trials, as well as differing clinical responses in individual patients.


Thermal effects of hooding incubators.

Thermal effects of hooding incubators. To determine the effect of covering infant incubators on incubator wall and air temperatures, as well as on infant temperatures. A within-subject ABA design, in which blankets covering the incubators were removed for a 30-minute period and then replaced. A neonatal intensive-care unit. Eight medically stable infants (gestational age, 28-33 weeks; birth weight, 913-1,947 g; and postnatal age, 2-39 days). Incubator wall and air temperatures as well as infant temperatures were measured during three study conditions: incubators covered (30 minutes), uncovered (60 minutes), and re-covered (30 minutes). Incubator air and wall temperature; infant temperature. All incubator walls decreased in temperature after being uncovered; the decrease ranged from 0.6-2.2 degrees C. Although infants maintained relatively stable body temperatures during the uncovered period, the energy cost to their thermoregulatory efforts is unknown.


Effects of age, parity, and adherence on pelvic muscle response to exercise. To examine factors that affect pelvic muscle response to 12 weeks of pelvic muscle exercise. Repeated measures design in which intravaginal pressures during pelvic muscle contractions were recorded at baseline and after four exercise levels. College of Nursing research site in Gainesville, Florida. Eighty-five parous, community-dwelling women, aged 35-78 years and without incontinence as a primary concern. A 12-week graded program of regular (three times per week, every other day) pelvic muscle exercise at home. The hypotheses were that younger age, lower parity, higher baseline intravaginal pressures, and adherence to the pelvic muscle exercise program each would result in significant improvement in maximum intravaginal pressures. The only factor showing significance in predicting a successful outcome was age (t = -2.29, df = 41, one-tail probability = .0136). Regular, graded exercise over several weeks is needed to build pelvic muscles, and some women who exercise do not improve. Although the reasons for not improving are unclear, age is a significant factor.


Arterial structure in hypertension and the effects of angiotensin converting enzyme inhibition. In hypertension, structural changes in the cardiovascular system affect not only small arteries and the heart but also the large arteries, particularly in elderly people. It has been suggested that structural alterations to the small arteries are responsible for the elevation in mean arterial pressure seen in hypertension, as a result of increased vascular resistance. However, the amplitude of pressure oscillation (pulse pressure) is influenced by other haemodynamic mechanisms that involve large arteries including a decrease in compliance and an increase in wave reflection. Structural alterations to the large arteries may, in hypertensive subjects, be responsible for an increase in the amplitude of pressure oscillation, leading to a disproportionate increase in systolic over diastolic blood pressure because of arterial (not arteriolar) changes. These findings not only contribute to a better understanding of the relationship between vascular structure and blood pressure levels but also to a better interpretation of hypertensive complications, particularly those related to the heart and large vessels. The reversal of structural arterial changes may become a goal in long-term antihypertensive treatment. Angiotensin converting enzyme (ACE) inhibitors in particular can reverse structural arterial changes, increase arterial compliance and produce a more pronounced decrease in systolic than in diastolic blood pressure.


Hypertension and the microcirculation: a brief overview of experimental studies. To review experimental findings on the importance of the microcirculation in hypertension. A significant part of the increase in vascular resistance found in hypertension involves alterations in the arteriolar network. Changes in vascular reactivity and amplification of normal microvascular autoregulatory loops are among the mechanisms involved in these microvascular alterations. Depending on the organ and the type of hypertension, different types of changes have been observed, including (1) changes in resting arteriolar diameter and increased tone, either throughout the arteriolar network or localized to certain arteriolar segments; (2) temporary closure of a significant fraction of the terminal arteriolar bed; and (3) degenerative processes in terminal arterioles and capillaries inducing anatomical rarefaction of the microvessels. Microvascular changes are responsible for only a portion of the increased resistance but they are extremely important in the global understanding of the hypertensive process, as they are potentially responsible for tissue damage and may be related to the increased risk of organ failure in hypertension.


Blood rheology in arterial hypertension. DETERMINANTS OF BLOOD RHEOLOGY: Blood flow depends on driving pressure and a resistance factor, the latter being related to geometrical hindrance and to the intrinsic viscosity of the blood. Since whole blood is non-Newtonian in nature, blood viscosity is strongly dependent on shear conditions. Low-shear areas occur in cardiovascular disease, and therefore the interaction between blood viscosity and flow conditions may affect vascular disorders. Increased shear stress secondary to increased viscosity may produce endothelial activation and release of endothelium-derived relaxing factors, leading to flow-dependent vasodilation. All the determinants of blood rheology, including plasma protein and erythrocyte factors may be altered in patients with arterial hypertension. BLOOD RHEOLOGY IN HYPERTENSION: A hyperviscosity state is created which is associated with an unfavourable prognosis, since it is correlated with blood pressure levels and the severity and complications of the disease including left ventricular hypertrophy. The mechanisms of haemorheological abnormalities in hypertension are still unclear. It is not known whether blood rheology is an independent variable in patients with hypertension or whether it is a covariable with other established indices of heterogeneity. However, many aetiopathological changes identified in hypertensive disease may contribute to the observed changes in blood rheology. Haemorheological changes in hypertension, through complex interactions with platelet activation and endothelial function, may contribute to the development of thrombosis and atherosclerosis. Moreover, in acute and chronic ischaemia and other conditions where compensatory mechanisms such as collateral formation and vasodilation are limited, rheological factors may become important determinants of blood flow and tissue oxygenation. TREATMENT EFFECTS: Many antihypertensive agents have direct or indirect potential effects on haemorheological variables. However, to date, most studies that have investigated the effects of therapy on rheological variables have not been performed in clinically relevant situations. Controlled studies that monitor both the acute and longterm effects of antihypertensive drugs on relevant haemorheological variables are required to show whether specific therapeutic approaches can correct abnormalities in blood rheology.


Professional and lay interrater reliability of urinary luteinizing hormone surges measured by OvuQuick test. To determine the reliability of women, unmotivated by fertility problems, to accurately assess and record the urinary luteinizing hormone surge indicated by color changes on OvuQuick test pads. A descriptive, correlational study testing the reliability and validity of an instrument. The participants' homes. 114 college-educated, white women. An OvuQuick Test Kit and a Menstrual Cycle Diary were mailed to each participant. The monthly diary and test pads of the participants were reassessed by a master's-prepared nurse. Women without medical or health-care training are reliable in judging the color changes on the OvuQuick test pads and recording these results in a menstrual diary. Investigator and subject assessment and recording of luteinizing hormone surge results agreed 95% (284 of 300 instances) of the time. In addition, the validity of the luteinizing hormone surge for predicting ovulation was accurate in 93% (26 of 28 instances) of the cases. OvuQuick is a reliable and valid test for home evaluation of luteinizing hormone surge and prediction of ovulation.


Antihypertensive therapy in renal disease and transplantation. HYPERTENSION AND RENAL DISEASE: In experimental models of renal disease not only protein intake and hyperlipidaemia but also hypertension may contribute to the progressive deterioration in renal function; in these models an imbalance in intrarenal haemodynamics appears to be a particularly important factor. ANTIHYPERTENSIVE THERAPY: A reduction in arterial pressure can alter the course of human chronic renal disease. However, it is not clear whether any one class of antihypertensive drug is superior to any other class in these patients. Angiotensin converting enzyme (ACE) inhibitors may prevent the progression from incipient to overt diabetic nephropathy and afford better protection than conventional treatment. In patients with non-diabetic renal disease there is no unequivocal evidence for a protective effect. In renal transplant recipients, mainly those taking cyclosporine, ACE inhibitors are equally effective compared to calcium antagonists in the control of hypertension, but their renal effects in transplant recipients without renal artery stenosis have not yet been assessed.


Myocardial fibrosis and the concepts of cardioprotection and cardioreparation. To examine the inter-relationship between effector hormones of the renin-angiotensin-aldosterone system and fibrosis, a determinant of abnormal myocardial stiffness, and to determine whether pharmacological interference with these hormones can prevent or regress this pathological structural remodeling. Two morphological expressions of myocardial fibrosis are evident, a perivascular and interstitial fibrosis, not related to cardiac myocyte necrosis, and microscopic scarring that replaces lost myocytes. The former, a reactive fibrosis, is related to elevations in circulating mineralocorticoids (aldosterone or deoxycorticosterone) with increased dietary sodium, and not to arterial hypertension or ventricular loading. Scarring follows the cytotoxicity associated with elevated plasma angiotensin II levels and the increased K+ excretion that accompanies chronic mineralocorticoid excess. Given the association of these hormones with fibrosis, the concept of cardioprotection was evaluated in various prevention trials. Reactive fibrosis was prevented in unilateral renal ischaemia by angiotensin converting enzyme (ACE) inhibition with captopril and in either primary or secondary hyperaldosteronism by antagonism of the aldosterone receptor with spironolactone. Scarring (and cell loss) was prevented in renal ischemia by captopril and by K(+)-sparing diuretics (spironolactone, amiloride) in primary hyperaldosteronism. In treatment trials, where reactive fibrosis was established, lisinopril promoted regression of the fibrosis and therefore was cardioprotective. Myocardial fibrosis is related to chronic mineralocorticoid excess (with increased dietary sodium), angiotensin II and increased K+ excretion. Cardioprotective and cardioreparative strategies that respectively prevent or regress the development of fibrous tissue have been demonstrated in experimental models and now merit clinical evaluation.


Curvature and separation discrimination at texture boundaries. Visual discrimination of contour curvature was investigated by using contours defined by the locus of points at which the phase of a square-wave grating was shifted by 180 degrees (a texture boundary). Curvature-increment thresholds were measured for contour curvatures from 0.31 to 10.65 deg-1, for grating spatial frequencies of 4.0 and 16.0 cycles per degree (cpd), and for gratings in either sine or cosine phase at the point of maximum curvature. Thresholds for these conditions were compared with curvature discrimination at black-white edges. Grating phase had no effect on performance at any curvature or grating frequency, but 16.0-cpd gratings produced a threshold elevation at all curvatures by an average factor of 2.4. Two-line separation discrimination was also measured for lines defined by texture boundaries. These data can be predicted by a model incorporating end-stopped complex cells of a type reported physiologically in primate area V2.


Contrast dependence of the oscillatory motion threshold across the visual field. Observer sensitivity to oscillatory step displacements of sine-wave gratings was investigated at various loci in the visual field (0-30 degrees) as a function of contrast. Detection thresholds at 10 Hz and high grating contrasts were approximately 11-15 arcsec in the fovea and 37-47 arcsec at 30 degrees eccentricity. At any given contrast, threshold displacement increases linearly with eccentricity. The data provide evidence against an interpretation based on cortical magnification, because the slope and the scale-free x intercept of the eccentricity function vary strongly with contrast. While foveal thresholds for high-contrast gratings are in the range of the hyperacuities, the oscillatory motion threshold falls off an order of magnitude more slowly than the traditional hyperacuities. Rather than conceiving of the oscillatory motion threshold as a spatial acuity limited by cortical magnification, we suggest an alternative approach that is based on a form of contrast discrimination. Oscillatory motion can be decomposed into the sum of a modulating counterphase grating and a static masking grating, both of which are in spatial quadrature (i.e., 90 degrees out of phase). At low grating contrast, oscillatory motion can be detected when the counterphase component exceeds a constant contrast value. Above a critical contrast value of the static component Cscrit, threshold rises as a power function of contrast with a slope near 1.0. The critical contrast value Cscrit increases linearly with eccentricity, indicating that oscillating gratings observed with the peripheral visual field are less easily masked compared with foveally fixated gratings.


Achromatic form perception is based on luminance, not brightness. Two figures were examined, one a subjective disk and the other a cup whose shape was revealed by shadows. The figures were presented in a single color on a background of a different color, and the observers adjusted the radiance of one color until, in the first case, the vividness of the subjective contour reached a minimum (minimum subjective contour) or, in the second case, the impression of depth that is due to shadows disappeared (shadow disappearance). The results for these two tasks followed the data for minimum flicker matches (made with the same stimuli) much more closely than those for direct brightness matching. We therefore claim that achromatic form perception in general and subjective contour and shadow perception in particular are based on the intensity dimension measured by flicker photometry, not on that measured by brightness matching. Finally, in agreement with these findings, bleaching of short-wavelength sensitive cones did not affect settings for subjective contours, shadows, or flicker photometry but did affect brightness matching.


Interference of diffusive light waves.

Interference of diffusive light waves. We examine interference effects resulting from the superposition of photon-density waves produced by coherently modulated light incident upon a turbid medium. Photon-diffusion theory is used to derive expressions for the ac magnitude and phase of the aggregate diffusive wave produced in full- and half-space volumes by two sources. Using a frequency-domain spectrometer operating at 410 MHz, we verify interference patterns predicted by the model in scattering samples having optical properties similar to those of skin tissue. Potential imaging applications of interfering diffusive waves are discussed in the context of the theoretical and experimental results.


Intramedullary nailing of acute femoral shaft fractures without a fracture table: technique of using a femoral distractor. Intramedullary nails were placed prospectively in 25 acute femoral shaft fractures in 25 patients without the use of a fracture table. A femoral distractor was used in 21 of the 25 patients to aid in obtaining and holding a reduction. Our goals were to determine if the technique was safe and effective for insertion of intramedullary nails in a wide spectrum of femoral fractures--with no increase in morbidity when compared to the use of the more familiar fracture table--and to determine the potential complications and pitfalls of using this technique. A retrospective evaluation of the most recent 25 patients with 27 femoral fractures that underwent intramedullary nailing on a fracture table was done to compare operative time, estimated blood loss, complications, and postoperative fracture alignment. In addition to the clinical evaluation, cadaveric dissections were undertaken to determine the exact location of the proximal distractor screw in relation to the contents of the femoral triangle. The femoral nerve was a minimum of 2.5 cm, and the femoral artery a minimum of 3.0 cm from the proximal screw. In comparing the two studies, no significant difference was noted in the age of the patients, fracture types or locations, associated injuries, operative time, estimated blood loss, final fracture reduction, or nail position. No complications were encountered in the placement of the proximal femoral distraction screw. Although the distraction method is technically difficult because the reduction is obtained entirely during the procedure, there are certain situations when this technique could be employed with the benefit of decreasing intraoperative patient manipulation, thereby shortening operative time.(ABSTRACT TRUNCATED AT 250 WORDS)


Fracture patterns and mechanisms in pedestrian motor-vehicle trauma: the ipsilateral dyad. Pedestrians struck by motor vehicles have the highest mortality and morbidity rates of all motor-vehicle traumas. Fracture patterns and mechanisms were reviewed in a retrospective study of 115 consecutive patients. The most common fracture was tibia-fibula (39 patients), followed by pelvic (35 patients) and femur fractures (31 patients). A majority (90%) of long-bone fractures were the result of a direct-blow mechanism, and pelvic fractures were caused usually by lateral-compressive forces. Unstable pelvic and femur fractures both correlated with mortality (p less than 0.05), whereas tibia-fibula fractures (open or closed) did not. The triad of head, pelvis, and knee injuries traditionally associated with pedestrian motor-vehicle accident (MVA) victims was not found to occur with any statistical significance in this study group. Several characteristic fracture patterns were discovered: femur fractures associated with an accompanying pelvic fracture, and the ipsilateral dyad, an upper- and lower-extremity fracture on the same side, were found to occur with statistical significance (p less than 0.05). A lower extremity fracture warrants particularly close attention to the examination of the corresponding upper extremity, and a femur fracture should alert the clinician to the possibility of pelvic injury. The ipsilateral dyad has not been described previously in the literature and should be appreciated by physicians evaluating and treating pedestrian MVA victims.


Mason type II radial head fractures: operative versus nonoperative treatment. The most appropriate treatment of Mason type II radial head fractures remains controversial. Recommended treatment has included closed reduction and immobilization, resection, or open reduction and internal fixation. The cases of 29 Mason type II radial head fractures treated at Naval Hospital Oakland from 1983 to 1989 were identified. Twenty-six or 90% were available for detailed follow-up. All cases underwent standardized elbow evaluations and results were compared using an elbow score based on a 100-point scale. The parameters evaluated were pain, motion, elbow and grip strength, and function in activities of daily living. In addition, injury and follow-up radiographs were analyzed. Mean follow-up was 18 months. There were 10 cases treated by open reduction and internal fixation and 16 cases treated by closed means. At final follow-up, the operatively treated group had a mean elbow score of 92 and 90% good/excellent results. The nonoperatively treated group had a mean elbow score of 77 and 44% good/excellent results. This difference was statistically significant (p less than 0.01). Radiographic analysis revealed a higher incidence of articular depression, displacement, and joint narrowing in the nonoperatively treated group. We conclude that displaced radial head fractures treated nonoperatively have a higher incidence of pain, functional limitations, loss of strength, and radiographic evidence of arthritis when compared to those treated by open reduction and internal fixation.


Operative treatment of olecranon nonunion. Records of five patients treated surgically for nonunion of the olecranon were reviewed. Four of the five fractures leading to nonunion were comminuted or oblique. Three nonunions occurred after tension band wiring, one nonunion occurred after open reduction internal fixation with a semitubular plate, and one nonunion occurred after treatment with a cast. The median interval from fracture to treatment of nonunion was 8 months. All nonunions were treated surgically. Four patients were treated with a tension band plate technique. All nonunions united at a median of 3 months. The median follow-up period was 36 months (range, 12-48 months).


A comparison of unicortical and bicortical end screw attachment of fracture fixation plates. Plate fixation is considered by many clinicians to be the treatment of choice for displaced diaphyseal fractures of the forearm. One possible complication associated with plate fixation is refracture with the plate in situ or after plate removal. With the plate in situ, refracture typically occurs through the last screw hole near the end of the plate. Some clinicians have advocated the use of unicortical end screws to minimize the risk of such refractures. In this study, we performed a series of in vitro tests to compare the breaking strength of plated bone analogues that used either unicortical or bicortical end screws. The plated constructs that used unicortical end screws were significantly weaker in the two most important physiologic loading modes. Based on these results, we conclude that the use of unicortical end screws may result in a greater risk of refracture with the plate in situ.


Skateboard and in-line skate fractures: a report of one summer's experience. During a 5 month period, 26 skateboarding and 10 in-line skating fractures were seen at our institution. The radius was the most commonly injured bone in both groups. Forty-two percent of skateboard fractures required reduction and another 16% required operative intervention. Epiphyseal fractures occurred in 42% of the skateboard riders who were skeletally immature. A greater proportion of high-energy fracture patterns was recorded in contrast to earlier reports. Also, a trend towards injuries occurring on the street, as opposed to home, has been noted. Skateboard riders continue to shun protective gear and hitting a surface irregularity is the most common cause of fall. In-line skaters, on average, wear more protective gear and are more likely to continue riding after their injury. Routine protective gear and avoidance of street riding should be encouraged. Instructions stressing balance and control as opposed to showmanship are recommended. Caution is given to first time in-line skaters, as this appears to be an injury-prone period.


Fibular osteosynthesis for delayed type II and type III femoral neck fractures in children. Seventeen transcervical/basal femoral neck fractures in children were treated by free fibular graft and cancellous lag screw. Two cases were failures of a previous surgery, and 15 had been untreated for 3 weeks or more. Four cases had radiological evidence of avascular necrosis of the head and one of the neck preoperatively; five cases had neck resorption. At an average of 48.1 months postsurgery all fractures had united and there was only one new case of avascular necrosis. Four cases had coxa vara, and four cases had premature epiphyseal closure. There were 13 good, three fair, and one poor result(s) using Ratliff's criteria. We recommend this procedure in cases with delayed initial appearance or failed previous surgery. Complications of the procedure such as long screw/graft and fibular fracture are preventable. The incidence of coxa vara in cases with neck resorption may be reduced by adding subtrochanteric osteotomy to the procedure.


The use of Ender nails in femoral shaft fractures: what are the remaining indications? The use of Ender nails for the treatment of femoral shaft fractures has been described as technically easier and less time consuming than current intramedullary nailing techniques. We reviewed our results with unlocked Ender nails in 26 stable and 17 unstable fracture patterns an average of 3-4 years after injury. Because of continued instability, 42% of the stable and 76% of the unstable groups required adjunctive stabilization in the form of skeletal traction, a cast, or an external fixator. Additionally, nail migration and shortening and loss of motion at the knee were seen in 14 fractures in each group. Although two thirds of the patients with stable fracture patterns obtained good or excellent results, no outcome in the unstable group was rated excellent and only 19% were considered good. We therefore recommend that rigid locked intramedullary nails be used in femoral diaphyseal injuries. The use of Ender nails should be limited to stable fracture patterns and locked with screws or wires. They may be particularly useful for fractures in femora with small medullary canals (less than or equal to 8 mm), fractures below noncemented femoral prostheses, and fractures in young children requiring intramedullary stabilization without injuring the physeal plates.


Alignment of supracondylar/intercondylar fractures of the femur after internal fixation by AO/ASIF technique. Fifty-nine supracondylar-intercondylar fractures of the femur in 57 patients were evaluated after a mean follow-up of 5 years 7 months (range 2 years to 11 years 3 months) after internal fixation using AO/ASIF technique. Axial alignment was compared with that of the uninjured side by orthoroentgenography in the upright position and by bilateral anteroposterior (AP) and lateral views of the femur. Identical values for varus/valgus were noted in 24%, for ante/recurvation in 72%, and for rotation in 61%; differences were within 5 degrees of varus/valgus in 74%, of ante/recurvation in 78%, and of rotation in 83%. Alignment differences were more frequent in complicated and intercondylar fractures according to the AO classification of fractures. We conclude that restoration of the distal femoral angle is far more difficult than restoration of the sagittal plane and rotation, but a satisfactory functional result appears to be compatible with angulation differences of less than or equal to 5 degrees in any plane and that this difference appears to be within the reasonably achievable limits. 93% of the patients were satisfied; 64% of patients were pain-free, and 27% had slight intermittent pain (not interfering with daily activity); 67% of the patients had unlimited walking distance, and 78% of the patients were able to walk without aid. Excellent and good results according to the rating systems of Neer et al., Pritchett, and Schatzker and Lambert were noted in 82, 39, and 26%, respectively. This discrepancy between alignment, pain, function, and results according to different rating systems underlines the need for future standardized, clearly defined reporting and classification of rating.


Assessment of bone viability in patients with osteomyelitis: preliminary clinical experience with laser Doppler flowmetry. The intraoperative determination of bone viability is of fundamental importance in the surgical management of osteomyelitis. Recurrent infection will result from inadequate debridement, whereas reconstructive problems will be magnified by overzealous resections. The purpose of this article is to report the use of laser Doppler flowmetry (LDF) as a surgical adjunct allowing quantitative determination of bone viability in patients with osteomyelitis. Twenty-five patients with osteomyelitis underwent surgical debridement using LDF to assist with the intraoperative identification of necrotic bone and have been observed for at least 6 months. The LDF probe is placed directly on the bone and the output signal is channeled into an oscilloscope that calculates and displays the mean value of the signal in millivolts (mV). All patients underwent radical surgical debridement, including hardware removal if present and resection of nonviable bone. Bone debridement was continued when possible until LDF measurements in excess of 100 mV were obtained. Information regarding bone vascularity obtained with the LDF had a direct influence on the extent of bone debridement in all cases. The patients have been observed for an average of 16 months. No complications were associated with the use of LDF. All readings were pulsatile. Five patients had recurrence of infection. The average LDF reading following debridement for patients with recurrent infection was 72 mV, compared to 107 mV for patients without recurrence (p less than or equal to 0.025). All fractures were healed, although some required supplemental surgical management, including bone grafting or external fixation.(ABSTRACT TRUNCATED AT 250 WORDS)


Type II floating knee: ipsilateral femoral and tibial fractures with intraarticular extension into the knee joint. Thirty-four patients with ipsilateral fractures of the femur and tibia with intraarticular extension into the knee of at least one fracture were reviewed at an average follow-up of 38 months. Joint involvement was present in 22 (65%) femoral fractures and 23 (68%) tibial fractures. In 11 (32%) patients, both fractures were intraarticular. In 71% of the patients, there were major associated injuries. Open fractures were common, occurring in 21 (62%) extremities. Associated vascular injuries were seen in seven (21%) cases. Ninety percent of the fractures were surgically stabilized. The average time to healing was 39 and 37.5 weeks for the femur and tibia, respectively. The average flexion of the knee was 96 degrees (5-140 degrees) with flexion contractures occurring in five (15%) knees. Results were graded according to criteria established by Karlström and Olerud. Only eight (24%) patients had good or excellent results. Complications were frequent, with deep infections occurring in 11 (32%) extremities, leading to above-knee amputations in three (9%) patients. This subgroup of floating knee injuries appears to be associated with a higher degree of systemic trauma, a higher percentage of open injuries, and a much graver prognosis.