[Efficacy of a novel warming blanket: prospective randomized trial]. Warming with an underbody warming system reduces intraoperative hypothermia in patients undergoing laparoscopic gastrointestinal surgery: a randomized controlled study. Forced‐air surface warming versus oesophageal heat exchanger in the prevention of peroperative hypothermia Intraoperative Patient Warming using Radiant Warming or Forced-air Warming during Long Operations Benefits of intraoperative skin surface warming in cardiac surgical patients. A comparative study of three warming interventions to determine the most effective in maintaining perioperative normothermia. Use of forced-air warming during and after outpatient arthroscopic surgery. Forced-air warming and fluid warming minimize core hypothermia during abdominal surgery. Preoperative warming combined with intraoperative skin-surface warming does not avoid hypothermia caused by spinal anesthesia in patients with midazolam premedication. Effect of preoperative warming on intraoperative hypothermia: a randomized-controlled trial Warmed intravenous infusion for controlling intraoperative hypothermia. Prevention of hypothermia by cutaneous warming with new electric blankets during abdominal surgery. The effects of intravenous fluids temperature on perioperative hemodynamic situation, post-operative shivering, and recovery in orthopaedic surgery. [A comparison of the effects of intravenous fluid warming and skin surface warming on peri-operative body temperature and acid base balance of elderly patients with abdominal surgery]. Preoperative combined with intraoperative skin-surface warming avoids hypothermia caused by general anesthesia and surgery. Methods of Patient Warming during Abdominal Surgery Preoperative Warming Versus no Preoperative Warming for Maintenance of Normothermia in Women Receiving Intrathecal Morphine for Cesarean Delivery: A Single-Blinded, Randomized Controlled Trial
BACKGROUND Perioperative hypothermia is a common complication of general anesthesia and occurs in up to 50 % of patients during ear , nose and throat ( ENT ) surgery . In this prospect i ve , r and omized controlled study the hypothesis that a new conductive warming blanket ( Barrier ® EasyWarm ® , Mölnlycke Health Care Erkrath , Germany ) is better in reducing the incidence of perioperative hypothermia in ENT surgery than insulation with a conventional hospital duvet alone was tested . MATERIAL S AND METHODS After approval of the local ethics committee and written informed consent 80 patients with a planned procedure time between 1 and 3 h were recruited .  Anesthesia was induced and maintained using propofol , remifentanil and rocuronium and the core temperature was measured using an esophageal temperature probe . Patients in the study group were warmed at least 30 min prior to induction of anesthesia using the novel warming blanket ( Barrier ® EasyWarm ® ) and patients in the control group were insulated with a st and ard hospital duvet . Data were tested using Fisher 's exact test , Student 's t-test or the Mann-Whitney U-test as appropriate . Time-dependent changes in core temperature were evaluated using repeated measures analysis of variance ( ANOVA ) and post hoc Scheffé 's test . Results are expressed as mean ± SD or as median and interquartile range ( IQR ) as appropriate . A p < 0.05 was considered to be statistically significant . RESULTS The ANOVA did not identify a significantly higher core temperature in the study group at any time point . Furthermore , Fisher 's exact test showed no differences in the incidence of intraoperative ( 12 out of 29 versus 10 out of 32 patients , p = 0.44 ) or postoperative hypothermia ( 12 out of 29 versus 9 out of 32 patients , p = 0.30 ) between the groups . No adverse effects were observed . CONCLUSIONS In the studied patient group the new conductive warming blanket ( Barrier ® EasyWarm ® ) showed no superiority compared to conventional thermal insulation alone BACKGROUND Intraoperative hypothermia is a common event during laparoscopic abdominal surgery . On one h and , intraoperative hypothermia can delay the metabolism and prevent tissue damage . One the other h and , long-term and severe intraoperative hypothermia may also lead to perioperative complications , such as increasing of peripheral resistance , coagulation dysfunction , intraoperative hemorrhage and postoperative shivering . Maintenance of normothermia during surgical procedures may improve the quality of patient care . OBJECTIVES This study investigated the feasibility and efficacy of intraoperative cutaneous warming with an underbody warming system during laparoscopic gastrointestinal surgery . METHODS 110 patients undergoing laparoscopic surgery for gastrointestinal cancer between January and December 2011 were r and omized into the laparoscopic control ( Control ) group and laparoscopic intervention ( Intervention ) group . Nasopharyngeal temperature , prothrombin time , activated partial thromboplastin time , and thrombin time were measured before and during surgery , intraoperative and postoperative complications , as well as shivering after anesthesia and visual analog scale score for pain evaluation after surgery were also recorded . Clinical risk factors that may cause intraoperative hypothermia during laparoscopic surgery were also analyzed by correlation analysis . RESULTS The two groups were comparable at the baseline . Intraoperative hypothermia was observed in 29 patients ( 52.7 % ) in Control group and 3 ( 5.5 % ) in Intervention group . Nasopharyngeal temperature in Control group was significantly decreased since 30min after the start of operation until the end of surgery comparing to that at the start of anesthesia , but there was no difference in the Intervention group . In Intervention group , the nasopharyngeal temperature was remaining at ∼36.5 ° C , indicating the feasibility and efficiency of the underbody warming system in preventing intraoperative hypothermia during laparoscopic gastrointestinal surgery . Moreover , with anesthesia and operation time increased , there was no significant change of coagulation function , hemoglobin level as well as less intraoperative hemorrhage , less postoperative shivering and lower visual analog scale score in Intervention group comparing to Control group . Multivariate logistic regression analysis revealed that anesthesia time and volume of CO2 were independent risk factors for perioperative hypothermia . CONCLUSIONS Cutaneous warming with an underbody warming system is a feasible and effective method to prevent intraoperative hypothermia during laparoscopic gastrointestinal surgery Background : In a prospect i ve , r and omized , placebo‐controlled study we investigated the efficacy of 2 different heating methods in 24 patients undergoing abdominal surgery of at least 2 h expected duration Forced-air warming is the most commonly used and effective method of active warming . A new radiant warming device ( Suntouch ™ , Fisher and Paykel ) may provide an alternative when the skin surface available for warming is limited . We conducted a r and omized controlled trial to compare the efficacy of the Suntouch ™ radiant warmer and forced-air warming . With ethics committee approval , 60 surgical patients having procedures anticipated to be more than two hours in duration were recruited . Patients were r and omized to either radiant warming or forced-air warming . All intravenous fluids were warmed but prewarming was not used . The final intraoperative core temperatures ( ° C ) for the radiant warming and forced-air warming groups were 36.0±0.5 and 36.4±0.6 ( P=0.002 ) respectively . No other patient variables were significantly different . The Suntouch ™ is not as effective as the forced air warming for intraoperative warming during long surgical procedures . The device may be useful when forced-air warming is not possible We have investigated patients undergoing cardiac surgery with hypothermic bypass to see if the addition of skin surface warming during systemic rewarming on bypass ( heated group , n = 43 ) would improve perioperative thermal balance compared with conventional management without skin warming  ( control group , n = 43 ) in an open , r and omized , controlled study . Intraoperative skin warming with a water mattress and forced warm air over the face , neck and shoulders attenuated the afterdrop in nasopharyngeal temperature after weaning from bypass ( 2.3 ( 1.2 ) degrees C and 1.3 ( 0.5 ) degrees C in the control and heated groups , respectively ) ( P < 0.05 ) and result ed in higher rectal temperature 4 h after surgery . Despite similar st and ard coagulation tests , heated patients had lower blood loss via the chest tubes ( 600 ( 264 ) ml vs 956 ( 448 ) ml in control patients ) ( P < 0.05 ) and less requirements for i.v . colloid infusion ( 1662 ( 404 ) ml vs 1994 ( 389 ) ml ) ( P < 0.05 ) . There was a significant inverse correlation between rectal temperature on arrival in the ICU and postoperative blood loss ( r = 0.57 , P < 0.001 ) . These data suggest that additional skin surface warming with a water mattress and forced warm air helped to preserve perioperative thermal balance and may contribute to reduced bleeding after cardiac surgery UNLABELLED Perioperative hypothermia poses a challenge because of its deleterious effects on patient recovery .  The current practice of applying two cotton blankets on patients during surgery is thought to be less ideal than using reflective insulation or forced-air warming . We studied 300 patients who underwent unilateral total knee replacement and were r and omized equally to three groups : ( a ) the two-cotton-blanket group , ( b ) the one-reflective-blanket with one-cotton-blanket group , and ( c ) the forced-air-warming with one-cotton-blanket group .  Tympanic temperature readings were taken before surgery in the induction room , on arrival at the recovery room , and at 10-min intervals until discharge from the recovery room . On arrival at the recovery room , the forced-air-warming group had significantly higher temperatures ( adjusted for sex , age , and patient 's induction room temperature ) of 0.577 degrees C + /- 0.079 degrees C ( 95 % confidence interval [ CI ] , 0.427 - 0.726 ; P < 0.001 ) and 0.510 degrees C + /- 0.08 degrees C ( 95 % CI , 0.349 - 0.672 ; P < 0.001 ) more than the reflective-blanket and two-cot-ton-blanket groups , respectively . The forced-air-warming group took a significantly ( P < 0.001 ) shorter time of 18.75 min ( 95 % CI , 13.88 - 23.62 ) to achieve a temperature of 36.5 degrees C in the recovery room as compared with 41.78 min ( 95 % CI , 36.86 - 46.58 ) and 36.43 min ( 95 % CI , 31.23 - 41.62 ) for the reflective-blanket and two-cotton-blanket groups , respectively . The reflective technology was less effective than using two cotton blankets , and the forced-air warming was most efficient in maintaining perioperative normothermia . IMPLICATION S Perioperative hypothermia has deleterious effects on patient recovery . We found in patients having knee surgery that reflective technology was less effective than using two cotton blankets , whereas active surface warming with the forced-air method was most effective in maintaining normothermia According to a two-phase protocol , 127 patients undergoing arthroscopic knee surgery were r and omly assigned to receive intraoperative warming from a forced-air blanket ( n = 69 ) or conventional warmed cotton blankets ( n = 58 ) . During the initial phase ( Phase I ) , active warming was applied during the intraoperative period only , permitting double-blind assessment of postoperative events . In Phase II , warming was continued into the recovery area , which unblinded the assessment . Active warming raised skin temperature perioperatively , and reduced the decline in core temperature compared to the control group . Postoperatively , core temperature increased toward preoperative values at similar rates in both treatment groups , but was still lower in control patients after an hour in the postanesthesia care unit ( PACU ) . Postoperative shivering occurred in 35 % of all patients and was not prevented by either intraoperative or combined intraoperative and postoperative warming . However , significantly fewer actively warmed patients experienced prolonged postoperative shivering . The addition of postoperative warming appeared to provide little , if any , additional benefit . Despite the decreased duration of postoperative shivering in the actively warmed group , we were unable to demonstrate any reduction in the PACU stay OBJECTIVE To evaluate the effect of intraoperative combined forced-air warming and fluid warming system on  patient 's core temperature , blood loss , transfusion dem and , extubation time , and incidence of postoperative shivering . METHODS Forty patients with American Society of Anesthesiologists physical status I and II , aged 18 - 70 years , scheduled for elective abdominal surgery were r and omly assigned to receive intraoperative warming from a forced-air blanket and fluid warming system or conventional cotton blanket , 20 in each group . The core temperature was recorded every 20 minutes during the operation , as well as the blood loss , blood transfusion , extubation time , and incidence of postoperative shivering . RESULTS The core temperature at the end of the surgery in the warming group was significantly different from that in the control group ( 36.4 + /- 0.4 degrees C vs. 35.3 + /- 0.5 degrees C , P < 0.001 ) . Application of intraoperative warming significantly shortened the time between the end of the surgery and extubation ( P < 0.01 ) . Postoperative shivering occurred in 30 % of the patients in the control group compared to no patient in the warming group ( P < 0.01 ) . CONCLUSION Active warming with air-forced blanket and fluid warming system provides sufficient heat to prevent hypothermia during abdominal surgery CONTEXT AND OBJECTIVE Inadvertent perioperative hypothermia is common during spinal anesthesia and after midazolam administration . The aim of this study was to evaluate the effects of intraoperative skin-surface warming with and without 45 minutes of preoperative warming in preventing intraoperative and postoperative hypothermia caused by spinal anesthesia in patients with midazolam premedication . DESIGN AND SETTING Prospect i ve and r and omized study at Hospital das Clínicas , Universidade Estadual Paulista , Botucatu . METHODS Thirty patients presenting American Society of Anesthesiologists ( ASA ) physical status I and II who were scheduled for elective lower abdominal surgery were utilized . The patients received midazolam premedication ( 7.5 mg by intramuscular injection ) and st and ard spinal anesthesia . Ten patients ( Gcontrol ) received preoperative and intraoperative passive thermal insulation . Ten patients ( Gpre+intra ) underwent preoperative and intraoperative active warming . Ten patients ( Gintra ) were only warmed intraoperatively . RESULTS After 45 min of preoperative warming , the patients in Gpre+intra had significantly higher core temperatures than did the patients in the unwarmed groups ( Gcontrol and Gintra ) before the anesthesia ( p < 0.05 ) but not at the beginning of surgery ( p > 0.05 ) . The patients who were warmed intraoperatively had significantly higher core temperatures than did the patients in Gcontrol at the end of surgery ( p < 0.05 ) . All the patients were hypothermic at admission to the recovery room ( T CORE < 36 degrees C ) . CONCLUSIONS Forty-five minutes of preoperative warming combined with intraoperative skin-surface warming does not avoid but minimizes hypothermia caused by spinal anesthesia in patients with midazolam premedication Purpose The purpose of this study was to evaluate the effects of preoperative forced-air warming on intraoperative hypothermia . Methods In this r and omized-controlled trial , adult patients scheduled for elective , non-cardiac surgery under general anesthesia were stratified by scheduled surgical duration ( < 2.5 hr or ≥ 2.5 hr ) and then r and omized to a pre-warming group using a BairPaws ™ forced-air warming system for at least 30 min preoperatively or to a control group with warmed blankets on request . All patients were warmed intraoperatively via convective forced-air warming blankets .  Perioperative temperature was measured using the SpotOn ™ temperature system consisting of a single-use disposable sensor applied to the participant ’s forehead . The primary outcome was the magnitude of intraoperative hypothermia calculated as the area under the time-temperature curve for core temperatures < 36 ° C between induction of general anesthesia and leaving the operating room . Secondary outcomes included surgical site infections , packed red blood cell requirements , and 24 hr postoperative opioid consumption . Results Two hundred participants were analyzed ( 101 control ; 99 pre-warmed ) . Pre-warmed participants had a lower median [ interquartile range ] magnitude of hypothermia than controls ( 0.00 [ 0.00 - 0.12 ] ° C·hr−1vs 0.05 [ 0.00 - 0.36 ] ° C·hr−1 , respectively ; median difference , −0.01 ° C·hr−1 ; 95 % confidence interval , −0.04 to 0.00 ° C·hr−1 ; P = 0.005 ) . There were no between-group differences in the secondary outcomes . Conclusion A minimum of 30 min of preoperative forced-air convective warming decreased the overall intraoperative hypothermic exposure . While redistribution hypothermia still occurs despite pre- and intraoperative forced-air warming , their combined application results in greater preservation of intraoperative normothermia compared with intraoperative forced-air warming alone . Trial registration www . clinical trials.gov ( NCT02177903 ) . Registered 25 June 2014.RésuméObjectifL’objectif de cette étude était d’évaluer les conséquences du réchauffement préopératoire par air forcé sur l’hypothermie peropératoire . MéthodesDans cette étude r and omisée contrôlée , des patients adultes devant subir une chirurgie élective non cardiaque sous anesthésie générale ont été stratifiés en fonction de la durée prévue de l’intervention ( < 2,5 h ou ≥ 2,5 h ) puis r and omisés dans un groupe de réchauffement préalable utilisant un système à air forcé BairPaws ™ pendant au moins 30 min en préopératoire ou dans un groupe témoin avec couvertures chauffantes sur dem and e. Tous les patients ont été réchauffés pendant l’intervention au moyen de couvertures chauffantes à air forcé par convection . La température périopératoire a été mesurée au moyen du système de surveillance de la température SpotOnMD consistant en un capteur jetable à usage unique placé sur le front des patients . Le critère principal d’évaluation était l’ampleur de l’hypothermie peropératoire calculée comme l’aire sous la courbe température-temps pour des températures central es < 36 ° C entre l’induction de l’anesthésie générale et la sortie de la salle d’opération . Les critères d’évaluation secondaires ont inclus les infections du site chirurgical , le nombre de culots de globules rouges nécessaires et la consommation d’opioïdes au cours des 24 heures postopératoires . RésultatsLes résultats de 200 participants ont été analysés ( 101 contrôles ; 99 patients préréchauffés ) . L’amplitude médiane de l’hypothermie [ écart interquartile ] des participants préréchauffés a été plus faible que celle des contrôles ( respectivement , 0,00 [ 0,00 - 0,12 ] ° C·hr−1 contre 0,05 [ 0,00 - 0,36 ] ° C·hr−1 ; différence entre médianes , −0,01 ° C·hr−1 ; intervalle de confiance à 95 % , −0,04 à 0,00 ° C·hr−1 ; P < 0,005 ) . Il n’y a pas eu de différence entre les groupes sur les critères d’évaluation secondaires . Conclusion Un minimum de 30 min de réchauffement préopératoire au moyen d’un système à air forcé à convection a diminué l’exposition globale à l’hypothermie peropératoire . Bien qu’une hypothermie de redistribution survienne toujours en dépit du réchauffement peropératoire à l’air forcé , leur application combinée entraîne une meilleure conservation de la normothermie peropératoire , comparativement au réchauffement peropératoire à l’air forcé seul . Enregistrement de l’essai cliniquewww.essaiscliniques.gov ( NCT02177903 ) . Enregistré le 25 juin 2014 OBJECTIVE to verify the effectiveness of warmed intravenous infusion for hypothermia prevention in patients during the intraoperative period . METHOD experimental , comparative , field , prospect i ve and quantitative study undertaken at a federal public hospital . The sample was composed of 60 adults , included based on the criteria of axillary temperature between 36ºC and 37.1ºC and surgical abdominal access , divided into control and experimental groups , using the systematic probability sampling technique . RESULTS 22 patients ( 73.4 % ) from both groups left the operating room with hypothermia , that is , with temperatures below 36ºC ( p=1.0000 ) . The operating room temperature when patients arrived and patients ' temperature when they arrived at the operating room were statistically significant to affect the occurrence of hypothermia . CONCLUSION the planning and implementation of nursing interventions carried out by baccalaureate nurses are essential for preventing hypothermia and maintaining perioperative normothermia We have evaluated the efficacy of new electric warming blankets , which meet the requirements of the international st and ard for perioperative electrical and thermal safety , in preventing intraoperative hypothermia . We studied 18 patients undergoing abdominal surgery , allocated to one of two groups : in the control group , there was no prevention of intraoperative hypothermia ( n = 8) and in the electric blanket group , two electric blankets covered the legs and upper body ( n = 10 ) . Anaesthesia duration was similar in the two groups ( mean 201 ( SEM 11 ) min ) , as was ambient temperature ( 20.5 ( 0.1 ) degrees C ) . Core temperature decreased during operation by 1.5 ( 0.1 ) degrees C in the control group , but only by 0.3 ( 0.2 ) degree C in the electric blanket group ( P < 0.01 ) . Five patients shivered in the control group compared with one in the electric blanket group ( P < 0.05 ) . We conclude that cutaneous warming with electric blankets was an effective means of preventing intraoperative hypothermia during prolonged abdominal surgery BACKGROUND Perioperative hypothermia is physiologically stressful because it elevates blood pressure , heart rate and plasma catecholamine concentration that may increase the risk of cardiac complications , bleeding , wound infection , and post-anaesthesia care unit stay . This study was design ed to evaluate the effects of warming intravenous fluids on perioperative hemodynamic situation , post-operative shivering and recovery in orthopaedic surgery patients . METHODS Perioperative pulse rate , blood pressure , intraoperative esophageal and skin temperature were measured in sixty patients undergoing orthopaedic surgery that were r and omly divided into two groups according to intraoperative IV fluids management . In 30 patients ( hypothermia group ) all IV fluids infused were at room temperature . In the other 30 patients ( normothermia group ) all IV fluids were warmed using a dry IV fluid warmer . RESULTS The core and skin temperatures of the hypothermia and normothermia groups decreased significantly between the induction of anesthesia and the end of surgery , but the drop was greater in the hypothermia group ( P < 0.005 ) . Postoperative mean arterial blood pressure ( non-invasive ) increased significantly more in the hypothermia group versus normothermia group ( p < 0.005 ) . Shivering was observed in 21 of 30 in the hypothermia group and 11 of 30 in the normothermia group ( p < 0.005 ) and recovery time was significantly lower in the normothermia group ( 36 + /- 5 vs. 26 + /- 3 min , p < 0.005 ) . CONCLUSION Intraoperative IV fluid warming reduces perioperative changes to the hemodynamic situation , post-operative shivering , and recovery time PURPOSE The purpose of this study was to compare the effects of intravenous fluid warming and skin surface warming on peri-operative body temperature and acid base balance of abdominal surgical patients under general anesthesia . METHOD Data collection was performed from January 4th , to May 31 , 2004 . The intravenous fluid warming(IFW ) group ( 30 elderly patients ) was warmed through an IV line by an Animec set to 37 degrees C. The skin surface warming ( SSW ) group ( 30 elderly patients ) was warmed by a circulating-water blanket set to 38 degrees C under the back and a 60W heating lamp 40 cm above the chest . The warming continued from induction of general anesthesia to two hours after completion of surgery . Collected data was analyzed using Repeated Measures ANOVA , and Bonferroni methods . RESULTS SSW was more effective than IFW in preventing hypothermia(p= .043 ) , preventing a decrease of HCO(3)(-)(p= .000 ) and preventing base excess ( p= .000 ) respectively . However , there was no difference in pH between the SSW and IFW ( p= .401 ) groups . CONCLUSION We conclude that skin surface warming is more effective in preventing hypothermia , and HCO(3)(- ) and base excess during general anesthesia , and returning to normal body temperature after surgery than intravenous fluid warming ; however , skin surface warming was n't able to sustain a normal body temperature in elderly patients undergoing abdominal surgery under general anesthesia STUDY OBJECTIVES To evaluate the effects of intraoperative skin-surface warming with and without 1 hour of preoperative warming , in preventing intraoperative hypothermia , and postoperative hypothermia , and shivering , and in offering good conditions to early tracheal extubation . DESIGN Prospect i ve , r and omized , blind study . SETTING Teaching hospital . PATIENTS 30 ASA physical status I and II female patients scheduled for elective abdominal surgery . INTERVENTIONS Patients received st and ard general anesthesia . In 10 patients , no special pre caution s were taken to avoid hypothermia . Ten patients were su bmi tted to preoperative and intraoperative active warming . Ten patients were only warmed intraoperatively . MEASUREMENTS AND MAIN RESULTS Temperatures were recorded at 15-minute intervals . The patients who were warmed preoperatively and intraoperatively had core temperatures significantly more elevated than the other patients during the first two hours of anesthesia . All patients warmed intraoperatively were normothermic only at the end of the surgery . The majority of the patients warmed preoperatively and intraoperatively or intraoperatively only were extubated early , and none had shivering . In contrast , five unwarmed patients shivered . CONCLUSIONS One hour of preoperative warning combined with intraoperative skin-surface warming , not simply intraoperative warming alone , avoided hypothermia caused by general anesthesia during the first two hours of surgery . Both methods prevented postoperative hypothermia and shivering and offered good conditions for early tracheal extubation Background Keeping abdominal surgery patients warm is common and warming methods are needed in power outages during natural disasters . We aim ed to evaluate the efficacy of low-cost , low-power warming methods for maintaining normothermia in abdominal surgery patients . Methods Patients ( n = 160 ) scheduled for elective abdominal surgery were included in this prospect i ve clinical study . Five warming methods were applied : heated blood transfusion/fluid infusion vs. unheated ; wrapping patients vs. not wrapping ; applying moist dressings , heated or not ; surgical field rinse heated or not ; and applying heating blankets or not . Patients ’ nasopharyngeal and rectal temperatures were recorded to evaluate warming efficacy . Significant differences were found in mean temperatures of warmed patients compared to those not warmed . Results When we compared temperatures of abdominal surgery patient groups receiving three specific warming methods with temperatures of control groups not receiving these methods , significant differences were revealed in temperatures maintained during the surgeries between the warmed groups and controls . Discussion The value of maintaining normothermia in patients undergoing abdominal surgery under general anesthesia is accepted . Three effective economical and practically applicable warming methods are combined body wrapping and heating blanket ; combined body wrapping , heated moist dressings , and heating blanket ; combined body wrapping , heated moist dressings , and warmed surgical rinse fluid , with or without heating blanket . These methods are practically applicable when low-cost method is indeed needed BACKGROUND : Rates of hypothermia for women undergoing spinal anesthesia for cesarean delivery are high and prevention is desirable . This trial compared the effectiveness of preoperative warming versus usual care among women receiving intrathecal morphine , which is thought to exacerbate perioperative heat loss . METHODS : A prospect i ve , single-blinded , r and omized controlled trial compared 20 minutes of forced air warming ( plus intravenous fluid warming ) versus no active preoperative warming ( plus intravenous fluid warming ) in 50 healthy American Society of Anesthesiologists grade d II women receiving intrathecal morphine as part of spinal anesthesia for elective cesarean delivery . The primary outcome of maternal temperature change was assessed via aural canal and bladder temperature measurements at regular intervals . Secondary outcomes included maternal thermal comfort , shivering , mean arterial pressure , agreement between aural temperature , and neonatal outcomes ( axillary temperature at birth , Apgar scores , breastfeeding , and skin-to-skin contact ) . The intention-to-treat population was analyzed with descriptive statistics , general linear model analysis , linear mixed-model analysis , & khgr;2 test of independence , Mann-Whitney , and Bl and -Altman analysis . Full ethical approval was obtained , and the study was registered on the Australia and New Zeal and Clinical Trials Registry ( Trial No : 367160 , registered at http://www.ANZCTR.org.au/ ) . RESULTS : Intention-to-treat analysis ( n = 50 ) revealed no significant difference in aural temperature change from baseline to the end of the procedure between groups : F ( 1 , 47 ) = 1.2 , P = .28 . There were no other statistically significant differences between groups in any of the secondary outcomes . CONCLUSIONS : A short period of preoperative warming is not effective in preventing intraoperative temperature decline for women receiving intrathecal morphine . A combination of preoperative and intraoperative warming modalities may be required for this population
In the fixed effect model , the warming group had significantly less pain and lower incidence of wound infection , compared with the no-warming group .
In the r and om effect model , the warming group was also associated with lower risk of post-anesthetic shivering .
Both in the r and om and the fixed effect models , the warming group was associated with significantly less blood loss .
Perioperative warming of surgical patients is effective in reducing postoperative wound pain , wound infection and shivering .
Systemic warming of the surgical patient is also associated with less perioperative blood loss through preventing hypothermia-induced coagulopathy .
OBJECTIVE The objective of this review was to systematic ally analyze the trials on the effectiveness of perioperative warming in surgical patients .