***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: We have investigated the role of aluminized metal foil ( space blanket , UN 320 ) , used pre-emptively , in post-anaesthetic  shivering and patients ' subjective perception of cold after general anaesthesia of short duration . Sixty-eight ASA I and II patients undergoing orthopaedic and plastic surgery on the peripheries were allocated r and omly to two groups : those in group 1 were wrapped ( not less than 60 % of body surface area ) in the space blanket before induction of anaesthesia . In group 2 patients had st and ard surgical draping . In all subjects , anaesthesia was induced with fentanyl and propofol , and maintained with nitrous oxide and enflurane in oxygen , after a laryngeal mask airway was positioned . Patients were asked to grade their perception of cold on a visual analogue scale , before induction and on recovery . Skin ( dorsum of h and ) and core ( nasopharyngeal ) temperatures were recorded at 15-min intervals . Occurrence of shivering and cold scores were recorded by blinded observers . Groups were similar in age and gender ; duration of anaesthesia was also similar ( mean 41.6 ( SEM 4.8 ) vs 47.5 ( 3.3 ) min , respectively ) . The incidences of shivering were 15 % and 63 % in groups 1 and 2 , respectively ( P < 0.001 ) . Cold scores were 2.4 ( 0.4 ) and 5.7 ( 0.5 ) , respectively ( P < 0.001 ) . Skin temperatures increased with increasing duration of anaesthesia in both groups but were greater at 15 , 30 and 45 min in group 1 ( 33.38 ( 0.25 ) vs 31.56 ( 0.31 ) , 34.46 ( 0.25 ) vs 32.45 ( 0.31 ) and 35.22 ( 0.36 ) vs 33.13 ( 0.34 ) , respectively ; P < 0.001 each comparison ) . Core temperature increased slightly in group 1 and decreased in group 2 ( P = 0.11 ) . ( ABSTRACT TRUNCATED AT 250 WORDS 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 Mild perioperative hypothermia , which is common during major surgery , may promote surgical-wound infection by triggering thermoregulatory vasoconstriction , which decreases subcutaneous oxygen tension . Reduced levels of oxygen in tissue impair oxidative killing by neutrophils and decrease the strength of the healing wound by reducing the deposition of collagen . Hypothermia also directly impairs immune function . We tested the hypothesis that hypothermia both increases susceptibility to surgical-wound infection and lengthens hospitalization . METHODS Two hundred patients undergoing colorectal surgery were r and omly assigned to routine intraoperative thermal care ( the hypothermia group ) or additional warming ( the normothermia group ) . The patient 's anesthetic care was st and ardized , and they were all given cefam and ole and metronidazole . In a double-blind protocol , their wounds were evaluated daily until discharge from the hospital and in the clinic after two weeks ; wounds containing culture-positive pus were considered infected . The patients ' surgeons remained unaware of the patients ' group assignments . RESULTS The mean ( + /- SD ) final intraoperative core temperature was 34.7 + /- 0.6 degrees C in the hypothermia group and 36.6 + /- 0.5 degrees C in the normothermia group ( P < 0.001 ) Surgical-wound infections were found in 18 of 96 patients assigned to hypothermia ( 19 percent ) but in only 6 of 104 patients assigned to normothermia ( 6 percent , P = 0.009 ) . The sutures were removed one day later in the patients assigned to hypothermia than in those assigned to normothermia ( P = 0.002 ) , and the duration of hospitalization was prolonged by 2.6 days ( approximately 20 percent ) in hypothermia group ( P = 0.01 ) . CONCLUSIONS Hypothermia itself may delay healing and predispose patients to wound infections . Maintaining normothermia intraoperatively is likely to decrease the incidence of infectious complications in patients undergoing colorectal resection and to shorten their hospitalizations Changes in mean body temperature and muscle protein metabolism were studied in elderly patients undergoing large bowel surgery .  Two groups were studied : in one , efforts were made to maintain the patients normothermic during and after surgery by warming the fresh gases , the i.v . fluids , by placing warmed cotton padding around the exposed parts of the body and by covering the patients with a metallized plastic sheet in the recovery period . The other group received routine management . Otherwise the anaesthetic technique was comparable . The excretion of the amino acid 3-methylhistidine ( 3-MeH ) , an indicator of muscle protein breakdown , and urea nitrogen loss were measured in the urine collected the day before , and on the 2nd and 4th postoperative days . Prevention of heat loss during and after surgery caused a significant decrease in muscle protein degradation and nitrogen loss 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 Mild intraoperative hypothermia is common . We therefore studied the effects of mild hypothermia on  propofol pharmacokinetics , hepatic blood flow , and atracurium duration of action in healthy volunteers . Six young volunteers were studied on two r and omly assigned days , at either 34 degrees C or 37 degrees C. Anesthesia was induced with thiopental , 3 mg/kg , and maintained with 70 % N2 O and 0.6 % isoflurane . Core hypothermia was induced by conductive and convective cooling . On the other study day , normothermia was maintained by a Bair Hugger Registered Trademark ( Augustine Medical , Inc. , Eden Prairie , MN ) forced-air warmer . Propofol , 1 mg/kg lean body mass ( LBM ) , then was given , followed by a 4-h infusion at 5 mg centered dot kg-1 centered dot h-1 . After 2 h , atracurium 0.5 mg/kg was administered as an intravenous bolus . Indocyanine green was administered for estimation of hepatic blood flow . Arterial blood was assayed for propofol and indocyanine green concentration . Pharmacokinetic analysis was performed using NONMEM . Results are reported as means + /- SEM .  Propofol blood concentrations averaged approximate equals 28 % more at 34 degrees C than at 37 degrees C ( P < 0.05 ) . Hepatic blood flow decreased 23 % + /- 11 % in normothermic volunteers during the propofol infusion , and 33 % + /- 11 % in hypothermic volunteers ( P = not significant ) . A three-compartment mamillary model fitted the data best . Inclusion of hepatic blood flow change from the prepropofol baseline as a covariate for total body clearance significantly improved the fit . The intercompartmental clearances were decreased in the presence of hypothermia . Core hypothermia prolonged the time to recovery of the first twitch in the train-of-four to 10 % of its control value ( T1 = 10 % ) after atracurium administration by approximate equals 60 % ( P < 0.05 ) , from 44 + /- 4 min to 68 + /- 7 min . In contrast , T1 = 25%-75 % remained unchanged . We conclude that 3 degrees C of core hypothermia increased propofol blood concentrations and prolonged atracurium duration of action . Hepatic blood flow was decreased during propofol administration , and this change was a significant predictor of propofol clearance , indicating that the effect of propofol on hepatic blood flow impairs the clearance of propofol itself . ( Anesth Analg 1995;80:1007 - 14 Background and objective Unintentional hypothermia of a patient is a common adverse effect during surgical procedures . Many strategies can be used to reduce heat loss . The aim of this prospect i ve , r and omised , controlled study was to determine whether the use of the thermal suit ( T-Balance ) could prevent surgical patients from experiencing thermal loss better than conventional measures . Methods We examined a group of consecutive patients undergoing transurethral resection of the prostate under spinal anaesthesia . Forty patients were r and omised to receive the special textile clothing , thermal suit ( group 1 ) or the conventional clothing ( group 2 , control ) . Heated blankets and a forced-air warming device ( Bair-Hugger ) were used when any patient felt cold or body temperature decreased below 35 ° C . Body temperatures were measured via mouth using an infrared thermometer and recorded at given points ( T1–T10 ) during the procedure . Results The mean temperatures were higher ( about 0.5 ° C ) in group 1 than in group 2 at the entrance to the recovery room ( P = 0.03 ) . The mean maximal decrease in temperature was 0.56 ° C in group 1 and 1.31 ° C in group 2 ( P = 0.000 between groups ) . One patient in group 1 and seven patients in group 2 needed warming with a Bair-Hugger , and 15 out of 20 patients in group 2 needed extra blankets during surgery or recovery . Conclusion The use of the thermal suit is a good alternative to conventional measures of warming in reducing heat loss during surgical procedure under regional anaesthesia Hypothermia is one of the common complications in the perioperative period . Currently , normothermia is maintained with forced air warming ( FAW ) or passive heat retention methods . We compared the efficacy of the Mediwrap blanket with FAW in maintaining normothermia during intra-operative period in thoracic surgery in a prospect i ve r and omised controlled trial on 30 patients .  Core temperature was measured at 30-min intervals in 
    Output:
    
There were no clear effects on bleeding , shivering or length of stay in post-anaesthetic care for either comparison .
No other adverse effects were reported .
There is no clear benefit of extra thermal insulation compared with st and ard care .
Forced air warming does seem to maintain core temperature better than extra thermal insulation , by between 0.5 ºC and 1 ºC , but the clinical importance of this difference is unclear