***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: 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 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 PURPOSE In this study an examination was done of the effects of the American Society of PeriAnesthesia Nurses ( ASPAN ) Evidence -Based Clinical Practice Guidelines on body temperature , shivering , thermal discomfort , and time to achieve normothermia in patients undergoing total knee replacement arthroplasty ( TKRA ) under spinal anesthesia . METHODS This study was an experimental study with a r and omized controlled trial design . Participants ( n=60 ) were patients who underwent TKRA between December 2011 and March 2012 . Experimental group ( n=30 ) received active and passive warming measures as described in the ASPAN 's guidelines . Control group ( n=30 ) received traditional care .  Body temperature , shivering , thermal discomfort , time to achieve normothermia were measured in both groups at 30 minute intervals . RESULTS Experimental group had slightly higher body temperature compared to control group ( p=.002 ) . Thermal discomfort was higher in the experimental group before surgery but higher in the control group after surgery ( p=.034 ) . It decreased after surgery ( p=.041 ) in both groups . Time to achieve normothermia was shorter in the experimental group ( p=.010 ) . CONCLUSION ASPAN 's guidelines provide guidance on measuring patient body temperature at regular intervals and on individualized and differentiated hypothermia management which can be very useful in nursing care , particularly in protecting patient safety and improving quality of nursing Purpose Previous studies have demonstrated that amino acid infusions exert enhanced thermogenic effects during general anesthesia . This study was conducted to investigate whether amino acid infusions started after development of intraoperative core hypothermia can accelerate rewarming . Methods Twenty-two patients scheduled for major abdominal surgery were included in this study . When tympanic temperature reached 35.5 ° C , patients were r and omly assigned to receive amino acids ( amino acid group ; n = 11 ) or saline ( saline group ; n = 11 ) . A continuous infusion of a mixture of 18 amino acids or saline was started at 200 ml h−1 . Tympanic , forearm , and digit temperatures were recorded . Forearm minus fingertip skin-surface temperature gradients ( temperature gradient ) were calculated . Postoperative shivering was also evaluated . Results Tympanic membrane temperature and temperature gradient were similar between the two groups at each time point during the study period . Temperature gradient at extubation in the amino acid group was significantly lower than in the saline group although tympanic temperature at extubation was similar between the two groups . Postoperative shivering score was significantly lower in the amino acid group than in the saline group . Conclusions Amino acid infusions started after development of intraoperative core hypothermia failed to accelerate rewarming . However , amino acid infusions reduced the incidence of postoperative shivering . Use of amino acid infusions to reduce thermoregulatory vasoconstriction at emergence might contribute to a decrease in the development of postoperative shivering The warming effects of a Blanketrol water coil-heated hypothermia blanket and a Bair Hugger forced-warm air warming blanket were compared . Thirty-two patients admitted to the PACU with temperatures 34.4 degrees C ( 94 degrees F ) or lower were assigned to treatment with the Blanketrol ( Cincinnati Sub-Zero Products , Cincinnati , OH ) or the Bair Hugger ( Augustine Medical , Eden Prairie , MN ) in alternating fashion , and treatment continued until the patients ' temperatures reached 36.1 degrees C ( 97 degrees F ) . Every half hour each patient 's temperature was measured using a tympanic temperature device and recorded on the data collection sheet . Analysis of the findings showed that the forced-air warming blanket warmed patients to 36.1 degrees C ( 97 degrees F ) or higher significantly faster than the water coil-heated blanket ( P < .001 ) UNLABELLED The Thermostat device ( Aquarius Medical Corp. , Phoenix , AZ ) is used in a new technique to accelerate recovery from hypothermia by mechanically distending blood vessels in the h and , thereby increasing transfer of exogenous heat to the body core . We evaluated the use of the Thermostat device in patients with mild postoperative hypothermia ( < 36 degrees C ) . We studied adult patients undergoing elective surgery , general anesthesia , and neuromuscular blockade . Patients with an initial postoperative tympanic membrane temperature < 36 degrees C were r and omized into two groups : 1 ) Thermostat , which consisted of a hypothermia warming mitt/seal and thermal exchange chamber for 60 min , and 2 ) conventional treatment , which consisted of warm blankets and /or radiant heat . Of the 191 patients enrolled , 60 ( 31 % ) developed hypothermia and were r and omized to receive the Thermostat ( n = 30 ) or conventional methods ( n = 30 ) . Fourteen patients in the Thermostat group and 17 patients in the conventional group rewarmed to 36 degrees C before discharge from the recovery room ( P is not significant ) . There were no differences in vital signs , rewarming time , time to discharge from the recovery room , or postoperative temperature between groups . We conclude that patients with mild postoperative hypothermia rewarmed in a similar fashion , regardless of whether the Thermostat or conventional methods were used . IMPLICATION S We found that a commercially available negative pressure rewarming device ( Thermostat ; Aquarius Medical Corp. , Phoenix , AZ ) was not effective in accelerating rewarming in postoperative hypothermic surgical patients after general anesthesia Two homogeneous groups of 20 healthy women su bmi tted to elective gynaecological surgery , who presented after anaesthesia with peripheral vasoconstriction and shivering , were included in a r and omized , double-blind study . The first group received 10 mg ketanserin , a new pure antagonist of serotoninergic S2 receptors . The second group received 10 ml saline as placebo .  Blood pressure , heart rate , pulse wave amplitude , and rectal and cutaneous temperatures were measured before and 5 , 15 and 30 min after treatment . Vasoconstriction , shivering and discomfort were classified as intense , moderate or absent at these times . Venous and arterial blood gases were determined before and 15 min after treatment . Blood pressure and heart rate decreased slightly after ketanserin administration and this decrease was statistically significant . Increases in rectal temperature were similar in both groups . Peripheral temperature , measured in the big toe , significantly decreased in the placebo group but did not change after ketanserin .  Vasoconstriction , shivering , discomfort and pulse wave amplitude improved significantly following ketanserin . We conclude that ketanserin may be effective in treating this post-operative complication , the possible mechanism being the vasodilatation it causes ; a central serotoninergic blockade could also be implied Thirty  patients with post-operative hypothermia following major surgery ( thoracic , abdominal , orthopaedic ) were allocated r and omly to either active warming with a radiant heater ( 500 W ) or passive rewarming with a reflective blanket .  Rectal temperature , mean skin temperature ( at four measuring sites ) , continuous haemoglobin saturation and shivering were measured for 2 h post-operatively . Although post-operative heat supply with a radiant heater result ed in faster rewarming , there were no differences between the two groups with respect to haemoglobin saturation and shivering This study was design ed to determine if the forced warm air system is more effective than warmed cotton blankets or radiant heat lamps for rewarming postoperative patients . PACU admission temperatures were taken on 370 adult patients . The study population of 90 patients with admission temperatures of 35 degrees C ( 95 degrees F ) or less was r and omly assigned to one of three intervention groups : ( b ) warmed cotton blankets , ( L ) radiant heat lamps , or ( A ) forced warm air .  Oral or axillary temperatures were monitored every 15 minutes and the warming intervention continued until the patient reached the discharge criteria of 36 degrees C ( 96.8 degrees F ) . The three groups were comparable for sex , age , admitting temperature , OR time , and OR fluid . The mean rewarming times for patients who shivered were similar for all groups . For those patients who did not shiver , those treated with forced warm air  rewarmed significantly faster than patients in the other groups . Nonshivering patients treated with forced warm air were ready for discharge somewhat sooner than those treated with either of the other two interventions Effective rewarming devices have only become available recently . This investigation compares the efficiency of an new overhead radiant heater ( ARAGONA Thermal Ceilings TM , CTCX , 1000 W ) with that of an electric blanket ( 5 
    Output:
    
Active warming , particularly forced air warming , appears to offer a clinical ly important reduction in mean time taken to achieve normothermia ( normal body temperature between 36 ° C and 37.5 ° C ) in patients with postoperative hypothermia .
However , high- quality evidence on other important clinical outcomes is lacking ; therefore it is unclear whether active warming offers other benefits and harms .
High- quality evidence on other warming methods is also lacking ; therefore it is unclear whether other rewarming methods are effective in reversing postoperative hypothermia