***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 
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    Input: Background : Hypothermia during and after major abdominal surgery decreases host defenses , increases the incidence of coagulopathy and may alter blood pressure , cardiac contractility and myocardial stability . Methods : We design ed a prospect i ve r and omized study to compare the benefits of a forced air warming system with warm blanket treatments in minimizing the effects of hypothermia on 64 morbidly obese patients undergoing Roux-en-Y gastric bypass .  Results : Patients in the forced air warming group ( n = 32 ) had significantly higher perioperative body core temperature , lower central venous pressure and blood pressure readings , lower incidence of shivering , less blood loss intraoperatively and achieved a higher post anesthesia Aldrete Score than those patients in the warmed blanket group ( n = 32 ) . Conclusion : The forced air warming system is safe , cost effective and beneficial in minimizing the undesirable consequences of hypothermia in morbidly obese patients undergoing Roux-en-Y gastric bypass 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 BACKGROUND In-vitro studies indicate that platelet function and the coagulation cascade are impaired by hypothermia . However , the extent to which perioperative hypothermia influences bleeding during surgery remains unknown . Accordingly , we tested the hypothesis that mild hypothermia increases blood loss and allogeneic transfusion requirements during hip arthroplasty . METHODS Blood loss and transfusion requirements were evaluated in 60 patients undergoing primary , unilateral total hip arthroplasties who were r and omly assigned to normothermia ( final intraoperative core temperature 36.6 [ 0.4 ] degrees C ) or mild hypothermia ( 35.0 [ 0.5 ] degrees C ) .  Crystalloid , colloid , scavenged red cells , and allogeneic blood were administered by strict protocol . FINDINGS Intra- and postoperative blood loss was significantly greater in the hypothermic patients : 2.2 ( 0.5 ) L vs 1.7 ( 0.3 ) L , p < 0.001 ) . Eight units of allogeneic packed red cells were required in seven of the 30 hypothermic patients , whereas only one normothermic patient required a unit of allogeneic blood ( p < 0.05 for administered volume ) . A typical decrease in core temperature in patients undergoing hip arthroplasty will thus augment blood loss by approximately 500 mL. INTERPRETATION The maintenance of intraoperative normothermia reduces blood loss and allogeneic blood requirements in patients undergoing total hip arthroplasty Background Shivering is rare during  general anesthesia .  This observation suggests that anesthetics profoundly impair shivering . However , the effects of surgical doses of volatile anesthetics on control of shivering have yet to be evaluated . Furthermore , the effects of desflurane on sweating and thermoregulatory vasoconstriction remain unknown . Accordingly , the authors determined the concentration‐dependent effects of desflurane on sweating , vasoconstriction , and shivering 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 OBJECTIVE We evaluated the performance of a new temperature management system ( A rct ic Sun , Medivance , Inc. ) in maintaining normothermia during off-pump coronary artery bypass ( OPCAB ) . PATIENTS AND METHODS Ninety-eight unselected patients were prospect ively r and omized to either a conventional temperature management method ( consisting of a sterile forced-air warming blanket , warm intravenous fluids , and maintenance of a warm OR ) or the new A rct ic Sun system ( two pads , A rct ic Sun Energy Transfer Pads placed on the patient 's back with temperature-controlled water flowing through the pads ) . RESULTS The  mean age , body surface area , and total operating time were similar in both groups . Despite significantly lower room temperatures ( p<0.001 ) in the A rct ic Sun group , the system maintained higher bladder and nasopharyngeal temperatures ( p<0.001 and p<0.001 , respectively ) . A core temperature of at least 36 degrees C was achieved in 97 % of the A rct ic Sun patients compared with 42 % in the conventional group . Additionally , intra-operative blood loss for the A rct ic Sun patients was significantly less ( p=0.01 ) . CONCLUSIONS The A rct ic Sun system significantly outperformed conventional techniques in achieving and maintaining normothermia during off-pump coronary artery bypass OBJECTIVE Perioperative hypothermia might be detrimental to the patient undergoing off-pump coronary artery bypass surgery . We assessed the efficacy of the Allon thermoregulation system ( MTRE Advanced Technologies Ltd , Or-Akiva , Israel ) compared with that of routine thermal care in maintaining normothermia during and after off-pump coronary artery bypass surgery . METHODS Patients undergoing off-pump coronary artery bypass surgery were perioperatively and r and omly warmed with the 2 techniques  ( n = 45 per group ) . Core temperature , hemodynamics , and troponin I , interleukin 6 , interleukin 8 , and interleukin 10 blood levels were assessed . RESULTS The mean temperature of the patients in the Allon thermoregulation system group ( AT group ) was significantly ( P < .005 ) higher than that of the patients receiving routine thermal care ( the RTC group ) ; less than 40 % of the latter reached 36 degrees C compared with 100 % of the former . The cardiac index was higher and the systemic vascular resistance was lower ( P < .05 ) by 16 % and 25 % , respectively , in the individuals in the AT group compared with in the individuals in the RTC group during the 4 postoperative hours . End-of-surgery interleukin 6 levels and 24-hour postoperative troponin I levels were significantly ( P < .01 ) lower in the patients in the AT group than in the RTC group . The RTC group 's troponin levels closely correlated with their interleukin 6 levels at the end of the operation ( R = 0.51 , P = .002 ) . CONCLUSIONS Unlike routine thermal care , the Allon thermoregulation system maintains core normothermia in more than 80 % of patients undergoing off-pump coronary artery bypass surgery . Normothermia is associated with better cardiac and vascular conditions , a lower cardiac injury rate , and a lower inflammatory response . The close correlation between the increased interleukin 6 and troponin I levels in the routine thermal care group indicates a potential deleterious effect of lowered temperature on the patient 's outcome STUDY OBJECTIVE To evaluate the postoperative hemodynamic and thermoregulatory consequences of intraoperative core hypothermia . DESIGN Prospect i ve , r and omized clinical trial . SETTING Operating room and postanesthesia care unit of a university hospital . PATIENTS 74 healthy , ASA status I , II , and III patients ( average age 58 yrs ) undergoing elective colon surgery . INTERVENTIONS Patients were r and omly assigned to be kept normothermic or approximately 2.5 degrees C hypothermic during surgery . Anesthesia was maintained with isoflurane , nitrous oxide , and fentanyl . Postoperatively , surgical pain was treated with patient-controlled analgesia ( PCA ) opioid . MEASUREMENTS AND MAIN RESULTS An observer blinded to group assignment and core temperatures evaluated shivering , thermal comfort , surgical pain , heart rates ( HRs ) , and blood pressures ( BPs ) during the first six postoperative hours . Morphometric characteristics , oxygen saturation , fluid balance , PCA-administered opioid , and visual analog pain scores were comparable in the two groups . Hypothermic patients felt uncomfortably cold during recovery , and their postoperative core temperatures remained significantly less than in the normothermic patients for more than four hours . Peripheral vasoconstriction and shivering were common in the hypothermic patients but rare in those kept normothermic . HRs and BPs were comparable in the two groups . CONCLUSIONS These data confirm that the effects of intraoperative hypothermia on postoperative HR and BP are modest in relatively young , generally healthy patients . In contrast , intraoperative hypothermia caused substantial postoperative thermal discomfort , and full recovery from hypothermia required many hours . Delayed return to care normothermia apparently result ed largely from postoperative thermoregulatory impairment An attempt was made to reduce heat loss in elderly patients undergoing major abdominal surgery . Two groups were studied . In one group , efforts were made to minimize heat loss by using a hot-water humidifier in the anaesthetic circuit , a hot-water circulating mattress under the patient and warming all i.v . fluids . Otherwise , the surgical and anaesthetic techniques were comparable . The same anaesthetic technique of nitrous oxide , oxygen , pancuronium and fentanyl with intermittent positive pressure ventilation was used in all cases . Nitrogen loss was measured in urine collected over 48 h from an indwelling urinary catheter inserted soon after induction of anaesthesia . Prevention of heat loss during anaesthesia and postoperative recovery caused a significant reduction in nitrogen loss OBJECTIVE To assess the relationship between body temperature and cardiac morbidity during the perioperative period . DESIGN R and omized controlled trial comparing routine thermal care ( hypothermic group ) to additional supplemental warming care ( normothermic group ) . SETTING Operating rooms and surgical intensive care unit at an academic medical center . SUBJECTS Three hundred patients undergoing abdominal , thoracic , or vascular surgical procedures who either had documented coronary artery disease or were at high risk for coronary disease . OUTCOME MEASURE The relative risk of a morbid cardiac event ( unstable angina/ischemia , cardiac arrest , or myocardial infa rct ion ) according to thermal treatment . Cardiac outcomes were assessed in a double-blind fashion . RESULTS Mean core temperature after surgery was lower in the hypothermic group ( 35.4+/-0.1 degrees C ) than in the normothermic group ( 36.7+/-0.1 degrees C ) ( P<.001 ) and remained lower 
    Output:
    
Maintaining perioperative normothermia reduces blood loss and transfusion requirement by clinical ly important amounts