Randomized Prospective Comparison of Forced Air Warming Using Hospital Blankets versus Commercial Blankets in Surgical Patients

Background: The purpose of this study was to evaluate the efficacy of an experimental approach to forced air warming using hospital blankets or a Bair Hugger warming unit (Augustine Medical Inc., Eden Prairie, MN) to create a tent of warm air.

Methods: Adult patients undergoing major surgery were studied. Patients were randomized to receive forced air warming using either a commercial Bair Hugger blanket (control group, n = 44; set point, 43[degrees]C) or standard hospital blankets (experimental group, n = 39; set point, 38[degrees]C). Distal esophageal temperatures were monitored. Patients were contacted the following day regarding any problems with the assigned warming technique.

Results: Surface area covered was 36 +/- 12% (mean +/- SD) in the experimental group and 40 +/- 10% in the control group. Final temperatures at the end of surgery were similar between groups: experimental, 36.2 +/- 0.6[degrees]C; control, 36.4 +/- 0.7[degrees]C. A similar number of patients had esophageal temperature less than 36[degrees]C at the end of surgery in both groups (experimental, 12 of 39 [31%]; control, 12 of 44 [27%]). The majority of patients were satisfied with their anesthetic and warming technique: experimental, 38 of 39 patients; control, 44 of 44 patients. There were no thermal injuries.     

Randomized prospective comparison of forced air warming using hospital blankets versus commercial blankets in surgical patients

BACKGROUND: The purpose of this study was to evaluate the efficacy of an experimental approach to forced air warming using hospital blankets or a Bair Hugger warming unit (Augustine Medical Inc., Eden Prairie, MN) to create a tent of warm air. METHODS: Adult patients undergoing major surgery were studied. Patients were randomized to receive forced air warming using either a commercial Bair Hugger blanket (control group, n = 44; set point, 43 degrees C) or standard hospital blankets (experimental group, n = 39; set point, 38 degrees C). Distal esophageal temperatures were monitored. Patients were contacted the following day regarding any problems with the assigned warming technique. RESULTS: Surface area covered was 36 +/- 12% (mean +/- SD) in the experimental group and 40 +/- 10% in the control group. Final temperatures at the end of surgery were similar between groups: experimental, 36.2 +/- 0.6 degrees C; control, 36.4 +/- 0.7 degrees C. A similar number of patients had esophageal temperature less than 36 degrees C at the end of surgery in both groups (experimental, 12 of 39 [31%]; control, 12 of 44 [27%]). The majority of patients were satisfied with their anesthetic and warming technique: experimental, 38 of 39 patients; control, 44 of 44 patients. There were no thermal injuries. CONCLUSIONS: Standard hospital blankets heated to 38 degrees C forced air were equally as effective as commercial blankets heated with forced air at 43 degrees C. However, based on concerns expressed by the manufacturer, this experimental technique should not be used until further safety evaluation has been undertaken.     

A reusable, custom-made warming blanket prevents core hypothermia during major neonatal surgery

PURPOSE: To introduce a reusable model of neonatal forced air warming blanket for intraoperative use during major noncardiac neonatal surgery and to determine clinical efficacy of this reusable blanket compared with the commonly used disposable blankets. METHODS: Delivered air temperature and calorie uptake of standard thermal bodies within the reusable blankets, Bair Hugger(R) blanket model 530 and model 555 were studied. Also, an efficacy study was conducted in 90 neonatal patients scheduled for major noncardiac surgery comparing the reusable blanket, the Bair Hugger(R) blanket model 530 and passive heat conservation as a control. The covered reusable blanket was used as a rescue procedure if the core temperature was < 35.5 degrees C. RESULTS: Delivered air temperature and heat transfer from the covered reusable blanket did not differ significantly from those of the Bair Hugger(R) blanket model 530 and model 555 (despite 0.75 degrees C-1.2 degrees C of heat trapped under the sheet and 1.3 Kcal less energy transfer). Temperatures measured underneath patients (correlated to poorly perfused areas) were highest using the Bair Hugger(R) blanket model 555. The reusable blanket was efficacious in preventing intraoperative core hypothermia and not different from the Bair Hugger(R) blanket model 530. About 1/3 of the patients in the control group had presented a core temperature < 35.5 degrees C but were successfully rescued using the reusable blanket. No adverse events were associated with any of these warming methods. CONCLUSION: This study shows the clinical efficacy of our reusable blanket for the prevention of core hypothermia during major neonatal surgery, which is not different from commonly used disposable blankets.     

Heat conservation during abdominal surgery]

Intraoperative hypothermia is a major problem in anesthetic management. We compared the heat conserving effect of a forced air warming system (Bair Hugger, Augustine Medical Inc.) with that of a warming blanket. Sixteen patients undergoing abdominal surgery were studied. Patients were anesthetized with nitrous oxide and oxygen combined with epidural anesthesia. Patients received tympanic, rectal, bladder and core temperature monitorings. Patients were divided randomly to Bair Hugger group (BH, n = 8) or warming blanket group (WB, n = 8). Temperature were measured every one hour over three hours. The BH group showed significantly higher temperatures than WB group. Bair Hugger system is an efficient way to maintain intraoperative body temperature.     

Efficacy of forced-air warming systems with full body blankets

PURPOSE: Postoperative hypothermia after cardiac surgery is still a common problem often treated with forced-air warming. This study was conducted to determine the heat transfer efficacy of 11 forced-air warming systems with full body blankets on a validated copper manikin. METHODS: The following systems were tested: 1) Bair Hugger 505; 2) Bair Hugger 750; 3) Life-Air 1000 S; 4) Snuggle Warm; 5) Thermacare; 6) Thermacare with reusable Optisan blanket; 7) WarmAir; 8) Warm-Gard; 9) Warm-Gard and reusable blanket; 10) WarmTouch; and 11) WarmTouch and reusable blanket. Heat transfer of forced-air warmers can be described as follows: Q = h x DeltaT x A. Where Q = heat flux (W), h = heat exchange coefficient (W x m-2 x degrees C-1), DeltaT = temperature gradient between blanket and manikin surface (degrees C), A = covered area (m2). Heat flux per unit area and surface temperature were measured with 16 heat flux transducers. Blanket temperature was measured using 16 thermocouples. The temperature gradient between blanket and surface (DeltaT) was varied and h was determined by linear regression analysis. Mean DeltaT was determined for surface temperatures between 32 degrees C and 38 degrees C. The covered area was estimated to be 1.21 m2. RESULTS: For the 11 devices, heat transfers of 30.7 W to 77.3 W were observed for surface temperatures of 32 degrees C, and between -8.8 W to 29.6 W for surface temperatures of 38 degrees C. CONCLUSION: There are clinically relevant differences between the tested forced-air warming systems with full body blankets. Several systems were unable to transfer heat to the manikin at a surface temperature of 38 degrees C.     

Shortening the discharging time after total hip replacement under combined spinal/epidural anesthesia by actively warming the patient during surgery.

BACKGROUND: To compare passive thermal insulation by reflective blankets with forced-air active warming on the efficacy of normothermia maintenance and time for discharging from the recovery room after combined spinal/epidural anesthesia for total hip arthroplasty. METHODS: DESIGN: Prospective, randomized study. SETTING: Inpatient anesthesia at three University Departments of orthopedic surgery. PATIENTS: 50 ASA physical status I-III patients, who were scheduled for elective total hip arthroplasty. INTERVENTIONS: Patients received combined spinal/epidural anesthesia (CSE) with intrathecal injection of 15 mg of 0.5% hyperbaric bupivacaine. All procedures started 8-10 a.m., and operating room temperature was maintained between 21-23 degrees C, with relative humidity ranging between 40-45%. As warming therapy patients received either passive thermal insulation of the trunk, the two upper limbs and the unoperated lower limb with reflective blankets (group passive, n = 25), or forced-air active warming of the two upper limbs (group active, n = 25). Core temperature was measured before CSE placement (baseline), and then every 30 min until recovery of normothermia. RESULTS: Demographic data, duration of surgery, intraoperative blood losses, and crystalloid infusion were similar in the two groups. Arterial blood pressure decreased in both groups compared with baseline values, while no differences in heart rate were observed during the study. Core temperatures in passive group patients decreased more markedly than in actively warmed patients, with a 1 degree C difference between the two groups at the end of surgery (p < 0.0005). At recovery room entry seven patients in group active (24%) and 16 patients in group passive (64%) showed a core temperature < 36 degrees C (p < 0.01). Achievement of both discharging criteria and normothermia required 32 +/- 18 min in active group and 74 +/- 52 min in passive group (p < 0.0005). CONCLUSIONS: Forced-air cutaneous warming allows the anesthesiologist to maintain normothermia during combined spinal/epidural anesthesia for total hip replacement even if the convective blanket is placed on a relatively small skin surface with reflex vasoconstriction. Maintaining core normothermia decreased the duration of postanesthesia recovery and may, therefore, reduce costs of care.     

Convective warming combined with vasodilator therapy accelerates core rewarming after coronary artery bypass surgery

In a prospective, randomized, controlled study, we have investigated the effect of forced air warming on the rate of change of nasopharyngeal and rectal temperatures in 20 patients after coronary artery bypass grafting. All patients had nasopharyngeal temperatures less than 36 degrees C on arrival in the intensive care unit and received an infusion of glyceryl trinitrate 15 mg h-1, but none received inotropes. Ten patients were warmed under an aluminized plastic "space" blanket (control group) and 10 were warmed under a "Bair Hugger" blanket connected to its power unit on "high" setting (Bair Hugger group). The rates of increase in nasopharyngeal temperature were 0.4 and 0.95 degrees C h-1, respectively, in the control and Bair Hugger groups (P < 0.01) during the first 2 h after operation. Over the same period of time, rectal temperatures increased at a rate of 0.25 and 0.75 degrees C h-1 in the control and Bair Hugger groups, respectively (P < 0.01).      

Skin-surface warming: heat flux and central temperature

The authors determined the efficacy of four postoperative warming devices by measuring cutaneous and tympanic membrane temperatures, and heat loss/gain using 11 thermocouples and ten thermal flux transducers in five healthy, unanesthetized volunteers. Overall thermal comfort was evaluated at 5-10 min intervals using a 10-cm visual analog scale. The warming devices were: 1) a pair of 250-W infrared heating lamps mounted 71 cm above the abdomen; 2) the Thermal Ceiling MTC XI UL (500 W) set on "high" and mounted 56 cm above the volunteer; 3) a 54-by-145-cm circulating-water blanket set to 40 degrees C placed over the volunteer; and 4) the Bair Hugger forced air warmer with an adult-sized cover set on "low" (approximately 33 degrees C), "medium" (approximately 38 degrees C), and "high" (approximately 43 degrees C). Following a 10-min control period, each device was placed over the volunteer and activated for a 30-min period. All devices were started "cold" and warmed up during the study period. The Bair Hugger set on "medium" decreased heat loss more than each radiant warming device and as much as the circulating-water blanket. All methods reached maximum efficacy within 20 min. Set on "high," the Bair Hugger increased skin-surface temperature more than the circulating-water blanket. The Bair Hugger (all settings) and the water blanket raised skin temperature more than the radiant heaters. The circulating-water blanket was the most effective device for heating an optimally placed transducer on the chest (directly under and parallel to the radiant heat sources, and touching the water and Bair Hugger blankets).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of sympathetic blockade on the efficiency of forced-air warming during combined spinal-epidural anesthesia for total hip arthroplasty.

STUDY OBJECTIVE: To evaluate if active cutaneous warming of the two upper limbs with reflex vasoconstriction is less effective in maintaining intraoperative normothermia than warming the vasodilated unoperated lower limb during combined spinal-epidural anesthesia (CSE). DESIGN: Prospective, randomized study. SETTING: Inpatient anesthesia at university departments of orthopedic surgery. PATIENTS: 48 ASA physical status I, II, and III patients, who were scheduled for elective total hip arthroplasty. INTERVENTIONS: Patients received CSE with intrathecal injection of 15 mg of 0.5% hyperbaric bupivacaine. All procedures started 8 to 10 AM, and operating room temperature was maintained between 21 degrees and 23 degrees C, with relative humidity ranging between 40% and 45%. For warming therapy, patients received active forced-air warming of either the two upper limbs (Group Upper body, n = 24), or the unoperated lower limb (Group Lower extremity, n = 24). Core temperature was measured before CSE placement (baseline), and then every 30 minutes until completion of surgery. Time for fulfillment of clinical discharging criteria from the recovery area was evaluated by a blinded observer. MEASUREMENTS AND MAIN RESULTS: Demographic data, duration of surgery, intraoperative blood losses, crystalloid infusion, and hemodynamic variables were similar in the two groups. Core temperature slightly decreased in both groups, but at the end of surgery the mean core temperature was 36.2 degrees +/- 0.5 degree C in Group Upper body and 36.3 +/- 0.5 in Group Lower extremity (NS). At recovery room arrival, seven patients in Group Upper body (29%) and three patients in Group Lower extremity (12.5%) had a core temperature less than 36 degrees C (NS). Shivering was observed in one patient in Group Upper body and in two patients in Group Lower extremity (NS). Clinical discharging criteria were fulfilled after 37 +/- 16 minutes in Group Upper body and 30 +/- 32 minutes in Group Lower extremity (NS). CONCLUSIONS: Forced-air cutaneous warming allows the anesthesiologist to maintain normothermia during CSE for total hip replacement even if the convective blanket is placed on a relatively small skin surface with reflex vasoconstriction. Placing the forced-air warming system on the vasodilated unoperated lower limb may be troublesome to the surgeons and does not offer clinically relevant advantages in warming efficiency.     

Evaluation of two warming systems after cardiopulmonary bypass

We have compared the Thermomat electric undermattress (JMW Systems, Edinburgh, UK) and the Bair Hugger (Augustine Medical, Courtelary, Switzerland) forced-air warming blanket in 30 adult patients after cardiac surgery. All patients were warmed to an oesophageal temperature of 38 degrees C before termination of cardiopulmonary bypass (CPB); those with oesophageal temperatures < 35.5 degrees C at skin closure were allocated randomly to be rewarmed in the intensive care unit either on the Thermomat (n = 15) or under the Bair Hugger blanket (n = 15), at their highest settings. Oesophageal and lateral thigh skin temperatures were recorded every 15 min for 4 h. There was a significantly faster increase in core temperature (0.5 vs 0.75 degrees C h-1; P < 0.0002) and skin temperature (0.86 vs 1.3 degrees C h-1; P < 0.001) in the Bair Hugger group. However, there was no difference in the number of patients who reached a core temperature of 36 degrees C (15 Bair Hugger, 14 Thermomat) or 37 degrees C (11 Bair Hugger, seven Thermomat), or in the number of patients who reached a skin temperature of 37 degrees C in 4 h (four Bair Hugger, one Thermomat). Twelve patients in the Bair Hugger group reached a skin temperature of 36 degrees C compared with two in the Thermomat group (P < 0.001). The Bair Hugger warmed faster than the Thermomat both centrally and peripherally, and warmed more patients to a core temperature of 37 degrees C in 4 h, but did not reduce the time to tracheal extubation or alter important clinical aspects of postoperative course.      

Simulated clinical evaluation of four fluid warming devices*

The fluid warming capabilities of the Bair Hugger, Hotline, Standard Ranger and Fluido devices were evaluated in the laboratory with gravity flow via a 14G cannula (1 m head of fluid) and with the fluid bag pressurised to 300 mmHg. The resulting flows (70-450 ml.min(-1)) were recorded. At a room temperature of 22 degrees C, no device warmed the fluid to 37 degrees C. However, the Standard Ranger with gravity flow and the Fluido with both gravity and pressurised flow achieved 35 degrees C, whereas the Bair Hugger and Hotline with both gravity and pressurised flow, and the Standard Ranger with pressurised flow, achieved only 24-31 degrees C. However, from the way delivered temperatures changed with flow, we calculated that all four devices would achieve close to 37 degrees C at the flows specified by the manufacturers: 17, 83, 150 and 800 ml.min(-1) for the Bair Hugger, Hotline, Standard Ranger and Fluido, respectively.     

Predictors of Hypothermia during Spinal Anesthesia

Background: Body temperature often is ignored during regional anesthesia, despite evidence that hypothermia occurs commonly. Because hypothermia is associated with adverse clinical outcomes, it is important to recognize predictors of hypothermia and to monitor and control body temperature in patients at risk. The current study was designed to determine the predictors of core hypothermia in patients receiving spinal anesthesia for radical retropubic prostatectomy.

Methods: Forty-four patients undergoing radical retropubic prostatectomy were studied. A lumbar intrathecal injection of 18-22 mg bupivacaine, 0.75%, with 20 [mu]g fentanyl was given. No active warming measures were used other than intravenous fluid warming. The following clinical variables were assessed as potential predictors of core (tympanic) temperature at admission to the postanesthesia care unit: duration of surgery, average ambient operating room temperature, body habitus, age, and spinal blockade level.

Results: The mean core temperature at admission to the postanesthesia care unit was 35.1 +/- 0.6[degrees]C (range, 33.6-36.3[degrees]C). Duration of surgery, ambient operating room temperature, and body habitus were not predictors of hypothermia. A high level of spinal blockade and increasing age were predictors of hypothermia. For each incremental increase in block level, core temperature decreased by 0.15[degrees]C, and for each increase in age, core temperature decreased by 0.3[degrees]C.     

Effect of forced-air warming on the performance of operating theatre laminar flow ventilation

Forced‐air warming exhaust may disrupt operating theatre airflows via formation of convection currents, which depends upon differences in exhaust and operating room air temperatures. We investigated whether the floor‐to‐ceiling temperatures around a draped manikin in a laminar‐flow theatre differed when using three types of warming devices: a forced‐air warming blanket (Bair Hugger?); an over‐body conductive blanket (Hot Dog?); and an under‐body resistive mattress (Inditherm?). With forced‐air warming, mean (SD) temperatures were significantly elevated over the surgical site vs those measured with the conductive blanket (+2.73 (0.7) °C; p < 0.001) or resistive mattress (+3.63 (0.7) °C; p < 0.001). Air temperature differences were insignificant between devices at floor (p = 0.339), knee (p = 0.799) and head height levels (p = 0.573). We conclude that forced‐air warming generates convection current activity in the vicinity of the surgical site. The clinical concern is that these currents may disrupt ventilation airflows intended to clear airborne contaminants from the surgical site.     

Core and thenar skin temperature variation during prolonged abdominal surgery: comparison of two sites of active forced air warming

BACKGROUND: This study was designed to compare the efficacy of two different sites of active forced air warming, upper body or lower body, to maintain normothermia; and their respective effect on thenar skin temperature in relation to the accelerographic monitoring of neuromuscular blockade during long-lasting abdominal surgery. METHODS: Twenty-six patients were randomised into two groups: upper body, (n=13) and lower body, (n=13), for intraoperative forced air warming. General anaesthesia was induced with thiopentone, sufentanil, and maintained with a mixture of N2O/O2/isoflurane. Pancuronium, 0.1 mg x kg(-1) was used to facilitate tracheal intubation. Reinjection doses of 0.01 mg x kg(-1) were administered once 25% recovery of first twitch height of train-of-four stimulation had occurred, or if surgical relaxation was estimated as inadequate by the surgeon. Thenar skin temperature and core temperature were monitored continuously. RESULTS: A similar trend for core temperature profile was observed in both groups. After an initial mild hypothermia, normothermia was reached progressively. Normothermia was obtained faster with lower body forced air warming than with upper body (2 h versus 3 h), P<0.05. Thenar skin temperature significantly increased during the first 90 min of surgery. This rise was significantly higher in the upper body group at 40 min and 60 min, P=0.03 and P=0.01, respectively. Stabilisation of thenar skin temperature occurred after 2 h without any further significant difference between groups. Muscle relaxant requirements were not significantly different between the groups. CONCLUSION: This study suggests that during long-lasting abdominal surgery, normothermia is maintained after 2-3 h by either upper or lower body active forced air warming. After an initial post-induction mild hypothermia, normothermia was achieved faster with lower body surface warming. Thenar skin temperature trend showed that it remained above 32 degrees C during most of the procedure in both groups.     

Convection heating in pediatric general surgery - a comparison of warming alternatives in a mannequin study

BACKGROUND: Numerous methods of patient warming are used to prevent intraoperative hypothermia in children. Commercially available forced air warming blankets are effective, but are single-use items. We tested a custom-designed heat dissipation unit (HDU) against one such commercially available blanket. METHODS: Air temperatures at various points around a mannequin under simulated operating conditions were recorded using thermistors and thermal imaging. The only variable changed was the heating method: a forced air blanket or a customized HDU with two draping techniques - cotton drapes with and without a plastic 'undersheet'. RESULTS: The three methods produced similar temperature increases and plateaux across the 11 thermistor points measured. There were no significant differences between temperatures at 1 h. A plastic sheet did not appear to enhance the effectiveness of the HDU in this study. Thermal imaging photography suggested more uniform heating of the mannequin with the HDU arrangements. CONCLUSIONS: The custom-built HDU compares favorably in our mannequin study with a Bair Hugger forced air warming blanket. As it is reusable, it offers considerable potential savings.     

Thermal softening of tracheal tubes: an unrecognized hazard of the Bair Hugger active patient warming system

The Bair Hugger system is a new and highly effective active patient warming system which produces a layer of warm air between the patient and the warming system. We report an instance of marked softening and distortion of a polyvinyl chloride tracheal tube caused by this layer. We also present laboratory data indicating that this is a likely problem under routine theatre conditions, with suggestions for prevention.      

Delayed forced air warming prevents hypothermia during abdominal aortic surgery

We have evaluated the efficacy of the delayed forced air warming during abdominal aortic surgery in 18 patients. Patients were allocated randomly to one of two groups: the control group (n = 9) received no intraoperative warming device; the Bair-Hugger group (n = 9) had active skin surface warming with an upper body cover. The device was activated when core temperature decreased to less than 36 degrees C. The reduction in core temperature was 0.6 degrees C during the first hour after induction and 0.4 degrees C during the second hour in both groups. In the control group, core temperature continued to decrease until the end of surgery, whereas in the Bair-Hugger group, the reduction in core temperature stopped after 1 h of warming, and then rewarming began. At the end of surgery, core temperature in the Bair- Hugger group was similar to core temperature before induction, and was higher than core temperature in the control group (P < 0.003).      

Predictors of hypothermia during spinal anesthesia

BACKGROUND: Body temperature often is ignored during regional anesthesia, despite evidence that hypothermia occurs commonly. Because hypothermia is associated with adverse clinical outcomes, it is important to recognize predictors of hypothermia and to monitor and control body temperature in patients at risk. The current study was designed to determine the predictors of core hypothermia in patients receiving spinal anesthesia for radical retropubic prostatectomy. METHODS: Forty-four patients undergoing radical retropubic prostatectomy were studied. A lumbar intrathecal injection of 18-22 mg bupivacaine, 0.75%, with 20 microg fentanyl was given. No active warming measures were used other than intravenous fluid warming. The following clinical variables were assessed as potential predictors of core (tympanic) temperature at admission to the postanesthesia care unit: duration of surgery, average ambient operating room temperature, body habitus, age, and spinal blockade level. RESULTS: The mean core temperature at admission to the postanesthesia care unit was 35.1 +/- 0.6 degrees C (range, 33.6-36.3 degrees C). Duration of surgery, ambient operating room temperature, and body habitus were not predictors of hypothermia. A high level of spinal blockade and increasing age were predictors of hypothermia. For each incremental increase in block level, core temperature decreased by 0.15 degrees C, and for each increase in age, core temperature decreased by 0.3 degrees C. CONCLUSIONS: Although high-level spinal blockade has been associated with decreased thermoregulatory thresholds, no previous study has shown that a higher level of blockade is associated with a greater magnitude of core hypothermia in the clinical setting. As with general anesthesia, advanced age is associated with hypothermia during spinal anesthesia.     

Efficacy of postoperative rewarming after cardiac surgery.

OBJECTIVE: To compare the efficacy of forced-air warmers and radiant heaters on rewarming after cardiac surgery in a prospective randomized study. METHODS: Fifty male patients who had undergone coronary artery bypass graft surgery were studied. The control group (Gr. C, n=10) was nursed under a standard hospital blanket. Two groups were treated with forced-air warmers: WarmTouch 5700 (Gr. WT, n=10) and Bair Hugger 500 (Gr. BH, n=10). Two other groups were treated by radiant heaters: the Aragona Thermal Ceilings CTC X radiant heater (Gr. TC, n=10) and a self assembled radiant heater of 4 Hydrosun 500 infrared lamps (Gr. HY, n=10). Changes of oesophageal temperature, mean skin temperature, mean body temperature and relative heat balance were calculated from oesophageal temperature, 4 skin temperatures and oxygen consumption (VO(2)). RESULTS: All actively treated groups with exception of the TC group showed significantly faster oesophageal warming than the control group. The mean body temperature increased 1.1 (0.7-1.7) degrees Ch(-1) in Gr. WT, 1.3 (0.7-1.5) degrees Ch(-1) in Gr. BH, 0.8 (0.5-1.4) degrees Ch(-1) in Gr. TC and 0.7 (0.4-1.0) degrees Ch(-1) in Gr. HY compared to Gr. C with 0.4 (0.2-0.7) degrees Ch(-1). The mean VO(2) and the maxima of the VO(2) during the study period did not differ significantly between the groups. CONCLUSION: In the current setting active warming, forced-air warming more than radiant warming, increased speed of rewarming two- to threefold in comparison to insulation with a blanket.     

Third-degree burns due to intraoperative use of a Bair Hugger warming device

We report the case of a 3-year-old boy who underwent correction of transposition of the great arteries who developed burns from use of a patient warming device. His repair had been delayed because he was from a developing country, and he was offered surgery as part of a humanitarian effort. Postoperatively he was noted to have second- and third-degree burns from use of a Bair Hugger (Augustine Medical, Eden Prairie, MN) warming system after cardiopulmonary bypass.