Preventing hypothermia: convective and intravenous fluid warming versus convective warming alone.
OBJECTIVE
To test the hypothesis that warming intravenous (i.v.) fluids in conjunction with convective warming results in less intraoperative hypothermia (core temperature < 36.0 degrees C) than that seen with convective warming alone.


METHODS
Prospective, randomized study.


METHODS
University affiliated tertiary care teaching hospital.


METHODS
61 ASA physical status, I, II, and III adults undergoing major surgery and general anesthesia with isoflurane.


METHODS
All patients received convective warming. Group 1 patients received warmed fluids (setpoint 42 degrees C). Group 2 patients received room temperature fluids (approximately 21 degrees C).


RESULTS
Lowest and final intraoperative distal esophageal temperatures were higher (p < 0.05) in Group 1 (mean +/- SEM: 35.8 +/- 0.1 degrees C and 36.6 +/- 0.1 degrees C) versus Group 2 (35.4 +/- 0.1 degrees C and 36.1 +/- 0.1 degrees C, respectively). Compared with Group 1, more Group 2 patients were hypothermic at the end of anesthesia (10 of 26 patients, or 38.5% vs. 4 of 30 patients, or 13%; p < 0.05). After 30 minutes in the recovery room, there were no differences in temperature between groups (36.7 +/- 0.1 degrees C and 36.5 +/- 0.1 degrees C in Groups 1 and 2, respectively). Intraoperative cessation of convective warming because of core temperature greater than 37 degrees C was required in 33% of Group 1 patients (vs. 11.5% in Group 2; p = 0.052).


CONCLUSIONS
The combination of convective and fluid warming was associated with a decreased likelihood of patients leaving the operating room hypothermic. However, average final temperatures were greater than 36 degrees C in both groups, and intergroup differences were small. Care must be taken to avoid overheating the patient when both warming modalities are employed together.
Department of Anesthesiology, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH 44109, USA.
C E
CE
Smith
R
R
Desai
V
V
Glorioso
A
A
Cooper
A C
AC
Pinchak
K F
KF
Hagen
D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D004947:Esophagus / Q000502:physiology; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D007035:Hypothermia / Q000517:prevention & control*; D007275:Injections, Intravenous; D007431:Intraoperative Complications / Q000517:prevention & control*; D007530:Isoflurane / Q000008:administration & dosage; D008297:Male; D008614:Meperidine / Q000627:therapeutic use; D008875:Middle Aged; D011446:Prospective Studies; D012768:Shivering / Q000187:drug effects / Q000502:physiology
D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D008614:Meperidine; D007530:Isoflurane