The effect of heated breathing circuit on body temperature and humidity of anesthetic gas in major burns.
BACKGROUND
Cold and dry gas mixtures during general anesthesia cause the impairment of cilliary function and hypothermia. Hypothermia and pulmonary complications are critical for the patients with major burn. We examined the effect of heated breathing circuit (HBC) about temperature and humidity with major burned patients.


METHODS
Sixty patients with major burn over total body surface area 25% scheduled for escharectomy and skin graft were enrolled. We randomly assigned patients to receiving HBC (HBC group) or conventional breathing circuit (control group) during general anesthesia. The esophageal temperature of the patients and the temperature and the absolute humidity of the circuit were recorded every 15 min after endotracheal intubation up to 180 min.


RESULTS
There was no significant difference of the core temperature between two groups during anesthesia. The relative humidity of HBC group was significantly greater compared to control group (98% vs. 48%, P < 0.01). In both groups, all measured temperatures were significantly lower than that after intubation.


CONCLUSIONS
The use of HBC helped maintain airway humidity, however it did not have the effect to minimize a body temperature drop in major burns.
Department of Anesthesiology and Pain Medicine, Hangang Sacred Heart Hospital, College of Medicine, Hallym University, Seoul, Korea.
In-Suk
IS
Kwak
Do Young
DY
Choi
Tae-Hyung
TH
Lee
Ji Young
JY
Bae
Tae-Wan
TW
Lim
Kwang-Min
KM
Kim
Anesthesia; Closed circuit; General anesthesia; Humidity; Hypothermia