Unexpectedly high incidence of hypothermia before induction of anesthesia in elective surgical patients.
OBJECTIVE
Perioperative hypothermia is a frequently observed phenomenon of general anesthesia and is associated with adverse patient outcome. Recently, a significant influence of core temperature before induction of anesthesia has been reported. However, there are still little existing data on core temperature before induction of anesthesia and no data regarding potential risk factors for developing preoperative hypothermia. The purpose of this investigation was to estimate the incidence of hypothermia before anesthesia and to determine if certain factors predict its incidence.


METHODS
Data from 7 prospective studies investigating core temperature previously initiated at our department were analyzed. Patients undergoing a variety of elective surgical procedures were included.


METHODS
Core temperature was measured before induction of anesthesia with an oral (314 patients), infrared tympanic (143 patients), or tympanic contact thermometer (36 patients). Available potential predictors included American Society of Anesthesiologists status, sex, age, weight, height, body mass index, adipose ratio, and lean body weight. Association with preoperative hypothermia was assessed separately for each predictor using logistic regression. Independent predictors were identified using multivariable logistic regression.


RESULTS
A total of 493 patients were included in the study. Hypothermia was found in 105 patients (21.3%; 95% confidence interval, 17.8%-25.2%). The median core temperature was 36.3°C (25th-75th percentiles, 36.0°C-36.7°C). Two independent factors for preoperative hypothermia were identified: male sex and age (>52years).


CONCLUSIONS
As a consequence of the high incidence of hypothermia before anesthesia, measuring core temperature should be mandatory 60 to 120minutes before induction to identify and provide adequate treatment to hypothermic patients.
Department of Anesthesiology, University of Goettingen, Robert-Koch-Str 40, 37075 Goettingen, Germany. Electronic address: anna.wetz@med.uni-goettingen.de.
Anna J
AJ
Wetz
Department of Anesthesiology, University of Goettingen, Robert-Koch-Str 40, 37075 Goettingen, Germany.
Thorsten
T
Perl
Department of Anesthesiology, University of Goettingen, Robert-Koch-Str 40, 37075 Goettingen, Germany.
Ivo F
IF
Brandes
Institute of Medical Statistics, University of Goettingen, Humboldtallee 32, 37073 Goettingen, Germany.
Markus
M
Harden
Department of Anesthesiology, University of Goettingen, Robert-Koch-Str 40, 37075 Goettingen, Germany.
Martin
M
Bauer
Department of Anesthesiology, University of Goettingen, Robert-Koch-Str 40, 37075 Goettingen, Germany.
Anselm
A
Bräuer
D000328:Adult; D000367:Age Factors; D000368:Aged; D000768:Anesthesia, General / Q000009:adverse effects; D001831:Body Temperature; D017558:Elective Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000453:epidemiology* / Q000209:etiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D011300:Preoperative Care / Q000379:methods* / Q000592:standards*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D012737:Sex Factors
Core temperature; Hypothermia; Hypothermia before induction of anesthesia; Incidence of hypothermia; Predictor of hypothermia