The effect of a forced-air warming blanket on patients' end-tidal and transcutaneous carbon dioxide partial pressures during eye surgery under local anaesthesia: a single-blind, randomised controlled trial.
Surgical drapes used during eye surgery are impermeable to air and hence risk trapping air underneath them. We investigated the effect of a forced-air warming blanket on carbon dioxide accumulation under the drapes in patients undergoing eye surgery under local anaesthesia without sedation. Forty patients of ASA physical status 1 and 2 were randomly assigned to either the forced-air warmer (n = 20) or a control heated overblanket (n = 20). All patients were given 1 l.min(-1) oxygen. We measured transcutaneous and end-tidal carbon dioxide partial pressures, heart rate, arterial pressure, respiratory rate, temperature and oxygen saturation before and after draping, then every 5 min thereafter for 30 min. The mean (SD) transcutaneous carbon dioxide partial pressure in the forced-air warming group stayed constant after draping at 5.7 (0.2) kPa but rose to a maximum of 6.4 (0.4) kPa in the heated overblanket group (p = 0.0001 for the difference at time points 15 min and later). We conclude that forced-air warming reduces carbon dioxide accumulation under the drapes in patients undergoing eye surgery under local anaesthesia.
Department of Anaesthesiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
S
S
Sukcharanjit
Department of Anaesthesiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
A S B
AS
Tan
Department of Ophthalmology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
A V P
AV
Loo
School of Medicine, Bristol University, Bristol, UK.
X L
XL
Chan
Department of Anaesthesiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
C Y
CY
Wang
D000368:Aged; D000772:Anesthesia, Local; D001831:Body Temperature; D002245:Carbon Dioxide / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D010313:Partial Pressure; D016037:Single-Blind Method
D002245:Carbon Dioxide