[Accuracy of intraoperative urinary bladder temperature monitoring during intra-abdominal operations].
OBJECTIVE
This study investigates whether the site of abdominal surgery or the urine flow rate affects the accuracy of urinary bladder temperature monitoring.


METHODS
After approval by the local ethics committee we studied 7 patients during upper abdominal and 10 patients during lower abdominal surgery. Temperatures were recorded with a Hi-Lo Temp Esophageal-Stethoscope (Mallinckrodt Medical) and a Foley Catheter Temperature Sensor FC400-18 (Respiratory Support Products, Mallinckrodt Medical). Each probe and its recording unit were calibrated over a range of 30-40 degrees C against a reference quartz thermometer (Hewlett Packard Model 2801 A) in a water bath before the investigation. Urine flow rate was measured using a urometer. Temperatures and urine flow rate were recorded every 30 min. Agreement between the methods of measurement was assessed as described by Bland and Altman.


RESULTS
124 measuring points could be analyzed. Bladder temperature had a bias (B) of -0.06 degree C compared to oesophageal temperature. Limits of agreement (LOA; +/- 2 s) were +/- 0.68 degree C. In upper abdominal surgery (B: 0.02 degree C; LOA: +/- 0.42 degree C) a higher precision of oesophageal temperature estimation could be demonstrated compared to lower abdominal surgery (B: -0.14 degree C; LOA: +/- 0.82 degree C). Lower urine flow rates generally increased the limits of agreement. Regarding lower abdominal surgery the bias additionally increased to -0.22 degree C.


CONCLUSIONS
Urinary bladder temperature recording is a clinically acceptable method to measure core temperature during abdominal surgery. The accuracy during lower abdominal surgery is decreased compared to upper abdominal surgery, especially in case of a urine flow rate below 250 ml/h.
Bräuer
A
A
Zentrum Anaesthesiologie, Rettungs- und Intensivmedizin, Georg-August-Universität Göttingen. abraeue@gwdg.de
Martin
J D
JD
Schuhmann
M U
MU
Braun
U
U
Weyland
W
W
D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000368:Aged; D001831:Body Temperature / Q000502:physiology*; D002138:Calibration; D004947:Esophagus / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D001743:Urinary Bladder / Q000502:physiology*; D014563:Urodynamics / Q000502:physiology