Temperature gradients at various points within the human pelvis as measured during laparoscopy

Temperatures have been measured during pelvic laparoscopy, under general anesthesia, in 59 women. Temperatures on the serosal surface of the rectum, the mesovarium, the ovarian arteries and the surface of the external iliac artery have been compared with the temperature deep in the rectal cavity on the rectal mucosa. The mean temperatures recorded at all sites within the pelvic cavity were lower than the mean temperatures recorded on the rectal mucosa. The mean differences between rectal mucosa and the other pelvic sites are: rectal mucosa -0.20 +/- standard error of the mean (SEM) 0.03C, mesovarium -0.28 +/-SEM 0.04C, ovarian artery -0.35 +/- SEM 0.05C and external iliac artery -0.44 +/- SEM 0.06C. All differences are highly significant from zero and do not appear to be related to the time from the onset of anesthesia, the temperature of the gas used to fill the abdominal cavity, the time from the last menustrual period and any pathology present in the pelvis. The results are consistent with a previous suggestion, by Grayson,2 that the human rectal mucosa may be an organ of heat production and that arterial blood within the pelvis may be precooled by counter current heat exchange with veins draining cold blood from the extremities.