Body temperature evaluation during induced pneumoperitoneum with CO₂: an experimental study in pigs

In prolonged laparoscopic procedures, hypothermia is frequently observed. The possible influence of the vasodilating action of CO(2), due to its increased levels in the blood during the laparoscopic procedures, has yet to be studied. The objective of this study was, therefore, to evaluate body temperature patterns in pigs subjected to pneumoperitoneum with CO(2).

Thirty male pigs were allocated into three groups of ten animals each: group I, anesthetic procedure and abdominal puncture only; group II, the same as for group I and insufflation with CO(2); and group III, the same as for group I and insufflation with medical grade compressed air. After anesthetic induction and surgical preparation, rectal and esophageal temperatures were measured every 10 min. Blood was collected during the experiment for the gasometric measurement of pCO(2). Animals were insufflated with no gas loss and were kept anesthetized for 180 min. For statistical analysis, Friedman and Kruskal-Wallis tests were used at a level of significance of 95% (P < 0.05).

Animals in groups I and II (P = 0.000) had a statistically significant drop in both esophageal and rectal temperatures during the experiment, but not animals in group III. However, when the groups were compared among themselves, no statistically significant differences were found at any of the times measured. A statistically significant drop in pCO(2) levels was observed for groups I and III, but not for animals in groups II.

The use of CO(2) did not significantly affect body temperature variation in pigs subjected to pneumoperitoneum. However, CO(2) produced a temperature drop pattern different than that of compressed air, indicating that CO(2) may lead to thermoregulatory changes and influence the peripheral temperature drop.