Effect of temperature of insufflated CO2 during and after prolonged laparoscopic surgery

Background: Pneumoperitoneum with room temperature carbon dioxide (CO2) has been shown to decrease core temperature and urine output. Methods: The effect of 37 degrees C (warm) and room temperature (cool) CO2 pneumoperitoneum on core temperature, urine output, and central hemodynamics was compared in 26 randomized patients undergoing prolonged laparoscopic surgery (>90 min). Results: The core temperature (p < 0.05) and cardiac index (p < 0.05) were significantly higher after warm than after cool pneumoperitoneum. Urine output was significantly higher during warm (2.3 +/- 1.6 ml/kg/h) than during cool (0.9 +/- 0.7 ml/kg/h) insufflation (p < 0.05). Two of 13 patients with warm and 11 of 13 patients with cool pneumoperitoneum needed mannitol to maintain adequate diuresis (p < 0.05). Conclusions: Warm insufflation probably causes a local vasodilation in the kidneys and may be beneficial to patients with borderline renal function.