Cold nebulization used to prevent heat loss during laparoscopic surgery: an experimental study in pigs

Prolonged abdominal laparoscopy is responsible for a significant drop in core body temperature. Various modifications of the conditioning for the insufflating carbon dioxide (CO(2)) to prevent the specific hypothermia related to the insufflated gas have been tested. This study aimed to investigate the effects on core temperature of insufflation with unheated humidified CO(2) using the Aeroneb system compared with the use of standard gas and gas made hot and wet using a warming and humidifying system (Pall system).

A prospective four-session study was conducted to investigate a homogeneous group of four pigs. After inducation of general anesthesia, all the animals were treated successively with the following protocols in a randomized order at 8-day intervals: control (no pneumoperitoneum), standard (unheated, unhumidified CO(2)), Aeroneb (unheated, humidified CO(2) by cold nebulization), and Pall (heated, humidified CO(2)). The core temperature of the animals was recorded every 10 min.

Analysis of variance (ANOVA) confirmed a difference between the insufflation conditions in the evolution of temperature over time (p = 0.004). The method of contrast showed the following results. After 30 min, the core temperature of the Aeroneb group fell significantly less than that of the standard group (p = 0.036). After 100 min, the core temperature of the Pall group fell significantly less than that of the standard group (p = 0.024). After 80 min, the core temperature of the standard group fell significantly more than that of the control group (p = 0.035). In the Aeroneb group, the core temperature dropped less than in the Pall and control groups, but the difference did not reach statistical significance.

Cold humidification of insufflating CO(2) prevents heat loss associated with pneumoperitoneal insufflation at least as efficaciously as warmed humidification of the gas.