Changes in pH of peritoneal fluid associated with carbon dioxide insufflation during laparoscopic surgery in dogs

To evaluate changes in pH of peritoneal fluid associated with CO2 insufflation during laparoscopy in dogs.

13 client-owned dogs and 10 purpose-bred teaching dogs.

Laparotomy was performed on control dogs; peritoneal fluid pH was measured at time of incision of the abdominal cavity (time 0) and 30 minutes later. Laparoscopic insufflation with CO2 was performed and routine laparoscopic procedures conducted on the teaching dogs. Insufflation pressure was limited to 12 mm Hg. Intraperitoneal fluid pH was measured by use of pH indicator paper at 4 time points. Arterial blood gas analysis was performed at the same time points.

Peritoneal fluid pH did not change significantly between 0 and 30 minutes in the control dogs. For dogs with CO2 insufflation, measurements obtained were a mean of 8.5, 24.5, 44.5, and 72.0 minutes after insufflation. The pH of peritoneal fluid decreased significantly between the first (7.825 +/- 0.350) and second (7.672 +/- 0.366) time point. Blood pH decreased significantly between the first (7.343 +/- 0.078), third (7.235 +/- 0.042), and fourth (7.225 +/- 0.038) time points. The PaCO2 increased significantly between the first (39.9 +/- 9.8 mm Hg) and fourth (54.6 +/- 4.4 mm Hg) time points. Base excess decreased significantly between the first and all subsequent time points.

Pneumoperitoneum attributable to CO2 insufflation caused a mild and transient decrease in peritoneal fluid pH in dogs. Changes in peritoneal fluid associated with CO2 insufflation in dogs were similar to those in other animals.