Background: There are varying data regarding the degree and extent of abdominal acidification
during laparoscopy. The aim of this study was to determine the extent of peritoneal acidification
during carbon dioxide insufflation and the effects of different pressures, insufflation rates, and free
intraperitoneal fluids.
Materials and Methods: Sixteen male Sprague-Dawley rats weighing 250–300 g were anesthetized
and a two-point pH probe was inserted in the abdominal cavity. After closure of the abdominal wall,
each group of 4 rats was subjected to one of four insufflation regimens: low pressure (2 mm Hg, no
leakage); high pressure (10 mm Hg, no leakage); leakage (2 mm Hg, leakage 0.5 mL/min); and fluid
(2 mm Hg, 10mL intraperitoneal 0.9% NaCl). During insufflation peritoneal pH was continuously
measured.
Results: Carbon dioxide insufflation significantly decreased the peritoneal pH to <7.0 only in areas
exposed to the insufflation gas. Neither changes in pressure nor insufflation rate had major effects
on the peritoneal pH. The addition of 10mL normal saline into the abdominal cavity significantly
enhanced the pH change during insufflation.
Conclusion: Acidification associated with carbon dioxide pneumoperitoneum is limited to the area
of inspection and manipulation. The increased acidification following injection of normal saline could
offer a useful mechanism to alter the inflammatory response.
