Randomized trial of different intraabdominal pressures and acid-base balance alterations during laparoscopic cholecystectomy.

Background: Experimental and clinical studies document risks of acid-base balance alterations toward acidosis and hypercapnia during intraperitoneal carbon dioxide insufflation. The aim of this study was to assess the influence of different insufflation pressures on arterial blood gas changes and acid-base alterations during laparoscopic cholecystectomy and immediately postoperatively. Methods: Thirty patients were randomized to receive either 10 or 15 mmHg insufflation pressure. Anesthesia was standardized for both groups. The following parameters of acid-base balance were recorded: pH, pCO 2 , pO 2 , base excess (BE), HCO 3 . Suitable data were analyzed by the Mann-Whitney U-test. Results: Pneumoperitoneum with carbon dioxide caused a decrease in pH toward acidosis that was either respiratory or mixed in origin. There were no statistically significant differences in acid--base balance alterations between the two groups of patients. Conclusions: Carbon dioxide pneumoperitoneum causes alterations of the acid-base balance, mostly of respiratory or mixed type. Lowering of the insufflation pressure from 15 to 10 mmHg does not contribute to the elimination of acid--base balance alterations during laparoscopic cholecystectomy.