Background: Acute increases in intraabdominal pressure (IAP) induce systemic and regional circulatory changes. Besides, mechanical compression on the capillary beds may decrease oxygen availability to the tissues. The purpose of this clinical study was to analyze the effects of increased IAP on acid-base disturbances and plasma lactate levels during prolonged carbon dioxide pneumoperitoneum.
Methods: Twenty-eight patients undergoing laparoscopic sigmoidectomy were included in this study. Fourteen of them (group A) had IAP of 15 +/- 1 mmHg while the remaining 14 (group B) had IAP of 10 +/- 1 mmHg. The control group included six patients undergoing conventional sigmoidectomy.
Results: A progressive significant increase in PaCO2 was observed in the laparoscopic groups (p < 0.01). Plasma lactate levels in group A significantly increased 90 min after insufflation (p < 0.05) and reached the highest value 1 h after deflation (9.9 +/- 1 vs 31.9 +/- 2.5 mg/dl, p < 0.005). Simultaneously, arterial pH decreased in all groups; however, at 1 h after surgery, it was significantly lower (p = 0.02) in group A. There was a significant correlation between acid concentration due to lactate and lactate concentration (GA: R2 = 0.717, p = 0.03; GB: R2 = 0.879, p = 0.006 and GC: R2 = 0.853, p = 0.008).
Conclusion: High IAP causes lactic acidic accumulation in patients undergoing prolonged laparoscopic procedures.