Diaphragm Function Is Not Impaired By Pneumoperitoneum After Laparoscopy

Open cholecystectomy is known to induce a major restrictive respiratory syndrome. These respiratory disturbances, although of reduced magnitude, still persist after laparoscopic cholecystectomy. To determine the role of pneumoperitoneum per se in the respiratory dysfunction observed after this procedure, seven patients were studied before and 2 hours after laparoscopy. This diagnostic procedure avoids the upper midline incision and the surgical injury of cholecystectomy. Ventilatory performance and diaphragm function were assessed as follows: (1) during quiet tidal breathing by obtaining measurements of esophageal, gastric, and transdiaphragmatic pressures; determining the ratio of gastric pressures to esophageal pressures; and abdomen-rib cage partitioning of tidal volume obtained from two differential linear transformers and (2) during maximal respiratory efforts by obtaining measurements of vital capacity and maximal transdiaphragmatic pressure during Muller's maneuver and a sniff test. Although a large residual pneumoperitoneum (assessed as the maximal height of the suprahepatic space: H(max) = 30.3 +/- 7.8 mm) was observed after laparoscopy, we did not find any change suggestive of diaphragm dysfunction. We thus conclude that postoperative residual pneumoperitoneum per se is unable to explain the diaphragm dysfunction observed after open or laparoscopic cholecystectomy.