THE EFFECTS OF NEUROMUSCULAR BLOCK ON PEAK AIRWAY PRESSURE AND ABDOMINAL ELASTANCE DURING PNEUMOPERITONEUM

Administration of muscle relaxants is considered as necessary to preve nt high intraabdominal and peak inspiratory pressures induced by pneum operitoneum during laparoscopy. In the present study, we hypothesized that neuromuscular block does not alter pulmonary or abdominal elastic properties in pigs receiving general anesthesia. To test this hypothe sis, changes in peak ah-way pressure and abdominal elastance during in traabdominal CO2 insufflation from 0 to 15 mm Hg were recorded in anes thetized pigs, with or without muscle relaxants. A 100% increase in pe ak inspiratory airway pressure was obtained. This was unaffected by ne uromuscular block induced by atracurium (13.2 +/- 5.0 mm Hg vs 25.0 +/ - 4.8 mm Hg for the control group and 12.6 +/- 5.0 mm Hg vs 23.5 +/- 6 .2 mm Hg for the paralyzed group). Abdominal pressure/volume relations hips were independent of muscle relaxant administration (calculated el astance was 3.98 +/- 1.56 mm Hg/L without muscle relaxant vs 3.86 +/- 1.37 mm Hg/L in the atracurium group). We conclude that high peak insp iratory airway pressures and intraabdominal pressures during laparosco py are not affected by neuromuscular block. These findings also questi on the necessity of muscle relaxants in clinical anesthetic practice d uring laparoscopic surgery.