RESPIRATORY MECHANICS DURING LAPAROSCOPIC CHOLECYSTECTOMY - THE EFFECTS OF THE ABDOMINAL-WALL LIFT

The abdominal wall Lift (AWL) has been proposed for laparoscopic chole cystectomy to reduce hemodynamic effects caused by carbon dioxide (CO, ) and high intraabdominal pressures (IAP). Data concerning effects of AWL on respiratory mechanics are scant. We therefore used a noninvasiv e method to evaluate whether the AWL could offset these effects. The P ETCO2, airflow, and airway pressure were continuously measured in nine patients undergoing laparoscopic cholecystectomy using an AWL with mi nimal CO, insufflation. We used a least-squares method to calculate ma ximal airway pressure (Pmax), elastance (Ers), and resistances (Rrs) o f the respiratory system. After CO, insufflation, the initiation of AW L resulted in a significantly decreased IAP (from 13 to 6 mm Hg; P < 0 .001) and Rrs (from 20.6 to 17.8 cm H2O.L-1.s(-1); P = 0.029), whereas Ers was partly modified (34.0 to 33.3 cm H2O/L; not significantly dif ferent). With AWL, we hypothesized that the diaphragm remained flat an d stiff, outweighing the beneficial effect of the decrease of IAP on E rs. PETCO2 significantly increased after AWL and at the end of the pro cedure. We conclude that AWL partly reverses the impairment of the res piratory mechanics induced by CO, insufflation during laparoscopic sur gery. Implications: The abdominal wall lift (AWL), acting on the abdom inal chest wall, had some benefits during laparoscopic surgery by limi ting CO, peritoneal insufflation and several side effects, such as hem odynamics. We examined the consequences of this technique on respirato ry mechanics in nine patients undergoing laparoscopic cholecystectomy. Our findings suggest that the AWL decreases intraabdominal pressure a nd respiratory resistances without a significant effect on respiratory elastance.