DIAPHRAGMATIC AND ABDOMINAL MUSCLE-ACTIVITY AFTER ENDOSCOPIC CHOLECYSTECTOMY

We studied diaphragmatic and abdominal muscle activity immediately and 16 h after laparoscopic cholecystectomy (LAPC). Tidal volumes (VT), p artitioning of VT between the rib cage and the abdomen, and esophageal , gastric, and transdiaphragmatic pressures were recorded for 5 min ev ery 15 min up to 90 min after the end of anesthesia in 10 young patien ts submitted to an elective LAPC. All had chest radiographs in full in spiration and expiration as well as lung function tests (LFTs) before and 16 h after surgery. In 5 of the 10 patients, thoracoabdominal patt erns of breathing were also measured before both LFTs. After LAPC, VT did not change. There was no significant shift from abdominal to thora cic respiration. No paradoxical respiration developed. Functional resi dual capacity (FRC) and residual volume (RV) remained normal. However, all measures of LFTs requiring maximum inspiratory effort decreased u p to 20%. Tonic and phasic activity of the abdominal muscle appeared e arly in the recovery period and disappeared after 75 min. The diaphrag m adjusted to this additional load so that VT remained constant. These results indicate that diaphragm function is intact during quiet breat hing after LAPC, but slightly reduced when maximum effort is needed. H owever, this represents a net gain over the changes previously describ ed after classic ''open'' cholecystectomy (OC).