Diaphragmatic activity after laparoscopic cholecystectomy

Abstract

Background: Laparoscopic cholecystectomy is presumed to induce a reduction in diaphragmatic activity. Indirect indices of diaphragmatic function based on tidal changes in pressures and cross-section area measurements can be unreliable in the postoperative phase. The present study evaluates diaphragmatic activity by directly recording diaphragmatic EMG (EMG(dia)) data, along with indirect indices. Methods: Thirteen adult patients (American Society of Anesthesiologists physical status I or II) undergoing laparoscopic cholecystectomy were examined preoperatively for inspiratory tidal changes in gastric (P(gas-insp)) and esophageal (P(eso- insp)) pressures, and tidal changes in ribcage (V(thor)) and abdominal (V(abd)) cross-section areas and then again at 1, 6, and 24 h postoperatively combined with EMG(dia) recordings. Variations in inspiratory gastric (ΔP(gas-insp)) and inspiratory transdiaphragmatic (ΔP(di-insp) pressures were derived from the above. Results: Laparoscopic cholecystectomy induced a significant reduction in mean ΔP(gas-insp), mean ΔP(di-insp), and mean V(abd) indicating a reduction of diaphragmatic activity postoperatively. ΔP(di-insp) decreased from 11.8 ± 4.0 cm H2O preoperatively to 5.7 ± 5.7 cm H2O at 1 h and 6.6 ± 5.1 cm H2O at 6 h postoperatively (mean ± SD; P < 0.05). V(abd) decreased from 327.0 ± 113.0 ml preoperatively to 174.0 ± 65.0 ml at 1 h and 175.0 ± 98.0 ml at 6 h postoperatively (mean ± SD; P < 0.05). These values had partially recovered at 24 h. Conclusion: The direct and indirect indices of diaphragmatic activity taken together confirm the presence of reduction in diaphragmatic activity after laparoscopic cholecystectomy followed by its partial recovery at 24 h.