Changes in breathing control and mechanics after laparoscopic vs open cholecystectomy

Hypothesis: We hypothesized that there might be different effects on breathing control and respiratory mechanics after laparoscopic vs open cholecystectomy. Design: Randomized clinical trial. Settings: A general hospital in Greece. Patients: Of 53 patients assessed for eligibility, 18 and 10 were randomly allocated to the laparoscopic and open cholecystectomy groups, respectively. These 28 patients had normal spirometry measurements and American Society of Anesthesiologists' class I physical status. Main Outcome Measures: Measurements of breathing control and mechanics variables. Tidal volume, inspiratory time, breathing frequency, mean inspiratory flow, duty cycle, central respiratory drive, and mean inspiratory impedance were recorded before surgery on the second and eighth postoperative days. Airway resistance was recorded before surgery and on the eighth post-operative day, with all measurements being performed under no influence of analgesia. Results: Two days after surgery, inspiratory time, breathing frequency, and central respiratory drive were significantly changed compared with preoperative values for both methods, whereas mean inspiratory impedance was significantly increased (P<.001) for the laparoscopic procedure. Eight days after surgery, changes were seen only for the laparoscopic group: duty cycle and airway resistance were significantly reduced (P=.01) and increased (P=.04), respectively, compared with preoperative data. Conclusion: Laparoscopic cholecystectomy seems to be associated with small but sustained alterations in the control of breathing and mechanics, which might have an unfavorable clinical impact on patients with compromised lung function.