Lung function after open versus laparoscopic cholecystectomy

Postoperative lung function and gas exchange were studied in 36 patients after cholecystectomy. Twenty-four of the patients underwent laparoscopic cholecystectomy while the remaining twelve were operated with open technique. Before surgery all patients had normal ventilatory volumes (forced vital capacity, FVC and forced expired volume in 1 s, FEV₁) and normal gas exchange. Two hours postoperativley FVC was reduced to 64±16% (P<0.05) of the preoperative level in the laparoscopic group and to 45±23% (P<0.05) after open cholecystecomy. On the first postoperative day FVC was virtually normal in the laparoscopic patients (77±17% of preoperative level, NS), whereas the open surgery patients still had a decreased FVC (56±13% of preoperative, P<0.05). FEV₁ in the postoperative period followed the same course as FVC. Gas exchange was significantly impaired in the early postoperative period in all patients but no difference between the two groups was found. Two hours postoperatively Pao₂ was reduced to 85% (P<0.05) of preoperative value and Paco₂ had increased by 0.5 kPa (p<0.05). The alveolo-arterial oxygen tension difference (PA-ao₂) had increased by approximately 45% to a mean of 3.7 kPa (P<0.05). On the first postoperative day gas exchange was still significantly impaired in the open surgery patients. Atelectasis detected by computed X-ray tomography of the lungs were found in both groups. However, the amount of atelectasis tended to be smaller in the laparoscopic group than in the open surgery patients. In summary, cholecystectomy irrespective of whether it was performed by open or laparoscopic technique was followed by deterioration in ventilatory function and gas exchange. However, the magnitude of this impairment was less pronounced in laparoscopic cholecystectomy patients than in the open surgery patients which may suggest that this minimal invasive procedure is favourable with respect to postoperative lung function.