[Does insufflation of the abdomen in laparoscopic surgery affect acid-base and ventilatory parameters?]

The cardiopulmonary and metabolic changes experienced by patients undergoing laparoscopic cholecystectomy with CO2 pneumoperitoneum are not well understood. The purpose of this study is to determine changes of basal parameters during laparoscopy and evaluate their prognostic value. One hundred patients (26 obese, 39 older than 60 years, 7 obese and older than 60) undergoing laparoscopic cholecystectomy for uncomplicated cholecystolithiasis were included in the study. Arterial blood gases, respiratory and ventilatory parameters, heart rate, blood pressure were determined before the induction of pneumoperitoneum, at the peak of operation and after exsufflation. The obtained variables were statistically evaluated. Pneumoperitoneum caused significant hypercapnia and a decrease of pH accompanied with increase of expiratory CO2 concentration, which continued after exsufflation (p < 0.001). The changes were more expressed in older and obese patients and were solely of a respiratory type. No significant changes were observed in the heart rate, blood pressure, minute ventilation, PaO2, SaO2, base excess. Although changes were highly significant, there was no impact on clinical status--all patients survived without problems. The authors conclude that observed increase of carbon dioxide levels and decrease of pH had no impact on survival of patients. Changes were caused mostly by CO2 absorption from the abdominal cavity. Laparoscopic cholecystectomy is a safe and effective procedure even in older and obese patients, especially when insufflation is as low as possible.