Twenty patients having laparoscopic cholecystectomies were studied for
changes in thoracic and lung compliance at 5, 10 and 15 mmHg of intra
-abdominal pressure. Fifteen mmHg of intra-abdominal pressure decrease
d the thoracic and the lung static compliance by 49 and 39% respective
ly. This was unaffected by the degree of head elevation. During the pr
ocedure the end-tidal carbon dioxide increased by a mean of 1.6 kPa at
1 h and 2.0 kPa at 2 h. This did not appear to be related to either t
he mean intra-abdominal pressure or the total volume of carbon dioxide
insufflated. The physiological changes and implications for anaesthet
ic practice are considered.