Respiratory Changes

The head-down position facilitates the development of atelectasis (see Chapter 28 ). Steep head-down tilt results in decreased functional residual capacity, total lung volume, and pulmonary compliance. These changes are more marked in obese, elderly, or debilitated patients. In healthy patients, no major changes are seen.^[39] The head-up position is usually considered to be more favorable to respiration. ^{[39] [158]} Changes in patient position during laparoscopy induce only minimal alterations in gas exchange ^{[20] [23]} and thoracopulmonary compliance.^[14]