Intermittent positive pressure breathing (IPPB) versus incentive spirometer (IS) therapy in the postoperative period.

The increase of the inflationary lung volume created by a respiratory maneuver is critical for preventing postoperative alveolar collapse. We measured this volume as achieved with IPPB or incentive spirometry (IS) in 20 postoperative surgical patients. Using IPPB, with gas flow and peak airway pressures carefully adjusted for each patient, a value of 2240 +/- 630 cc (mean +/- 1 SD) was obtained compared to 1960 +/- 650 cc with IS. This difference is highly significant (p less than 0.0005 by the Wilcoxon test). We conclude that IPPB, by careful application, and with monitoring of tidal volumes, is likely to provide better prophylaxis of postoperative pulmonary complications, particularly in patients with compromised lung function and in an intensive care unit, where enough trained personel are available.