Comparison of Three Methods of Respiratory

pulmonary complications continue to be vexing problems during the postoperative period in patients undergoing major surgery. Using abdominal distention, pulmonary signs, and purulent sputum as criteria, Wightman’ reported an incidence of 21 percent for serious pulmonary complications in a prospective survey of patients undergoing surgery. Employing the same criteria together with abnormal chest roentgenograms, Lazlo et al2 described an incidence of 80 percent in a similar group of patients. Methods used to prevent these complications have been both diverse and innovative. Techniques such as inhalation of carbon dioxide, resistance breathing through blow bottles,6 percutaneous tracheal cannulation,7 and intermittent positive-pressure breathing (IPPB )8 have been employed. Their popularity has waxed and waned, while their success in reducing the incidence of these pulmonary problems has been, at best, questionable.9.’#{176} More recently, sustained maximal inhalations, using the technique of incentive spirometry,’#{176}” have achieved considerable popularity. This is reflected in the development of a variety of different incentive spirometers varying in their complexity and cost. Not only have uniform standards of usage not been established for this technique, but its usefulness as a superior method for preventing pulmonary complications has not been conclusively documented.’2 Since pulmonary complications have continued to