Introduction

Postoperative pulmonary complications are defined as pulmonary abnormalities occurring in the postoperative period that produce clinically significant identifiable disease or dysfunction that adversely affects the clinical course [1]. The definition includes pneumonia, atelectasis, respiratory failure, pulmonary embolism, pleural effusion, pneumothorax, pulmonary edema, and hypoxemia. These problems complicate approximately 2–3% of all surgeries varying with the invasiveness of the procedure and the presence of patient-related risk factors [2]. Pulmonary complications are described in 19–59% of thoracic procedures, 16–17% of upper abdominal surgeries, but only 0–5% of lower abdominal procedures [1]. They are most commonly seen in the first week after surgery, especially in the first 24–72 postoperative hours and can be particularly problematic because attention may be relaxed after transfer from a post-anesthesia care unit.

Taken together, they are the most expensive form of postoperative complication, are more common than postoperative cardiac complications, lead to longer hospital stays, and increase the relative risk of death to 14.9 (95% confidence limits 4.76–26.9) particularly from pneumonia [3]. They may cause as much as 84% of postoperative thoracotomy deaths [1].