Predicting Postoperative Pulmonary Complications: The Sleeping Giant Stirs

• Postoperative complications
• Risk assessment
• Pneumonia
• Smoking
• Lung diseases, obstructive
• Health status indicators

Since the seminal article in 1977 about risk prediction of postoperative medical complications, the bulk of published research in this field has focused on cardiac complications (1, 2). Yet, mounting evidence indicates that pulmonary complications are as clinically important as cardiac complications in frequency, mortality, and length of hospital stay after various surgeries (2–4). With publication in this issue of the study by Arozullah and colleagues (5), the sleeping giant of risk prediction for postoperative pulmonary complications stirs.

To develop a risk index for predicting postoperative pneumonia, the investigators used data from the prospective cohort study of the Veterans Affairs National Surgical Quality Improvement Program (NSQIP) (6). The primary aim of the NSQIP was to develop models to adjust for severity of patients' preoperative risk when assessing surgical quality of care, as determined by postoperative mortality and morbidity rates. Research nurses gathered data from diverse “medical record” sources (such as chart, computerized laboratory reports, operative report, anesthesia log, and discussion with care providers) and assessed patients directly only by telephone or letter 30 days after surgery. Primary outcome measures of the NSQIP were all-cause mortality and major postoperative complications within 30 days of surgery. Procedures associated with all types of anesthesia were included, and transplantations and operations with very low mortality rates were excluded. In addition, investigators limited eligible operations from high-volume centers to balance the data set with low-volume centers (6).

Arozullah and colleagues retrospectively used this ongoing Veterans Affairs database to assess incidence and determine predictors of postoperative pneumonia after noncardiac operations (5). The investigators further excluded patients who were ventilator dependent or had pneumonia before surgery, as well as those who had postoperative respiratory failure or unplanned intubation before pneumonia was diagnosed. Of note, Arozullah and colleagues reported separately on incidence …