Age Risk Factor
Healthy older patients still carry a substantial risk of pulmonary complications after surgery. This is in sharp contrast to perioperative cardiac risk.

Smetana, G. W., Lawrence, V. A., & Cornell, J. E. (2006). Preoperative pulmonary risk stratification for noncardiothoracic surgery: systematic review for the American College of Physicians. Annals Of Internal Medicine, 144(8), 581-595.