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Key Clinical Questions

imageWhat risk factors predict postoperative pulmonary complications?

imageWhat role does diagnostic testing play in the evaluation of perioperative pulmonary risk?

imageWhat objective tools are available for performing a preoperative pulmonary risk assessment?

imageWhat strategies are effective to reduce and manage postoperative pulmonary risk?

A comprehensive preoperative evaluation must include assessment of the risk of postoperative pulmonary complications. While few would argue this point, pulmonary risk is often underappreciated as clinicians typically focus the majority of their energy on the preoperative cardiac evaluation and preventing venous thromboembolic complications. Highlighting the risk of this approach, postoperative respiratory problems occur with similar frequency and greater morbidity than cardiovascular complications.

Pulmonary complications following anesthesia and surgery result from central nervous system suppression and altered respiratory dynamics. Administration of sedating agents and neuromuscular blockade exposes the patient to the risk of aspiration. Furthermore, regardless of the type of anesthetic technique utilized, patients will experience a reduction in lung volumes perioperatively. Reduction in lung volumes is the primary mechanism that may lead to atelectasis and predispose a patient to the additional complications of pneumonia and respiratory failure. This reduction in lung volumes is greatest for patients undergoing thoracic and upper abdominal surgery. Table 51-1 lists specific postoperative pulmonary complications and diagnostic considerations for each.

TABLE 51-1Common Postoperative Pulmonary Complications


Clinicians intuitively recognize several risk factors for pulmonary complications, but some predictors of postoperative respiratory problems are not obvious. Additionally, clinicians may struggle with the appropriate utilization of preoperative pulmonary diagnostic testing. Recently published risk indices and practice guidelines provide valuable assistance in the identification of risk factors and the performance of evidence-based preoperative evaluation.


Several different patient characteristics increase postoperative pulmonary risk (Table 51-2). While most of these patient-specific factors are nonmodifiable, their identification is important for providing patients, surgeons and anesthesiologists with an accurate assessment of perioperative risk and to identify patients for whom one should employ risk reduction strategies.

TABLE 51-2Patient-Specific Risk Factors for Postoperative Pulmonary Complications

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