Chapter 11. Evaluation of the Patient with Pulmonary Disease

1. Postoperative pulmonary complications are a significant source of morbidity, mortality, and excess costs in modern anesthesia practice.

2. Pulmonary disease is the predominant patient-related risk factor for postoperative pulmonary complications, with other factors including age, general health status, and cigarette smoking. The predominant procedural risk factor is the site of surgery, with thoracic and upper abdominal surgery associated with the highest risk.

3. Routine screening or other testing for pulmonary function is not indicated. Rather, testing should be used to make an initial diagnosis in a patient with previously undiagnosed pulmonary disease, to monitor the status of patients with respiratory disease, or to assist with postoperative management.

4. Once pulmonary disease has been identified, it should be optimally treated before surgery. For example, patients with reactive airway disease may require adjustment of bronchodilator and corticosteroid therapy if their airway reactivity is not under optimal control.

5. The perioperative period is an excellent opportunity to provide tobacco interventions in patients who smoke cigarettes.

6. Useful intraoperative techniques to decrease the incidence of postoperative pulmonary complications include prophylaxis to minimize bronchospasm, rational use of neuromuscular blocking agents, and limiting tidal volumes during mechanical ventilation.

7. Postoperatively, therapies that promote lung expansion may reduce the risk of pulmonary complications.

Postoperative pulmonary complications can range from atelectasis to exacerbation of underlying chronic lung disease to respiratory failure. They remain a significant source of morbidity in modern practice, occurring in up to 25% of surgical patients1 and significantly prolonging the length of hospital stay.2,3 They are also among the most costly postoperative complications; for example, one study found that the median incremental hospital cost for postoperative pulmonary complications was $52,466 versus $7789 for cardiovascular complications.4 The goal of this chapter is to provide the anesthesiologist with a framework to (1) identify which patients are at an increased risk for postoperative pulmonary complications, with an emphasis on the role of preexisting pulmonary diseases, (2) understand the underlying pathophysiology of pulmonary diseases that can impact perioperative management, (3) optimize medical management of patients with pulmonary disease prior to surgery, and (4) plan the perioperative management of patients with pulmonary disease to optimize their outcome.

The definition of pulmonary complications varies widely. This variation makes comparisons of reported incidences and risk factors problematic among studies. Although nonspecific definitions such as cough or an abnormal lung examination or changes on a chest radiograph5,6 have been utilized, a more useful definition of a postoperative pulmonary complication is a pulmonary abnormality that significantly affects the clinical course. Examples of clinically relevant pulmonary complications include bronchospasm requiring therapy, pulmonary infections such as pneumonia, and respiratory failure requiring mechanical ventilatory support. Patient risk factors for pulmonary complications are listed in Table 11-1