The goal of a preoperative evaluation of patients with pulmonary disease is to decrease the occurrence of postoperative pulmonary complications (Table 47-1). A reasonable stepwise approach to preoperative pulmonary assessment is necessary to achieve these goals (Figure 47-1).
TABLE 47-1Common Postoperative Pulmonary Complications ||Download (.pdf) TABLE 47-1 Common Postoperative Pulmonary Complications
|General complications ||Specific cardiothoracic surgical complications |
Exacerbation of COPD
Prolonged invasive or noninvasive ventilation
Phrenic nerve injury
Gastroesophageal anastomotic leak
Stepwise approach to preoperative pulmonary assessment. (Reproduced with permission from Bapoje SR, Whitaker JF, Schulz T, Chu ES, Albert RK. Preoperative evaluation of the patient with pulmonary disease. Chest. 2007;132(5):1637–1645.)
Prior to elective surgery, a thorough study of the medical history and physical health of the patient should be performed focusing on smoking history, exercise tolerance, pre-existing lung disease, recent respiratory infections, and occupational exposures to allergens or toxins. There are several preoperative and intraoperative risk factors for these complications (Table 47-2). An appropriate cardiovascular evaluation should also be performed.
TABLE 47-2Risk Factors for Postoperative Pulmonary Complications ||Download (.pdf) TABLE 47-2 Risk Factors for Postoperative Pulmonary Complications
|Preoperative risk factors ||Intraoperative risk factors |
Age > 65 years
History of smoking
NYHA class II pulmonary hypertension
Poor nutritional status
Poor exercise tolerance
Recent respiratory infection
Low albumin < 3.5 g/dL
Long duration of surgery (>3.5–4 h)
Site of surgery
Use of long-acting neuromuscular blockers
Recent studies have not showed an increased risk of postoperative pulmonary complications due to asthma. Patients with pulmonary hypertension (right ventricular systolic pressure greater than 35 mmHg) and a New York Heart Association functional class greater than 2 have an increased risk of postoperative congestive heart failure, cardiac ischemia, arrhythmias, stroke, respiratory failure, hepatic dysfunction, renal dysfunction, or the need for vasopressor or inotropic support.
Surgical site is an important predictor of postoperative pulmonary complications. The incidence of complications increases as the surgical incision site approaches the diaphragm. Complication rates highest in upper abdominal and thoracic surgeries.
The American Society of Anesthesiology (ASA) physical status classification can also assist with risk stratification. The rate of pulmonary complications increases with each ASA physical status (I 1.2%, II 5.4%, III 11.4%, IV 10.9%).
COMPONENTS OF PREOPERATIVE PULMONARY ASSESSMENT
Guidelines issued by the American College of Physicians state that pulmonary function testing (PFT) should be performed as part of a preoperative pulmonary assessment in patients with the following: