Preoperative identification and evaluation of the patient with lung disease.

Preoperative pulmonary function evaluation begins with the bedside, clinical identification of the presence of significant lung disease. Once a patient is so identified, preoperative pulmonary-function studies are indicated. The optimal screening studies for most patients are spirometry and arterial blood gas analysis. Patients who are identified as having marginal function by screening techniques should be studied further by more specialized studies, including radioisotopic evaluation of regional lung function. If a patient is identified as an operative candidate, but one who has increased risk of postoperative morbidity, prophylactic measures should be instituted to reduce postoperative complications. The essence of such measures is increased care preoperatively, intraoperatively, and postoperatively. The use of preoperative evaluation of pulmonary function presents a different magnitude of problem in defining the risk of morbidity in contrast to that of mortality. Available data provide a firm basis for the identification of the patient at increased risk of morbidity. After 23 years and dozens of spirometric studies involving thousands of patients, it is apparent that there is no spirometric number, percentage, or category that will absolutely separate the operable from the inoperable patient. There are estimates of risk--guidelines, to be sure--but no absolutes. The patient whose lung function would have been considered to prohibit lung resection in the 1950s has been successfully operated on in the 1980s. In dealing with the risk of mortality, the physician should always bear in mind that, although statistics apply to groups, they often do not apply to individual patients.