Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: ACCP evidenced-based clinical practice guidelines (2nd edition)
Background: This section of the guidelines is intended to provide an evidence-based approach to the preoperative physiologic assessment of a patient being considered for surgical resection of lung cancer. Methods: Current guidelines and medical literature applicable to this issue were identified by computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee. Results: The preoperative physiologic assessment should begin with a cardiovascular evaluation and spirometry to measure the FEV1. If diffuse parenchymal lung disease is evident on radiographic studies or if there is dyspnea on exertion that is clinically out of proportion to the FEV 1, the diffusing capacity of the lung for carbon monoxide (DLCO) should also be measured. In patients with either an FEV1 or DLCO < 80% predicted, the likely postoperative pulmonary reserve should be estimated by either the perfusion scan method for pneumonectomy or the anatomic method, based on counting the number of segments to be removed, for lobectomy. An estimated postoperative FEV1 or DLCO < 40% predicted indicates an increased risk for perioperative complications, including death, from a standard lung cancer resection (lobectomy or greater removal of lung tissue). Cardiopulmonary exercise testing (CPET) to measure maximal oxygen consumption (V̇O2max) should be performed to further define the perioperative risk of surgery; a V̇O2max of < 15 mL/kg/min indicates an increased risk of perioperative complications. Alternative types of exercise testing, such as stair climbing, the shuttle walk, and the 6-min walk, should be considered if CPET is not available. Although often not performed in a standardized manner, patients who cannot climb one flight of stairs are expected to have a V̇O2max of < 10 mL/kg/min. Data on the shuttle walk and 6-min walk are limited, but patients who cannot complete 25 shuttles on two occasions will likely have a V̇O2max of < 10 mL/kg/min. Desaturation during an exercise test has not clearly been associated with an increased risk for perioperative complications. Lung volume reduction surgery (LVRS) improves survival in selected patients with severe emphysema. Accumulating experience suggests that patients with extremely poor lung function who are deemed inoperable by conventional criteria might tolerate combined LVRS and curative-intent resection of lung cancer with an acceptable mortality rate and good postoperative outcomes. Combining LVRS and lung cancer resection should be considered in patients with a cancer in an area of upper lobe emphysema, an FEV1 of > 20% predicted, and a DLCO of > 20% predicted. Conclusions: A careful preoperative physiologic assessment will be useful to identify those patients who are at increased risk with standard lung cancer resection and to enable an informed decision by the patient about the appropriate therapeutic approach to treating their lung cancer. This preoperative risk assessment must be placed in the context that surgery for early-stage lung cancer is the most effective currently available treatment for this disease.