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  • In the American College of

    2019-04-15

    In 2013, the American College of Chest Physicians provided a guideline to the preoperative physiological assessment of patients being considered for surgical resection of lung cancer. It has been recommended that patients must be assessed by a multidisciplinary team before operation, regardless of age. During the preoperative period, optimal medical care for patients who have chronic respiratory disease should include smoking cessation, optimal pharmacologic and oxygen therapy when indicated, and prompt treatment of exacerbations. Patients with lung cancer are predisposed to atherosclerotic cardiovascular disease because of cigarette smoking, and the prevalence of underlying coronary artery disease is about 11–17%. The risk of major postoperative cardiac complications, including myocardial ischemia, pulmonary edema, ventricular fibrillation or primary cardiac arrest and cardiac-related death, is about 2–3% following lung resection. As a consequence, a preoperative cardiovascular risk assessment should be first performed. The Thoracic Revised Cardiac Risk Index (ThRCRI) is the preferred risk scoring tool to assess cardiac risk in patients undergoing noncardiac surgical procedures. The risk score was based on weight values of high-risk surgery as follows (including lobectomy or pneumonectomy): 1.5 points; previous ischemic SNDX275 manufacturer disease: 1.5 points; previous stroke or transient ischemic attack: 1.5 points; and serum creatinine ≥ 2 mg/dL: 1 point. Patients with ThRCRI ≥2 or any cardiac condition requiring medication or a newly suspected cardiac condition or limited exercise tolerance (inability to climb two flights of stairs) should be referred for a cardiac consultation and noninvasive testing, and the treatment results should be noted in these patients (Fig. 1). The next step is to assess FEV1 and DLCO. The Predicted PostOperative (ppo) lung functions should be calculated by the operation methods. For pneumonectomy candidates, ventilation/perfusion scan (V/Q scan) method was suggested to calculate the ppo values of FEV1 or DLCO (ppo values = preoperative values × (1 − fraction of total perfusion for the resected lung), where the preoperative values are taken as the best measured postbronchodilator values. For lobectomy patients, ppo values of FEV1 or DLCO was calculated by segmental counting (ppo values = preoperative values × (1 – y/z), where the preoperative values are taken as the best measured postbronchodilator value, y is the number of functional or unobstructed lung segments to be removed and z is the total number of functional segments. If both the percent of ppoFEV1 and ppoDLCO values are greater than 60%, the patient is considered to be at low risk. This indicates that the expected risk of mortality is below 1% for perioperative death and cardiopulmonary complications following resection, and major anatomic resections including pneumonectomy can be safely performed. No further tests are required in this group. If either the percent ppoFEV1 or the percent of ppoDLCO are within 30–60% of predicted values, a low technology exercise test (e.g. stair climb test or shuttle walk test) should be performed. If either stair climbing test is greater than 22 m or shuttle walk distance greater than 400 m, patients are regarded as at low risk of anatomic resection. A formal cardiopulmonary exercise test is indicated when the percent of ppoFEV1 or ppoDLCO <30%, or when the performance of the stair-climbing test or the shuttle walk test is not satisfactory. On the other hand, VO2 max >20 mL/kg/min or at 75% indicates a low risk. If VO2 max is between 10 and 20 mL/kg/min or 35–75%, the patients will be considered moderate risk which implies that the morbidity and mortality rates may vary according to the values of split lung functions, exercise tolerance and extent of resection. The risks and benefits of the operation should be thoroughly discussed with the patient. The actual risks are affected by patient factors (comorbidities, age), structural aspects (center volume, specialization), process factors (management of complications) and surgical access (thoracotomy vs. minimally invasive). Conversely, VO2 max <10 mL/kg/min or 35% predicted indicates a high risk of mortality which may be higher than 10%. This will cause considerable risk of severe cardiopulmonary morbidity and residual functional loss. At this point, patients should be advised about alternative surgical (minor resections or minimally invasive surgery) or nonsurgical options. For patients who are considered for surgery but have a high risk outcome, a preoperative or postoperative pulmonary rehabilitation is recommended. In patients with lung cancer being considered for surgery who undergo neoadjuvant therapy, it is suggested that repeated pulmonary functional testing with diffusion capacity be performed after completion of neoadjuvant therapy.