A 60-year-old man is evaluated for a right lung mass, which was discovered on a chest x-ray performed one month ago due to persistent cough. He has had no chest pain, dyspnea, or hemoptysis. The patient has no other medical conditions and takes no medications. He is an ex-smoker with a 20-pack-year history. Physical examination shows clear lungs, normal heart sounds, and no lymphadenopathy or abdominal organomegaly. CT scan shows a 4-cm mass in the right oblique fissure with no enlarged lymph nodes. Bronchoscopy-guided biopsy reveals squamous cell carcinoma. A subsequent PET scan shows no metastatic lesions, and a right pneumonectomy is planned. Which of the following is likely to provide the best assessment of postoperative pulmonary morbidity in this patient?

Question

A 60-year-old man is evaluated for a right lung mass, which was discovered on a chest x-ray performed one month ago due to persistent cough.  He has had no chest pain, dyspnea, or hemoptysis.  The patient has no other medical conditions and takes no medications.  He is an ex-smoker with a 20-pack-year history.  Physical examination shows clear lungs, normal heart sounds, and no lymphadenopathy or abdominal organomegaly.  CT scan shows a 4-cm mass in the right oblique fissure with no enlarged lymph nodes.  Bronchoscopy-guided biopsy reveals squamous cell carcinoma.  A subsequent PET scan shows no metastatic lesions, and a right pneumonectomy is planned.  Which of the following is likely to provide the best assessment of postoperative pulmonary morbidity in this patient?

Quizplus · Accepted Answer

Indications for lung resection include malignancy, severe chronic obstructive pulmonary disease (COPD), and persistent infection despite medical treatment. An important consideration prior to lung resection is whether the patient has enough pulmonary reserve to maintain adequate lung function following surgery. FEV1 and diffusion capacity of the lung for carbon monoxide (DLCO), obtained by preoperative pulmonary function testing, are the best predictors of postoperative outcomes following lung resection surgery. Based on preoperative FEV1 and DLCO measurements, the percentage of planned lung resection (eg, approximately 50% in unilateral pneumonectomy) is used to estimate postoperative FEV1 and DLCO. Patients with an estimated postoperative FEV1 or DLCO of <40% are at elevated risk of postoperative morbidity. (Choice A) End-tidal CO₂ measurement (capnography) is indicative of aerobic metabolism and can be used to monitor correct endotracheal tube placement or to measure the effectiveness of cardiopulmonary resuscitation. (Choice C) Maximal inspiratory pressure (or negative inspiratory force) is a measurement of inspiratory muscle strength. It is often used to monitor patients with hypoventilation due to neuromuscular disease (eg, myasthenia gravis, Guillain-Barré syndrome) and help assess the need for mechanical ventilation. (Choice D) Measurement of oxygen saturation during exercise is used to evaluate the need for home supplemental oxygen therapy in patients with COPD. (Choice E) The ratio of residual volume to total lung capacity increases in patients with COPD due to air trapping and lung hyperinflation; a high ratio correlates with poorer overall outcomes in patients with COPD, but it is not predictive of postoperative outcomes following lung resection. Educational objective: FEV1 and diffusion capacity of the lung for carbon monoxide (DLCO) are the best predictors of postoperative outcomes following lung resection surgery. References: Brunelli A, Kim AW, Berger KI, Addrizzo-Harris DJ. Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/23649437)

A 60-Year-Old Man Is Evaluated for a Right Lung Mass