Abstract
Pneumonectomy has the highest perioperative risk among pulmonary resections. Postoperative mortality can be as high as 12% in elective cases, increasing up to 30% in emergent situations. Existing comorbidities and advanced age are common in the patient population undergoing these procedures. Potentially serious and sometimes life-threatening pulmonary and cardiac complications are not uncommon. Here we present a typical case and then review the prevention and management of various postoperative complications.
Keywords
arrhythmias, cardiovascular, complications, pneumonectomy, pulmonary, respiratory
Case Synopsis
A 72-year-old man is scheduled for a right-sided pneumonectomy for non–small-cell lung cancer. He has a past medical history of long-standing smoking, diabetes mellitus, and hypertension. He has a remote history of non–Q-wave myocardial infarction with a coronary artery stent placed in his left anterior descending artery. He had a nuclear medicine stress test performed 1 year previously that was negative for myocardial ischemia. His medications include aspirin, simvastatin, and metoprolol.
His surgical course is uncomplicated and includes a combined general anesthetic–thoracic epidural technique with a standard posterolateral chest incision. There is minimal blood loss, and he receives limited intraoperative and postoperative fluid. The chest tube is removed on postoperative day 1. On postoperative day 3, the patient has increasing dyspnea, and a chest radiograph shows that the left lung has diffuse bilateral pulmonary infiltrates, in keeping with pulmonary edema. Because of progressive respiratory distress, he is intubated, and mechanical ventilation is commenced. The patient’s oxygen saturation remains between 90% and 94% on 100% oxygen, 10 cm H 2 O positive end-expiratory pressure, and optimal ventilator settings. A pulmonary artery catheter is judiciously inserted, and appropriate placement is confirmed by chest radiograph. The cardiac output and wedge pressure are low, there is moderate pulmonary artery hypertension and a transpulmonary gradient, and the right atrial pressure is elevated. A transesophageal echocardiogram shows mild right ventricular and right atrial dilation, with no demonstrable intracardiac shunt. A diagnostic bronchoalveolar lavage is performed and is negative for inflammatory cells or organisms (subsequent cultures are negative). A diagnosis of postpneumonectomy pulmonary edema, complicated by right ventricular dysfunction, is made. Supportive therapy includes diuresis, lung-protective ventilatory support, low-dose dobutamine, steroids, and inhaled prostacyclin (for increased pulmonary artery pressure and refractory hypoxemia). On postoperative day 5, hemodynamically unstable atrial fibrillation develops, and the patient is cardioverted. An amiodarone infusion is commenced. The patient’s troponin level increases to 1.1 ng/mL. He is fully heparinized, and β-blockade is intensified. After 14 days of supportive therapy, including an early tracheostomy, he is successfully weaned from mechanical ventilation. After discharge from the intensive care unit, an angiogram shows stable coronary artery disease.
Problem Analysis
Definition and Recognition
Pneumonectomy is one of the surgical curative options for non–small-cell lung cancer. It is most frequently performed for bronchogenic carcinoma involving the hilum, and is part of a multimodal treatment approach combined with chemotherapy and radiotherapy. It is rarely performed for inflammatory lung disease, traumatic lung injury, congenital lung disease, and irreversible atelectatic conditions. If pneumonectomy is considered for a centrally located lesion, a parenchymal-sparing sleeve lobectomy may have some benefit. Although it is technically a more complex operation, there may be some advantages such as preserved pulmonary function, avoidance of postpneumonectomy complications, and improved patient quality of life.
Extrapleural pneumonectomy (EPP) is typically done for local control of malignant pleural mesothelioma. In addition to a pneumonectomy, an EPP operation requires an en bloc resection of lung, pleura, pericardium, and diaphragm.
Pneumonectomy is a major operation that results in changes in anatomy and cardiopulmonary physiology. Potentially serious and sometimes life-threatening postpneumonectomy pulmonary, cardiovascular, or other complications are relatively frequent. These are summarized in Box 43.1 .
Pulmonary
Hypoxemia
Postoperative respiratory failure
Pneumonia
Acute lung injury
Chronic pulmonary debility or deficiency
Postpneumonectomy pulmonary edema
Postpneumonectomy syndrome
Bronchopleural fistula
Pulmonary embolism
Empyema
Esophagopleural fistula
Hemothorax
Chylothorax
Contralateral pneumothorax
Pneumomediastinum
Mediastinal infection (mediastinitis)
Vocal cord paralysis
Atelectasis
Cardiovascular
Supraventricular tachyarrhythmias
Sustained ventricular tachycardia/fibrillation
Nonsustained ventricular tachycardia
Bradyarrhythmias
Myocardial infarction
Intracardiac shunt
Cardiac tamponade or herniation
Pneumopericardium
Miscellaneous
Postpneumonectomy paralysis
Postpneumonectomy scoliosis
Difficulty interpreting pulmonary artery catheter data
Wound infection
Deep vein thrombosis
Renal failure
Risk Assessment
Many postoperative complications can be minimized by appropriate patient selection. A thorough assessment of the patient’s respiratory mechanics (forced expiratory volume over 1 second [FEV 1 ]), cardiopulmonary reserve (maximum oxygen uptake [VO 2 max]), and lung parenchymal function (diffusing capacity of the lung for carbon monoxide [DLCO] and arterial blood gas analysis) is required ( Fig. 43.1 ). Predicted postoperative DLCO is the strongest predictor of increased operative mortality and respiratory morbidity. Evaluation of and optimal therapy for any coexisting diseases or conditions, including obesity, cigarette smoking, reversible lung disease, and coronary artery disease, is also important.
Mortality
Right-sided pneumonectomy is associated with a greater mortality rate compared with left-sided pneumonectomy (10%–12% vs. 1%–3.5%). The indication for pneumonectomy may affect outcome; for example, pneumonectomy for lung cancer has a mortality rate of 3% to 4%, whereas that performed for benign disease may be as high as 26%. Emergent pneumonectomy in cases of trauma or massive hemoptysis is associated with mortality rates greater than 30%. Also, pneumonectomy performed by thoracic surgeons has a lower mortality than that performed by general surgeons. Associated lung disease, history of coronary artery disease, history of congestive heart failure, hypertension, atrial fibrillation, cerebrovascular accident, cigarette smoking, and a 10% or greater weight loss over the 6-month period before surgery all contribute to higher mortality risk.
Postoperative Pulmonary and Cardiac Function
Multiple studies have looked at postoperative changes in pulmonary and cardiac function after pneumonectomy. These are summarized in Box 43.2 .
Pulmonary
Decreased lung volumes (<50%)
Decreased FEV 1 and FVC (<50%)
Annual decrease in FEV 1 by 3–4 mL/yr
Decreased DLCO (<50%)
Decreased lung compliance
Increased airway resistance
Increased or decreased deadspace
Little or no change in P o 2 and P co 2
Cardiovascular
Decrease in right ventricular ejection fraction
Increase in right ventricular end-diastolic volume
Transient increase in pulmonary systolic pressures
Increase in right atrial pressures
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