Adjustments in cardiorespiratory function after pneumonectomy: Results of the pneumonectomy project

Abstract

To assess lung function, gas exchange, exercise capacity, and right-sided heart hemodynamics, including pulmonary artery pressure, in patients long term after pneumonectomy. Among 523 consecutive patients who underwent pneumonectomy for lung cancer between January 1992 and September 2001, 117 were alive in 2006 and 100 were included in the study. During a 1-day period, each patient had complete medical history, chest radiographs, pulmonary function studies, resting arterial blood gas analysis, 6-minute walk test, and Doppler echocardiography. Most patients (N = 73) had no or only minimal dyspnea. On the basis of predicted values, functional losses in forced expiratory volume in 1 second and forced vital capacity were 38% ± 18% and 31% ± 24%, respectively, and carbon monoxide diffusing capacity decreased by 31% ± 18%. There was a significant correlation between preoperative and postoperative forced expiratory volume in 1 second (P < .01), and more hyperinflation was associated with better lung function (P < .01 for forced expiratory volume in 1 second). Gas exchange was normal at rest (Pao(2) = 88 ± 10 mm Hg; Paco(2) = 42 ± 3 mm Hg), and exercise tolerance (6-minute walk) was also normal (83% ± 17% of predicted values). Thirty-two patients had some degree of pulmonary hypertension, but in most of those cases, it was mild to moderate (mean systolic pressure of 36 ± 9 mm Hg) and not associated with significant differences in lung function (P = .57 for forced expiratory volume in 1 second), gas exchange (P = .08), and exercise capacity (P = .66). These findings indicate that despite worsening of lung function by approximately 30% after pneumonectomy, most patients can adjust to living with only 1 lung. Pulmonary hypertension is uncommon and in most cases only mild to moderate.