Adjustments in cardiorespiratory function after pneumonectomy: results of the pneumonectomy project.

OBJECTIVE: To assess lung function, gas exchange, exercise capacity, and right-sided heart hemodynamics, including pulmonary artery pressure, in patients long term after pneumonectomy.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: 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.