Longterm effects of pulmonary resection on cardiopulmonary function

Abstract

Background: Major lung resection decreases ventilatory capacity and reduces exercise tolerance, impairing postoperative quality of life. But we have often seen respiratory symptoms improve during several years of postoperative followup. In the current study, we evaluated postoperative changes in cardiopulmonary function on exertion of patients with lung cancer surviving for more than three years, and the corresponding changes of their respiratory symptoms. Methods: The effects of pulmonary resection on cardiopulmonary function were evaluated in eight patients with lung cancer. Pulmonary function tests and hemodynamic study at rest and during exercise were performed before, in the early (4 to 6 months) and late (42 to 48 months) postoperative phases after major lung resection. Results: None of the eight patients had any remarkable symptoms before lung resection. In the early postoperative study, the general condition of five patients deteriorated compared with their preoperative status. In the late postoperative study, four patients showed an improvement of their daily activities from the early postoperative phase. Pulmonary function in the late postoperative phase did not show major changes except for airway resistance and percentage of carbon monoxide diffusing capacity as compared with the early phase, which showed deterioration as compared with the preoperative period. Cardiac index and stroke volume index were significantly decreased during exercise on maximal effort in the late postoperative phase compared with other phases. These results suggest that the peak blood flow per unit of remaining lung during exercise becomes lower with time after lung resection, indicating deterioration of the condition of the pulmonary vascular bed. The deterioration was also revealed from the pressure-flow curve. Conclusions: The condition of the pulmonary vascular bed after major lung resection does not improve, even in the late postoperative phase, although clinical symptoms were sometimes improved compared with the early postoperative period.