Functional and oximetric assessment of patients after lung reduction surgery.

Objective: The goal of this study was to clarify the issue of functional oxygen requirement by regimented exercise oximetry in patients undergoing lung reduction surgery.

Methods: Thirty-seven patients underwent lung reduction surgery and were followed up for at least 3 months. Patients routinely completed a 6-week program of cardiopulmonary rehabilitation. Preoperative and postoperative spirometry, dyspnea scores, 6-minute walk distances, respiratory mechanics, and exercise oximetry were recorded.

Results: After the operation, patients had a 37% increase in forced vital capacity and a 59% increase in forced expiratory volume in 1 second. Six-minute walk distance increased from 913 +/- 310 feet before the lung reduction operation to 1202 +/- 274 feet 6 months after the operation (p < 0.001). Maximal inspiratory and expiratory pressures were significantly increased in 16 patients after lung reduction surgery. Perceived dyspnea was significantly improved. Exercise pulse oximetry demonstrated that 83% of patients met American Thoracic Society criteria for supplemental oxygen use before lung reduction surgery. After the operation, 70% of patients continued to meet American Thoracic Society criteria for supplemental oxygen use. Notably, 10 patients with exertional desaturation while breathing room air discontinued supplemental oxygen use because of a reduction in dyspnea.

Conclusions: These findings demonstrate significant subjective and functional improvements related to lung reduction surgery. Exercise-induced hypoxia was not reversed by lung reduction surgery. Discontinuance of supplemental oxygen use owing to reduction in dyspnea and improved physical performance may not be warranted in lieu of continued exertional desaturation.