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.

Self-selected walking velocity for functional ambulation in patients with end-stage emphysema.

PURPOSE: Considerable attention has been given to ambulation and dyspnea in the population with chronic obstructive pulmonary disease; however, previous studies leave the question of what constitutes functional ambulation in this population unanswered. This article examines ambulation for functional independence in the community for patients with-end-stage emphysema based on their self-selected walking velocity (SSWV) during a 6-minute walk (6 MW) and a timed get up and go (GUG) test. METHODS: Fifty-nine patients (28 women, 31 men; mean age of 65.1 +/- 7.2 years) referred for lung transplantation or lung volume reduction surgery (mean forced expiratory volume in 1 second [FEV1] of 0.60 +/- 0.20 L; mean FEV1 as percent of predicted [FEV1%] of 22.7 +/- 8.7%) each had a 6 MW and GUG test performed on the same day. Calculations for SSWV and estimated energy expenditure were determined using the horizontal walking formula by the American College of Sports Medicine. RESULTS: No statistically significant gender differences were identified for distance walked (235.1 +/- 92.0 m), rest time taken (33.2 +/- 58.5 seconds), actual walk time (5.5 +/- 1.0 minutes), or SSWV (42.2 +/- 13.9 m/min or 1.6 +/- 0.5 miles per hour) during the 6 MW. Men tended to walk farther and faster but rested more. The SSWV during the GUG test was similar (mean 41.8 +/- 10.9 m/min or 1.6 +/- 0.4 miles per hour) to the SSWV during the 6 MW. Estimated energy expenditure was approximately 1.6 to 3.4 metabolic equivalents (METS; mean 2.3 +/- 0.5 METS). CONCLUSION: The literature defines independent community ambulation as the ability to walk at least 332 m at a near-normal velocity of approximately 80 m/min. This study population was significantly impaired for both distance and the velocity required to ambulate independently in the community. Documentation of both rest time and walk time taken during a 6 MW test will enable SSWV to be calculated and interpreted as it relates to independent community ambulation.