Distance and oxygen desaturation in 6-min walk test predict prognosis in COPD patients

• Published in: Respiratory medicine 2007-03, Vol.101 (3), p.561-567
• Main Authors: Takigawa, Nagio, Tada, Atsuhiko, Soda, Ryo, Date, Hiroshi, Yamashita, Motohiro, Endo, Shigeto, Takahashi, Syuji, Kawata, Noriko, Shibayama, Takuo, Hamada, Noboru, Sakaguchi, Motoi, Hirano, Atsushi, Kimura, Goro, Okada, Chiharu, Takahashi, Kiyoshi
• Format: Article
• Language: English
• Subjects: 6-min walk test; Aged; Biological and medical sciences; Body mass index; Carbon Dioxide - physiology; Chronic obstructive pulmonary disease, asthma; Confidence intervals; COPD; Emphysema; Exercise Test - methods; Female; Forced Expiratory Volume - physiology; Humans; Hyperinflation; Hypertension; Lung - surgery; Lung volume reduction surgery; Lungs; Male; Medical sciences; Middle Aged; Miscellaneous; Mortality; Multivariate analysis; Ostomy; Oxygen - physiology; Oxygen desaturation; Oxygen therapy; Pneumology; Prognosis; Pulmonary Disease, Chronic Obstructive - mortality; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary Disease, Chronic Obstructive - therapy; Pulmonary rehabilitation; Pulmonary/Respiratory; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Rehabilitation; Respiratory Function Tests - methods; Serum Albumin - analysis; Surgery; Survival Analysis; Treatment Outcome; Walking - physiology
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2006.06.017

Summary The aim of the present study was to predict the prognosis of Chronic obstructive pulmonary disease (COPD) patients who underwent comprehensive pulmonary rehabilitation (PR). A total of 144 patients who performed PR between 1992 and 1999 was assessed. After PR, 67 patients underwent lung volume reduction surgery (LVRS). Baseline data before PR consisted of body mass index, serum albumin levels, use of supplement oxygen at home, pulmonary function, arterial blood gas analysis, and distance and fall of hemoglobin oxygen saturation (Δ S pO2 ) in 6-min walk test. In addition to pre-PR factors, treatment with LVRS was taken into the analysis. The prognostic significance of variables influencing survival was determined by univariate analysis with Log rank test or multivariate analysis using Cox's proportional hazard model. By a median follow-up time of 8.4 years, the median survival time was 8.1 years (95% confidence interval: 6.9–9.4 years). Albumin level, P aCO2 , distance and Δ S pO2 were significant prognostic factors in univariate analysis. LVRS did not affect the prognosis. The multivariate analysis showed short distance and increase of Δ S pO2 as significant independent predictors of the risk of death. 6-min walk test was very useful for predicting the prognosis of the COPD patients.