Gait speed as a functional capacity indicator in patients with chronic obstructive pulmonary disease

Walking distance is generally accepted as a functional capacity determinant in chronic obstructive pulmonary disease [COPD]. However, the use of gait speed in COPD patients has not been directly investigated. Thus, the aim of our study was to assess the use of gait speed as a functional capacity indicator in COPD patients. A total 511 patients with mild-to-very severe COPD and 113 healthy controls were included. The lung functions [pulmonary function test], general health- and disease-related quality of life [Medical Outcomes Study 36-Item Short-Form of Health Survey, St George's Respiratory Questionnaire], and gait speed [6-minute walk test] were assessed. The mean gait speed values were slower in moderate [75.7 +/- 14.0 m/min], severe [64.3 +/- 16.5 m/min], and very severe [60.2 +/- 15.5 m/min] COPD patients than controls [81.3 +/- 14.3 m/min]. There were significant correlations between gait speed and age, dyspnea-leg fatigue severities, pulmonary function test results [FEV [1], FVC, FVC%, FEV[1] /FVC ratio, PEF, PEF%], and all subscores of Medical Outcomes Study 36-Item Short-Form of Health Survey and activity, impact and total subscores of St George's Respiratory Questionnaire in patients with moderate, severe, and very severe COPD. However, these correlations were higher especially in patients with severe and very severe COPD. As a conclusion, according to our results gait speed slows down with increasing COPD severity. Also, gait speed has correlations with age, clinical symptoms, pulmonary functions, and quality of life scores in COPD patients. Thus, we consider that gait speed might be used as a functional capacity indicator, especially for patients with severe and very severe COPD

Can spirometry, pulse oximetry and dyspnea scoring reflect respiratory failure in patients with chronic obstructive pulmonary disease exacerbation?

To evaluate the extent to which oximetry, spirometry and dyspnea scoring can reflect hypoxemia and hypercapnia among patients admitted to the emergency department [ED] with acute exacerbations of chronic obstructive pulmonary disease. Spirometry, oxygen saturation by pulse oximetry [SpO[2]], arterial blood gas analysis and dyspnea scoring assessments were made in the ED. Correlations of these parameters were evaluated by means of Pearson's test. Pulse oximetry cutoff values to express hypoxemia were demonstrated by receiver operating characteristic [ROC] curves. 76 patients with a mean age of 68.0 years were included in the study. Mean spirometric values, expressed as percentages of predicted values, were forced expiratory volume in 1 s [FEV[1]] = 23.1 +/- 9%; forced vital capacity [FVC] = 32.8 +/- 11%, and mean FEV1/FVC = 72.4 +/- 21.6%. While there was a positive correlation between the SpO[2],SaO[2] and PaO[2] values [r = 0.91 and 0.80, respectively], a negative correlation [r = -0.74] was observed between PaCO[2]and SpO[2]. In determining hypoxemia, both SpO[2] and FEV1 were sensitive [83.9 and 90.3%, respectively] while dyspnea scoring was the most sensitive [93.5%]. In the evaluation by means of an ROC curve, a saturation of 88.5% for the pulse oximeter was the best cutoff value to reflect hypoxemia [sensitivity 95.6%, specificity 80.6%]. SpO[2] alone appears to be as highly specific as a combination of other tests in the evaluation of hypoxemia. A cutoff value for SpO2 of