Use of a mucus clearance device enhances the bronchodilator response in patients with stable COPD.

STUDY OBJECTIVE: To determine whether the use of a mucus clearance device (MCD) [Flutter; Axcan Scandipharm; Birmingham, AL] could improve the bronchodilator response to inhaled ipratropium and salbutamol delivered by a metered-dose inhaler in patients with stable, severe COPD. PATIENTS: Twenty-three patients with severe COPD were studied. Mean +/- SD age was 71.7 +/- 6.3 years. Mean FEV(1) was 0.74 +/- 0.28 L or 34.5 +/- 12.7% predicted. METHODS: Patients were tested in random order on 2 subsequent days after using an MCD or a sham MCD. A bronchodilator (four puffs; each puff delivering 20 microg of ipratropium bromide and 120 microg of salbutamol sulfate) was administered by metered-dose inhaler with a holding chamber after use of the MCD or sham MCD. Spirometry was performed before and after use of the MCD or sham MCD, and at 30 min, 60 min, and 120 min after the bronchodilator. Six-minute walk distance was tested between 30 min and 60 min; oxygen saturation, pulse, and a dyspnea score were recorded before and after walking. RESULTS: Immediately after use of the MCD, but not the sham MCD, there was a statistically significant (p < 0.05) improvement in FEV(1) and FVC (11 +/- 24% vs 1 +/- 7% and 18 +/- 33% vs 6 +/- 18%, respectively). Whether patients were pretreated with the MCD or sham MCD, there was a significant improvement in FEV(1) and FVC compared to baseline with combined bronchodilator therapy. At 120 min, the change in FEV(1) after treatment with the MCD was greater than with the sham MCD (186 +/- 110 mL vs 130 +/- 120 mL; p < 0.05). When comparing the MCD to the sham MCD, 6-min walk distance was greater (174 +/- 92 m vs 162 +/- 86 m; p < 0.05), with less dyspnea before and at the end of walking. CONCLUSION: Patients with severe COPD may demonstrate a significant bronchodilator response to combined ipratropium and salbutamol delivered by metered-dose inhaler. This response may be enhanced and additional functional improvement obtained with the prior use of a bronchial MCD.

A randomized trial to evaluate the sustained efficacy of a mucus clearance device in ambulatory patients with chronic obstructive pulmonary disease.

OBJECTIVE: To determine whether a mucus clearance device (MCD) (Flutter; Axcan Scandipharm, USA) could consistently improve the bronchodilator response and exercise performance in patients with chronic obstructive pulmonary disease (COPD) when used in an ambulatory setting over a one-week period. SUBJECTS: Fifteen patients with severe COPD (mean age 71+/-10 years) were studied. METHODS: A randomized crossover design compared an MCD with a sham MCD (SMCD), in which each were tested for one week. At the beginning and end of each study week, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were measured before and after MCD or SMCD. A bronchodilator aerosol (ipratropium bromide and salbutamol sulphate) was then given, and FEV1 and FVC were remeasured 30 min, 60 min and 120 min later. A 6 min walk test (6MWT) was also performed. RESULTS: FEV1 improved significantly (P<0.05) after bronchodilator administration with both the SMCD and MCD. The improvement was always greater with MCD use than with SMCD. At the baseline measure, 120 min postbronchodilator administration, the mean FEV1 improved by 24+/-24% with SMCD use and 60+/-28% with MCD use (P<0.05). After one week of use, the corresponding values at 120 min were 19+/-24% and 43+/-26% (P<0.05). Similar findings were obtained for FVC. 6MWT distances increased by 29+/-12 m (P<0.05) after one week of MCD use, whereas it decreased slightly (by 16+/-18 m) after SMCD. The decline in saturation with the 6MWT was smaller with MCD use than with SMCD use. After one week, the decline in saturation with MCD use was similar to baseline levels, although patients were walking farther. After one week, dyspnea was lower on walking with MCD use than with SMCD use. CONCLUSION: Patients with COPD had an increased response to bronchodilator therapy after use of the MCD compared with SMCD use. The increase persisted after one week of use, and was associated with improved exercise performance as measured by the 6MWT.

Examination of pulse oximetry tracings to detect obstructive sleep apnea in patients with advanced chronic obstructive pulmonary disease.

Nocturnal hypoxemia and obstructive sleep apnea (OSA) are common comorbidities in patients with chronic obstructive pulmonary disease (COPD). The authors sought to develop a strategy to interpret nocturnal pulse oximetry and assess its capacity for detection of OSA in patients with stage 3 to stage 4 COPD. A review of consecutive patients with COPD who were clinically prescribed oximetry and polysomnography was conducted. OSA was diagnosed if the polysomnographic apnea-hypopnea index was >15 events/h. Comprehensive criteria were developed for interpretation of pulse oximetry tracings through iterative validation and interscorer concordance of ≥80%. Criteria consisted of visually identified desaturation 'events' (sustained desaturation ≥4%, 1 h time scale), 'patterns' (≥3 similar desaturation/saturation cycles, 15 min time scale) and the automated oxygen desaturation index. The area under the curve (AUC), sensitivity, specificity and accuracy were calculated. Of 59 patients (27 male), 31 had OSA (53%). The mean forced expiratory volume in 1 s was 46% of predicted (range 21% to 74% of predicted) and 52% of patients were on long-term oxygen therapy. Among 59 patients, 35 were correctly identified as having OSA or not having OSA, corresponding to an accuracy of 59%, with a sensitivity and specificity of 59% and 60%, respectively. The AUC was 0.57 (95% CI 0.55 to 0.59). Using software-computed desaturation events (hypoxemia ≥4% for ≥10 s) indexed at ≥15 events/h of sleep as diagnostic criteria, sensitivity was 60%, specificity was 63% and the AUC was 0.64 (95%CI 0.62 to 0.66). No single criterion demonstrated important diagnostic utility. Pulse oximetry tracing interpretation had a modest diagnostic value in identifying OSA in patients with moderate to severe COPD.

Clinical reproducibility of the Epworth Sleepiness Scale.

STUDY OBJECTIVES: The Epworth Sleepiness Scale (ESS) is widely used as a subjective measure of sleepiness. To our knowledge, no study has evaluated its reproducibility in the clinical setting. METHODS: A retrospective chart review of patients referred to the sleep clinic at Mount Sinai Hospital for evaluation of sleep-disordered breathing from a local private snoring clinic between January 2000 and October 2001 was carried out. Patients were snorers and referred because of suspicion of sleep apnea. Clinical information including results of the ESS scores from the two institutions was analyzed to evaluate reproducibility. RESULTS: There were 142 patients evaluated: 76% men with a mean (SD) age of 44 (11) years, body mass index of 31 (6.1) kg/m(2), and apnea-hypopnea index of 41 (34) events per hour. The average time interval between ESS administrations was 71 (92) days. The average ESS score was 11.1 (5.2) at the Snoring Clinic and 11.2 (5.3) at Mount Sinai Hospital. The Bland-Altman plot of the difference against the mean of the ESS score demonstrated a wide scatter of data and variability where 2 SDs ranged 7.8 above and below the mean. A difference between the sequential ESS scores of 5 or more was seen in 23% of the subjects. CONCLUSION: The ESS score is highly variable when administered sequentially to a clinical population being evaluated for a potential sleep-related breathing disorder.