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Clinical InvestigationMaximal Inspiratory Pressure: Learning Effect and Test-Retest Reliability in Patients With Chronic Obstructive Pulmonary Disease
Section snippets
Method
Data for this study were acquired from COPD patients during a 4-week period prior to participating in a pulmonary rehabilitation program. The study was approved by the appropriate institutional committees on human research and informed consent was obtained from all patients. Patients qualified for the study if they (1) had clinically stable COPD with moderate to severe airflow obstruction (FEV1 <65 percent predicted), (2) had no clinical evidence of asthma and <30 percent improvement in FEV1
Results
The sample was 69 men and 22 women with moderate to severe COPD (Table 1). Most patients were taking standard pharmacologic therapies, including inhaled β-agonists, oral β-agonists, and methylxanthines. Nine were using home oxygen. Ten were currently smoking, one had never smoked, and the remainder had quit smoking. The sample was middle class as indicated by the Hollingshead Index.12
Performance gradually improved as demonstrated by the mean (SD) PImax for each test session: first −53 (24) cm H2
Discussion
The mean PImax was consistent with values reported for similar groups of patients with moderate to severe COPD.4,13, 14 The results of this study supported the notion that in naive COPD patients, performance of PImax improves with practice of the PImax maneuver. The third and fourth test of PImax produced reliable data.
ACKNOWLEDGMENTS
We gratefully acknowledge the Bioinstrumentation and Biostatistics Facilities of the Research Resources Center, University of Illinois at Chicago, which provided support services necessary to conduct this study.
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Manuscript received April 28; revision accepted January 7.
Supported by a grant (NR01428) from the National Center for Nursing Research.