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M Peavler

Publications and source records attributed to M Peavler.

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Exercise conditioning in the rehabilitation of patients with chronic obstructive pulmonary disease.

Fifty-nine patients with severe chronic obstructive pulmonary disease (COPD) performed pulmonary function and exercise tests before and after participation in a 12-day pulmonary rehabilitation inpatient program. Postdischarge follow-ups were performed at three months. Training consisted of twice daily aerobic exercise of 30 to 40 minutes' duration. Intensity of training was determined after exercise testing and approached the maximal limits of ventilation. In general, the program failed to demonstrate significant changes in pulmonary function. Exceptions were mid-expiratory flow rate (FEF25-75) (p less than .02) and peak flow rate (p less than .05). Evaluation of exercise capacity via maximal exercise testing yielded significant increases in caloric expenditure (p less than .001), peak exercise oxygen consumption (p less than .001), and work output (p less than .0001). Peak exercise ventilation increased significantly (p less than .005) due to an increase in tidal volume (p less than .002). Work efficiency improved with training, but the change was not statistically significant. Resting oxygen consumption and carbon dioxide production were decreased (p less than .05); tidal volume was increased (p less than .005). However, the significant increase noted in tidal volume did not alter minute ventilation. In general, the changes noted at 12 days were maintained at three months postdischarge. These data support the hypothesis that a short-term, in-hospital program of general exercise conditioning can improve work output, gas exchange, and mechanical efficiency without significantly affecting spirometric indices. These changes may translate into improved performance of activities of daily living and a sense of general well-being.

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Predicting maximal exercise ventilation in patients with chronic obstructive pulmonary disease.

Shortness of breath is a chief complaint of many individuals with cardiopulmonary diseases. Exercise testing is often used to help differentiate cardiac from pulmonary involvement. In assessing pulmonary dysfunction during exercise it is essential to know the point at which ventilatory limitation will occur. Numerous authors have presented regression equations based on the FEV1 for predicting either MVV or VEmax. Resting pulmonary function studies were obtained from 53 patients with COPD. Symptom-limited maximal exercise testing was completed on a cycle ergometer using increments of 10 watts/min. Each regression equation for predicting MVV or VEmax was then applied to the data set. Results showed that the FEV1 correlated with the measured VEmax (r = .81) as did PEF (r = .81), MVV (r = .78), IC (r = .78), DCO (r = .68), VA (r = .67), VE (r = .65) and FVC (r = .64). Single post-bronchodilator FEV1 measurements ranged from 0.56 to 1.64 L (mean 1.0 L) while VEmax ranged from 16 to 78 L/min (mean 37.69 L/min). The equation VEmax = 37.5 X FEV1 was the most robust equation found in the literature for predicting VEmax in this sample. This equation was not statistically different from the line of identity when predicted VEmax was plotted against the measured VEmax. The intercept was 0.91 with a slope of 0.98. In addition, this equation had a smaller mean square error in predicting VEmax than those of the other equations investigated.

Adult↗

Evaluation of the pendant oxygen-conserving nasal cannula during exercise.

There is much recent evidence that patients with chronic pulmonary disease who are hypoxemic benefit from continuous therapy with oxygen. These benefits include reduction in symptoms of cor pulmonale, reduction in mortality, and improvement in quality of life. Oxygen therapy is very expensive, and steady-flow delivery of oxygen is wasteful, since almost the entire benefit of the oxygen presented to the patient occurs at the very beginning of inspiration. We previously described a conserver nasal cannula (CNC) which stores oxygen during exhalation for delivery during subsequent inspirations. The CNC achieves adequate arterial oxygen saturation (SaO2) at one fourth to one half of the flow in liters of steady-flow oxygen delivery. Because some patients found the mustache configuration objectionable, a pendant nasal cannula (PNC) was designed, displacing the reservoir off of the face and onto the anterior wall of the chest. While both cannulas require some breathing by nose to function, the PNC is more esthetically acceptable. No studies with exercise have been reported using the PNC. We evaluated the PNC during treadmill exercise in ten subjects with chronic obstructive pulmonary disease and hypoxemia on exercise. We compared the PNC with steady-flow oxygen during steady level treadmill walking sufficient to cause oxygen desaturation while breathing room air at oxygen presentations of 0.5 through 3.0 L/min. At comparable workloads the SaO2 achieved by PNC required one third of the oxygen flow required by steady-flow oxygen to achieve an equivalent SaO2. These differences were statistically significant (p less than 0.01). We conclude that the PNC provides effective delivery of oxygen during exercise, as well as at rest, while minimizing oxygen flow rate and thus substantially reducing the economic burden normally associated with supplemental oxygen delivery.

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