Evaluation of Intermittent Long-term Negative-Pressure Ventilation in Patients with Severe Chronic Obstructive Pulmonary Disease

Abstract

We tested the hypothesis that intermittent ventilatory assistance in patients with severe chronic obstructive pulmonary disease (COPD) improves pulmonary function and exercise capacity. Twenty stable patients with severe COPD were recruited from outpatient pulmonary clinics and were randomized to use a poncho wrap, negative-pressure ventilator or to receive standard care. After 6 months, the patients receiving standard care were switched over to the ventilator and vice versa, and follow-up was continued for an additional 6 months. After 3 to 6 months of ventilator use, we observed no clinically significant improvements in FEV1, FVC, blood gas determinations, maximal inspiratory and expiratory pressures, and exercise duration. However, 11 of our patients dropped out of the study because of an inability to tolerate the ventilator, and all but one of the nine who completed the study expressed dissatisfaction with it, using it for less time (4.1 h/day) than we recommended. Musculoskeletal pain and inconvenience were the most frequently voiced complaints. Because we did not document that ventilator use actually rested the respiratory muscles in our patients and because duration of ventilator use may have been too brief, we cannot conclude that intermittent rest of respiratory muscles in patients with severe COPD fails to bring about improvement. On the other hand, our results demonstrate that the poncho wrap ventilator is poorly tolerated by patients with severe COPD in a typical outpatient setting. We suggest that future trials seek to utilize better tolerated ventilatory assist devices.

Negative-pressure ventilation: is there still a role?

“…In contrast with the two previous studies, ZIBRAK et al [47] showed no improvement in pulmonaryfunction test, blood gases and exercise endurance in a group of 20 stable patients with severe COPD (Pa,CO 2= 6.4¡1.3 kPa (48¡10 mmHg)) treated with poncho-wrap ventilator for 2-6 h a day for 6 months. However, 11 of the 20 patients dropped out the study because of intolerance of the ventilator, and all but one of the nine patients who completed the study expressed dissatisfaction with it.…”

“…All negative-pressure ventilators restrict motion and back pain is a common problem. NPV has been associated with rib fractures and pneumothorax [47]. In the study by CORRADO et al [9], two of 26 (8%) patients reported uneasiness and back pain and two others experienced vomiting during NPV.…”

“…On the basis of the hypothesis that chronic hypercapnia in severe COPD patients may be caused by an excessive load on the inspiratory muscles, several studies have evaluated the effects of NPV in terms of improvement in arterial blood gases, muscle function, and exercise performance [47,[53][54][55][56]. CROPP and DIMARCO [53] performed a short-term controlled study on patients with severe COPD.…”

Noninvasive ventilation in chronic ventilatory failure due to chronic obstructive pulmonary disease

“…The use of negative pressure devices at home and during sleep in patients with COPD has been largely unsuccessful [3,5]. In two controlled trials, patients were generally unable to sleep during negative pressure ventilation, and most either failed to complete the protocol because of lack of improvement or discomfort associated with the use of the equipment [5], or did not wish to continue treatment after the study was completed [3]. Negative pressure devices are cumbersome and relatively inefficient, particularly when the impedance to inflation is high, and may not be able to provide adequate ventilation during sleep.…”

Noninvasive ventilation and obstructive lung diseases

“…eucapnic) emphysematous patients. However, randomized trials failed to prove efficiency of this treatment and compliance was poor [24,25]. A previous controlled, randomized study [26] showed no beneficial effects on arterial blood gases, walking tests, level of dyspnoea, and quality of life in 184 COPD patients treated during 12 weeks with effective negative intermittent pressure ventilation by poncho, as compared to a sham ventilation with poncho.…”