Rationale: Long-term noninvasive positive pressure ventilation (NIPPV) might improve the outcomes of pulmonary rehabilitation in COPD patients with chronic respiratory failure.
Objective: To investigate whether nocturnal NIPPV in addition to pulmonary rehabilitation as compared to pulmonary rehabilitation alone improves health-related quality of life, functional status, and gas exchange in COPD patients with chronic hypercapnic respiratory failure.
Measurements: Seventy-two COPD patients were randomly assigned to nocturnal NIPPV in addition to rehabilitation (n = 37) or rehabilitation alone (n = 35). Before and after the 3-months intervention period outcome measures were assessed.
Results: The Chronic Respiratory Questionnaire total score improved 15.1 points with NIPPV + rehabilitation, compared to 8.7 points with only rehabilitation. The difference of 7.5 points was not significant (p = 0.08). However, compared to rehabilitation alone, the difference in the fatigue domain was greater with NIPPV + rehabilitation (mean difference 3.3 points, p <0.01), as was the improvement in the Maugeri Respiratory Failure questionnaire total score (mean difference -10%, p <0.03) and its cognition domain (mean difference -22%, p <0.01). Furthermore, the addition of NIPPV improved daytime arterial carbon dioxide pressure (mean difference -0.3 kPa; p <0.01), and daily step count (mean difference 1269 steps/ day, p <0.01). This was accompanied by an increased daytime minute ventilation (mean difference 1.4 L; p <0.001).
Conclusion: Noninvasive ventilation augments the benefits of pulmonary rehabilitation in COPD patients with chronic hypercapnic respiratory failure as it improves several measures of health-related quality of life, functional status, and gas exchange.
Editor's Comment. This study randomized 72 patients with severe COPD (GOLD stages III-IV) and chronic hypercapnic respiratory failure, defined as a PaCO2 > 6 kPa (45 torr), to receive either pulmonary rehabilitation alone or in combination with nocturnal NIPPV. The primary desired outcome, an improvement in the Chronic Respiratory Questionnaire score, was not seen, but patients on NIPPV were less tired and showed some evidence of improved cognitive function. Also, although the 6MWD was not improved, there were signs of increased submaximal activity with a significant increase in the daily step count. All this suggests some benefit with nocturnal NIPPV, but longer term outcomes, including effects on exacerbation rate and mortality, remain unclear. The benefits that were seen also need to be balanced against the use of intrusive and not inexpensive equipment. In addition the optimal settings and blood gas endpoints for maximal benefit remain undefined. This may be a potential treatment option in selected patients with COPD-associated hypercapnic respiratory failure but requires weighing patient acceptance and comfort and equipment cost against some recognizable short-term gains, but with unknown long-term benefits, if any.
-SK