Acute effects of NPPV in interstitial lung disease with chronic hypercapnic respiratory failure

SummaryObjectiveA case series evaluating the acute effects of noninvasive positive pressure ventilation (NPPV) in patients with chronic hypercapnic respiratory failure (HRF) secondary to interstitial lung diseases (ILD).Patients and methodsTen patients with ILD were retrospectively evaluated. All had restrictive lung function (mean TLC, 47.6 ± 12.6% predicted) and chronic hypercapnic respiratory failure (mean pH = 7.39 ± 0.02). Arterial blood gas analysis and lung function were compared before and after the application of controlled pressure-limited NPPV.ResultsDaytime PaCO2 during spontaneous breathing decreased by 5.4 ± 1.3 mmHg (95% confidence interval, 4.5–6.3), from 57.7 ± 5.1 mmHg to 52.3 ± 5.9 (p < 0.001); while daytime PaO2 increased by 3.4 ± 3.3 mmHg (95% confidence interval, 1.0–5.8), from 63.7 ± 3.5 mmHg to 67.1 ± 3.4 (p = 0.01); and TLC increased by 3.9 ± 4.5% (95% confidence interval, 0.7–7.1), from 47.6 ± 12.6% mmHg to 51.5 ± 10.0% (p = 0.023).ConclusionsIn patients with ILD and chronic HRF controlled NPPV is tolerated and can acutely improve blood gas levels. Further studies examining the long-term benefits need to be explored.