Objective: A 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 methods: Ten 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.
Results: Daytime PaCO(2) during spontaneous breathing decreased by 5.4+/-1.3mmHg (95% confidence interval, 4.5-6.3), from 57.7+/-5.1mmHg to 52.3+/-5.9 (p<0.001); while daytime PaO(2) increased by 3.4+/-3.3mmHg (95% confidence interval, 1.0-5.8), from 63.7+/-3.5mmHg 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).
Conclusions: In 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.