Role of Bi-pap in acute respiratory failure due to acute exacerbation of COPD.

OBJECTIVE To assess the efficacy of Bi-level Positive Airway Pressure (Bi-pap), administered by nasal mask in patients with acute respiratory failure due to acute exacerbation of COPD. DESIGN Prospective non-randomized study in a hospital setting. METHODS Eighteen patients were recruited from those admitted in the Chest Unit of Jinnah Postgraduate Medical Centre, Karachi with acute exacerbation of COPD. Along with conventional treatment, Bi-pap was administered by a nasal mask. Arterial blood gas analysis, respiratory and heart rate and subjective sensation of dyspnoea, before and during Bi-pap application were monitored. RESULTS The respiratory rate decreased from 33.2 +/- 5.3/min to 22.0 +/- 3.5 (P < 0.001), heart rate also decreased from 113.2 +/- 7.6/min to 90.2 +/- 11.9 (P < 0.001). A rise in pH was observed from 7.2 +/- 0.09 to 7.4 +/- 0.06 (P > 0.41 n.s.), PaCO2 decreased from 76.5 +/- 15.5 to 51.3 +/- 10.5 (P < 0.001). PaO2 also increased from 52.1 +/- 14.3 to 62.9 +/- 11.5 (P < 0.01). The mean hospital stay was shorter i.e., 10.6 +/- 5.6 days and the hospital mortality rate 11.1%. Bi-pap administered by nasal mask was generally well tolerated with few minor complications. CONCLUSION Bi-pap is particularly useful in patients presenting with acute respiratory failure due to acute exacerbation of COPD particularly in our setting where invasive ventilation is not easily available.