SEVERE EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY-DISEASE TREATEDWITH BIPAP(R) BY NASAL MASK

Bi-level pressure support ventilation via a nasal mask (NIPSV) was pro vided to 28 consecutive unselected patients with acute respiratory fai lure due to exacerbation of chronic obstructive pulmonary failure (COP D). If NIPSV improved gas exchange within 2 h, it was continued. Other wise, patients would be promptly intubated. The patients median age wa s 68 years (minimum 56, maximum 82). The arterial blood gas drawn befo re initiating NIPSV showed (FiO(2) 21%) a mean PaO2 of 41.3 +/- 6 mm H g, a mean PaCO2 of 66 +/- 15 mm Hg and a mean pH of 7.31. Upon admissi on the mean respiratory rate was 36 breaths/min and the median Apache II score was 20.5 (minimum 13, maximum 32). Despite oxygen administrat ion all patients failed to improve their PaO2 and/or showed a consiste nt and dangerous hypercapnic response. NIPSV was performed with a medi an inspiratory positive airway pressure of 14 cm H2O (minimum 10, maxi mum 20) and a median expiratory positive airway pressure of 4 cm H2O ( minimum 3, maximum 6). Eighteen patients (64%) were successfully venti lated with NIPSV, while in 10 (36%) NIPSV failed. A high Apache II sco re, but not admission blood gas exchange or respiratory rate, seems to be correlated with the failure to ventilate with NIPSV. The results o f our preliminary experience suggest the use of NIPSV as an initial ap proach to acute respiratory failure due to exacerbation of COPD, parti cularly in patients with an Apache II score of less than 29.