Non-invasive ventilation in patients with severe hypercapnic encephalopathy in a conventional hospital ward

OBJECTIVE: To report our experience with non-invasive ventilation (NIV) at two levels of pressure (Bi-PAP) on a general respiratory medicine ward with patients in hypercapnic impaired consciousness and/or coma who had not previously been in an intensive care unit (ICU). METHODS: This was a prospective study of 13 patients, mean age 81 years (65-96), treated with NIV through a face mask. Ten had chronic obstructive pulmonary disease, with a mean FEV1 in stable condition of 35.2 +/- 14.6%. Glasgow scores upon admission were greater than or equal to7. Arterial gases were monitored until suspension of NIV. RESULTS: After NIV for a mean 19 :+/- 5 h/day in the first 48 hours and later of 6 +/- 1 h/day until a total of 74 +/- 9 h, 9 patients (69%) survived. The mean initial pH for these patients was 7.17 +/- 0.028 and the mean initial pCO2 was 101 +/- 9 nun Hg. In 7 cases (78%), coma was reversed in the first 48 h and a significant improvement in pH was observed in the 12-24 h analysis. Mean pH upon discharge was 7.44 +/- 0.013 and mean pCO2 was 54 +/- 2.8 mmHg. Four patients died, even though their initial or subsequent arterial gases at 12-24 h were not significantly different from those of the survivors. CONCLUSION: NIV on a general respiratory medicine ward can offer an alternative to oro-tracheal intubation for patients with hypercapnic impaired consciousness and/or coma who do not meet the criteria for admission to the ICU.