Objectives: To assess the use of nasal intermittent positive pressure ventilation (NIPPV) in treating acute-on-chronic respiratory failure in a general medical ward.
Design: Retrospective analysis of clinical outcome.
Setting: A general medical ward of a tertiary respiratory medicine referral centre.
Subjects: Altogether 75 patients admitted with acute exacerbations of chronic respiratory failure and treated NIPPV.
Main outcome measures: Blood gas tensions determined at admission to hospital and during NIPPV, tolerance of NIPPV and mortality.
Results: During treatment with NIPPV, the mean (SD) PaO2 increased rapidly by 2.31 (3.58) kPa (p < 0.0001), while the mean PaCO2 fell by 1.07 (1.74) kPa (p < 0.0001) and the mean pH increased by 0.03 (0.07) (p = 0.001). Altogether 57 (76%) of patients tolerated NIPPV, and (9.3%) died in hospital. Improvement in PaO2 was more noticeable in patients with chronic obstructive pulmonary disease (+3.13 (3.49) kPa, p < 0.0001) than in those with restrictive chest wall disease (+1.20 (3.07) kPa, p = 0.25) or obstructive sleep apnoea (+0.18 (3.64), p = 0.88). The reduction in PaCO2 was similar in all three groups.
Conclusions: In routine treatment of unselected patients with acute-on-chronic respiratory failure who are being cared for on a general ward, NIPPV rapidly improves hypoxaemia and hypercapnia, is well tolerated and is associated with low mortality.