Automatic nasal continuous positive airway pressure titration in the laboratory, patient outcomes
Manual titration of nasal continuous positive airway pressure (NCPAP) treatment for obstructive sleep apnoea (OSA) is time consuming and expensive. There are now 'intelligent' NCPAP machines that try to find the ideal pressure for a patient by monitoring some combination of apnoeas, hypopnoeas, inspiratory flow limitation and snoring. Although these machines usually find similar pressures to skilled technicians, it is not clear if their use in the sleep laboratory influences subsequent acceptance by patients. 122 patients with OSA undergoing a trial of NCPAP were randomly allocated to either manual or automatic (Horizon, DeVilbiss) titration of pressure during their first night on NCPAP in a hospital sleep laboratory. The primary outcome (available on 112 patients) was the acceptance of NCPAP or otherwise, six weeks following the initial titration night. Baseline indicators of severity were compared in the groups, as were the pressures selected and the patients' subsequent improvement in sleepiness. Initial OSA severity was not significantly different in the two groups. The mean NCPAP pressures (cmH2O) in the two groups were similar (manual 8.7 SD2.5, automatic 8.2 SD2.1). The % of patients successfully established on CPAP at six weeks was 64% and 73% for the manual and automatic groups respectively: 13% versus 2% had given up completely (manual and automatic respectively, P<0.05) and there were about equal numbers (23% versus 25%) in each group who were still undecided. The improvement in the Epworth sleepiness score was similar in the two groups. The substitution of automatic NCPAP titration instead of a manual titration during the first night of NCPAP in patients with OSA does not reduce the numbers accepting the treatment at six weeks, and may slightly improve it. This has important cost saving potential.