Table 2 Baseline sleep and gas exchange data in all patient groups
CPAPBVSp Value
Minimum Spo2 (%)55 (14)53 (20)0.75
%TST <90 (%)74 (52–99)90 (57–100)0.47
%TST <80 (%)19 (7–53)33 (14–72)0.28
TST (min)251 (108–333)328 (259–345)0.11
Sleep efficiency (%)69 (42–87)78 (65–84)0.38
% NREM88 (7)87 (8)0.67
% REM12 (7)13 (8)0.67
NREM RDI (events/h)93 (59–112)70 (19–97)0.14
REM RDI (events/h)61 (57–91)48 (30–68)0.13
% hypopnoeas of TRDI79 (25–87)77 (45–92)0.69
ESS15 (8–17)14 (12–19)0.59

  • Data presented as mean (SD) or median (interquartile range) as appropriate.

  • BVS, bilevel ventilatory support; CPAP, continuous positive airway pressure; Spo2, oxygen saturation; TST, total sleep time; NREM, non-rapid eye movement sleep; REM, rapid eye movement sleep; ESS, Epworth Sleepiness Scale; RDI, respiratory disturbance index; TRDI, total respiratory disturbance index.