Table 2.

Resting data during stable sleep on optimal or sub-optimal CPAP

	Optimal CPAP	Sub-optimal CPAP
VI (l min−1)	8.0 ± 0.3	7.8 ± 0.3
VT (l) *	0.56 ± 0.02	0.54 ± 0.03
TI (s) *	1.72 ± 0.05	1.85 ± 0.06
TE (s) *	2.47 ± 0.08	2.31 ± 0.08
CPAP (cmH2O) *	11.3 ± 0.7	8.4 ± 0.8
PIF (l s−1) *	0.47 ± 0.02	0.41 ± 0.02
pET,co2(Torr) *	42.5 ± 0.8	43.5 ± 0.8
PEPI (cmH2O) *	1.8 ± 0.1	5.4 ± 0.7
RUA,0.2 (cmH2O l−1 s) *	1.3 ± 0.2	3.8 ± 0.5
RUA,MAX (cmH2O l−1 s) *	2.8 ± 0.3	17.6 ± 2.8
EMGDI Phasic (% max) *	8.0 ± 1.1	9.1 ± 1.7
EMGDI Tonic (% max)	15.7 ± 3.3	17.0 ± 3.4

Pre-arousal respiratory data on optimal and sub-optimal CPAP during NREM sleep in 20 patients with OSA. See Table 1 for definitions.

^*P < 0.05 different between CPAP conditions.