Table 2– Breathing pattern

Parameter	SB	Li-NPPV	Hi-NPPV	p-value
Parameter	SB	Li-NPPV	Hi-NPPV	SB versus Li-NPPV	SB versus Hi-NPPV	Li-NPPV versus Hi-NPPV
f_R breaths·min⁻¹	24.8±8.4	21.3±6.3	22.9±3.3	ns	ns	ns
t_I s	1.25±0.3	1.1±0.19	0.74±0.1	ns	<0.05	<0.001
t_E s	1.46±0.75	1.98±0.77	1.93±0.34	ns	ns	ns
t_I/t_tot	0.48±0.09	0.37±0.08	0.27±0.05	<0.001	<0.001	<0.001
V_T L	0.4±0.1	0.56±0.11	0.67±0.13	<0.001	<0.001	<0.001
V_T/t_I L·s⁻¹	0.33±0.08	0.52±0.11	0.93±0.18	<0.05	<0.001	<0.05
V′_E L·min⁻¹	9.6±3.5	11.7±2.3	15.2±2.0	<0.01	<0.001	<0.001
Air leakage L·min⁻¹		10.62±5.27	16.11±7.88			<0.05

Data are presented as mean±sd, unless otherwise stated. SB: spontaneous breathing; Li: low-intensity; NPPV: noninvasive positive pressure ventilation; Hi: high-intensity; f_R: respiratory frequency; t_I: inspiratory time; t_E: expiratory time; t_tot: total time of respiratory cycle; V_T: tidal volume; V′_E: minute ventilation; ns: nonsignificant.