Using intra-breath oscillometry in obesity hypoventilation syndrome to detect tidal expiratory flow limitation: a potential marker to optimize CPAP therapy

Table 1 Definition of intra-breath oscillometry variables

Parameter	Unit	Definition
Vt	Liter	Tidal volume
Frequency	min^− 1	Breathing frequency
Ti/Ttot		Inspiratory time divided by breathing cycle time
ReE	cmH₂O·s·L^− 1	Respiratory resistance at the end of expiration
ReI	cmH₂O·s·L^− 1	Respiratory resistance at the end of inspiration
ΔR	cmH₂O·s·L^− 1	Difference between ReE and ReI
ΔXmean	cmH₂O·s·L^− 1	Difference between the mean values of expiratory and inspiratory reactance
XeE	cmH₂O·s·L^− 1	Respiratory reactance at the end of expiration
XeI	cmH₂O·s·L^− 1	Respiratory reactance at the end of inspiration
ΔX	cmH₂O·s·L^− 1	Difference between XeE and XeI
AXV	cmH₂O·s	Area of the reactance vs. volume diagram
AXV’	cmH₂O	Area of the reactance vs. flow diagram
ARV	cmH₂O·s	Area of the resistance vs. volume diagram
ARV’	cmH₂O·s·L^− 1	Area of the resistance vs. flow diagram

ISSN: 1471-2466