Perioperative evaluation of respiratory impedance using the forced oscillation technique: a prospective observational study

Table 3 Relationships between spirometry and postoperative FOT findings

	%VC		%FEV1.0		%FVC		FEV1.0/FVC ratio
	Coefficient	p value	Coefficient	p value	Coefficient	p value	Coefficient	p value
Postoperative R5 (cmH₂O/L/s)	−0.285	0.1585	−0.290	0.1513	−0.262	0.1968	−0.097	0.6358
Postoperative R20 (cmH₂O/L/s)	−0.180	0.3785	−0.283	0.1617	−0.171	0.4028	−0.197	0.3358
Postoperative R5-R20 (cmH₂O/L/s)	−0.437	0.0256	−0.320	0.1113	−0.396	0.0450	0.029	0.8866
Postoperative X5 (cmH₂O/L/s)	0.672	0.0002*	0.720	<0.0001*	0.684	0.0001*	0.336	0.0935
Postoperative Fres (Hz)	−0.742	<0.0001*	−0.708	<0.0001*	−0.741	<0.0001*	−0.229	0.2602
Postoperative ALX (cmH₂O/L)	−0.699	<0.0001*	−0.734	<0.0001*	−0.706	<0.0001*	−0.335	0.0939

Abbreviations: R5 respiratory resistance at 5 Hz, R20 respiratory resistance at 20 Hz, X5 respiratory reactance at 5 Hz, Fres resonance frequency, ALX area of low respiratory reactance, VC vital capacity, FVC forced vital capacity, FEV1.0 forced expiratory volume in the first second. *P < 0.01

ISSN: 1471-2253