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

Table 2 Relationships between spirometry and preoperative FOT findings

	%VC		%FEV1.0		%FVC		FEV1.0/FVC ratio
	Coefficient	p value	Coefficient	p value	Coefficient	p value	Coefficient	p value
Preoperative R5 (cmH₂O/L/s)	−0.371	0.0623	−0.381	0.0551	−0.319	0.1129	−0.222	0.2751
Preoperative R20 (cmH₂O/L/s)	−0.326	0.1036	−0.338	0.0915	−0.294	0.1455	−0.167	0.4139
Preoperative R5-R20 (cmH₂O/L/s)	−0.268	0.1855	−0.340	0.0897	−0.191	0.3505	−0.354	0.0758
Preoperative X5 (cmH₂O/L/s)	0.595	0.0013*	0.526	0.0058*	0.555	0.0033*	0.176	0.3911
Preoperative Fres (Hz)	−0.642	0.0001*	−0.573	0.0022*	−0.599	0.0012*	−0.227	0.2640
Preoperative ALX (cmH₂O/L)	−0.615	0.0008*	−0.558	0.0030*	−0.573	0.0022*	−0.221	0.2790

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