Table 3.

Multiple logistic and linear regression analysis of the relationship between the Fluid Retention Index (FRI) and the perioperative variables.

Fluid Retention Index (FRI)	Factors in multivariate analysis	Odds ratio (95% CI)	P-value
FRI > 4.0(Dehydration)	Age (year)	0.94 (0.91–0.96)	<0.001
	Food intolerance (days)	1.22 (1.09–1.36)	<0.001
	Urine output (L)	0.102 (0.026–0.391)	<0.001
	Infused Ringer (L)	2.01(1.34–3.02)	<0.001
	Postoperative P-glucose (mmol/L)	0.72 (0.55–0.94)	0.02
FRI continuous scale 1–6	Extubation time (min)	1.011 (1.077–1.015)	<0.001
	MAP before induction (mmHg)	0.992 (0.984–0.999)	0.024
	Infused Ringer (L)	1.41 (1.28–1.55)	<0.001
	Urine output (L)	0.32 (0.25–0.41)	<0.001
	PACU time (min)	0.996 (0.992–0.999)	0.006
	MAP ratio surgery/baseline	1.76 (1.00–3.10)	0.048

The variables are presented in the order they were included in the stepwise regression.

MAP, mean arterial pressure; PACU, postoperative care unit.