Table 5.

Multivariable regression analysis

	Final model
	Regression coefficient B	95% CI B	SE of B	P
Constant	0.601	0.476–0.726	0.064	<0.001
Systemic circulation
Vasopressor support*	0.059	0.035–0.084	0.012	<0.001
Central venous pressure (CVP; cmH2O)	0.006	0.003–0.009	0.002	<0.001
Pulse pressure index (PPI)	0.418	0.275–0.561	0.073	<0.001
Mean arterial pressure (MAP; mmHg)	−0.001	−0.002–0.000	0.001	0.006
Membrane capacitance
Reactance (Xc/m)	−0.001	−0.003–0.000	0.001	0.045
Renal function
Pre-admission eGFR, mL/min	−0.001	−0.002–0.000	0.000	0.097

RRI = 0.601 + vasopressor support × 0.059 + CVP × 0.006 + PPI × 0.418 – MAP × 0.001 – reactance/m × 0.001 – preadmission eGFR × 0.001.

^*0 = no vasopressor support; 1 = vasopressor support.

Sample size = 92; mean adjusted R² = 0.587 [minimum 0.552 − maximum 0.638]; mean standard error of estimate = 0.053.

SE indicates standard error.