Three broad classifications of acute respiratory failure etiologies based on regional ventilation and perfusion by electrical impedance tomography: a hypothesis-generating study

Annals of Intensive Care

Table 3 ROC areas and cutoff value of parameters for identifying PE, DLD and FLD in 93 ARF patients

Items	Parameters used	ROC area	95% CI	Cutoff value	Sensitivity (%)	Specificity (%)
Identification of PED (14/93 PED)	DeadSpace_%	0.894^a	0.821–0.945	> 30.37%	78.6	92.4
	Defect_Q score	0.787^a	0.672–0.902	> 3.5	21.4	100
	VQ Match_%	0.752^a	0.624–0.885	< 36.6%	35.7	96.2
	Shunt_%	0.697^a	0.575–0.819	< 3.23%	7.1	91.1
	LR-V/Q (%)	0.750^a	0.577–0.923	> 1.72	50	94.9
	d-Dimer (mg/L FEU)	0.457	0.328–0.586	> 6.1	14.3	60.8
Identification of DLD (21/93 DLD)	Defect_V score	0.837	0.754–0.920	< 0.5	76.2	79.2
	Defect_Q score	0.726	0.621–0.832	< 0.5	85.7	55.6
	Defect_V+Q score	0.893	0.828–0.959	< 0.5	66.7	90.3
Identification of FLD (58/93 FLD)	Defect_V score	0.832	0.750–0.915	> 2.5	39.7	97.1
	Defect_V+Q score	0.745	0.644–0.846	> 4.5	20.7	97.1
	Shunt_%	0.674	0.565–0.783	> 29.3%	34.5	91.4
	DeadSpace_%	0.728	0.621–0.835	< 7.9%	25.9	91.4

PED: pulmonary embolism-related disease; DLD: diffuse lung involvement disease; FLD: focal lung involvement disease; ARF: acute respiratory failure; ROC: receiver operating characteristic; CI: confidence interval; LR-V/Q (%): relative regional ventilation/corresponding regional perfusion of the lower right region of interest
^aP < 0.05 vs. d-dimer