Reliability of the nitrogen washin-washout technique to assess end-expiratory lung volume at variable PEEP and tidal volumes

Intensive Care Medicine Experimental

Table 1 Statistical modeling of the bias between EELV _WI-WO and EELV _CT as a function of confounding variables

	AIC	Statistical significance
Model 1: No explanatory variable	2992
Model 2: Adjusting for V_T	2994	V_T: p = 0.55
Model 3: Adjusting for PEEP	2868	PEEP: p < 0.0001
Model 4: Adjusting for EELV_Base	2980	EELV_Base: p < 0.0001
Model 5: Final model adjusting for V_T, PEEP, EELV_Base and their three-way interaction	2821	three-way interaction: p < 0.0001
		V_T × PEEP interaction: p < 0.0001
		V_T × EELV_Base: p < 0.001
		PEEP × EELV_Base: p < 0.0001
		V_T: p < 0.001
		PEEP: p < 0.0001
		EELV_Base: p < 0.05

AIC, Akaike information criterion; EELV, end-expiratory lung volume; EELV_Base, EELV baseline value (ARDS onset, PEEP 0 cm H₂O); PEEP, positive end-expiratory pressure; V_T, tidal volume.