Acute renal failure – definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group

Table 2 Physiologic markers of renal function

Specific for	Measurable	Acceptable?¹	Realistic/time-related?²
GFR	PAH	No	No
	Creatinine	Yes	Yes
	Creatinine clearance	2-hour: yes	Yes
		24-hour: yes	No
	BUN	Yes	Yes
	Inulin clearance	Yes	No
	Iohexol/iopromide	Yes	Yes
	Iothalmate	Yes	Yes
	I¹³¹-MAG	Yes	No
	Cr⁵²-EDTA	Yes	No
Renal blood flow	Angiography	Yes	No
	Indicator dilution (thermal or PAH)	Yes	No
	BOLD MRI	Yes	No
	Ultrasound	Yes	Yes
Tubular function	Urine output	Yes	Yes
	Input-output balance	Yes	Yes
	Urinalysis	Yes	Yes
	FeNa	Yes	Yes
	Osmolality	Yes	Yes
	Creatinine (U/P)	Yes	Yes
	Tubular proteins	No	No

¹The term 'acceptable' refers to the consensus view that each one of these tests represents a marker that reflects the function being measured with sufficient specificity and sensitivity for experimental and clinical use. ²The term 'realistic' refers to consensus of the current feasibility of using such markers in clinical practice. BOLD, blood oxygenation level dependent; BUN, blood urea nitrogen; MRI, magnetic resonance imaging; PAH, para-aminohippuric acid; U/P, urine/plasma.