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.

Bellomo et al. Critical Care 2004 8:R204   doi:10.1186/cc2872

Open Data