Acute kidney injury – ‘screen’ (tests)

All of these tests should be considered in patients with acute renal failure. Be selective, but keep an open mind even if the diagnosis appears to be clear. The list applies also to patients with a lesser degree of renal impairment who have an acute or immunological renal illness. The blue spot indicates ­ do it in everyone.

Test Essential Comments
FBC + plats, film, diff film essential in ARF
(ESR) misleading; do CRP instead
CRP
Clotting screen additional tests if abnormal
Group & save
Biochemistry
Calcium & phosphate even a high-normal Ca is abnormal
Myoglobin, CK if rhabdomyolysis possible
Blood cultures do in almost all with ARF of whatever cause
Other cultures wound, sputum, catheters etc
Hepatitis and HIV serology urgent HepB +HIV may need dialysis; but also for other disease
CMV, VZV if to be immunosuppressed; consider EBV and HIV also
ASOT / throat swab / other if post-strep GN possible
Other serology leptospires syphilis, hantavirus, etc., (rarely)
MSU
Bence Jones protein patients >35y with poorly explained ARF
Urinary prot 24h or spot protein/creatinine ratio
CXR
Renal ultrasound USUALLY URGENTLY REQUIRED
ECG if >40 or any risk factors for cardiac arrest
Pulmonary function in systemic disease, acutely and after recovery
Immunoglobins, prot elec in most patients
Complement in almost all
ANF, etc and DNA antibodies if ANF positive
ENA if suspect interstitial nephritis or atypical SLE
Rheumatoid factor
ANCA all possibly inflammatory disease
Anti-GBM all possible RPGN
Cryoglobulins if C4 low or otherwise indicated

 

Acknowledgements:   Neil Turner, David Kluth and John Neary were the main authors for this page. The last modified date is shown in the footer.