ACUTE KIDNEY INJURY Martin Havrda

Acute kidney injury - RIFLE Risk –50% rise of s-creatinine –25% drop of GFR –Urine output < 0,5 ml/kg.h during 6 hours Injury –100% rise of s-creatinine –50% drop of GFR –Urine output < 0,5 ml/kg.h during 12 hours Failure –200% rise of s-creatinine –75% drop of GFR –Urine output < 0,5 ml/kg.h during 24h or anuria for 12h Loss –Loss of renal function (need of dialysis) for > 4 weeks ESRD –Loss of renal function (need of dialysis) for > 3 months Acute Dialysis Quality Initiative, 2004 (Bellomo et al, Crit Care)

Acute kidney injury - AKIN Diagnostic criteria AKI –Sudden (during 48h) rise of s-creatinine ≥ 26 umol/l above the baseline ≥ 50% above the baseline –Urine output < 0,5 ml/kg.h during 6 hours –Valid only after the correction of volume depletion and exclusion of urinary tract obstruction. AKI stage … corresponding to RIFLE –Stage 1 = risk –Stage 2 = injury –Stage 3 = failure

Reason for acute or rapidly progressive loss of GFR? Prerenal injury. –Intact kidneys, functional drop of GFR. Vascular injury. –Malignant hypertension, HUS-TTP, vasculitis. Glomerular injury. Tubular obstruction. –LC, myoglobin, haemoglobin, uric acid, crystals Acute tubular necrosis. –Ischemic, toxic Acute tubulointerstitial nephritis. –Allergic, toxic... Postrenal injury.

New biomarkers Urinary tubular enzymes. Urinary low molecular weight proteins. NGAL. Urinary KIM-1. Urinary IL-18. Panels of biomarkers.

Prerenal loss of GFR (renal blood flow). Volume depletion –Vomiting, diarrhea, GIT bleeding. –Polyuria. –Combustion, sweating. –Frakture, crush injury. Hypotension –Shock –Relative hypotension (treatment of hypertension) Oedema –Heart failure, liver cirrhosis, nephrotic syndrome. Bilateral stenosis of renal arteries.. Hepatorenal syndrome. Medications that impair renal blood flow (RAS inhibitors, NSA, CyA)