Risk factors

  • chronic kidney disease = major risk factor for AKI

  • DM

  • HTN

  • obestiy

  • proteinuria

Causes

Pre-renal

  • hypovoelaemia

    • diarrhoea, vomiitng

    • diuretics

    • osmotic diuresis - from poorly controlled DM

    • haemorrhage

    • truama (shock)

    • sepsis (shock)

  • Decreased effective blood volume

    • heart failure

    • cirrhosis

  • Vasoregulation

    • NSAIDs

    • ACEi or ARB

    • Hypercalcaemia

Intrinsic

  • direct damage to nephron

    • complex

    • may be secondary to another illness

  • Acute tubular necrosis = most common

    • as result of pre-renal injury or

    • direct toxicity

      • hypotension

      • hypovolaemia

      • haemolysis

      • rhabdomyolysis

      • nephrotoxic meds

        • NSAID

        • lithium

        • aminoglycosides

    • pre rneal + ATN = 90% AKI

  • Medication induced

    • high mortality

  • Acute glomerulonephritis

    • small vessel vasculitis

    • uncommon but improtamtn

    • early diagnosis and appropriate treatment prevents end-stage CKD

Post-renal

  • blockage to flow of urine

  • back-pressure to kidney: damage to nephrons

  • obstructive nephropathy

    • uncommon = 5%

  • urinary tract sotnes

  • prostatic hypertrophy

  • intra-abdominal process encasing ureters

Prevention

CKD guidelines

  • check renal function as per guideliens

medications

  • Triple whammy

    • NSAID

      • blocks prostaglandin-mediated afferent arteriolar vasodilation

    • ACEi

      • blood flow to kidney can’t be reduced

      • efferent arteriolar vasoconstriction prevented

    • diuretics

      • decrease GFR exacerbated

  • Many cause intrinsic acute renal injuyr

    • frusemide

    • ppi

    • beta lactam

    • aminoglyucoside

    • colchicine

    • phenytoin

History

  • acute recent illness

  • symptoms of outflow obstruction

  • history of abdominal or pelvic malignancy

    • obstruction/myeloma

  • systemic symptoms

    • rahs

    • joint/muscle pain

  • current prescribed and OTC medicine or recent contrast radiology

  • pre-existing conditions

exam

  • hydration

  • systemic disease

    • fever

    • skin rashes

    • joint swelling

    • iriits

    • vasuclar disases

    • organomegaly

    • AA

    • bladder

  • urinalysis

  • ecg if K+ >5.5

Refer

  • discuss especially if active sediment

    • positive blood and protein

red flags

  • negligible UO for 6hrs or \<200mL over 12hrs

  • serum K+ >7 or \<5.5 with ECG changes

  • Volume overload

  • Cr >300 or change of 50%