Acute Renal Failure
Also written as ARF.
Acute renal failure is a common complication of malaria
Acute Renal Failure (ARF)
- Defined by urine output < 450 mL/day with rising blood urea ( 6.7 mMol/L) .
- Causes : Pre-renal failure : Hypovolemia, low cardiac output, renovascular obstruction.
- Intra-renal failure : Acute tubular necrosis (ischemic/toxic), glomerulonephritis, interstitial nephritis.
- Post-renal failure : Urinary obstruction (e.g., prostate enlargement, stones).
- Distinguishing Pre-renal vs. Intra-renal Failure : Test Pre-Renal Intra-Renal Urine Na⁺ (mMol/L) < 20 40 Urine/Plasma Osmolality Ratio 1.4 < 1.1 Urine/Plasma Urea Ratio 14 < 10
Read this in Liver Function Tests (LFTs)
Acute Renal Failure (ARF)
- Definition : Urine <450 mL/day + rising urea (normally 1.7-6.7 mMol/L)
- Urea rise : 5 mMol/L/day (up to 15 in surgery/trauma/bleeding)
Read this in KIDNEY FUNCTION TESTS & GASTRIC FUNCTION
What our notes say
- Acute renal failure is a common complication of malaria (Paediatrics Year 6 MBChB end of semester CAT: clinical case MCQs, 29 of 30 quest)
- Characterized by acute renal failure with tubular epithelial necrosis (Acute Tubular Injury (ATI): AKI Causes, Pathology & Prognosis)
- Monitor urine output closely — acute renal failure is the major cause of death (Blood Transfusion: ABO, Rh Blood Groups, Compatibility & HDN)
- Acute Renal Failure (ARF), now commonly referred to as Acute Kidney Injury (AKI), is a sudden decline in renal function, leading to decreased glomerular filtration rate (GFR), retention of waste products, fluid imbalance, and electrolyte disturbances. (CLINICAL BIOCHEMISTRY LAQs & SAQs)
- Acute renal failure with suspected systemic lupus erythematosus (renal pathology — Past Paper Questions & Answers)
- Sodium and water retention: acute renal failure, heart failure (secondary hyperaldosteronism). (Eoy paper 2 gen systemic Patho 2025 — Past Paper Questions & Answers)