Acute Renal Failure (Acute Kidney Injury - AKI) is a sudden, rapid decline in renal filtering function occurring within hours to days. It leads to nitrogenous waste accumulation (uremia), fluid overload, and dangerous electrolyte disturbances.
Clinical Classification of Causes
- 1. Pre-Renal AKI (Reduced Blood Flow to Kidneys):
- Severe dehydration, hypovolemic shock, or massive blood loss.
- Congestive heart failure (decreased cardiac output).
- Sepsis / Septic shock causing systemic vasodilation.
- Hepatorenal syndrome in advanced liver failure.
- 2. Intrinsic AKI (Direct Kidney Parenchymal Damage):
- Acute Tubular Necrosis (ATN) from severe ischemia or nephrotoxins.
- Nephrotoxic drugs: NSAIDs, Aminoglycoside antibiotics, Radiocontrast dyes.
- Glomerulonephritis, Acute Interstitial Nephritis (AIN).
- Autoimmune diseases (Systemic Lupus Erythematosus, Vasculitis).
- 3. Post-Renal AKI (Urine Outflow Blockage):
- Bilateral kidney stones or ureteral calculi.
- Benign Prostatic Hyperplasia (BPH) or prostate cancer in men.
- Bladder, cervical, or pelvic retroperitoneal tumors.
Symptoms of Acute Renal Failure
- Oliguria (significantly reduced urine output < 400 mL/day) or Anuria (no urine output).
- Fluid retention causing swelling (edema) in legs, feet, ankles, face, or abdomen.
- Severe fatigue, weakness, and nausea/vomiting due to uremic toxin buildup.
- Shortness of breath (dyspnea) from pulmonary fluid accumulation.
- Confusion, drowsiness, or seizures due to uremic encephalopathy or hyponatremia.
- Cardiac arrhythmias (irregular heartbeat) caused by severe hyperkalemia (high potassium).
🚨 Emergency Red Flag Warning Signs
Seek emergency ICU care immediately if experiencing: No urine output for 12+ hours, severe chest pain/shortness of breath, severe confusion, or seizures.
Treatment & Immediate Protocol
- Emergency hospitalization and vital organ monitoring.
- Hemodynamic fluid resuscitation for pre-renal hypovolemia OR strict fluid restriction if fluid overloaded.
- Immediate discontinuation of all nephrotoxic medications.
- Correction of hyperkalemia (calcium gluconate, insulin + dextrose, sodium polystyrene).
- Surgical or endoscopic relief of urinary tract obstruction (Foley catheter, ureteral stent).
- Emergency Hemodialysis for severe refractory hyperkalemia, fluid overload, or uremia.
