Acute Renal Failure

Overview

Acute renal failure is a syndrome of decreased renal function, measured by serum creatinine or urine output, occurring over hours-days. It includes different aetiologies and multifactorial. It is usually reversible and accompanied by reduction in urine volume. When faced with an abnormally high creatinine it is important to establish if this is acute, acute on chronic or chronic renal disease. There may be many possible causes of acute renal failure. The clinical picture is often dominated by the underlying condition. If the cause cannot be rapidly corrected the renal function, temporary renal replacement therapy may be required.

Signs and Symptoms

Reduced urine output, Marked hypotension, Postural hypotension (valuable sign of hypovolemia), Flank pain, Hematuria, Edema, Nausea, Poor peripheral perfusion(delayed capillary return)

Common Causes

Heart failure, Blood or fluid loss, Renal artery occlusion, Toxicity (NSAIDs, ACEIs, ARBs), Shock (hemorrhagic, septic), Acute tubular necrosis, Glomerulonephritis, Infection, Infiltration (sarcoid), Vasculitis, Disseminated intravascular coagulation, Hemolytic uraemic syndrome, Stone, Stricture, Prostatic enlargement, Pelvic malignancy

Risk Factors

Advanced age, Peripheral artery disease, Diabetes mellitus, High blood pressure, Heart failure, Liver diseases, On NSAIDs (ibuprofen), ACE inhibitors and aminoglycosides drugs, Undergoing chemotherapy or radiotherapy, Prolonged hospitalisation

Investigation Techniques

Full blood count , Coagulation profile, Urea and creatinine, Electrolytes, Calcium and phosphates, C-reactive protein, Albumin, Urine FEME, Renal ultrasound, Chest X-ray, ECG

Treatment and Prevention

Treat the underlying cause, Optimising systemic hemodynamics. Note the fluid status, whether hypovolaemia or fluid overload, before administering any fluids, Correct metabolic acidosis Restoration of blood volume will correct acidosis, however sodium bicarbonate may be used if acidosis is severe, Giving sodium bicarbonate will generate CO2 thus adequate ventilation is therefore needed to prevent respiratory acidosis worsening the clinical picture, Sodium bicarbonate may also aggravates fluid overload in vulnerable patients, Renal replacement therapy