Acute Renal Failure .pdf

ACUTE RENAL FAILURE DR. Bandar AL-haguri ACUTE RENAL FAILURE ❖ Definition: Acute renal failure (ARF) refers to a sudden onset and reversible loss of renal function, which develops over a pe...

ACUTE RENAL FAILURE DR. Bandar AL-haguri ACUTE RENAL FAILURE ❖ Definition: Acute renal failure (ARF) refers to a sudden onset and reversible loss of renal function, which develops over a period of days to weeks and is usually accompanied by a reduction in urine volume. ❖ Etiological of ARF:  Prerenal: 1. Hypovolemia: Hemorrhage Fluid loss due to vomiting, diarrhea, and dehydration. Diabetic ketoacidosis. Acute pancreatitis. Sepsis. 2. Congestive heart failure. 3. Decompensated: Liver cirrhosis Hepatorenal syndrome 4. Renal artery or veins occlusion/ stenosis.  Intrinsic renal disease: Intrinsic renal 1. Tubular disease: Acute tubular necrosis. It can be ischemic or toxic cause. ✓ Ischemic: caused by prolonged pre-renal cause for ARF, that resulted in tubular ischemic injury. ✓ Toxic: Drugs: (Gentamycin, Cephalosporin NSAID), Hyperuricemia, Multiple myeloma methyl alcohol, excess salicylates, paraldehyde, and radio-contrast dye. 2. Untreated prerenal failure 3. Acute glomerulonephritis 4. Interstitial nephritis drugs: Hypersensivity drugs Systemic infection 1  ACUTE RENAL FAILURE DR. ABDULNASSER AL-QADI 5. Vascular: Vasculitis  Post –renal (obstructive): 1. Obstructive uropathy. 2. Bilateral ureter obstruction stone. 3. Ureter structure obstruction. 4. Urethra stone obstruction. 5. Urethra structure obstruction. ❖ Pathophysiology: 1. Reduction of the GFR results in uremic manifestations and hyperkalemia. 2. As a result of increased filtration per nephron 10-20% of the filtered water and sodium are excreted in urine (in contrast to 0.5 to l % in the normal situation). In cases where the GFR is only reduced to 35ml/min this can result in urine volume greater than 400ml/day resulting in non-oliguric ARF. 3. In the early diuretic phase tubular regeneration occurs but the afferent arteriolar constriction persist resulting in an increasing urinary volume but no decrease in the serum creatinine. As the renal vasoconstriction decreases the GFR increases, and the creatinine starts dropping. 4. Loss of tubular functions leads to acidosis and hyperkalemia. 5. Disturbances in calcium and phosphorous and renal anemia are less prominent than in CRF. ❖ Clinical Manifestations: 1. Decrease urine output 300 ml during 24 h. 2. Sever fatigue, malaise, weakness, drowsiness, confusion, convulsion, and shortness of breath, seizures, or coma in severe cases. 3. Anorexia, nausea, vomiting, pale and anemia. 4. Fluid retention, causing swelling in your legs, ankles, or feet. 5. Flank pain (between ribs and hips). 6. Cardiovascular (edema lower limb, pulmonary edema, uremic pericarditis, precordial effusion and dyspnea). 7. Itching due to position of uremic to toxin. 8. Acidosis: uremic acidosis. ❖ Diagnosis of ARF: 1. Raised blood urea & creatinine. 2  ACUTE RENAL FAILURE DR. ABDULNASSER AL-QADI 2. Urine analysis normal in acute renal failure while abnormal in chronic renal failure 3. Abdominal U/S kidney: normal size in acute renal failure while abnormal in chronic renal failure 4. CBC: anemia. 5. Elevated ESR. 6. Serum electrolyte 7. Hyperkalemia: Hypercalcemia ❖ Management of ARF: 1. Pre-renal AKI: Volume Replacement: If dehydration or blood loss is the cause, Optimize Cardiac Function: If heart failure is the cause, Avoid Nephrotoxic Medications: Such as NSAIDs, certain antibiotics, and contrast dyes. Address Underlying Causes: Such as sepsis or other systemic conditions. 2. Intrinsic (Renal) AKI: Avoid Nephrotoxic Medications: As mentioned above. Optimize Hemodynamics: Ensure adequate blood flow to the kidneys. Dialysis: In cases of severe AKI or when there are life-threatening complications like hyperkalemia, metabolic acidosis, or fluid overload. 3. Post-renal AKI: Relieve Obstruction: This is the primary treatment. Methods include: Catheterization: For bladder outlet obstruction. Nephrostomy tubes: For obstructions higher up in the urinary tract. Treat Underlying Causes: Such as prostate enlargement or tumors. 4. General Management: Monitor Fluid and Electrolyte Balance: Regularly check serum creatinine, electrolytes, and urine output. Nutritional Support: A diet low in potassium, phosphorus, and sodium might be recommended. Proteins are restricted 0.8 gm/ K/gm/day Medication Review: Adjust doses of medications cleared by the kidneys. 5. Post renal: Nephrostomy. 3 ACUTE RENAL FAILURE DR. ABDULNASSER AL-QADI Dialysis indication: 1. Acute or sudden illness. 2. Metabolic acidosis. 3. Electrolyte imbalance such as severe hyperkalemia. 4. Overload of fluid in the body that diuretics cannot relieve. 5. Acute poisoning. 6. Uremic encephalopathy. 7. Uremic pericarditis. 8. Pulmonary edema 4