AKI.pptxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Dyydgdyxyxydydyf

1. ACUTE KIDNEY INJURY Dr. Tushabe Supervisor Dr Tutu

2. Outline Definition Etiology Pathophysiology Diagnostic criteria Management

3. Definition Previously denoted as Acute Renal Failure can be defined as a sudden and often reversible reduction in kidney function as measured by increased creatinine or decreased urine volume.

4. Etiology Prerenal Intra renal Post renal Can overlap and can be interrelated

5. Pre renal etiology As a result of reduced blood flow to the kidneys Hypovolemia: hemorrhage, severe burns, GI fluid loss such as diarrhea, vomiting, high output stomas Hypotension: septic shock, anaphylaxis, cardiogenic shock(decreases cardiac output), massive PE, acute coronary syndrome Renal vasoconstriction: NSAIDs, iodinated contrast, amphotericin B, calcineurin inhibitors, hepatorenal syndrome Glomerular efferent arteriolar vasodilation: ACE inhibitors, ARBS

6. Intrinsic renal etiology Conditions that affect the glomerulus or tubule Acute tubular necrosis: ischemia from prolonged prerenal injury. Drugs such as vancomycin, Amp B, pentamidine, aminoglycosides, iodinated contrast Acute interstitial Nephritis: drugs such as beta lactam abx , penicillins , NSAIDs, PPI, 5-ASA, auto immune conditions such as SLE, hereditary AIN Glomerulonephritis: SLE, post infectious glomerulonephritis, cryoglobinemia , igA nephropathy, igA vasculitis Intratubular obstruction: multiple myeloma, tumor lysis syndrome, hemolytic anemia, toxins such as ethylene glycol

7. Post renal etiology Obstructive causes which lead to congestion and urinary backflow Renal/ ureteral calculi Tumors Blood clots Neurogenic bladder Urethral obstruction

8. Pathophysiology The common end point in acute tubular necrosis is a cellular insult secondary to ischemia or direct toxins, which results in effacement of the brush border, cell death and decreased function of tubular cells

9. Criteria for diagnosis RIFLE AKIN( Acute Kidney Injury Network) KDIGO( Kidney Disease: Improving Global Outcome) Among these, KDIGO is the most recent and most commonly used tool

10. KDIGO criteria Increase in serum creatinine by 0.3mg/dl or more within 48 hours Increase in serum to 1.5 times or more than the baseline of the prior 7 days Urine volume of less than 0.5mL/kg/ hr for at least 6 hours

11. RIFLE criteria Defines 3 categories of impairment- risk, injury and failre and 2 categories of long term renal outcomes- loss and ESRD Whichever criterion shows the most impairment is used for classification. When baseline Cr is unknown, a baseline GFR between 75 and 100ml/min is assumed, or the modified diet in Renal Disease equation can be used to calculate an estimated baseline AKIN criteria is the modified RIFLE. RIFLE and KDIGO systems have higher sensitivity than AKIN.

12. Management Best way to determine if the AKI is prerenal or not is a fluid challenge Many causes overlap between prerenal and intrinsic Some AKI patients tend to develop fluid overload, correct with diuretics to avoid pulmonary and cardiac complications Find cause and manage appropriately In some cases short term RRT is needed for AKI until the kidneys function recovers.

13. Contn …. Acidosis(<7.2 despited normal or low PP of c02 in arterial blood) Electrolyte imbalance( hyperkalemia of >6.5mmol/L) Intoxication( lithium, ethyl glycol) Overload( especially severe pulmonary edema) Uremia(encephalopathy, pericarditis, neuropathy)