24 radman acute renal failure


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24 radman acute renal failure

  1. 1. DR. SAMI ABDO RADMAN Acute Renal Failure
  2. 2. Acute Renal Failure <ul><li>Definition </li></ul><ul><li>Acute renal failure (ARF) is a syndrome defined as an abrupt decrease in glomerular filtration rate sufficient to result in retention of nitrogenous waste products (blood urea nitrogen [BUN] and creatinine ) and perturbation of extracellular fluid volume and electrolyte and acid-base homeostasis </li></ul>
  3. 3. <ul><li>Usually, but not invariably , reversible over a period of days or weeks. </li></ul><ul><li>Detsufficiently severe to result in uraemia </li></ul><ul><li>Oliguria is usually, but not invariably, a feature. </li></ul><ul><li>Cause sudden, life-threatening biochemical erioration in renal function is disturbances </li></ul><ul><li>Is a medical emergency .. </li></ul>
  4. 4. Causes <ul><li>ARF can result from </li></ul><ul><li>(1) diseases that cause a decrease of renal blood flow ( prerenal azotemia ( </li></ul><ul><li>(2 diseases that directly involve renal parenchyma ( renal azotemia) </li></ul><ul><li>(3) diseases associated with urinary tract obstruction ( postrenal azotemia) </li></ul>
  5. 5. Prerenal uraemia <ul><li>Is the most common form of ARF </li></ul><ul><li>There is impaired perfusion of the kidneys with blood. </li></ul><ul><li>Hypovolaemia, </li></ul><ul><li>Hypotension, </li></ul><ul><li>Impaired cardiac pump efficiency or </li></ul><ul><li>Vascular disease limiting renal blood flow, </li></ul><ul><li>Or combinations of these factors </li></ul><ul><li>Excretory function in prerenal uraemia improves once normal renal perfusion has been restored. </li></ul>
  6. 6. CLINICAL MANIFESTATIONS <ul><li>Thirst, dizziness </li></ul><ul><li>Hypotension and tachycardia, </li></ul><ul><li>Reduced jugular venous pressure, </li></ul><ul><li>Decreased skin turgor, </li></ul><ul><li>Dry mucous membranes, </li></ul><ul><li>Reduced axillary sweating. </li></ul><ul><li>History of intake of hypotensive drugs </li></ul>
  7. 7. Management <ul><li>Correction of hypovolaemia and hypotension, </li></ul><ul><li>Treatment of the undelying cause </li></ul><ul><li>recovery typically takes 1 to 2 weeks after normalization of renal perfusion </li></ul>
  8. 8. Postrenal uraemia <ul><li>Obstruction of the urinary tract at any point from the calyces to the external urethral orifice. </li></ul><ul><li>Clinical exam: </li></ul><ul><li>Tenderness on the suprabubic region or renal angle </li></ul><ul><li>History of stones </li></ul><ul><li>History of Prostatic disease </li></ul><ul><li>Treatment </li></ul><ul><li>Removal of the obstruction </li></ul>
  9. 9. Renal Azotemia <ul><li>Acute uraemia due to renal parenchymal disease (Acute tubular necrosis, ATN) </li></ul><ul><li>This is most commonly due to acute renal tubular necrosis ( Due to acute ischemic or nephrotoxic insult ) </li></ul><ul><li>Causes </li></ul><ul><ul><li>Haemorrhage </li></ul></ul><ul><ul><li>Burns </li></ul></ul><ul><ul><li>Diarrhoea and vomiting </li></ul></ul><ul><ul><li>Diuretics </li></ul></ul><ul><ul><li>Myocardial infarction </li></ul></ul>
  10. 10. <ul><li>Congestive cardiac failure </li></ul><ul><li>Snake bite </li></ul><ul><li>Myoglobinaemia </li></ul><ul><li>Haemoglobinaemia (due to haemolysis, e.g. in falciparum malaria, 'blackwater fever) </li></ul><ul><li>Hepatorenal syndrome </li></ul><ul><li>Drugs, e.g. aminoglycosides, NSAIDs, ACE inhibitors </li></ul>
  11. 11. <ul><li>N.B: </li></ul><ul><li>In liver failure, acute renal result from rapidly reversible vasomotor abnormalities within the kidney. </li></ul><ul><li>A kidney removed from a patient with hepatic cirrhosis and liver failure dying with oliguric renal failure may function normally immediately after transplantation into a normal individual </li></ul>
  12. 12. Pathogenesis <ul><li>Intrarenal microvascular vasoconstriction : </li></ul><ul><li>Tubular cell injury </li></ul><ul><ul><li>Ischaemic injury results in rapid depletion of intracellular ATP stores resulting in cell death </li></ul></ul><ul><li>Glomerular contraction reducing the surface area available for filtration </li></ul><ul><li>Obstruction of the tubule by debris shed from ischaemic tubular cells </li></ul>
  13. 13. Clinical Course <ul><li>Depending on the severity and duration of the renal insult. </li></ul><ul><li>Oliguria is common in the early stages: non-oliguric renal failure is usually a result of a less severe renal insult. </li></ul><ul><li>Recovery of renal function typically occurs after 7-21 days, </li></ul><ul><li>ATN may last for up to 6 weeks, even after a relatively short-lived initial insult </li></ul>
  14. 14. Clinical and biochemical features <ul><li>The features of the causal condition together with features of rapidly progressive uraemia </li></ul><ul><li>serum urea and creatinine concentrations depend upon the rate of tissue breakdown(trauma, sepsis and surgery) </li></ul><ul><li>Pulmonary oedema </li></ul>
  15. 15. <ul><li>Symptoms of uraemia such as </li></ul><ul><ul><li>anorexia, </li></ul></ul><ul><ul><li>nausea, vomiting </li></ul></ul><ul><ul><li>pruritus develop, </li></ul></ul><ul><ul><li>drowsiness, fits, coma and haemorrhagic episodes. </li></ul></ul><ul><ul><li>Epistaxes and gastrointestinal haemorrhage </li></ul></ul><ul><ul><li>Severe infection may have initiated the acute renal failure or have complicated it owing to the ( impaired immune defences ) </li></ul></ul>
  16. 16. URINALYSIS in ARF <ul><li>Anuria suggests complete urinary tract obstruction OR severe cases of prerenal or intrinsic renal ARF </li></ul><ul><li>Wide fluctuations in urine output raise the possibility of intermittent obstruction, </li></ul><ul><li>Polyuria in partial urinary tract obstruction </li></ul><ul><li>Transparent hyaline casts In prerenal ARF, </li></ul><ul><li>(secreted by epithelial cells of the loop of Henle) </li></ul>
  17. 17. <ul><li>Hematuria and pyuria are common in patients with intraluminal obstruction or prostatic disease. </li></ul><ul><li>Epithelial casts present in ATN (ischemic or nephrotoxic ARF) </li></ul><ul><li>Red blood cell casts indicate glomerular injury </li></ul>
  18. 18. <ul><li>Eosinophiluria is common in antibiotic-induced allergic interstitial nephritis </li></ul><ul><li>Bilirubinuria may provide a clue to the presence of hepatorenal syndrome. </li></ul><ul><li>Urine should be tested for free haemoglobin and myoglobin, </li></ul>
  19. 19. Laboratory findings in ARF <ul><li>Blood tests include measurement of serum urea, electrolytes, creatinine, calcium, phosphate, albumin, </li></ul><ul><li>Increase serum Creatinin </li></ul><ul><li>Hyperkalemia, hyperphosphatemia, hypocalcemia </li></ul><ul><li>Severe anemia in the absence of hemorrhage indicates hemolysis </li></ul><ul><li>Systemic eosinophilia suggests allergic interstitial nephritis </li></ul>
  20. 20. RADIOLOGICAL INVESTIGATIONS <ul><li>A plain film of the abdomen </li></ul><ul><li>Ultrasonography </li></ul><ul><li>Pelvicalyceal dilatation is usual with urinary tract obstruction </li></ul><ul><li>Retrograde or anterograde pyelography </li></ul>
  21. 21. Management <ul><li>General measures </li></ul><ul><ul><li>Consistent documentation of fluid intake and output, </li></ul></ul><ul><ul><li>Measurement of daily bodyweight </li></ul></ul><ul><li>Emergency measures </li></ul><ul><ul><li>Correction of acidosis with intravenous sodium bicarbonate </li></ul></ul><ul><ul><li>Pulmonary oedema Duiretics </li></ul></ul><ul><ul><li>Treatment of sepsis </li></ul></ul><ul><li>Fluid and electrolyte balance </li></ul><ul><li>Diet </li></ul><ul><ul><li>Protien restriction (40 gm daily) </li></ul></ul><ul><ul><li>sodium and potassium restriction </li></ul></ul>
  22. 22. Management …cont <ul><li>Dialysis is indicated in </li></ul><ul><ul><li>Symptoms of uraemia </li></ul></ul><ul><ul><li>Complications of uraemia, such as pericarditis </li></ul></ul><ul><ul><li>Hyperkalaemia not controlled by conservative measures </li></ul></ul><ul><ul><li>Pulmonary oedema </li></ul></ul><ul><ul><li>Severe acidosis </li></ul></ul><ul><ul><li>For removal of drugs causing the acute renal failure, e.g. Gentamicin, lithium, severe aspirin overdose. </li></ul></ul>