TOC |  STAT Kidney


REF: Acute Renal Failure     |  Normotensive Ischemic Acute Renal Failure 2007
Cleveland Clinic J of Med  July 2002 Vo. 69:569 - Joseph V. Nally (

RX of the complications of intrinsic Acute Renal Failure:

  1. Rx for fluid overload:  fluid & salt restriction, diuretics, dialysis or ultrafiltration.
  2. Rx for hyponatremia:  water intake restriction
  3. Rx for hyperkalemia:  K diet restriction, avoid K+ sparing diuretics, Kayexalate 30 g 3-4x/d PO + 100 mL 20% sorbitol to prevent constipation (or 30-50 g in 200 mL sorbitol rectal enema q6h), Ca-gluconate 10% 10 mL amp over 5 min (be careful if pt on digoxin), NaHCO3 7.5% 1-2 amp + insulin 10-15 u in 500 mL D5W over a couple hours; IV Furosemide 40-80 mg; Florinef (fludrocortisone 0.1-1 g/d.)
    *   Dialysis !
  4. Rx for Metab. acidosis:  restrict diet protein <40-60 g/d; NaHCO3, Dialysis.
  5. Hypocalcemia Rx:  CaCO3, or Ca-gluconate 10% 10-20 mL
  6. Hyperphosphatemia Rx:  restrict diet phosphate intake, phosphate binding agents (CaCO3, Al-OH)
  7. Hypermagnesemia Rx:  avoid Mg++ containing antacids
  8. Hyperuricemia Rx:  usually not needed if < 15 mg/dL
  9. Nutrition Rx:  diet protein 0.5 g/kg/d, carbohydrate 100 g/d
  10. Drug dosage:  adjust for degree of renal impairment.
  11. Dialysis for intractable fluid overload, hyperkalemia, metab. acidosis, & uremic symptoms & signs.

Measures to prevent acute renal failure in hospitalized patients:


How to evaluate patients wirh Acute Renal Failure

Review records perform history & physical examination

Examine the urine sediment

Calculate urinary indices

Urine findings in Prenal azotemia vs Acute Renal Failure

Laboratory Tests               Prenal azotemia  or
 Acute renal failure or
 Postrenal azotemia
Specfic gravity        >1.018       <1.012
Urine osmolality      > 300 - 500      < 300 - 400
Urine Na (meq)      < 20 meq/l       > 40 meq/l
Urine/plasma creatinine       > 40         < 20
Renal failure index (U Na/ U/P creat)        < 1            >2
Fractional excreation Na (U/P Na/ U/P creat)x100      <1        >2
Response to fluid challenge    ++    ?
Urine sediment normal                                 hyaline cast brown granular casts, cellular debris

Differential Diagnosis of Acute Renal Failure - 3 Types

A. PRERENAL AZOTEMIA (due to underperfusion of an otherwise normal kidney)

  1. Hypovolemia: hemorrhage, GI fluid losses, diuretics, third spacing (pancreatitis, peritonitis, burns, traumatized tissue)
  2. Heart failure: CHF, MI, pericardial tamponade, acute PE
  3. Peripheral vasodilatation: bacteremia, antihypertensive medications
  4. Increased renal vascular resistance: anesthesia, surgical operation, hepatorenal syndrome.
  5. Renovascular obstruction, bilateral: thromboembolism

B. POSTRENAL AZOTEMIA  (due to obstruction of the urinary tract)
      - diagnosed by renal ultrasonography  to detect the Urinary Tract Obstruction.

  1. Urethral/bladder obstruction: prostate enlargement, plugged Foley catheter, stone, trauma, tumor(cancer), spasm, swelling (inflammation or infection), neurogenic bladder (+/ ganglionic blocking agents)
  2. Bilateral ureter obstruction a. Intraureteral: blood clots, sulfonamide & uric acid crystals, pyogenic debris, stones, edema, necrotizing papillitis. b. Extraureteral: tumor (cervix, prostate, endometriosis), periureteral fibrosis, accidental ureteral ligation during pelvic operation.


  1. Nephrotoxins, including hypersensitivity reactions
    a. Antibiotics: aminoglycosides, amphotericin B, vancomycin, sulfa, tetracycline, pesticides, fungicides; cephalosporin, pentamidine, Foscanet, Acyclovir, Indinavir, Ritonavir.  
    b. X ray contrast media or toxins  (esp. in Diabetes Mellitus)
    c. Heavy metals: mercury, lead, arsenic, bismuth, uranium, cadmium
    d. Ethylene glycol poisoning, carbon tetrachloride, other oranic solvents, pesticides, fungicides
    e. Other drugs & chemical agents: ACE Inhibitors; anesthetics (methoxyflurane, enflurane),  phenacetin, diphenylhydantoin, phenylbutazone, uric acids, calcium, poisonous mushroom, venom, NSAID, methotrexate, cis-platinum, cyclosporin, etc.
  2. Ischemic disorders - Acute Tubular Necrosis (ATN)
  3. Major blood vessel disease:
    renal artery thromboembolism, stenosis, bilateral renal vein thrombosis, dissecting aortic aneurysm.
  4. Diseases of glomeruli & small blood vessels:
  5. Interstitial nephritis:
    a. Drugs as Penicillin semisynthetic analogues, sulfonamides, tetracycline, cephalosporin, rifampin, coumadin, lasix, thiazide, azathioprine, allopurinol, phenytoin, tagamet, acyclovir.
    b. Diffuse infection
    c. Hypercalcemia  or hyperuricemia nephritis
    d. Postpartum renal failure
    e. SLE glomerulonephritis
    f . Vasculitis: polyarteritis nodosa, Sarcoidosis
  6. Renal allograft rejection

(REF: Harrison's Med Text )



Acute Renal Failure
Cleveland Clinic J of Med  July 2002 Vo. 69:569 - Joseph V. Nally

Acute Renal Failure
Naveen Singri, MD; Shubhada N. Ahya, MD; Murray L. Levin, MD
JAMA Feb.12, 2003 Vol. 289:747  

ACP Best Dx/Best Rx 2007

Acute Renal Failure

Mary Jo Shaver, M.D., Sudhir V. Shah, M.D.
University of Arkansas for Medical Sciences

Definition/Key Clinical Features  

* An abrupt decrease in renal function occurring over hours to days sufficient to result in retention of nitrogenous waste

* Usual criteria are as follows:

* Epidemiology

* Prognosis

* Clinical manifestations


Differential Diagnosis

* Prerenal azotemia

* Renal azotemia

* Postrenal azotemia (obstruction of collecting system)


Best Tests for Acute Renal Failure

* History

* Physical examination

* Laboratory studies

* Imaging studies


Best Therapy for Acute Renal Failure

Prevention of Acute Renal Failure

* Identify patients with risk factors

* Avoid nephrotoxic agents

* Apply preventive strategies in specific circumstances

* Rhabdomyolysis

Management of Acute Renal Failure

* Emergent intervention

* Dialysis

* Supportive therapy

* Treatment of complications


Best References