Acute Renal Failure Causes and Complications

TMP-SMX Treatment

• TMP-SMX with one-third of therapeutic dose once daily

Acute Renal Failure (ARF)

• Definition: Rapid and usually reversible decline in renal function leading to retention of nitrogenous waste products and disturbance in water and electrolyte balance
• Etiology:
  • Pre-renal causes:
    • Dehydration
    • Gastroenteritis
    • Hemorrhage
    • Burns
    • Sepsis
    • Capillary leak
    • Hypoalbuminemia
    • Cardiac failure
    • Anaphylaxis
  • Intrinsic renal causes:
    • Glomerulonephritis
    • Interstitial nephritis
    • Acute tubular necrosis
    • Vascular
    • Malignancy
    • Developmental abnormalities
  • Post renal causes:
    • Bilateral PU obstruction or unilateral affection of single kidney
    • Bladder neck obstruction
    • Neurogenic bladder
    • Vesico-ureteric reflux
    • Posterior urethral valves
    • Tumors and other causes of extrinsic compression
    • Urolithiasis
    • Urethral strictures

Clinical Manifestations

• Presenting signs and symptoms may be dominated or modified by the precipitating factor
• C/P related to renal failure: Pallor, oliguria, edema, hypertension, vomiting, and lethargy
• History may be a key for the underlying cause

Urinary Tract Infection (UTI)

• Definition: Actively multiplying organism within the UT with significant bacteriuria that may be symptomatic or not
• Etiology:
  • Urinary pathogens
  • Route of infection: Ascending infections from fecal flora
  • Risk Factors:
    • Female gender
    • Uncircumcised male
    • Vesicoureteral reflux
    • Toilet training
    • Voiding dysfunction
    • Obstructive uropathy

Clinical Manifestations and Classification

• Two basic forms of UTIs: Pyelonephritis and Cystitis
• Cystitis:
  • Symptoms: Dysuria, urgency, frequency, suprapubic pain, incontinence, and possibly malodorous urine
  • Does not cause high fever and does not result in renal injury
• Pyelonephritis:
  • Symptoms: Abdominal, back, or flank pain, fever, malaise, nausea, vomiting, and occasionally diarrhea
  • Fever may be the only manifestation

Examination and Lab Findings

• Careful attention to volume status
• Physical examination:
  • Tachycardia, dry mucous membranes, and poor peripheral perfusion suggest inadequate circulating volume and possibility of pre-renal AKI
  • Hypertension, peripheral edema, rales, and a cardiac gallop suggest volume overload and possibility of intrinsic AKI
• Lab findings:
  • Increased blood urea, serum creatinine
  • Electrolyte disturbances
  • Metabolic acidosis
  • May be anemia, leucopenia, and thrombocytopenia