CURRENT Essentials of Critical Care.pdf

Chapter 14 Renal Disorders 211Pigment Nephropathy:Rhabdomyolysis & Hemolysis■ Essentials of Diagnosis• Acute renal failure in setting of severe muscle breakdown or hemolysis• Dark-colored brown or red urine• Muscle pain, weakness may be present in rhabdomyolysis• Symptoms of anemia observed in severe hemolysis• In rhabdomyolysis: elevated creatinine kinase and aldolase, reducedBUN:creatinine ratio; urine dipstick positive for heme inabsence of red cells• In hemolysis: elevated serum free hemoglobin, reduced haptoglobin• AST and LDH often elevated in both• Massive cellular release of myoglobin or hemoglobin toxic torenal tubules• Risk factors for pigment nephropathy: reduced renal perfusionstates, hypovolemia■ Differential Diagnosis• Rhabdomyolysis• Trauma: crush injury, electric burn, heat stress• Excessive contraction: seizure, tetanus, malignant hyperthermia,neuroleptic malignant syndrome• Electrolytes: hypokalemia, hypophosphatemia• Infection: clostridial toxin (gas gangrene), pyomyositis• Polymyositis, dermatomyositis• Drugs: combined HMG-CoA reductase inhibitors and fibric acidderivatives, amphetamine• Hemolysis: transfusion reactions; drugs and toxins (quinine,fava beans, snake venom); mechanical lysis (prosthetic heartvalves, extracorporeal circulation)■ Treatment• Fluid resuscitation to restore adequate renal perfusion• Initiate diuresis with mannitol or furosemide once euvolemic• Alkalinization of urine confers theoretical benefits• Monitor electrolyte imbalance: hyperkalemia, hypocalcemia,hyperphosphatemia• Manage as acute renal failure/acute tubular necrosis■ PearlIn crush injury, especially involving the thighs, patient must be monitoredfor not only the development of renal failure from rhabdomyolysisbut also for compartment syndrome.ReferenceHolt SG: Pathogenesis and treatment of renal dysfunction in rhabdomyolysis.Intensive Care Med 2001;27:803. [PMID: 11430535]