Critical Care Medicine-Renal, Electrolyte and Acid Base Disorders>>>>>Acute Renal Failure
Question 4#

A 33-year-old muscular male is brought to emergency room after being rescued from under a collapsed concrete building. Physical examination reveals multiple lower extremity bone fractures and skin lacerations. CT scan is negative for traumatic brain injury. Vitals are as follows:

• HR 110 bpm
• BP 100/65 mm Hg
• RR 20/min
• SpO₂ 96%
• temp 37.5°C

and laboratory parameters are as follows:

• Hb 10 g/dL
• Na 143 meq/L
• K 4.0 meq/L
• Cl 109 meq/L
• creatine kinase (CK) 15 000 units/L

He has received a liter of lactated ringers so far. His urine output is dark brown and only 10 mL for the past hour.

Which of the following is the next BEST step in the management of this patient?

A. Administer 40 mg of furosemide
B. Administer 1 g/kg of mannitol
C. Administer 1 L of normal saline (0.9% NS)
D. Administer 50 meq of sodium bicarbonate

Correct Answer is C

Comment:

Correct Answer: C

Patients with rhabdomyolysis-induced AKI present with an elevated CK and reddish brown urine with absent erythrocytes on microscopic examination. They could have associated electrolyte abnormalities including hyperkalemia, hyperphosphatemia, and hypocalcemia. Early aggressive intravascular volume expansion is the most important measure to prevent worsening AKI from rhabdomyolysis. The goal is to enhance renal perfusion and flush the renal tubules off obstructing casts. 

Fluid repletion is continued until the plasma CK level is stable and maintained <5000 units/L. The Renal Disaster Relief Task Force (RDRTF) of the International Society of Nephrology (ISN) recommends use of isotonic solution due to its ready availability and equivalent efficacy at volume expansion compared to sodium bicarbonate. Despite the theoretical benefits of using sodium bicarbonate in severe rhabdomyolysis, there is no concrete evidence that suggests that alkaline diuresis is more effective than saline diuresis in preventing AKI.

References:

1. Better OS, Stein JH. Early management of shock and prophylaxis of acute renal failure in traumatic rhabdomyolysis. N engl J Med. 1990;322(12):825. PMID:2407958.
2. Vanholder R, Sever M, Erek E, Lameire N. Rhabdomyolysis. J Am Soc Nephrol. 2000;11(8):1553-1561.
3. Sever MS, Vanholder R, Lameire N. Management of crush-related injuries after disasters. N Engl J Med. 2006;354(10):1052.
4. Huerta-Alardin AL, Varon J, Marik PE. Bench-to-bedside review: rhabdomyolysis-an overview for clinicians. Crit Care. 2005;9(2):158. Epub 2004 Oct 20.