WBR0232

Author	[[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Musculoskeletal/Rheumatology, SubCategory::Neurology
Prompt	[[Prompt::A 26 year old male is brought to the ER with severe muscle pain especially in the thighs. He is an alcoholic and has been drinking heavily for the past 48 hours. He is a smoker and also uses marijuana and cocaine occasionally. He has no other significant medical history. His vitals are pulse 118/min, BP: 100/60 mmHg, RR: 22/min, Temp: 100F. Lungs are clear. Skin and mucus membranes are dry. There is generalized muscle tenderness and strength is decreased globally. You start to hydrate the patient with isotonic saline. EKG taken is normal. Urine analyses are pending. Patients laboratory testing shows the following: Na: 147 mEq/L K: 5 mEq/L Chloride: 107 mEq/L Bicarbonate: 18 mEq/L BUN: 60 mg/dl Creatinine: 2.3 mg/dl Glucose:72 mg/dl Ca: 8mg/dl CK: 50,000 U/L Which of the following the most appropriate course of action?]]
Answer A	AnswerA::Start intravenous bicarbonate
Answer A Explanation	AnswerAExp::'''Correct''' : Once the patient is adequately hydrated with isotonic saline infusion, next step would be to save kidney’s by alkalizing urine with adequate bicarbonate infusion as the patient’s creatine kinase levels are very high.
Answer B	AnswerB::Start intravenous mannitol
Answer B Explanation	[[AnswerBExp::Incorrect : The benefit of loop diuretics or mannitol in rhabdomyolysis is not established. Experimental studies suggested that mannitol might be protective by causing a diuresis, which minimizes intratubular heme pigment deposition and cast formation.]]
Answer C	AnswerC::Start intravenous calcium
Answer C Explanation	[[AnswerCExp::Incorrect : To minimize the late occurrence of hypercalcemia, calcium supplementation for hypocalcemia should be avoided unless significant signs and symptoms of hypocalcemia develop or calcium administration is required for the management of hyperkalemia.]]
Answer D	AnswerD::Start intravenous kayexalate
Answer D Explanation	[[AnswerDExp::Incorrect : Hyperkalemia should be anticipated and may occur even in the absence of severe renal failure. Hyperkalemia should be aggressively treated. Dialysis may be required to treat severe hyperkalemia. In this patient with normal EKG, protecting the kidneys would be the most appropriate next step.]]
Answer E	AnswerE::Start intravenous furosemide
Answer E Explanation	[[AnswerEExp::Incorrect : Furosemide would worsen the condition.]]
Right Answer	RightAnswer::A
Explanation	[[Explanation::Rhabdomyolysis is a syndrome characterized by muscle necrosis and the release of intracellular muscle constituents into the circulation. Creatine kinase levels are typically markedly elevated, and muscle pain and myoglobinuria may be present. The severity of illness ranges from asymptomatic elevations in serum muscle enzymes to life-threatening disease associated with extreme enzyme elevations, electrolyte imbalances, and acute kidney injury. In addition to treating the underlying rhabdomyolysis or hemolysis, the prevention of AKI requires early and aggressive fluid resuscitation. Among patients with rhabdomyolysis, fluid repletion should be continued until plasma CK levels decrease to less than 5000 U/L and urine is dipstick negative for hematuria. Acute renal failure probability reduces when peak creatine kinase levels are under 5000 to 10,000 U/L. A forced alkaline diuresis, in which the urine pH is raised to above 6.5, may diminish the renal toxicity of heme and should be started once appropriate hydration is done. Educational Objective: References: ]]
Approved	Approved::Yes
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