WBR0231

Author	[[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Endocrine
Prompt	[[Prompt::A 23 yr old male came to the emergency department with complaints of headache and palpitations. By time you attended the patient, he is asymptomatic. He reveals three similar episodes in the past that resolved spontaneously. A diagnosis of pheochromocytoma is confirmed after a positive test for 24-hour urine metanephrines and catecholamines. MRI of the abdomen shows an intraadrenal tumor. He was treated on phenoxybenzamine and beta-blockers sufficiently. The patient is appropriately prepared and is take for the procedure. During the procedure, the patient becomes hypotensive with dropping from120/80 to 80/50. Which is the appropriate treatement for the patient’s hypotension?]]
Answer A	AnswerA::Stop the alpha blockers
Answer A Explanation	AnswerAExp::'''Incorrect''' : Removal of alpha blockade could be done, but it is never going to be as effective as crystalline solution in the management of hypotensive crisis.
Answer B	AnswerB::Bolus of normal saline with continuous saline infusion
Answer B Explanation	[[AnswerBExp::Correct : Bolus of normal saline with continuous saline infusion is the best way to treat intra-oprerative hypotension.]]
Answer C	AnswerC::Bolus of colloid with continuous saline infusion
Answer C Explanation	[[AnswerCExp::Incorrect : Bolus of colloid with continuous saline infusion could be an appropriate option. Colloid does restore intravascular volume and has a benefit of decreased chance of pulmonary edema. However studies haven’t showed that this is superior to crystalline solution in management of hypotension and it is very expensive too.]]
Answer D	AnswerD::Dopamine
Answer D Explanation	[[AnswerDExp::Incorrect : Dopamine is not the appropriate drug for hypotension in these patients. These patients are usually on long-term alpha blockade and hence the vascular tone response is generally reduced.]]
Answer E	AnswerE::Dobutmaine
Answer E Explanation	[[AnswerEExp::Incorrect : Dobutamine also wont be effective in these patients as the vascular tone response is generally reduced because of the long-term alpha blockade.]]
Right Answer	RightAnswer::B
Explanation	[[Explanation::Pheochromocytoma is a tumor of chromaffin tissue found either in the adrenal medulla or in extra-adrenal sites that secrete catecholamines. Screen with plasma-free metanephrines (metanephrine and normetanephrine) or 24-hour urine metanephrines and catecholamines. Preoperatively, use adrenergic blockade first to control hypertension, followed by beta blockade to control tachycardia. Most commonly phenoxybenzamine is used. Even with adequate preoperative management, pheochromocytoma patients develop intraoperative complications. Patient hypotension is after the removal of tumour where there is decrease in circulatory catecholamine and alpha blockade and hence decreases in the vascular tone. The resulting hypotension responds to bolus of normal saline with continuous saline infusion. Educational Objective: References: ]]
Approved	Approved::Yes
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