WBR0230

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. He is currently on no medications. On examniation, you see a anxious and diaphorectic person in no acute distress. His temperature is 36.7 C, blood pressure is 130/70 mmHg, pulse is 102/min and respiartions are 16/min. Her oxygen saturation is 97% on room air. Other system examination was normal. A diagnosis of pheochromocytoma is confirmed after a positive test for 24-hour urine metanephrines and catecholamines. What is the next line of action for the patient.]]
Answer A	AnswerA::MRI of the abdomen
Answer A Explanation	AnswerAExp::'''Incorrect''' : MRI is done while the patient is on alpha blockers. MRI is more sensitive for extraadrenal tumours. MRI can also differentiate malignant pheochromcytoma.
Answer B	AnswerB::CT of the abdomen
Answer B Explanation	AnswerBExp::'''Incorrect''' : CT of the abdomen is also done while the patient is on alpha blockers. Though both MRI/CT are equally sensitive, however MRI is more sensitive for extraadrenal tumours.
Answer C	AnswerC::Alpha blockers
Answer C Explanation	AnswerCExp::'''Correct''' : Phenoxybenzamine is the preferred drug for pheochromocytoma to control hypertension. Patients should be treated with drugs for 0-14 days prior to the surgery.
Answer D	AnswerD::Beta blockers
Answer D Explanation	AnswerDExp::'''Incorrect''' : Never give beta blockade first; otherwise, unopposed alpha adrenergic stimulation will lead to refractory hypertension.
Answer E	AnswerE::MIBG
Answer E Explanation	[[AnswerEExp::Incorrect : MIBG resembles norepinephrine which is taken by pheochromcytoma. MIBG is sensitive and usually done when you see a tumour in CT/MRI with normal biochemical testing or a positive biochemical testing witn CT/MRI unable to locate a tumor.]]
Right Answer	RightAnswer::C
Explanation	[[Explanation::Once a diagnosis of pheochromocytoma is made by biochemical confirmation, patients should be put on ]]alpha blockers with]] liberal salt and fluid intake to restore the intravascular volume. Preoperatively, use adrenergic blockade first to control hypertension, followed by beta blockade to control tachycardia. Most commonly phenoxybenzamine is used. Never give beta blockade first; otherwise, unopposed alpha adrenergic stimulation will lead to refractory hypertension. Patients should be treated with drugs for 0-14 days prior to the surgery. Educational Objective: References: ]]
Approved	Approved::Yes
Keyword
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::