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Zorluk: KolayBreast and Endocrine Surgery

A 4242-year-old man is scheduled for a left-sided adrenalectomy after being diagnosed with a pheochromocytoma. He originally presented to the clinic with episodic headaches, profound sweating, and palpitations. His blood pressure during those episodes was often ≥180/110\geq 180/110 mm Hg. Laboratory evaluation confirmed elevated 2424-hour urine fractionated metanephrines. The patient is currently asymptomatic with a blood pressure of 145/90145/90 mm Hg. To prevent a life-threatening intraoperative cardiovascular complication, which of the following is the most appropriate initial pharmacological step prior to his surgery?

  1. A
    Initiation of a beta-adrenergic antagonist
  2. B
    Initiation of an angiotensin-converting enzyme inhibitor
  3. Initiation of an alpha-adrenergic antagonistCevap
  4. D
    Initiation of a glucocorticoid
  5. E
    Immediate surgery without prior pharmacological preparation

Cevap

Initiation of an alpha-adrenergic antagonist is the necessary first step.
The correct answer is the initiation of an alpha-adrenergic antagonist. Pheochromocytomas are tumors that secrete catecholamines (epinephrine, norepinephrine). Direct surgical manipulation of the tumor or the stress of anesthesia induction can trigger a massive, sudden release of these hormones into the bloodstream, leading to a life-threatening hypertensive crisis, arrhythmias, or myocardial infarction. To prevent this, patients must undergo adequate preoperative pharmacological preparation. The standard initial step is the administration of a non-selective alpha-adrenergic antagonist (such as phenoxybenzamine) for 10 to 14 days prior to surgery. This effectively blocks the alpha-1 and alpha-2 receptors, promoting vasodilation, normalizing blood pressure, and allowing for volume expansion to counteract the chronic volume depletion caused by persistent catecholamine-induced vasoconstriction.

Adım Adım Çözüm

1
Identify the patient's diagnosis and the planned surgical procedure.
The patient has a pheochromocytoma and is scheduled for a unilateral adrenalectomy.
Surgical manipulation of a pheochromocytoma can release massive amounts of catecholamines into the bloodstream.
2
Determine the required preoperative medical optimization to prevent intraoperative complications.
An alpha-adrenergic antagonist (such as phenoxybenzamine) must be initiated first.
Alpha-blockade induces vasodilation and normalizes blood pressure, effectively protecting the patient from a catecholamine-induced hypertensive crisis during surgery.

Anahtar Kavram

Preoperative pharmacological preparation for pheochromocytoma requires initial alpha-adrenergic blockade to prevent an intraoperative hypertensive crisis. Beta-blockade is only added subsequently to control tachycardia.
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