pheo-preoperative-alpha-blockade

name	pheo-preoperative-alpha-blockade
description	Pre-operative preparation protocol for Pheochromocytoma, focusing on alpha-blockade titration and volume expansion. Trigger when a clinician asks "prep for pheo surgery", "alpha blockade vs beta blockade", or "doxazosin titration".

Pheochromocytoma Pre-operative Alpha-Blockade

Standard preparation protocol to ensure cardiovascular stability during and after surgical resection of PPGL.

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Step 1 — Initiate Alpha-Adrenergic Blockade

Start 7 to 14 days prior to surgery.

1. Primary Agent:
   • Phenoxybenzamine (Non-selective): Start 10 mg BD, titrate up by 10-20 mg every 2-3 days.
   • Alternative: Doxazosin or Terazosin (Selective): Start 1-2 mg daily, titrate up to 10-16 mg daily.
2. Goal of Titration:
   • BP < 130/80 mmHg (sitting) and > 90 mmHg SBP (standing).
   • Moderate orthostatic hypotension is a sign of achieved blockade.

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Step 2 — Initiate Beta-Blockade (ONLY second)

Start only 2-3 days AFTER effective alpha-blockade is established.

• Indications: Tachycardia (HR > 100) or arrhythmias.
• Agents: Metoprolol, Atenolol, or Propranolol.
• Contraindication: NEVER start beta-blockade first (Unopposed Alpha-stimulation risk).

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Step 3 — Volume Expansion

Start 2 days prior to surgery.

• Objective: Prevent post-resection hypotension.
• Action: High-sodium diet (>5000 mg/day) and increased fluid intake.
• Inpatient: 1-2 liters of normal saline overnight before surgery.

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Clinical Guardrails

• ECG Monitoring: Essential during titration in patients with cardiac history.
• The Lakhani Rule: In elderly patients or those with coronary artery disease (like Mr. Mohan), titrate more slowly and target a less aggressive BP (e.g., 140/90).

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Source: Lenders JW, et al. Pheochromocytoma and Paraganglioma: An Endocrine Society Clinical Practice Guideline. 2014.