What are the recommended pre‑operative endocrine management steps for patients with diabetes mellitus, hypothyroidism, hyperthyroidism, adrenal insufficiency, and pheochromocytoma?

Preoperative Endocrinologic Management

Pheochromocytoma

All patients with pheochromocytoma or secreting paraganglioma must receive preoperative alpha-blockade for at least 10-14 days before surgery to prevent hypertensive crises and arrhythmias. 1

Alpha-Blockade Protocol

• First-line treatment is alpha-adrenergic blockade using phenoxybenzamine (non-competitive α-blocker) starting at 10 mg twice daily with dose adjustments every 2-4 days, or alternatively doxazosin (competitive selective α1-blocker) which may have fewer side effects 1
• Blood pressure targets: <130/80 mmHg supine and systolic BP preferably >90 mmHg upright 1
• If target BP not achieved: add calcium channel blockers (nifedipine slow release) or metyrosine 1
• Beta-blockade is indicated only for tachyarrhythmias and must never be started before alpha-blockade to avoid unopposed alpha-stimulation 1
• Constipation should be treated or prevented as part of preoperative preparation 1

Adrenal Insufficiency and Glucocorticoid Excess

In all patients with glucocorticoid excess (either overt or subclinical), hydrocortisone 150 mg/day must be administered during surgery and postoperatively to prevent adrenal crisis. 1

Stress-Dose Glucocorticoid Protocol

• Intraoperative: Hydrocortisone 100 mg IV at induction followed by continuous infusion of 200 mg/24 hours 2
• Alternative regimen: Hydrocortisone 50 mg IV/IM every 6 hours 2
• Postoperative: Continue IV hydrocortisone 200 mg/24 hours until patient can take oral medications 2
• Once oral intake established: Double the usual oral hydrocortisone replacement dose for 48 hours for uncomplicated recovery 2
• For major or complicated surgery: Continue doubled oral doses for up to one week before tapering to maintenance 2

Special Considerations for Glucocorticoid Management

• Patients on chronic glucocorticoids: The evidence for high-dose supplementation is sparse, but err on the side of administering stress-dose steroids if there is any doubt, as short-term glucocorticoid administration has no long-term adverse consequences 2
• Patients with CYP3A4-inducing drugs or obesity: Maintain high index of suspicion for adrenal crisis and consider continuous infusion to reduce decompensation risk 1
• Etomidate use: Single induction doses do not require additional supplementation, though clinical judgment is required 1

Early Recognition of Impending Adrenal Crisis

• Cardinal signs (may be late): Volume-resistant hypotension 1
• Earlier warning signs include: non-specific malaise, somnolence, obtunded consciousness, cognitive dysfunction, orthostatic hypotension (check sitting and supine BP), hyponatremia (though not always present), and persistent pyrexia 1
• Do not reduce or withdraw steroid supplementation while patient is pyrexial 1

Diabetes Mellitus

Perioperative glycemic control has the strongest association with postsurgical outcomes in diabetic patients. 3

Preoperative Optimization

• Assess current glycemic control and adjust insulin and non-insulin diabetic medications based on type of diabetes, insulin regimen, and predisposition to hyperglycemia or hypoglycemia 3
• Minimize fasting period and prioritize diabetic patients on routine surgical lists 1
• Children with adrenal insufficiency and diabetes require frequent blood glucose monitoring as they are more vulnerable to glycemic control problems than adults 1

Perioperative Glucose Management

• Maintenance of normal blood glucose in the perioperative period benefits both diabetic and non-diabetic patients 4
• Monitor for hypoglycemia after pheochromocytoma resection due to sudden reduction in catecholamine levels 1, 5

Thyroid Disease

Patients with thyroid dysfunction can safely undergo operations unless they have untreated hyperthyroidism or severe hypothyroidism. 3

Hyperthyroidism

• Untreated hyperthyroidism is a contraindication to elective surgery due to risk of thyroid storm, which is associated with significant perioperative morbidity and mortality 4, 6
• Achieve euthyroid state preoperatively before proceeding with elective procedures 6

Hypothyroidism

• Severe hypothyroidism increases perioperative morbidity and mortality and should be treated before elective surgery 4, 6
• Mild to moderate hypothyroidism generally does not require delay of surgery 6, 3

Pediatric Considerations

Children with adrenal insufficiency require special attention to prevent hypoglycemia and adrenal crisis. 1

Pediatric Glucocorticoid Protocol

• Bolus hydrocortisone at induction followed by either immediate continuous infusion OR subsequent four-hourly IV boluses postoperatively 1
• Dosing based on age and body weight with frequent blood glucose monitoring 1
• Minimize fasting period and prioritize on surgical lists 1

Obstetric Patients

Pregnant women with adrenal insufficiency may require higher maintenance doses during later stages of pregnancy (from 20th week onwards). 1

Labor and Delivery Protocol

• At onset of labor: Hydrocortisone 100 mg IV 1
• During labor: Either continuous IV infusion of hydrocortisone 200 mg/24 hours OR 50 mg IM every 6 hours until after delivery 1