What is the recommended steroid replacement therapy regimen for patients post pituitary (hypophysectomy) resection?

Steroid Replacement After Pituitary Resection

For patients post-pituitary resection, initiate hydrocortisone 50 mg intravenously intraoperatively, then measure morning serum cortisol on postoperative day 2-3 to guide further management: if cortisol ≥4.1 μg/dL (113 nmol/L), discontinue steroids; if <4.1 μg/dL, start maintenance hydrocortisone 15-20 mg daily in divided doses. 1, 2, 3

Intraoperative and Immediate Postoperative Management

Initial Steroid Dosing:

• Administer hydrocortisone 50 mg IV at induction or during surgery 4
• Avoid higher doses (≥100 mg) or postoperative dexamethasone, as these may unnecessarily suppress the HPA axis and lead to prolonged steroid dependence (44.4% vs 7.1% discharge on steroids) 4
• For major surgery with anticipated prolonged stress, consider hydrocortisone 100 mg IV bolus followed by continuous infusion of 200 mg over 24 hours 5, 6

Critical Principle:

• Most patients with non-functioning pituitary adenomas have intact HPA axis preoperatively (80.6%) and do not require routine perioperative steroid coverage 7
• The surgical stress response typically produces adequate endogenous cortisol in patients with preserved adrenal function 2, 3

Postoperative Assessment Protocol

Day 2-3 Morning Cortisol Measurement:

• Draw 8:00 AM serum cortisol on postoperative day 2-3, at least 24 hours after last hydrocortisone dose 1, 2, 7
• Cortisol ≥4.1 μg/dL (113 nmol/L): Predicts adequate long-term adrenal reserve with 95.1% sensitivity and 100% specificity—discontinue steroids 1
• Cortisol ≥10 μg/dL (270 nmol/L): Indicates definite adrenal sufficiency—no further replacement needed 2, 3
• Cortisol <2.2 μg/dL (60 nmol/L): Indicates sustained adrenal insufficiency—initiate maintenance therapy 2, 3
• Cortisol 2.2-4.1 μg/dL (60-113 nmol/L): Gray zone requiring clinical judgment and possible repeat testing 1, 3

Maintenance Therapy for Confirmed Adrenal Insufficiency

Physiologic Replacement Regimen:

• Hydrocortisone 15-20 mg daily in divided doses (typically 10 mg morning, 5 mg afternoon, 5 mg evening) 5, 8, 6
• Maximum 30 mg daily for residual symptoms 8
• Critical: Always start corticosteroids BEFORE thyroid hormone replacement to avoid precipitating adrenal crisis, as thyroid hormone accelerates cortisol clearance 5, 8, 6

For Primary Adrenal Insufficiency (rare post-pituitary surgery):

• Add fludrocortisone 0.05-0.1 mg daily for mineralocorticoid replacement 8

Follow-Up and Reassessment

6-Week Evaluation:

• Repeat morning cortisol and consider low-dose ACTH stimulation test (1 μg) 2, 7
• Peak cortisol >550 nmol/L (20 μg/dL) during stimulation testing is 100% sensitive and specific for sustained HPA axis integrity 2
• Wean steroids if recovery documented 4

Long-Term Monitoring:

• Reassess at 3 months, 6 months, and 12 months for potential HPA axis recovery 5, 2
• Many patients recover adrenal function within 6-12 months post-surgery 2, 7

Stress Dosing Education (Essential for All Patients on Maintenance)

Patient Education Requirements:

• Teach stress dosing: double maintenance dose during febrile illness or minor stress 8, 6
• Provide emergency injectable hydrocortisone 100 mg for self-administration 5, 8, 6
• Issue medical alert bracelet/card identifying adrenal insufficiency 5, 8, 6
• Instruct on signs of adrenal crisis: severe weakness, hypotension, nausea/vomiting, confusion 5, 8

For Major Stress/Surgery While on Maintenance:

• Hydrocortisone 100 mg IV bolus, then 50 mg IV every 6 hours or 200 mg/24h continuous infusion 5, 8, 6
• Taper to double maintenance dose over 5-7 days once stable 5, 6

Common Pitfalls to Avoid

Excessive Steroid Administration:

• Routine high-dose perioperative steroids (≥100 mg) increase unnecessary long-term steroid dependence from 7.1% to 33.3% 4
• Postoperative dexamethasone further suppresses HPA axis recovery 4
• Only 5.55% of patients develop true early postoperative adrenal insufficiency 3

Delayed Cortisol Assessment:

• Measuring cortisol too early (within 24 hours of last hydrocortisone dose) yields unreliable results 2
• ACTH levels provide no additional diagnostic value beyond cortisol measurement 2

Premature Hormone Replacement:

• Starting levothyroxine before hydrocortisone can precipitate life-threatening adrenal crisis 5, 8, 6
• Testosterone and estrogen also accelerate cortisol clearance 5

Failure to Recognize Relative Adrenal Insufficiency:

• Adrenal crisis can occur even with "normal" cortisol levels during severe physiologic stress 8, 6
• For unexplained hypotension unresponsive to fluids, give empiric hydrocortisone 100 mg IV immediately 5, 6

Special Populations

Patients with Preoperative Cushing's Disease:

• Require different management due to chronic HPA suppression—not covered by this protocol 5

Patients with Known Preoperative Adrenal Insufficiency:

• Continue physiologic replacement throughout perioperative period 5
• May require stress-dose steroids if hypotension develops, but not routinely prophylactic 5