Postoperative Management After Transsphenoidal Pituitary Excision
Immediate Postoperative Priorities
All patients require strict fluid and electrolyte monitoring with careful input/output tracking in a setting where expert endocrinology consultation is immediately available. 1, 2
Glucocorticoid Management
- Initiate hydrocortisone 200 mg/24h by continuous IV infusion immediately postoperatively for all patients until adrenal function is assessed, as the surgery itself disrupts the hypothalamic-pituitary-adrenal axis 2, 3
- Continue IV hydrocortisone while the patient is fasting or experiencing postoperative vomiting 3
- Critical pitfall: If both adrenal insufficiency and hypothyroidism are present, always start glucocorticoids before thyroid hormone replacement to prevent precipitating an adrenal crisis 4, 2
- Transition to oral hydrocortisone once tolerating oral intake, maintaining doubled doses for 48 hours to one week after major surgery 3
Water and Electrolyte Complications
Diabetes insipidus (DI) occurs in 26% and SIADH in 14% of patients postoperatively, requiring vigilant monitoring. 1, 2
Diabetes Insipidus Management
- Monitor for polyuria (urine output >200-300 mL/hour for 2-3 consecutive hours) with dilute urine (specific gravity <1.005) 2
- Treat with desmopressin nasal spray 10-20 mcg intranasally or 0.5-2 mcg IV/SC when DI is confirmed 5
- Recognize that female sex, CSF leak, drain placement, posterior pituitary invasion by tumor, and posterior pituitary manipulation are risk factors 1, 4, 2
- Be aware of biphasic (initial DI followed by SIADH) or triphasic patterns (DI, then SIADH, then permanent DI) 2
SIADH Management
- Implement fluid restriction to 1L/day for mild symptoms or asymptomatic hyponatremia 2
- For severe symptomatic hyponatremia, correct at maximum rate of 6 mmol/L over 6 hours, then limit to 8 mmol/L over 24 hours 4, 2
- Never exceed correction rate of 1 mmol/L/hour to prevent osmotic demyelination syndrome 4, 2
Structured Endocrine Assessment Timeline
Postoperative Day 2
- Assess adrenal function with morning cortisol level 4, 2
- Cortisol ≥430 nmol/L at 30 minutes in preoperative Synacthen test predicts HPA axis recovery 2
6 Weeks Postoperatively
- Repeat adrenal function testing 4, 2
- Cortisol on postoperative day 8 ≥160 nmol/L and basal cortisol at 6 weeks ≥180 nmol/L predict recovery 2
- Patients with early postoperative adrenal insufficiency do not necessarily require lifelong replacement—periodic reevaluation is essential 2
12 Months Postoperatively
- Perform complete endocrine evaluation of all pituitary axes: 4, 2
- TSH and free T4 for central hypothyroidism
- Testosterone (men) or estradiol (women) with FSH/LH for hypogonadotropic hypogonadism
- Morning cortisol for secondary adrenal insufficiency
- IGF-1 for growth hormone deficiency
Additional Postoperative Considerations
CSF Leak Monitoring
- CSF leak is the most common immediate complication and a risk factor for DI and SIADH 1, 6
- Monitor for clear rhinorrhea, postnasal drip, or headache worsening with upright position 6
Nasal Care
- Initiate saline nasal irrigation using 250 mL nasal douches twice daily to improve postoperative outcomes 2
Radiologic Surveillance
- Obtain first postoperative MRI at 3-4 months to assess extent of resection 2
- Use T2-weighted and T1-weighted images with fat suppression sequences 2
Patient Safety Measures
- All patients with confirmed adrenal insufficiency must obtain and carry a medical alert bracelet 4, 2, 3
- Educate patients on stress-dose steroids for illness, injury, or future procedures 3
High-Risk Patient Identification
Patients requiring heightened surveillance include those with:
- Female sex 1, 4, 2, 3
- Macroadenomas or elevated maximal tumor dimension 2, 7
- Preoperative pituitary dysfunction 2
- Intraoperative CSF leak, drain placement, or posterior pituitary manipulation 1, 4, 2
- Prolonged surgery duration 7
These patients warrant mandatory endocrine consultation and extended monitoring for fluid/electrolyte disturbances. 2