Postoperative Care After Transnasal Transsphenoidal Pituitary Surgery
Immediate Postoperative Monitoring (First 48-72 Hours)
All patients require strict fluid and electrolyte monitoring with continuous intake/output measurement, daily weights, and serial serum sodium checks every 2-4 hours initially to detect diabetes insipidus (DI) and SIADH, which occur in 26% and 14% of patients respectively. 1
Fluid and Electrolyte Management
- Monitor urine output, specific gravity, and serum sodium every 2-4 hours for the first 48-72 hours 2, 3
- Watch for three distinct patterns of water imbalance 1:
- Transient DI alone (most common - 26% of patients): excess dilute urine with potential hypernatremia
- Biphasic response: initial DI followed by SIADH
- Triphasic response: DI, then SIADH, then permanent DI
For diabetes insipidus presenting with polyuria (>250-300 mL/hr for 2-3 consecutive hours) and rising sodium: treat with desmopressin, but use cautiously to avoid iatrogenic SIADH and hyponatremia 4, 3
For SIADH (peaks on postoperative day 7): implement fluid restriction to 1L/day for mild symptoms or asymptomatic hyponatremia 2, 5
Critical Correction Rates for Hyponatremia
- Severe symptoms (seizures, altered mental status): correct 6 mmol/L over 6 hours, then limit total correction to 8 mmol/L over 24 hours 2
- Never exceed 1 mmol/L/hour correction rate to prevent osmotic demyelination 2
- Use 3% hypertonic saline only for severe symptomatic hyponatremia; otherwise use fluid restriction 2
Endocrine Assessment Timeline
Evaluate adrenal function on postoperative day 2, at 6 weeks, and at 12 months after surgery. 2, 1
Postoperative Day 2-3
- Measure morning cortisol (8 AM) 3
- If cortisol <10 mcg/dL: continue perioperative glucocorticoid coverage and reassess at 6 weeks 3
- Critical pitfall: In patients with both adrenal insufficiency and hypothyroidism, always start steroids before thyroid hormone replacement to avoid precipitating adrenal crisis 1, 6
6-Week Follow-up
- Reassess adrenal axis (morning cortisol or ACTH stimulation test) 2, 1
- Evaluate thyroid function (TSH, free T4) 6
- Assess gonadal function (testosterone in men, estradiol/FSH/LH in women) 6
12-Month Follow-up
- Complete endocrine evaluation for all pituitary axes 2, 1
- New persistent hypopituitarism is rare with experienced surgeons but requires long-term replacement 3
Radiologic Surveillance
Obtain the first postoperative MRI at 3-4 months after surgery to assess extent of resection. 2
- Use MRI with T2-weighted and T1-weighted images with fat suppression sequences 2
- Patients with gross total resection require less frequent follow-up than those with subtotal resection 2
- Long-term surveillance is recommended indefinitely, though optimal frequency remains undefined 2
Neurosurgical Monitoring
First 2 Weeks
- CSF leak is the most common immediate complication 7
- Monitor for vision changes or new neurological deficits 3
- Watch for meningitis signs (fever, headache, neck stiffness) 3
- Delayed epistaxis occurs in 0.6-3.3% of patients at 1-3 weeks postoperatively 5
Nasal Care
- Saline nasal irrigation using 250 mL nasal douches twice daily improves postoperative outcomes and distributes solution effectively to sinuses 2
- Sinonasal symptoms typically resolve spontaneously within 3-12 months 5
High-Risk Patients Requiring Endocrine Consultation
Female patients, those with CSF leak, drain placement, posterior pituitary manipulation during surgery, or tumor invasion of posterior pituitary require endocrine consultation. 1
Delayed Complications (Beyond 48 Hours)
- Delayed symptomatic hyponatremia: 3.6-19.8% incidence at 4-7 days postoperatively 5
- Vasospasm: reported at 8 days postoperatively in 30 cases 5
- New-onset hypopituitarism: 3.1% rate at 2 months 5
- Hydrocephalus: 0.4-5.8% rate within 2.2 months 5