What is the next step in managing a patient with a history of transsphenoidal pituitary surgery two years ago who now presents with a new seizure, decreased level of consciousness, borderline hyponatremia, hypomagnesemia, acute kidney injury, central hypothyroidism (low free T3 and free T4 with normal TSH), and a non‑contrast head CT showing no acute bleed but chronic lacunar infarcts and pansinusitis?

Immediate Management: Stress-Dose Corticosteroids and MRI Sella

This patient requires immediate intravenous stress-dose hydrocortisone (100 mg bolus, then 50–100 mg every 6–8 hours) without waiting for further testing, followed by urgent MRI of the sella with pituitary protocol to rule out recurrent pituitary pathology or apoplexy. 1

Critical Clinical Context

This post-transsphenoidal surgery patient presenting with seizure, altered mental status, and laboratory evidence of central hypothyroidism (low FT3 2.04 and FT4 0.52 with inappropriately normal TSH 2.24) is at high risk for life-threatening secondary adrenal insufficiency. 1 The constellation of findings—borderline hyponatremia (Na 133), acute kidney injury (creatinine 190.76), hypomagnesemia (Mg 0.79), and pansinusitis on CT—strongly suggests an acute pituitary crisis or recurrent pathology two years post-surgery. 2, 1

Step 1: Emergent Hormonal Resuscitation

Immediate Corticosteroid Administration

• Administer hydrocortisone 100 mg IV bolus immediately, then continue 50–100 mg IV every 6–8 hours. 1 Do not delay for cortisol levels or ACTH stimulation testing—treatment of suspected adrenal crisis must never be postponed for diagnostic procedures. 2
• Draw baseline cortisol and ACTH before the first dose if possible, but do not wait for results. 1
• The presence of central hypothyroidism (low FT3/FT4) in this post-pituitary surgery patient makes secondary adrenal insufficiency highly likely, and the acute presentation with seizure and decreased sensorium represents a potential adrenal crisis. 2, 3, 4

Fluid Resuscitation

• Infuse 2–4 liters of 0.9% isotonic saline over the first 24 hours, with an initial rate of approximately 1 L/hour. 2, 5 The acute kidney injury (creatinine 190.76) with borderline hyponatremia suggests prerenal azotemia from volume depletion, a hallmark of adrenal crisis. 2, 5
• Monitor hemodynamics closely; hypotension refractory to fluids may require vasopressor support. 2

Critical Sequencing Rule

• Never start thyroid hormone replacement before corticosteroids are on board. 1 Initiating levothyroxine in the setting of untreated adrenal insufficiency can precipitate acute adrenal crisis by accelerating cortisol metabolism. 1 Continue stress-dose steroids for at least one week before considering thyroid hormone replacement. 1

Step 2: Urgent Diagnostic Imaging

MRI Sella with Pituitary Protocol

• Order MRI of the sella with and without contrast using high-resolution pituitary cuts immediately (within hours, not days). 2, 1 This is the gold-standard imaging modality to detect:
  • Recurrent or residual pituitary adenoma
  • Pituitary apoplexy (hemorrhage or infarction)
  • Empty sella syndrome
  • Mass effect on the optic chiasm or cavernous sinuses 2
• The non-contrast head CT already performed shows no acute intracranial hemorrhage but is insensitive for pituitary pathology. 2 CT cannot reliably detect microadenomas, hemorrhage within the sella, or subtle mass effects. 2
• MRI will show T1 hyperintensity if hemorrhage is present, heterogeneous enhancement, and can assess stalk thickening or suprasellar extension. 1

Step 3: Electrolyte and Fluid Balance Monitoring

Sodium and Osmolality Surveillance

• Check serum sodium and serum osmolality every 4–6 hours initially. 1, 6 Post-pituitary surgery patients are at high risk for both diabetes insipidus (DI) and SIADH, which require opposite management strategies. 1, 6
• Measure urine output hourly via indwelling catheter and check urine osmolality and specific gravity. 1, 6
• Watch for three patterns: 1, 6
  • Transient DI: polyuria (>300 mL/hour) with dilute urine and rising serum sodium
  • Biphasic response: initial DI followed by SIADH (oliguria, concentrated urine, worsening hyponatremia)
  • Triphasic pattern: DI → SIADH → permanent DI

Magnesium Replacement

• Correct hypomagnesemia (Mg 0.79) cautiously with IV magnesium sulfate. 7 Dilute 50% magnesium sulfate to ≤20% concentration and infuse slowly to avoid hypermagnesemia. 7 Target serum magnesium 1.5–2.5 mEq/L. 7
• Hypomagnesemia can lower seizure threshold and must be corrected, but monitor closely in the setting of acute kidney injury (creatinine 190.76), as magnesium is renally excreted. 7 Maintain urine output ≥100 mL/hour during replacement. 7

Step 4: Seizure Management and Neurologic Monitoring

Antiepileptic Therapy

• If seizures recur, treat with standard antiepileptic drugs (e.g., levetiracetam or fosphenytoin). 2 Avoid excessive sedation if possible to allow serial neurologic assessments. 2
• Hyponatremia (Na 133) and hypomagnesemia (Mg 0.79) are both seizure precipitants and must be corrected. 2, 7

Level of Consciousness

• Decreased sensorium in the setting of suspected adrenal crisis warrants ICU-level monitoring. 2 Impaired cognition, confusion, and altered consciousness are typical features of adrenal crisis. 2
• If consciousness deteriorates further (Glasgow Coma Scale ≤8), intubate for airway protection. 2

Step 5: Address Acute Kidney Injury

• The elevated creatinine (190.76) with borderline hyponatremia and low urine sodium (not provided but implied by prerenal picture) suggests prerenal azotemia from volume depletion, a common feature of adrenal crisis. 2, 5
• Isotonic saline resuscitation (2–4 L over 24 hours) typically corrects both the AKI and hyponatremia in this setting. 5 Monitor creatinine daily; improvement confirms prerenal etiology. 5
• Avoid nephrotoxic agents and ensure urine output ≥100 mL/hour. 2, 7

Step 6: Treat Pansinusitis

• The CT shows fluid in bilateral maxillary, ethmoid, frontal, and sphenoid sinuses, consistent with pansinusitis. 2 This may represent a precipitating infection or a complication of prior transsphenoidal surgery. 8
• Start broad-spectrum antibiotics (e.g., amoxicillin-clavulanate or a third-generation cephalosporin) empirically, as infection is a common trigger for adrenal crisis. 2, 8
• Obtain ENT consultation for possible surgical drainage if sinusitis is severe or refractory. 2

Step 7: Endocrinology and Neurosurgery Consultation

• Obtain immediate endocrinology consultation for every case of suspected pituitary crisis, regardless of severity. 1 Endocrinology will guide long-term hormone replacement and interpret dynamic testing if needed. 1, 3, 9
• Neurosurgery consultation is mandatory if MRI shows recurrent adenoma, apoplexy with mass effect, or progressive neurologic deterioration. 1 Urgent transsphenoidal decompression is indicated for severe mass effect threatening the optic chiasm, worsening visual deficits, or altered consciousness. 1

Step 8: Steroid Tapering and Thyroid Hormone Initiation

• Once hemodynamically stable (typically 5–7 days), taper IV hydrocortisone to oral maintenance: switch to oral hydrocortisone 15–20 mg daily in divided doses (two-thirds in the morning, one-third early afternoon). 1
• Only after at least one week of adequate corticosteroid therapy, initiate levothyroxine for central hypothyroidism (start low, e.g., 25–50 mcg daily, and titrate based on free T4). 1
• Never discontinue corticosteroids abruptly; a gradual taper is mandatory. 1

Step 9: Patient Education and Discharge Planning

• Prior to discharge, provide "sick-day rules" education: double or triple oral hydrocortisone dose during illness, vomiting, or fever. 2, 1
• Prescribe an emergency intramuscular hydrocortisone kit (100 mg) with clear instructions for use. 1
• Issue a medical-alert bracelet indicating adrenal insufficiency. 2, 1
• Arrange close endocrinology follow-up within 1–2 weeks. 1

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Common Pitfalls to Avoid

• Do not wait for cortisol or ACTH results before starting stress-dose steroids. 2, 1 Delaying treatment in suspected adrenal crisis increases mortality. 2, 4
• Do not start thyroid hormone before corticosteroids. 1 This can precipitate life-threatening adrenal crisis. 1
• Do not rely on the non-contrast head CT to rule out pituitary pathology. 2 CT is insensitive for sellar lesions; MRI is mandatory. 2
• Do not correct hyponatremia too rapidly. 6 Limit sodium correction to ≤8 mmol/L per 24 hours to avoid osmotic demyelination syndrome. 6
• Do not assume the seizure is idiopathic. 2, 4 In a post-pituitary surgery patient with central hypothyroidism and hyponatremia, the seizure is likely secondary to metabolic derangements from hypopituitarism. 2, 4