CCS Case: Severe Symptomatic Hyponatremia

Case: Severe Symptomatic Hyponatremia

Clinical Setup

• Presentation: 72-year-old female on thiazide diuretic with confusion progressing to witnessed seizure, Na+ 118 mEq/L, euvolemic on exam, no focal deficits postictally.
• Location: Emergency Department.

Optimal Order Pathway

1. Immediate Orders (Minute 0–1):
   • Pulse oximetry, continuous cardiac monitoring, BP q15min, seizure precautions.
   • IV access; stop hypotonic fluids and offending drugs (thiazides, SSRIs, desmopressin).
2. Focused Exam (Minute 1–2):
   • Volume status (JVD, mucous membranes, edema, orthostatics), neuro exam (GCS, focality, papilledema), medication review.
3. Diagnostics (Minute 2–5):
   • Repeat BMP stat to confirm Na+, serum osmolality, urine osmolality + urine sodium (distinguish SIADH vs volume depletion vs adrenal/thyroid causes).
   • TSH, morning cortisol if adrenal insufficiency possible; head CT if trauma/fall or focal findings.
4. Therapeutics (Minute 5–15):
   • Severe symptoms (seizure/coma): hypertonic saline (3% NaCl) IV bolus stat to raise Na+ by 4–6 mEq/L acutely and stop seizures.
   • Then STOP hypertonic and switch to controlled correction: fluid restriction + address cause.
   • Correction limit: ≤8–10 mEq/L per 24 hours (lower if chronic/malnourished/alcoholic) to avoid osmotic demyelination.
   • Recheck Na+ every 1–2 hours initially; advance clock in short increments and track total rise.
   • Nephrology consult for refractory or diagnostically unclear cases.
5. Disposition (Minute 15–20):
   • Admit to ICU/stepdown with frequent Na+ monitoring until stable and asymptomatic.
   • Permanently discontinue/replace offending agent (switch thiazide to alternative antihypertensive).
6. Final 2 Minutes:
   • Counsel on fluid intake limits, medication review, warning signs of recurrence (confusion, gait instability).
   • Schedule nephrology and primary care follow-up with repeat BMP within days.