Patient handout

Hyponatremia symptom-triage (ED workup + cross-engine to syndrome)

PRODUCTION

1. Your condition

This handout is for hyponatremia symptom-triage (ed workup + cross-engine to syndrome). Your care team identified this based on: na <120 + seizure / coma / severe ams — acute severe symptomatic hyponatremia; stat 3% saline 100 ml iv bolus × 3 q10 min until sx improvement; avoid overcorrection >8-10 meq/24h to prevent ods (verbalis 2014 pmid 24484567).

Other reasons your team may use this plan: chronic na 125-134 + asymptomatic — outpatient workup; cause stratification (medication, hypothyroid, adrenal, siadh, hypervolemic, hypovolemic, reset osmostat); slow correction to prevent ods; na <135 + orthostatic / dry mucosa / decreased turgor / gi losses (v/d, diuretic, hemorrhage) / renal losses (csw) — hypovolemic hyponatremia; ivf ns 1-2 l bolus → replace volume; recheck na + correction trajectory; na <135 + edema + jvd + ascites + chronic disease — hypervolemic hyponatremia (chf, cirrhosis, nephrotic); fluid restriction 800-1000 ml/d + diuretic ± tolvaptan (caution cirrhosis) → route cardio.acute-hf.core.v1 / gi.cirrhosis.core.v1.

3. When to call your provider

Contact your care team if any of the following happen:

Sx development → ED
Refractory Na <130 → specialist
Suspected malignancy → STAT imaging + oncology

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

Na <120 + seizure / coma / RR <8 / cerebral herniation features — STAT 3% saline 100 mL IV bolus × 3 q10 min until sx improvement; AVOID overcorrection >8-10 mEq/24h to prevent ODS (Verbalis 2014 PMID 24484567)(life-threatening)
Na rise >8-10 mEq in 24h OR >18 mEq in 48h — high ODS / central pontine myelinolysis risk; STOP hypertonic + initiate D5W 3 mL/kg/h + desmopressin 1-2 µg IV q6-8h (Sterns NEJM PMID 30207998)(life-threatening)
Post-SAH/TBI + hyponatremia + hypovolemic (orthostatic, hemoconcentration) + urine Na >40 + uric acid normal/high — CSW (distinct from SIADH; needs VOLUME REPLACEMENT not restriction); NS / 3% saline + fludrocortisone 0.1-0.4 mg PO daily → route neuro.sah.core.v1 (Sterns CSW PMID 27797307)
Hyponatremia + hyperkalemia + hypotension + steroid history OR hyperpigmentation / Addison features — adrenal crisis; STAT hydrocortisone 100 mg IV bolus + fluids → route endo.adrenal-crisis.core.v1(life-threatening)
Hyponatremia + recent thiazide (HCTZ, chlorthalidone) OR MDMA OR endurance event with excessive water intake — drug/exercise-associated; discontinue thiazide; 3% saline if symptomatic; restrict + ICU if severe

5. Follow-up

Outpatient endocrinology if SIADH / hypothyroid / adrenal; nephrology if CKD / CSW / refractory; oncology if SIADH-paraneoplastic; cardiology / hepatology if hypervolemic; psychiatric if polydipsia; deprescribing thiazide / SSRI / carbamazepine if drug-induced; fluid restrict education; sodium intake counseling; recurrence prevention

6. Sources

Guideline: 2014 European/US Verbalis hyponatremia + 2014 Spasovski ERA-EDTA + 2015 Sterns NEJM + Hoorn pathophysiology + Sterns CSW + ODS prevention literature