Hyponatremia — Management Pathway

Step-by-step decision

Choose step by step as prompted; reaching an endpoint gives the management recommendation. You can go back a step or restart anytime.

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Full pathway

1. [Decision] Severe symptoms present?
   Are there severe (cerebral edema) symptoms? (Hyponatremia = serum sodium <135 mmol/L (mild 130–134, moderate 125–129, severe <125). Severe symptoms: seizure, coma/marked altered consciousness, respiratory distress, severe vomiting — indicating cerebral edema and needing emergency treatment regardless of the absolute sodium or acuity.)
   • Severe symptoms present → Severe symptoms → hypertonic saline
   • None / mild-moderate symptoms → None / mild-moderate symptoms
2. [End] Severe symptoms → hypertonic saline
   Emergency: 3% hypertonic saline 150 mL IV bolus (over 20 min), or 100 mL/10 min; recheck sodium every 20 min, repeat 1–2 times if needed, and stop the hypertonic saline once symptoms ease or sodium rises by 4–6 mmol/L. Strict rate limit to prevent osmotic demyelination: rise ≤8–10 mmol/L over 24 h (≤8 in high-risk: chronic, hypokalemia, alcohol use, malnutrition, liver disease), ≤18 mmol/L over 48 h.
3. [End] None / mild-moderate symptoms
   Assess volume status and cause: hypovolemic → isotonic saline volume repletion; euvolemic (SIADH) → fluid restriction ± treat the cause; hypervolemic (heart failure/cirrhosis) → fluid and sodium restriction + diuresis. Urine osmolality, urine sodium and serum osmolality help classify. Correct chronic cases slowly at 4–8 mmol/L/24 h; if corrected too fast → D5W ± desmopressin to re-lower.

Source guidelines & references

• European Society of Endocrinology (ESE) et al. 2014 Clinical Practice Guideline on diagnosis and treatment of hyponatremia. Eur J Endocrinol 2014

This pathway is our own synthesis of the decision logic in the guidelines above (not the guideline verbatim); thresholds and workflows change as guidelines update — in practice follow the latest guideline, your institution's protocol and the individual patient.

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