Hyponatremia Management Medical Slides

Present the stepwise approach: Step 1 — Serum osmolality: low (<280) = true hypotonic hyponatremia; normal (280-295) = pseudohyponatremia (lipids, proteins); high (>295) = translocational (hyperglycemia — correct sodium by 1.6-2.4 mEq/L per 100 mg/dL glucose above 100). Step 2 — Volume status assessment (clinical ± FENa, BUN/Cr). Step 3 — Urine osmolality: <100 = primary polydipsia or low solute intake; >100 = ADH-mediated. Step 4 — Urine sodium: <30 = volume depletion or low effective arterial volume; >30 = SIADH, adrenal insufficiency, hypothyroidism, diuretics.

Present the 2014 European guideline protocol for severe symptomatic hyponatremia (seizures, obtundation): 3% NaCl 100-150 mL IV bolus over 10-20 minutes, may repeat 1-2 times at 10-minute intervals targeting 4-6 mEq/L increase in first 1-2 hours (sufficient to reduce cerebral edema and stop seizures). Then SLOW correction to stay within 8 mEq/L per 24 hours and 18 mEq/L per 48 hours (some experts recommend 6 mEq/L per 24 hours for high-risk patients). Check sodium every 2-4 hours. High ODS risk: Na <105, chronic (>48 hrs), alcoholism, liver disease, malnutrition, hypokalemia.

Present the proactive DDAVP strategy: if sodium correction approaching or exceeding 8 mEq/L in 24 hours, administer DDAVP 1-2 mcg IV every 6-8 hours to halt free water excretion (induces therapeutic SIADH). Simultaneously administer D5W IV to re-lower sodium to the target range. The proactive approach (giving DDAVP prophylactically at the time of initial correction in high-risk patients) is increasingly favored — Sood 2013 showed DDAVP clamp protocol keeps correction within safe limits in >95% of patients. Key teaching point: the most common overcorrection scenario is volume-depleted patient given IV saline who then appropriately suppresses ADH and undergoes rapid aquaresis.