Hyponatremia — From Sodium to Safe Corrections

Welcome back to NEET PG 2026 Rapid Round. Today, we dive into hyponatremia — a crucial emergency topic frequently tested in previous years. We’ll cover how to quickly triage, spot causes, and safely correct sodium levels, while avoiding common exam traps.

First, confirm true hypotonic hyponatremia by checking serum osmolality. Remember, hypotonic means osmolality under 275 mOsm/kg. Rule out pseudohyponatremia caused by things like high lipids or proteins, and translocational hyponatremia from hyperglycemia.

Next, assess symptom severity. Severe signs include seizures, coma, or brain herniation threats. Moderate symptoms might be vomiting, confusion, or severe headache. Mild or no symptoms need less aggressive management.

To pinpoint the underlying cause, check the patient’s volume status. Hypovolemia often comes from vomiting or diuretics. Euvolemia can suggest SIADH, hypothyroidism, or adrenal insufficiency. Hypervolemia points to heart failure, liver disease, or nephrotic syndrome.

Treatment depends on these findings. Severe symptoms get quick 3% hypertonic saline boluses to raise sodium safely by 4 to 6 mEq/L initially. Hypovolemic cases respond to isotonic saline. SIADH takes fluid restriction and sometimes salt or loop diuretics. Hypervolemic states need fluid and salt restriction plus diuretics.

Know these key numbers—never exceed an 8 to 10 mEq/L sodium rise in 24 hours to avoid osmotic demyelination syndrome. Many sources suggest aiming for 4 to 6 mEq/L first day for chronic cases.

Let’s test this with some rapid MCQs.

Question one: A 65-year-old on thiazides has confusion with sodium 112, low osmolality, and urine sodium 50. What’s the best first step?

The correct answer: give a 3% sodium chloride bolus to quickly correct the severe symptomatic hyponatremia before addressing diuretics.

Question two: A young adult with pneumonia has sodium 122, euvolemic, concentrated urine with high sodium. Best next step?

Fluid restriction is the right move for SIADH here, not saline infusion, which may worsen dilution.

Question three: What combination increases osmotic demyelination risk?

The answer: chronic low sodium plus malnutrition and correction faster than 10 mEq/L in 24 hours.

If sodium rises too fast, the safest fix is to start D5W and desmopressin to slow down correction and prevent brain damage.

One more: Hyperglycemia with sodium 124 and glucose 600 mg/dL. True or false: This is pseudohyponatremia and needs no correction?

Actually, the sodium needs correcting upward for glucose level before treating sodium abnormalities.

Why use 3% saline boluses in emergencies? Boluses act quickly and can be precisely titrated to the needed 4–6 mEq/L rise without overshooting.

Why avoid normal saline in SIADH? Because kidneys keep the sodium and retain water, worsening hyponatremia with saline.

In persistent euvolemia, always check thyroid and adrenal function before diagnosing SIADH.

Remember potassium too — low potassium correction can raise sodium and cause overcorrection risk.

To wrap up, here’s a quick case: A middle-aged man with lung cancer develops confusion and hyponatremia with high urine sodium and osmolality indicating SIADH. Mild symptoms call for fluid restriction and salt tablets, while severe symptoms deserve 3% saline boluses.

The take-home mantra: Hypotonic first, check volume next; bolus when bad; 4–6 initial correction; never over 8–10; use desmopressin if sodium rises too fast.

That’s all for today’s session on hyponatremia. Stay sharp, stay safe, and control those corrections! Next episode, we’ll quickly cover hyperkalemia ECG patterns and emergency management.

Thank you for listening!

#NEETPG #NEETPG2026 #NEETPGPreparation #NEETPGExam #NEETPGSyllabus #NEETPGStudyPlan #NEETPGCoaching #NEETPGTopperTips #HowToCrackNEETPG #NEETPGQuestionPaper #NEETPGMockTest #NEETPGStrategy #NEETPGTips #NEETPGPreviousYearQuestions #NEETPGOnlineCoaching #NEETPGDailyRoutine #NEETPGNotes #NEETPGImportantTopics #NEETPGStudyMaterial