approach to hypernatremia, causes, investigation, pathophysiology, management

approach to hypernatremia, causes, investigation, pathophysiology, management

1. Approach to Hypernatremia CME Guide: Dr. B. D. Jha Dr. Praveen Kumar Giri Dr . Sahana Tamrakar Presented by: Gaurav Thakuri MBBS (NEPALESE ARMY INSTITUTE OF HEALTH SCIENCES)

2. Serum sodium level Hyponatremia Normal Hypernatremia <135meq/L 135-145meq/L >145meq/L Mild hypernatremia 146 to 149meq/L Moderate hypernatremia 150 to 169 meq /L Severe hyponatremia More than 170 meq /L

3. UNREPLACED WATER LOSS I.E IMPAIRED THIRST OR ACCESS TO H20 GI / INSENSIBLE LOSSES DIABETES INSIPIDUS OSMOTIC DIURESIS IATROGENIC CENTRAL NEPHROGENIC EXCESSIVE SWEATING DIARRHEA LAXATIVE ABUSE IDIOPATHIC NEUROSURGERY HEAD TRAUMA CNS INF MEDICATION LITHIUM, AMPHOTERICIN CHRONIC HYPERCALCEMIA UNCONTROLLED DM MANNITOL 3% NS INFUSION

4. WATER DEPRIVATION TEST Plasma osmolality ( mOsm /kg) Urine osmolality ( mOsm /kg) Interpretation 285- 295 > 600 Normal > 295* < 600* Diabetes insipidus

5. DIAGNOSIS EVALUATION STEP 1: CONSIDER HISTORY Explation for most cases of hypernatremia Water loss Primary neurologic disease or lack of access to water

6. Most manifestations are neurologic Fatigue For mild to moderate Headache Nausea/ vomiting Confusion Seizure For severe Coma

7. Step 2: CHECK Uosm Urine osmolarity < 300 mosm /kg 300 – 600 mosm /kg >600 mosm /kg DI Osmotic diuresis Impaired thirst or access to water

8. Water administration Choice of fluid Rate of administration Anticipated duration

9. Choice of fluid Oral / NG free water administration for asymptomatic patient. D5W should be used in situations of pure water loss as in DI Hypotonic fluid is preserved for situations of hypotonic fluid loss as in diarrhea But if associated with shock resuscitate w ith 0.9%NS until shock is resolved

10. Rate of fluid • TBW = body weight (kg) × Y. FREE WATER DEFICIT= TBW X ( Sr Na/140)- 1 Y= Children Adult men Adult women Elderly men Elderly women 0.6 0.6 0.5 0.5 0.45

11. ANTICIPATE DURATION OF THERAPY

12. •Harrison's Principles of Internal Medicine, 18th edition, Anthony S.Fauci , MD, Eugene Braunwald , MD, Dennis L. Kasper, MD, Stephen L. Standard treatment protocol of emergency health service package 2078 A step-wise approach vol II second edition Guyton and hall textbook of medical physiology 13 th edition http://www.youtube.com/@ StrongMed All images are copyright to their respective owners. All product names, logos and brands used are properties of their respective owners.