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Overview of hyponatremia in elderly.....
- 1. Overview of hyponatremia ByIrfat Mahjabeen
- 2. Introduction: • Serum sodium<136 mmol /L ( normal 136- 146 mmol / L ) • Most common electrolyte abnormality seen in elderly or in nursing home patients • Affects 15% to 30% of hospital inpatients • Age is a strong independent risk factor, and symptoms of hyponatremia are often masked in frailty. • Poor prognosis and increased mortality risk in elderly when associated with other comorbidities.
- 3. Classification: According to severity •Mild 130 – 135 mmol/L. • Moderate 125 – 129 mmol/L. • Severe < 125 mmol/L. According to rate of onset • Acute —less than 48 hours. • Chronic —48 hours or more. According to serum osmolarity • Hypertonic (Serum osm >295 mosm/L) • Isotonic/ pseudo hyponatremia (serum osm 275- 295 mosm/L) • *Hypotonic/ true hyponatraemia (Serum osm < 275 mosm/L
- 4. Hypotonic hyponatremia :according to volume status : TBW ↑↑ Na ↑ TBW ↓ Na ↓↓ TBW ↑ Na ↔
- 5. Physiology : • Hyponatremiadoes not always necessarily imply Na+ depletion • Plasma Na+ concentration depends on amount of extracellular water volume relative to sodium. • Plasma sodium conc is maintained by: o RAA system o Thirst o ADH secretion
- 7. Causes : Hypervolemia EuvolemiaHypovolemia • Heart failure • Liver failure • Nephrotic syndrome • hypoalbuminaemia • SIADH • Hypothyroidism • Primary Polydipsia • GI or extra-renal fluid losses • Diuretics • Primary hypoaldosteronism • Cerebral salt wasting syndrome In elderly patients, multiple factors are usually implicated in the development of hyponatremia. • the aging-related impaired water-excretory capacity • frequent exposure to medications and • diseases associated with hyponatremia.
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- 9. Clinical features : Posturalhypotension, gait abnormality, recurrent fall
- 10. Medication : • Antihypertensive: ACEI, amlodipine, thiazide*, indapamide • Anticancer drug : Cisplatin, vincristine • Antiarrythmic : amiodarone • Anti reflux : PPI • Antibiotic : Trimethoprim, ciprofloxacin • Antidepressant * : TCA, lithium, SSRI, MAOI, Phenothiazine • Antipsychotics *: Phenothiazine • Antiepileptics : Carbamazepine, valproate
- 11. Investigation : 1. serumosmolality 2. urine sodium concentration 3. urine osmolality 4. Others : - Serum electrolytes, urea, creatinine, and glucose - Urinary protein analysis and 24 hr urinary protein for NS, Liver function tests, clotting functions and albumin in cirrhosis - BNP, echocardiography if there are features of congestive cardiac failure - TSH, serum cortisol level MRI brain - serum lipids and serum protein electrophoresis
- 12. Hyponatraemia Assess serum osmolarity >100 mosm /L Isotonic 275 to 295 mosm /L • Hyperlipidemia • Hyperproteinemia Hypotonic <275 mosm/L Hypertonic >295 mosm/L • Hyperglycemia, • mannitol, • IV contrast <100 mosm /L • Primary polydipsia • Low solute intake Assess Urinary Na osmolality Diagnostic approach :
- 13. Assess urinary Naand volume status Diuretics or kidney disease Urinary Na < 30 Low effective arterial volume Urinary Na > 30 Decreased GFR/ inability to dilute urine Urinary Na osmolarity > 100 mosm/L Euvolumic • SIADH • 2ndary adrenal insufficiency • Hypothyroidism hypovolumic • D + V • 3rd space fluid loss • Burn Hypervolumic • cirrhosis, • NS, • HF • Hypoalbuminemia • Diuretics • CKD Hypovolemia • Primary Adrenal insufficiency • Cerebral salt wasting Yes NO
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- 15. Acute hyponatremia withmoderate or severe symptoms: • Aim is to improve symptoms, NOT correct Na+ back to normal • Critical care r/v if CNS symptoms as risk of developing brain edema • Hypertonic saline 3% NaCl, 150 ml via central line over 20 minutes. • Repeat VBG after 20 min - if no clinical improvement • Na level remains same - Repeat bolus dose of hypertonic saline, maximum 3 time. • Stop infusion : • If clinical symptoms improve • Serum Na concentration increased 5 mmol/L
- 16. Monitoring of Nalevel in acute hyponatremia: • Na+ should not rise > 10 mmol/l in first 24 hours. • Recheck Na+ level at 6, 12, 24 and 48 hours . • Urine output should not be 0.5 - 1 ml/hr. Increase U/O - rapid overcorrection of Na • Rapid overcorrection in chronic cases leads to a risk of osmotic demyelination syndrome. • If rapid overcorrection : • discontinuing the ongoing treatment. • consulting an expert to consider IV dextrose or desmopressin is suggested. • 1 L of 3% NaCl has 513 mEq of Na, whereas, isotonic NaCl has 154 mEq of Na
- 17. Acute or chronichyponatremia with mild or no symptoms: • Non-essential parenteral fluids • Stop if any provoking medication • Treatment of underlying cause.
- 18. Chronic hyponatremia :Assess volume status Hypovolemia • ECF volume replacement is recommended. • Isotonic saline Hypervolemia • Fluid restriction • Loop Diuretics • Tolvaptan Euvolemia • Fluid restriction • Loop Diuretics • Tolvaptan/ demecycline
- 19. Summary: • Evaluation andthe treatment of hyponatremia pose many challenges in the elderly population. • In elderly, hyponatremia can be iatrogenic. • Avoidance of polypharmacy, considering low dose of provoking medications/ alternative should be a priority in elderly people. • A sudden and acute fall in serum sodium concentration can result in severe cerebral oedema, leading to cerebral herniation and death. • Risk of morbidity from delaying in treatment is more than osmotic demyelination syndrome.
- 20. Reference : • Hyponatremiain the elderly: challenges and solutions - PMC (nih.gov) • Assessment of hyponatraemia - Differentials | BMJ Best Practice • Clinical practice guideline on diagnosis and treatment of hyponatraemiaThe guidelines wer e peer reviewed by the owner societies and by external referees prior to publication. | Euro pean Journal of Endocrinology | Oxford Academic (oup.com) • Hyponatraemia | Health topics A to Z | CKS | NICE • Management of Hyponatraemia Clinical Guideline (cornwall.nhs.uk) • http://www.gloshospitals.nhs.uk/media/documents/Hyponatraemia.pdf