Hyponatremia by Dr. Basil Tumaini
•Download as PPTX, PDF•
6 likes•872 views
Hyponatremia by Dr. Basil Tumaini. Presented at Association of Physicians of Tanzania Conference in 2018.
Recommended
More Related Content
What's hot
What's hot (20)
Similar to Hyponatremia by Dr. Basil Tumaini
Similar to Hyponatremia by Dr. Basil Tumaini (20)
More from Basil Tumaini
More from Basil Tumaini (20)
Recently uploaded
Recently uploaded (20)
Hyponatremia by Dr. Basil Tumaini
- 1. HYPONATREMIA Basil Tumaini MD MMED (Int. Med.) 19 November 2018 (Presented at APHYTA Conference)
- 2. Hyponatremia • Hyponatremia is decrease in serum Na concentration < 135 mEq/L • Plasma Na+ concentration depends on the amount of both Na+ and water in the plasma – Hyponatremia does not necessarily imply Na+ depletion – Assessing fluid status is the key to diagnosis Braun MM, Barstow CH, Pyzocha NJ. Diagnosis and management of sodium disorders: hyponatremia and hypernatremia. American family physician. 2015 Mar 1;91(5). tumainibasil@gmail.com
- 3. Hyponatremia severity • Mild (serum Na 130 – 134 mEq/L) • Moderate (serum Na 125 – 129 mEq/L) • Profound (serum Na125 mEq/L; effective osmolality 238mOsm/kg) Spasovski G, et al. Clinical practice guideline on diagnosis and treatment of hyponatraemia. Nephrol Dial Transplant. 2014 Feb 25. tumainibasil@gmail.com
- 4. Pathophysiology 𝑇𝑜𝑡𝑎𝑙 𝑏𝑜𝑑𝑦 𝑠𝑜𝑑𝑖𝑢𝑚 Total body water ECF volume status Clinical assessment RAAS =serum [Na] = water status ADH system • Inability of KD to excrete a water load/excess water intake • Persistent ADH stimulation: – Normal but persistent ADH secretion – Abnormal ADH secretion tumainibasil@gmail.com
- 5. Hypotonic hyponatremia • Commonest • Causes cellular swelling • Hypertonic hyponatremia and isotonic hyponatremia (pseudohyponatremia) are relatively less common tumainibasil@gmail.com
- 6. Assess volume status Hypovolemic hyponatremia Hypervolemic hyponatremiaEuvolemic hyponatremia Diuretic excess Addison disease Salt wasting GI 3rd spacing SIADH Psychogenic polydipsia Hypothyroidism Glucocorticoid def. CHF Cirrhosis Nephrotic syndrome AKI CKD N/S Restrict water Sts: N/S 3% NaCl in seizures, coma Vaptans Restrict water ± Diuretics Vaptans Na, Water Na, Water* Na, Water RenallossesNon-renallosses EdemastatesRenalfailure tumainibasil@gmail.com
- 7. Clinical presentation • Depends on – Age and comorbidity – Rate of fall in serum sodium – Severity of hyponatremia • Symptoms mainly involve CNS dysfunction • When accompanied by disturbances in total body Na content, signs of ECF volume depletion or overload also occur * Braun MM, Barstow CH, Pyzocha NJ. Diagnosis and management of sodium disorders: hyponatremia and hypernatremia. American family physician. 2015 Mar 1;91(5).
- 8. Clinical features • Anorexia, nausea and malaise initially • Headache, changes in mental status, including altered personality, lethargy, and confusion • As the serum Na falls to < 115 mEq/L, stupor, neuromuscular hyperexcitability, hyperreflexia, seizures, coma, and death can result * Braun MM, Barstow CH, Pyzocha NJ. Diagnosis and management of sodium disorders: hyponatremia and hypernatremia. American family physician. 2015 Mar 1;91(5).
- 9. History • Risk factors • Neurologic symptoms • Chronicity of hyponatremia – Acute 48hrs – Chronic ≥ 48hrs Hyponatremia is usually a chronic condition and it should be presumed to be chronic when the actual duration is unclear* * Sterns RH. Disorders of plasma sodium—causes, consequences, and correction. New England Journal of Medicine. 2015 Jan 1;372(1):55-65. tumainibasil@gmail.com
- 10. Physical examination • Vital signs • Clinical assessment of volume status: dehydration, edema and ascites • Other systems Sahay M, Sahay R. Hyponatremia: a practical approach. Indian journal of endocrinology and metabolism. 2014 Nov;18(6):760. tumainibasil@gmail.com
- 11. Investigations/Monitoring • Serum electrolytes and osmolality • Urine dipstick • Urine electrolytes and osmolality • Other investigations as appropriate Sahay M, Sahay R. Hyponatremia: a practical approach. Indian journal of endocrinology and metabolism. 2014 Nov;18(6):760. tumainibasil@gmail.com
- 12. Approach to a patient sodium abnormalities • Treatment depends on – Volume status – Duration of hyponatremia (whether acute/<48 h or chronic >48 h) – Presence or absence of symptoms – Etiology of hyponatremia Sahay M, Sahay R. Hyponatremia: a practical approach. Indian journal of endocrinology and metabolism. 2014 Nov;18(6):760. tumainibasil@gmail.com
- 13. Approach to a patient sodium abnormalities • Replace Na+ and water at the same rate they were lost • Asymptomatic chronic hyponatraemia – fluid restriction is often sufficient if asymptomatic – demeclocycline (ADH antagonist) may be required – If hypervolaemic (cirrhosis, CCF), treat the underlying disorder first tumainibasil@gmail.com
- 14. Approach to a patient sodium abnormalities • Acute or symptomatic hyponatremia, or if dehydrated – cautious rehydration with N/S – do not correct changes rapidly as osmotic demyelination syndrome may result • Maximum rise in serum Na+ 15mmol/L per day if chronic or 1mmol/L per hour if acute • Consider using furosemide when not hypovolemic to avoid fluid overload • Vasopressor receptor antagonists tumainibasil@gmail.com
- 15. Approach to a patient sodium abnormalities • In emergency: Seizures, coma • Consider hypertonic saline e.g. 3% NaCl (1 litre = 513mEq Na+) – a bolus of 100ml 3% NaCl IV over 10 min, repeated up to 3 doses till acute symptoms subside – Aim for a gradual increase in plasma Na+ to ≈125mmol/L frequent monitoring q2-4h – Beware heart failure and osmotic demyelination syndrome – The goal is to provide an urgent correction by 4 - 6 mmol/L to prevent brain herniation Sterns RH. Disorders of plasma sodium—causes, consequences, and correction. New England Journal of Medicine. 2015 Jan 1;372(1):55-65. tumainibasil@gmail.com
- 16. Use of hypertonic saline • Hypertonic (3%) saline (containing 513 mEq Na/L) may be used, but only with frequent (q 2 to 4 h) electrolyte determinations • For patients with seizures or coma, ≤ 100 mL/h may be administered over 4 to 6 h in amounts sufficient to raise the serum Na 4 to 6 mEq/L. • Amount (in mEq) may be calculated using the Na deficit formula as – (Desired change in Na) × TBW – where TBW is 0.6 × body weight in kg in men and 0.5 × body weight in kg in women. tumainibasil@gmail.com
- 17. Osmotic demyelination syndrome (formely CPM) • may follow too-rapid correction of hyponatremia • may affect the pons and other areas of the brain • Risk by alcoholism, undernutrition, or other chronic debilitating illness • Damage often is permanent Sterns RH. Disorders of plasma sodium—causes, consequences, and correction. New England Journal of Medicine. 2015 Jan 1;372(1):55-65. http://sumerdoc.blogspot.com/2008/07/central-pontine-myelinolysis.html tumainibasil@gmail.com
- 18. SIADH • Etiologies – Pulmonary: pneumonia, TB, abscess, aspergillosis – CNS: abscess, meningitis, encephalitis, GBS, stroke, SAH, SDH, head injury, neurosurgery, GBS, vasculitis or SLE – Neoplasms: lung – SCLC, pancreas, prostate, thymus, lymphoma – Drugs: SSRIs, phenothiazines, NSAIDS (syndrome like SIADH), cyclophosphamide – Other: AIP, trauma, major abdominal or thoracic surgery, symptomatic HIV ECF volume, sOsm, UOsm, Uric acid levels tumainibasil@gmail.com
- 19. SIADH Rx • Treat the cause • restrict fluid • Consider salt ± loop diuretic if severe • Drugs: – Vasopressin receptor antagonists (vaptans) – Demeclocycline tumainibasil@gmail.com
- 20. Vasopressin receptor (V) antagonists (vaptans) • V2: antidiuresis, V1a: vasoconstriction, V1b: ACTH release • The vasopressin receptor antagonists cause aquaresis • Vaptans do not deplete electrolytes and restriction of fluids is not needed • They do not stimulate the neurohormonal system and cause no renal impairment Nonselective (mixed V1A/V2): Conivaptan IV V2 selective (V2RA): e.g. Tolvaptan Sahay M, Sahay R. Hyponatremia: a practical approach. Indian journal of endocrinology and metabolism. 2014 Nov;18(6):760. tumainibasil@gmail.com
- 21. • The efficacy of Tolvaptan PO has been demonstated in several multicenter trials: SALT-1, SALT-2, SALTWATER • TEMPO 3:4 lead to the recommendation to monitor LFTs initially and 3-4 months thereafter • Tolvaptan use has been recommended by US FDA but not for greater than 4 wks tumainibasil@gmail.com
- 22. SIADH Rx • Demeclocycline – Initially 900-1200 mg daily in divided doses, – Maintenance 600 – 900 mg/d • Tolvaptan – 15 mg PO OD, increased if necessary up to 60 mg/d • Conivaptan – 20mg LD IV for 30 min – F/B 20mg/d IV continuous infusion for 24h x1-3days; – max: 40mg/d. Total duration4days tumainibasil@gmail.com
- 23. Thank you Je vous remercie Gracias Спасибо Vielen Dank 謝謝 شكرا Asanteni tumainibasil@gmail.com
Editor's Notes
- Hyponatremia is the commonest electrolyte abnormality among in-patients; up to 30%.
- Note that the ECF volume is not the same as effective plasma volume. For example, decreased effective plasma volume may occur with decreased ECF volume, but it may also occur with an increased ECF volume (eg, in heart failure, hypoalbuminemia, or capillary leak syndrome).
- osmolalityhypothalamic osmoreceptors [thirst]posterior pituitaryADHbasolateral aspect of collecting duct (CD) cellsaquaporin expression on luminal aspect of the CD cellswater absorption (&abolishes thirst) Normal but persistent ADH secretion Volume depletion True volume depletion Reduced tissue perfusion {baroreceptors: carotid sinus& aortic archsympath/ADH (neurohormonal); glomerular afferent arterioleRAS activity regulation; atria and ventriclesregulate release of natriuretic peptides} ……………….→water retention Abnormal ADH secretion
- True hyponatremiahypotonic hyponatremia Normal serum osmolality: 280-295 mOsm/kg
- Renal loss: urinary Na+ >20mmol/L; esp. thiazides. Non-renal loss: urinary Na+ <20mmol/L Urine Na concentration may not help in differentiation when metabolic alkalosis (as occurs with protracted vomiting) is present and large amounts of HCO3 are spilled in the urine, obligating the excretion of Na to maintain electrical neutrality GI: diarrhea, vomiting, fistulae, rectal villous adenoma 3rd spacing: Small bowel obstruction Euvolemic hyponatremia is the commonest and accounts for 60% of all cases of hyponatremia. The commonest cause of euvolemic hyponatremia is SIADH
- Older chronically ill patients develop more symptoms than younger otherwise healthy patients Symptoms are also more severe with faster-onset hyponatremia Symptoms generally occur when the effective plasma osmolality falls to < 240 mOsm/kg Overt neurologic symptoms most often are due to very low serum sodium levels (usually < 115 mEq/L), resulting in intracerebral osmotic fluid shifts and brain edema
- Symptoms can be subtle and consist mainly of changes in mental status Cardiac failure or oedema may help to indicate the cause. Hyponatremia also increases the risk of falls in the elderly
- Drugs: Diuretic use, SSRI, Li, Diet Diabetes Losses: diarrhea, vomiting, burns, trauma, heat exposure
- P/A CVS RS CNS
- Blood glucose Colonoscopy Plain abdominal x-ray Sweat chloride test Spot PCR CXR, ECG, echo Abd. USS Thyroid function testing: TSH±FT3/4 ACTH and ACTH stimulation tests, CT/ MRI brain and imaging of chest are done as needed Blood pH e.g. by ABG machine
- Treatment involves restricting water intake and promoting its loss, replacing any Na deficit, and treating the cause
- 1L N/S=154mEq Na
- In the current guidelines these formulae are not used. Instead 1ml/kg of 3% NaCl is estimated to raise the serum Na by 1mEq/l.
- Formely: central pontine myelinolysis irreversible and often fatal pontine demyelination seen in malnourished alcoholics or rapid correction of Na+. There is subacute onset of lethargy, confusion, pseudobulbar palsy, para- or quadriparesis, ‘locked-in’ syndrome, or coma When Na is replaced too rapidly (eg, > 14 mEq/L/8 h) and neurologic symptoms start to develop, it is critical to prevent further serum Na increases by stopping hypertonic fluids. In such cases, inducing hyponatremia with hypotonic fluid may mitigate the development of permanent neurologic damage
- SIADH: D.O.E. r/o: Addison disease: ECF volume, sOsm, UOsm Hypothyroidism Schwartz diagnostic criteria for ADH
- Some causes of SIADH can be corrected e.g. self‑limited disease (e.g. nausea, pain, surgery), cessation of drugs that cause SIADH and treatment of tuberculosis or meningitis Vasopressor receptor antagonists (‘vaptans’, eg tolvaptan) promote water excretion without loss of electrolytes, and appear to be effective in treating hypervolaemic and euvolaemic hyponatraemia ? Expensive Demeclocycline: Causes a nephrogenic form of diabetes insipidus, thereby decreasing urine concentration even in the presence of high plasma AVP levels. Appropriate doses of demeclocycline range from 600 to 1,200 mg/day administered in divided doses. Treatment must be continued for several days to achieve maximal diuretic effects; one should wait 3 to 4 days before deciding to increase the dose. Demeclocycline can cause reversible azotemia and sometimes nephrotoxicity, especially in patients with cirrhosis and should be discontinued if increasing azotemia occurs.
- Vaptans act on vasopressin receptors as antagonists The vasopressin receptor antagonists produce a water loss (aquaresis) without affecting sodium and potassium excretion Terlipressin-V1aHRS
- Vaptans are not recommended for hypovolemic hyponatremia
- Lithium