43 Levy Hyponatremia Et Al

Hyponatremia and Other Critical

Electrolyte Abnormalities

Phillip D. Levy, MD, MPH, FACEPAssociate Professor and Associate Director of Clinical Research

Department of Emergency MedicineAssistant Director of Clinical Research

Cardiovascular Research InstituteWayne State University School of Medicine

Disclosures• None relevant to this presentation

Objectives• To provide a brief review of

common electrolyte abnormalities encountered in the ED and discuss basic treatment

• To take a closer look at hyponatremia and evolving approaches to management

Potassium• Hyperkalemia

- Most common life-threatening electrolyte abnormality

- Three stage approach to treatment• Membrane stabilization• Shift potassium into cells• Remove potassium from the body

Common Causes

Pfenning et al. Critical Decisions in Emergency Medicine 2011;10;2-11.




Typical ECG Changes








Potassium• Hypokalemia

- Often coupled with hypomagnesemia- Frequently asymptomatic

• Cramps, weakness- Classic ECG findings

Common Causes









- Replete orally for mild to moderate decreases

• Each 0.3 mEq < normal = 100 mEq deficit- Prolonged therapy may be needed for

severe cases- Requires concurrent magnesium to

move intracellularly











Calcium• Hypercalcemia

– Most often caused by parathyroid disease and malignancy

– “Bones, moans, groans and stones”• Arrhythmias with concomitant electrolyte

abnormalities– Primary treatment is normal saline

• Furosemide can help with associated diuresis but no longer routinely recommended

• Bisphosphonates = definitive therapy

Common Causes














Calcium• Hypocalcemia

– Typically caused by hypoalbuminemia– Muscle cramping, paresthesias

• Chvostek sign• Trousseau sign

– Oral repletion for mild cases, IV for more significant deficits• Ionized calcium level more accurate than

total





total





total

Magenesium• Hypomagnesemia

– Typically caused by insufficient dietary intake, GI disorders, and medication effects

– Symptoms relatively non-specific– Treatment generally IV

• 0.5-2 gm/h• Watch for loss of deep tendon reflexes and

development of respiratory depression











Sodium• Hypernatremia

- Hypovolemia most common cause- Also consider diabetes insipidus

• Central (deficient production of AVP)• Nephrogenic (diminished response to AVP)


- Hypovolemia most common cause- Also consider diabetes insipidus

• Central (deficient production of AVP)• Nephrogenic (diminished response to AVP)


- Hypovolemic: replace free water deficit• TBW = 0.6 x current weight (kg)• Desired TBW = measured Na x current

TBW / normal Na• Body water deficit = desired TBW – current

TBW- Diabetes insipidus

• Central: DDAVP• Nephrogenic: thiazide diuretic


- Hypovolemic: replace free water deficit• TBW = 0.6 x current weight (kg)• Desired TBW = measured Na x current

TBW / normal Na• Body water deficit = desired TBW – current

TBW- Diabetes insipidus

• Central: DDAVP• Nephrogenic: thiazide diuretic

Hyponatremia• Most common electrolyte

abonormality• Classified by volume status

– Hypovolemic hyponatremia• Decrease in total body water with greater

decrease in total body sodium– Euvolemic hyponatremia

• Normal body sodium with increase in total body water

– Hypervolemic hyponatremia• Increase in total body sodium with greater

increase in total body water





























Hyponatremia• Critical diagnostic tests

– Urine osmolality– Serum osmolality– Urine sodium concentration

Hyponatremia• Subclassified by effective serum

osmolality– Hypertonic

• Pseudohypernatremia– Isotonic

• High protein or lipid concentration– Hypotonic

• < 280 mOsm/kg





• < 280 mOsm/kg





• < 280 mOsm/kg





• < 280 mOsm/kg

Hypotonic Hyponatremia• Hypovolemic

– Caused by GI loss, renal loss , or 3rd spacing• Non-renal: urine sodium < 20 mEq/L• Renal: urine sodium > 20 mEq/L

– Treat with IV normal saline

Hypotonic Hyponatremia• Hypovolemic

– Caused by GI loss, renal loss , or 3rd spacing• Non-renal: urine sodium < 20 mEq/L• Renal: urine sodium > 20 mEq/L

– Treat with IV normal saline

Hypotonic Hyponatremia• Isovolemic

– Glucocorticoid insufficiency– Hypothyroidism– Psychogenic polydipsia– Medications

• Amitriptyline, carbamazepine– Diuretic use with potassium depletion– SIADH

• Urine sodium > 20 mEq/L• Urine osmolality > 200 mOsm/kg

Hypotonic Hyponatremia• Hypervolemic

– Heart failure– Liver disease– CKD– Nephrotic syndrome

Hypotonic Hyponatremia• Treatment considerations

– Acute vs. chronic– Degree of sodium depletion

• Mild: 130-134 mEq/L• Moderate: 120-130 mEq/L• Severe: < 120 mEq/L

– Symptoms• Neurologic

– Underlying cause
















Hyponatremia and HF

Gheorghiade et al. Eur Heart J 2007;28:980-88.

45.0

40.0

35.0

30.0

25.0

20.0

15.0

10.0

5.0

0.0

(Day

s) o

r (%

)

6.4 5.5 6.03.2

12.4

7.1

42.5

34.8

P < .0001

Na < 135 mEq/LNa ≥ 135 mEq/L

Length of In-hospital Post-discharge Death or stay (days) mortality (%) mortality (%) rehospitalization

since discharge (%)

Vasopressin

Non-osmotic stimulation of AVP secretion

H20 retention Intravascular volume

Dilutional hyponatremia

Sympathetic activity

Vasoconstriction

Fibrosis Myocardial &

vascular hypertrophy

Aortic/ carotid sinus baroreceptors stimulation

Goldsmith and Gheorghiade JACC 2005;46:1785-91

Vasopressin Mediated

Maisel et al. Circ Heart Fail. 2011;4:613-20.

Hypotonic Hyponatremia• Treatment options

– Hypertonic saline (3% soln)• Reserved for acute, severe cases• Bolus 100 mL over 10 min q 1 hr x 2 doses• Infusion of 1-2 mL/kg/hr• Target correction: 0.5 mEq/L/hr

– Fluid restriction– Medication withdrawal– Diuresis– Democlocycline

Central Pontine Myelinolysis

Hypotonic Hyponatremia• Treatment options

– Hypertonic saline (3% soln)• Reserved for acute, severe cases• Bolus 100 mL over 10 min q 1 hr x 2 doses• Infusion of 1-2 mL/kg/hr• Target correction: 0.5 mEq/L/hr

– Fluid restriction– Medication withdrawal– Diuresis– Democlocycline

Vasopressin Antagonists• Conivaptan

– Dual V1/V2 receptor antagonist• Tolvaptan

– V2 receptor antagonist >>V1• Lixivaptan

– V2 receptor antagonist >>>V1

Cassagnol et al. J Pharm Practice 2011;24:391-9.

Cassagnol et al. J Pharm Practice 2011;24:391-9.

Improves Sodium But…

Konstam et al. JAMA 2007; 297:1319-31.

No Effect On “Outcomes”

Konstam et al. JAMA 2007; 297:1319-31.

Elhassan and Schrier. Expert Opin. Investig. Drugs 2011;20:373-80.

Final Thoughts• Obtain ECGs early with suspected or

confirmed electrolyte abnormalities– Irritable cardiomyocytes need attention

• Little has changed in therapeutic approach for most – Think normal saline for hyper-anything– Deficiencies tend to comingle

• Don’t ignore those low sodiums!– Especially in HF…

43 Levy Hyponatremia Et Al

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