1. Hyponatremia and Other Critical Electrolyte Abnormalities
Phillip D. Levy, MD, MPH, FACEP
Associate Professor and Associate Director of Clinical Research
Department of Emergency Medicine
Assistant Director of Clinical Research
Cardiovascular Research Institute
Wayne State University School of Medicine

2. Disclosures
None relevant to this presentation

3. 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

4. Potassium Hyperkalemia
Most common life-threatening electrolyte abnormality
Three stage approach to treatment
Membrane stabilization
Shift potassium into cells
Remove potassium from the body

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

6. Potassium Hyperkalemia
Most common life-threatening electrolyte abnormality
Three stage approach to treatment
Membrane stabilization
Shift potassium into cells
Remove potassium from the body

8. Typical ECG Changes
Pfenning et al. Critical Decisions in Emergency Medicine 2011;10;2-11.

9. Potassium Hyperkalemia
Most common life-threatening electrolyte abnormality
Three stage approach to treatment
Membrane stabilization
Shift potassium into cells
Remove potassium from the body

10. Potassium Hyperkalemia
Most common life-threatening electrolyte abnormality
Three stage approach to treatment
Membrane stabilization
Shift potassium into cells
Remove potassium from the body

11. Potassium Hypokalemia Often coupled with hypomagnesemia
Frequently asymptomatic
Cramps, weakness
Classic ECG findings

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

13. Potassium Hypokalemia Often coupled with hypomagnesemia
Frequently asymptomatic
Cramps, weakness
Classic ECG findings

14. Potassium Hypokalemia Often coupled with hypomagnesemia
Frequently asymptomatic
Cramps, weakness
Classic ECG findings

15. Potassium Hypokalemia 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

16. Potassium Hypokalemia 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

17. Potassium Hypokalemia 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

18. 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

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

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

28. Sodium Hypernatremia Hypovolemia most common cause
Also consider diabetes insipidus
Central (deficient production of AVP)
Nephrogenic (diminished response to AVP)

29. Sodium Hypernatremia Hypovolemia most common cause
Also consider diabetes insipidus
Central (deficient production of AVP)
Nephrogenic (diminished response to AVP)

30. Sodium Hypernatremia 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

31. Sodium Hypernatremia 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. Hyponatremia Critical diagnostic tests Urine osmolality
Serum osmolality
Urine sodium concentration

38. Hyponatremia Subclassified by effective serum osmolality Hypertonic
Pseudohypernatremia
Isotonic
High protein or lipid concentration
Hypotonic
< 280 mOsm/kg

39. Hyponatremia Subclassified by effective serum osmolality Hypertonic
Pseudohypernatremia
Isotonic
High protein or lipid concentration
Hypotonic
< 280 mOsm/kg

40. Hyponatremia Subclassified by effective serum osmolality Hypertonic
Pseudohypernatremia
Isotonic
High protein or lipid concentration
Hypotonic
< 280 mOsm/kg

41. Hyponatremia Subclassified by effective serum osmolality Hypertonic
Pseudohypernatremia
Isotonic
High protein or lipid concentration
Hypotonic
< 280 mOsm/kg

42. 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

43. 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

44. 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

45. Hypotonic Hyponatremia
Hypervolemic
Heart failure
Liver disease
CKD
Nephrotic syndrome

46. Hypotonic Hyponatremia
Treatment considerations
Acute vs. chronic
Degree of sodium depletion
Mild: mEq/L
Moderate: mEq/L
Severe: < 120 mEq/L
Symptoms
Neurologic
Underlying cause

47. Hypotonic Hyponatremia
Treatment considerations
Acute vs. chronic
Degree of sodium depletion
Mild: mEq/L
Moderate: mEq/L
Severe: < 120 mEq/L
Symptoms
Neurologic
Underlying cause

48. Hypotonic Hyponatremia
Treatment considerations
Acute vs. chronic
Degree of sodium depletion
Mild: mEq/L
Moderate: mEq/L
Severe: < 120 mEq/L
Symptoms
Neurologic
Underlying cause

49. Hypotonic Hyponatremia
Treatment considerations
Acute vs. chronic
Degree of sodium depletion
Mild: mEq/L
Moderate: mEq/L
Severe: < 120 mEq/L
Symptoms
Neurologic
Underlying cause

50. Hyponatremia and HF 42.5 45.0 Na < 135 mEq/L Na ≥ 135 mEq/L 40.0
34.8
35.0
30.0
25.0
(Days) or (%)
20.0
12.4
P < .0001
15.0
Data from the OPTIMIZE-HF registry.
7.1
10.0
6.4
6.0
5.5
3.2
5.0
0.0
Length of In-hospital Post-discharge Death or
stay (days) mortality (%) mortality (%) rehospitalization
since discharge (%)
Gheorghiade et al. Eur Heart J 2007;28: 50

51. Vasopressin Mediated Non-osmotic stimulation of AVP secretion
Aortic/ carotid sinus baroreceptors stimulation
 Fibrosis  Myocardial & vascular hypertrophy
 Sympathetic activity  Vasoconstriction
 Vasopressin
 H20 retention  Intravascular volume Dilutional hyponatremia
Goldsmith and Gheorghiade JACC 2005;46:

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

53. 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

55. Central Pontine Myelinolysis

56. 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

57. Vasopressin Antagonists
Conivaptan
Dual V1/V2 receptor antagonist
Tolvaptan
V2 receptor antagonist >>V1
Lixivaptan
V2 receptor antagonist >>>V1

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

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

63. Improves Sodium But…
Konstam et al. JAMA 2007; 297: 63

64. No Effect On “Outcomes”
Konstam et al. JAMA 2007; 297: 64

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

68. 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…