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
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.
Potassium
• Hyperkalemia
- Most common life-threatening
electrolyte abnormality
- Three stage approach to treatment
• Membrane stabilization
• Shift potassium into cells
• Remove potassium from the body
Typical ECG Changes
Pfenning et al. Critical Decisions in Emergency Medicine 2011;10;2-11.
Potassium
• Hyperkalemia
- Most common life-threatening
electrolyte abnormality
- Three stage approach to treatment
• Membrane stabilization
• Shift potassium into cells
• Remove potassium from the body
Potassium
• Hyperkalemia
- Most common life-threatening
electrolyte abnormality
- Three stage approach to treatment
• Membrane stabilization
• Shift potassium into cells
• Remove potassium from the body
Potassium
• Hypokalemia
- Often coupled with hypomagnesemia
- Frequently asymptomatic
• Cramps, weakness
- Classic ECG findings
Common Causes
Pfenning et al. Critical Decisions in Emergency Medicine 2011;10;2-11.
Potassium
• Hypokalemia
- Often coupled with hypomagnesemia
- Frequently asymptomatic
• Cramps, weakness
- Classic ECG findings
Potassium
• Hypokalemia
- Often coupled with hypomagnesemia
- Frequently asymptomatic
• Cramps, weakness
- Classic ECG findings
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
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
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
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
Pfenning et al. Critical Decisions in Emergency Medicine 2011;10;2-11.
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
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
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
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
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
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
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
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)
Sodium
• Hypernatremia
- Hypovolemia most common cause
- Also consider diabetes insipidus
• Central (deficient production of AVP)
• Nephrogenic (diminished response to AVP)
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
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
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
• 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
• 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
• 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
• 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
Hyponatremia
• Subclassified by effective serum
osmolality
– Hypertonic
• Pseudohypernatremia
– Isotonic
• High protein or lipid concentration
– Hypotonic
• < 280 mOsm/kg
Hyponatremia
• Subclassified by effective serum
osmolality
– Hypertonic
• Pseudohypernatremia
– Isotonic
• High protein or lipid concentration
– Hypotonic
• < 280 mOsm/kg
Hyponatremia
• Subclassified by effective serum
osmolality
– Hypertonic
• Pseudohypernatremia
– Isotonic
• High protein or lipid concentration
– Hypotonic
• < 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
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
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
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
42.5
45.0
Na < 135 mEq/L
Na ≥ 135 mEq/L
40.0
34.8
(Days) or (%)
35.0
30.0
25.0
20.0
P < .0001
12.4
15.0
10.0
6.4 5.5
5.0
0.0
Length of
stay (days)
7.1
6.0
3.2
In-hospital
mortality (%)
Post-discharge
Death or
mortality (%) rehospitalization
since discharge (%)
Gheorghiade et al. Eur Heart J 2007;28:980-88.
Vasopressin Mediated
Non-osmotic stimulation of
AVP secretion
Aortic/ carotid sinus
baroreceptors stimulation
 Sympathetic
activity
 Vasoconstriction
 Vasopressin
 Fibrosis
 Myocardial &
vascular hypertrophy
 H20 retention
 Intravascular volume
Dilutional hyponatremia
Goldsmith and Gheorghiade JACC 2005;46:1785-91
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…