navigating the ups and downs of electrolyte management
TRANSCRIPT
MICHAEL KENNEDY RPH, PHARMD
Navigating the Ups and Downs of Electrolyte Management
Learning Objectives
• Demonstrate an understanding of the relationship between various
electrolytes
• Identify electrolyte levels which require management
• Describe replacement strategies for abnormal electrolyte levels including
potassium, magnesium, calcium, phosphate, and sodium
• Select an appropriate therapy for electrolyte replacement
Disclosures
Will be provided with an honorarium from PANL for presenting
Potassium
Potassium
Found in many fruits and
vegetables including
apricots, bananas,
potatoes, soybeans, and
lentils
Normal range is 3.5-
5.0mmol/L
Hypokalemia
Typically defined as K+ <3.5 mmol/L
Causes
Diet
Medications such as diuretics
Diarrhea
Vomiting
Other electrolyte imbalances (magnesium)
Often discovered on routine bloodwork only vs symptomatic
May present as muscle weakness
ECG changes (prolonged QTc)
Presentation:
3.0-3.4mmol/L – usually asymptomatic
2.5-2.9mmol/L –asymptomatic/muscle weakness/ECG changes
<2.5mmol/L – more urgent cases, QTc changes/risk of MI increases
Hypokalemia Treatment Strategies
IV preparations
10mmol/20mmol mini-bags
Various 1000ml K+ bags
Orally
Slow K 600mg tablet
Micro K 600mg tablet
K-Dur 1500mg tablet
K-Lyte 25 mEq tablet
Liquid K-10 solution
Keep patient factors in mind
Liquid vs capsule vs tablet
IVF assessment important
D5W will cause insulin spike – can make hypokalemia worst
Assess IV access
10mmol IV max if peripherally
20mmol IV acceptable if given via
central line
Patients will report a burning
sensation if given too quickly
Hyperkalemia
Defined as K+ >5.0mmol/L
causes
Medication use
ACE/Septra
K+ sparing diuretics
Tissue breakdown
Overcorrection of hypokalemia
Renal dysfunction
Presentation:
5.1-5.4mmol/L – often
asymptomatic
5.5-6.5mmol/L – moderate
hyperkalemia, may present with
chest pain, nausea/vomiting
>6.5mmol/L – requires prompt
treatment, arrythmia
development/increased risk of MI
Hyperkalemia Treatment Strategies
Kayexalate
Calcium
Insulin + Glucose
Salbutamol
Loop diuretics
Dialysis
Often treatment strategies are combined
For example Insulin + Glucose + Salbutamol + IV Calcium together
Clinical Pearl
Kayexalate works by exchanging sodium ions for potassium ions in
the GI tract before it is eliminated from the body via stool
Ensure patient is moving bowels or has medications available to help
pass stool before giving kayexalate
Common strategy involves giving Kayexalate 30g po x 1 dose +
Lactulose 30ml po x 1 dose.
Magnesium
Magnesium
Found in almonds,
seafood, berries, bananas,
green leafy vegetables,
and even coffee (woo!)
Normal range 0.66-1.07
mmol/L
Hypomagnesemia
Defined as serum magnesium
<0.66 mmol/L
Causes
Renal failure
Malabsorption via GI tract
Alcohol
Medication use
Chemotherapy
Digoxin
Cyclosporin/tacrolimus
Aminoglycosides
Outcomes:
Tremors
Weakness
Delirium
Arrythmia development
Hypokalemia
Hypomagnesemia Treatment
Strategies
IV preparations
Magnesium sulfate
1g, 2g, 4g
Oral magnesium
Magnesium oxide
Magnesium citrate
Magnesium glucohyptenate
Hypermagnesemia
Defined as serum magnesium
>1.07mmol/L
Causes
Renal failure
Overcorrection from
hypomagnesemia therapy
Often a rare occurrence in the
absence of the above two causal
factors
Outcomes
Nausea/vomiting
Drowsiness
Hypotension/bradycardia
Muscle paralysis
Cardiac arrest
Hypermagnesemia Treatment
Strategies
Isotonic solutions IV (Normal saline infusion to aid in kidney function)
Loop diuretics
Dialysis
Clinical Pearl
Use IV preparations for more severe hypomagnesemia as oral preparations are poorly absorbed and can lead to diarrhea (thus more electrolyte imbalance)
Ensure rate of magnesium IV is appropriate (typically 1g IV per hour). Too quick will result in inability to absorb dose before eliminating from body
Potassium and Magnesium
Relationship
Hypomagnesemia leads to increased renal elimination of
potassium.
Attempting to correct potassium while hypomagnesemia present
often leads to repeated dosing/failure to correct/increased cost
and adverse effects associated with hypokalemia therapy
Can often correct mild hypokalemia by correcting hypomagnesemia
If both magnesium and potassium levels are low, attempts to correct
magnesium first should be made
Calcium
Calcium
Found in dairy products,
dark green vegetables
such as spinach, nuts,
and fortified products
(such as orange juice)
Normal range 2.15-2.62
mmol/L
Hypocalcemia
Defined as serum calcium <2.15
mmol/L
Causes
Medications
Bisphosphonates
Calcium binders
Chemotherapy
Renal failure
Hormonal imbalances
Hypomagnesemia
Outcomes
numbness in hands and feet,
muscle cramps, confusion, loss of
consciousness, seizures
Hypocalcemia Treatment
Strategies
Oral replacement
Calcium carbonate
Calcium citrate
Ensure spacing between doses to
allow for elemental iron absorption
(absorption tends to be highest
with doses of 500mg elemental
calcium or less)
Ensure vitamin D deficiency is
ruled out if long term calcium
replacements are an issue
IV replacement
Calcium gluconate
Calcium chloride
Calcium chloride offers 3x as
much elemental calcium vs
gluconate, but is also more likely
to cause tissue necrosis if
extravasation occurs
Hypercalcemia
Defined as serum calcium
>2.62mmol/L
Causes
Malignancy
Often seen in multiple myeloma
Too much oral intake?
Unlikely to cause hypercalcemia due to the inhibition of PTH release and decreased calcitriol synthesis
Increased PTH levels
Increased osteoclast activity
Outcomes
Mild: often asymptomatic
Moderate: polyurea, polydipsia,
nausea/vomiting, constipation
Severe: confusion, cognitive delay,
coma
Hypercalcemia Treatment
Strategies
IV fluid (Normal Saline) to ensure
adequate renal function
Calcitonin (salmon)
Denosumab
Bisphosphonates
Zoledronic acid
Pamidronate
Avoidance of high calcium
containing foods and vitamin D
supplementation important during
initial phase of correction
Be careful not to overshoot!
Clinical Pearl Ionized calcium levels
Ionized calcium is the most active form of
calcium (calcium not attached to proteins)
Ionized calcium is more reflective of a true
calcium level in a patient versus serum
calcium
If a patient has low albumin (<20g/L),
perform an ionized calcium level to rule out
hypocalcemia versus correcting calcium
levels based upon albumin
Ionized calcium uses a different reference
range versus serum calcium
Normal range: 1.18-1.32mmol/L
Phosphate
Phosphate
Found in eggs, yogurt,
salmon, chicken, sunflower
seeds, red meats, cola
Normal range 0.74-1.52
mmol/L
Hypophosphatemia
Defined as serum phosphate <0.74
mmol/L
Causes
Medications
antacids
Phosphate binders
IV iron
Inadequate intake
Vitamin D deficiency
Outcomes
Mild/moderate deficiency usually
asymptomatic
Severe cases can present with
decreased level of consciousness,
seizures, coma
Hypophosphatemia Treatment
Strategies
IV replacement
Available as potassium phosphate
IV
Oral replacement
Phosphate Novartis tablets
Jamp sodium phosphate tablets
and IV options when replacement
is needed in moderate to severe
cases
Oral replacements are given as
effervescent tablets
Be aware of patient at hand!
Hyperphosphatemia
Defined as serum phosphate >1.52
mmol/L
Causes
Medication use
Penicillin
Corticosteroids
Acute/chronic kidney disease
Tumour lysis syndrome
Rhabdomyolysis
Outcomes
Muscle cramping, numbness,
tingling, symptoms resulting from
subsequent hypocalemia
Hyperphosphatemia Treatment
Strategies
Acute hyperphosphatemia
IV fluid (Normal Saline) to support kidney function
Dialysis correction
IV calcium (rare cases)
Chronic hyperphosphatemia
(typically in CKD)
Phosphate restrictive diets
No Coke or Pepsi
Phosphate binders
Calcium containing Vs Non-calcium containing phosphate binders
Clinical Pearl Ensure phosphate levels are assessed early
as replacements can often take 8 hours or
more
IV potassium phosphate often given over 4
hours per replacement (unless in critical care
unit)
Patients with limited IV access can be
delayed replacing phosphate due to
multiple other medications needing access
Calcium and Phosphate Relationship
Inversely related
Low calcium = high
phosphate
High phosphate = low
calcium
Sodium
Sodium
Found in processed meats,
cheeses, sauces (i.e soy
sauce), and naturally (i.e
sea salt)
Normal range 135-145
mmol/L
Hyponatremia
Defined as serum sodium <135
mmol/L
Causes
Medications
Diuretics
Amiodarone
Carbamazepine
Amitriptyline
Exercise-induced
Water overdose!
Outcomes
Mild: headache, lethargic,
nausea/vomiting
Severe: symptoms usually
secondary to cerebral edema
Drop in serum osmolality results in an intracellular fluid shift thus leading to edema
Hyponatremia Treatment Strategies
Fluid restriction
Diuresis of excess water
Oral preparation
Sodium Chloride tablets (1000mg capsule
IV preparation
Sodium Chloride 3% solution (hypertonic saline)
Hypernatremia
Defined as serum sodium >145
mmol/L
Causes
Medications
Diarrhea
Vomiting
Dehydration
Outcomes
Mild: lethargy, weakness, irritability
Severe: rupture of cerebral veins,
hemorrhage
Hypernatremia Treatment
Strategies
Sodium restriction
Medication review
Volume correction using IV fluid
Often D5W is fluid of choice
Clinical Pearl GO SLOW!
Osmotic Demyelination Syndrome (ODS)
occurs when sodium levels are corrected
too quickly in the setting of hyponatremia
Destruction of the myelin sheath around
nerces found in the brain stem occur
Effects are often not seen until 2-6 days after
quick correction
Often leads to permanent dysfunctions
including changes in behavior,
disorientation, dysphagia, and even coma
The Range Dilemma
Try not to get fixated on the numbers
“I read that 10mmol KCL IV = 0.1mmol correction”
Depending on practice setting, electrolyte replacement can vary,
and the concept of “mild/moderate/severe” can change
Critical care
Inpatient Vs Outpatient
Anticipation of treatment effects
Treating the underlying condition
Easy to get lost in trying to correct electrolyte imbalaces day after
day when an underlying uncorrected condition can be a main contributory factor
Diarrhea
Nausea/vomiting
Decreased appetite
Medication interactions
Adherence
Questions
References
Goltzman, D. (2021). Treatment of hypocalcemia. Uptodate. Retrieved October 21 from https://www.uptodate.com/contents/treatment-of-hypocalcemia?search=hypocalcemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Kumon S, Usui R, Kuzuhara S, Nitta K, Koike M. (2017). The Improvement of the Outcome of Osmotic Demyelination Syndrome by Plasma Exchange. Intern Med. Retrieved October 22, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8267071/
Liamis, G., Milionis, H., Elisaf, M. (2010). Medication-induced hypophosphatemia: a review, QJM: An International Journal of Medicine. Retrieved on October 23, 2021, from https://academic.oup.com/qjmed/article/103/7/449/1585359
Mount, D. (2019). Clinical manifestations and treatment of hypokalemia in adults. Uptodate. Retrieved October 21, 2021, from https://www.uptodate.com/contents/clinical-manifestations-and-treatment-of-hypokalemia-in-adults?search=hypokalemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Mount, D. (2020). Treatment and prevention of hyperkalemia in adults. Uptodate. Retrieved October 21, 2021, from https://www.uptodate.com/contents/treatment-and-prevention-of-hyperkalemia-in-adults?search=hyperkalemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Shane, E., & Berenson, J. (2020). Treatment of hypercalemia. Uptodate. Retrieved October 21, 2021, from https://www.uptodate.com/contents/treatment-of-hypercalcemia?search=hypercalcemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
References
Sterns, R., Hoorn, E. (2021). Treatment of hypernatremia in adults. Uptodate. Retrieved on October 22, 2021, from https://www.uptodate.com/contents/treatment-of-hypernatremia-in-adults?search=hypernatremia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Sterns, R. (2021). Overview of the treatment of hyponatremia in adults. Uptodate. Retrieved on October 22, 2021, from https://www.uptodate.com/contents/overview-of-the-treatment-of-hyponatremia-in-adults?search=hyponatremia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Stubbs, J., Yu, A. (2021). Overview of the causes and treatment of hyperphosphatemia. Uptodate. Retrieved on October 22, 2021, from https://www.uptodate.com/contents/overview-of-the-causes-and-treatment-of-hyperphosphatemia?search=hyperphosphatemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Liamis, G., Milionis, H., Elisaf, M. (2010). Medication-induced hypophosphatemia: a review, QJM: An International Journal of Medicine. Retrieved on October 23, 2021, from https://academic.oup.com/qjmed/article/103/7/449/1585359
Yu, A. (2020). Hypomagnesemia: Evaluation and treatment. Uptodate. Retrieved on October 22, 2021, from https://www.uptodate.com/contents/hypomagnesemia-evaluation-and-treatment?search=hypomagnesemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Yu, A., Gupta, A. (2020). Hypermagnesemia: Causes, symptoms, and treatment. Uptodate. Retrieved on October 22, 2021, from https://www.uptodate.com/contents/hypermagnesemia-causes-symptoms-and-treatment?search=hypermagnesemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Yu, A., Stubbs, J. (2021). Hypophosphatemia: Evaluation and treatment. Uptodate. Retrieved on October 22, 2021, from https://www.uptodate.com/contents/hypophosphatemia-evaluation-and-treatment?search=hypophosphatemia%20treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1