Electrolytes by Dr. Rieck

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Initial Labs/EKG
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Transferred to VMMC
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Transferred to VMMC
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While being a good intern…
• Labs ordered in room
– CMR, CBC, INR, troponin drawn.
• Placed on GI consult list for EGD in AM
• Talking with pt when he suddenly loses
consciousness…
you look at the monitor while feeling for
a pulse…
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What do you do?
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Ca/Mg

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Vitals: BP 56/29, HR 36, intubated,
Converts to sinus bradycardia
Post code labs ordered
Started on norepi gtt

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Pt is stable, for now.
• Wife called regarding the developments
• Pt transitioned to DNR but continue care
– Entered torsades 5 minutes later and
pronounced
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Post Code First Code Admission

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Post Code First Code Admission

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Post Code First Code Admission

13. Afternoon Report
Chad Rieck, MD

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Major electrolyte derangements
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• Hypo
– Kalemia
– Magnesemia
– Calcemia
• Hyper
– Kalemia
– Magnesemia
– Calcemia

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Major electrolyte derangements due to
ammonium biflouride
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2HF + Ca++ CaF2
This can further change to form: Ca5F(PO4)3

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Major electrolyte derangements
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• Hypo
– Kalemia
– Magnesemia
– Calcemia
• Hyper
– Kalemia
– Magnesemia
– Calcemia

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Hyperkalemia
• Serum K level >5.5 mEq/L
– Mild 5.5-5.9 mEq/L
– Moderate 6-6.5 mEq/L
– Severe ≥ 6.5
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Common Hyperkalemia Triggers
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• “Pseudohyperkalemia”
• AKI/CKD
– Missed dialysis
• Hyperglycemia
– DKA, HHS
• Rhabdomyolysis
• Tumor lysis syndrome
• Adrenal disease
– Addison’s, congenital adrenal hyperplasia, hypoaldosteronism,
aldosterone deficiency, etc.

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• Muscle weakness/Paralysis
– Legs to trunk and arms
• Cardiac conduction abnormalities
– RBBB, LBBB, Bifascicular block, AVN block
– Sinus bradycardia, sinus arrest, slow idioventricular
rhythms, ventricular tachycardia, vfib, asystole
• Cardiac arrhythmia
• Metabollic encephalopathy
– Limited NH4 secretion
Hyperkalemia symptoms
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• Muscle weakness/Paralysis
– Legs to trunk and arms
• Cardiac conduction abnormalities
– RBBB, LBBB, Bifascicular block, AVN block
– Sinus bradycardia, sinus arrest, slow idioventricular
rhythms, ventricular tachycardia, vfib, asystole
• Cardiac arrhythmia
• Metabollic encephalopathy
– Limited NH4 secretion
Hyperkalemia symptoms
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• Muscle weakness/Paralysis
– Legs to trunk and arms
• Cardiac conduction abnormalities
– RBBB, LBBB, Bifascicular block, AVN block
– Sinus bradycardia, sinus arrest, slow idioventricular
rhythms, ventricular tachycardia, vfib, asystole
• Cardiac arrhythmia
• Metabollic encephalopathy
– Limited NH4 secretion
Hyperkalemia symptoms
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Hyperkalemia Treatment
• Urgent treatment if > 6.5 mEq/L
– Give 10-20 ml of 10% CaGluconate, repeat dose as
needed
– 10u regular insulin with glucose bolus
– Nebulized albuterol
– Consider drugs to lower total body K
• Diuretics
• Hemodialysis
• Stop drugs that increase K
• Kayexalate?
• Hemodialysis
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Kayexalate
Harel Z., Harel S., Shah P.S., Wald R., Perl J., and Bell C.M.: Gastrointestinal adverse events with sodium polystyrene sulfonate
(Kayexalate) use: a systematic review. Am J Med 2013; 126: pp. 264.e9-264.e24
• Introduced in 1958
– No RCT to test regarding efficacy or safety.
• Onset of action is 1-2 hours, duration 4-6
– Decrease K about 1mEq/L over 24 hours
• Adverse reactions:
– Anorexia, nausea, vomiting, constipation, GI irritation
– GI mucosal injury
• Systematic review of 58 cases, colonic necrosis most commonly identified
– Other seen include ischemic colitis, perforation, bleeding
» Mortality as high as 33% in these cases
– Increased sodium load
• Exacerbates heart failure in 2% of pt
• Worsens severe hypertension
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Kayexalate
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Hypokalemia
• 21% of hospitalized patients develop
hypokalemia
• Serum potassium <3.6
• Most common causes
– Vomiting, diarrhea, drug induced (wasters and
shifters)
• Symptoms
– Flaccid muscle weakness, irregular heart rate
– EKG changes include flat T waves, ST-segment
depression, U waves, arrhythmias
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Hypokalemia Management
• Decrease offending drugs
• Replete magnesium
• Replace potassium
– 10 mEq will increase serum K by 0.1
– PO and IV forms available
• IV forms have large volume of fluid. 60mEq is 1L of
fluid
• IV form should be given only with continuous
cardiac monitoring
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Hypocalcemia
• Serum level lower than 8.5 mg/dL
– Need to correct for hypoalbuminemia
• Corrected Calcium = (0.8 * (Normal Albumin - Pt's
Albumin)) + Serum Ca
– Ionized calcium < 4.65 mg/dL
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Physical Exam Findings
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• Chvostek’s sign
– Sensitivity 70%
– Specificity 75%
• Trousseau’s sign
– Sensitivity 94%
– Specificity 99%
Jesus, J.E and Landry, A. Chvostek’s and Trousseau’s Signs. N Engl J Med 2012, 367:e15 DOI
10.1056/NEJMicm1110569

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Hypocalcemia
• Symptoms:
– Fatigue, irritability, anxiety, depression
– Tetany due to neuromuscular irritability
• Troussea’s sign, chvostek’s sign
– Perioral numbness, paresthesia of hand/feet, muscle
cramps
– Severe levels cause laryngospasms, seizures
– Cardiovascular compromise
• Prolong QT interval
• Hypotension
• Torsades de pointes
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Hypocalcemia
• Treatment
– Screen for hypomagnesemia
– IV for acute serum decreases at ≤7.5 mg/dL
– Calcium gluconate preferred over CaCl due to
tissue necrosis if extravasation
– Dose either 1 to 2g (4.5 to 9 mEq) IV once
– 0.5mg/dL increase serum Ca for 1g given
– Once able to do PO, switch to calcium carbonate
and Vit D
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Hypomagnesemia
• Occurs in 12% of hospitalized pts
– Up to 65% in ICU pts
• Co-exists with hypoK, hypoCa, met alk
– 60% of pt with above will have hypoMg
• Symptoms
– N/V, Neuromuscular hyperexcitability, tingling,
weakness, cramps, apathy, delirium, coma
– Cardiovascular widening QRS, peaking T waves,
increasing PR interval, atrial and ventricular
arrhythmia
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• Repletion
– IV: Mg Sulphate 1g per 0.1 mg/dL (8 mEq)
• For unstable/symptomatic/severe deficiency
– PO: Mg Oxide 400mg per 0.1 mg/dL (10 mEq)
• Bioavailability is less than IV
• Diarrhea frequently occurs approaching 800mg
dose
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Hypomagnesemia

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Prevention of ventricular arrythmias
• Goal
– K > 4
– Mg > 2
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Repletion Cheat Sheet
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Route Preferred
Formulation
Dosage Response
Potassium Oral
IV
Potassium
Chloride
10meq tabs .1 increase
serum K for
10meq given
Magnesium Oral
IV
Magnesium
Oxide
Magnesium
Sulfate
2-4 tabs/day
(420mg; 20meq/tab)
2g IV
.2 increase for
2g IV
Calcium IV- acute
Oral- maintenance
Calcium
Gluconate
Calcium
Carbonate
1-2amp (rapid)
1-2g/day
.5mg/dL
increase serum
Ca for 1g given
(1 amp = 1 gram
in this case)

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Wellness
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