Hyperkalemia: Difference between revisions

(Major update: stepwise management (stabilize-shift-remove), insulin dose with glucose monitoring, Lokelma, calcium caution in digoxin, ECG progression, cardiac arrest protocol, references with PMIDs)
(Strip excess bold)
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==Background==
==Background==
*Serum potassium '''>5.0 mEq/L''' (some define >5.5 mEq/L)
*Serum potassium >5.0 mEq/L (some define >5.5 mEq/L)
*'''Life-threatening when >6.5 mEq/L''' or with ECG changes
*'''Life-threatening when >6.5 mEq/L''' or with ECG changes
*Most common electrolyte disorder causing [[cardiac arrest]]
*Most common electrolyte disorder causing [[cardiac arrest]]
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===Causes===
===Causes===
*'''Decreased excretion''' (most common mechanism):
*Decreased excretion (most common mechanism):
**[[Acute kidney injury]] / [[chronic kidney disease]]
**[[Acute kidney injury]] / [[chronic kidney disease]]
**'''Medications''': ACE inhibitors, ARBs, K-sparing diuretics (spironolactone, amiloride), NSAIDs, trimethoprim, heparin
**Medications: ACE inhibitors, ARBs, K-sparing diuretics (spironolactone, amiloride), NSAIDs, trimethoprim, heparin
**[[Adrenal insufficiency]] (hypoaldosteronism)
**[[Adrenal insufficiency]] (hypoaldosteronism)
**Type 4 renal tubular acidosis
**Type 4 renal tubular acidosis
*'''Transcellular shift''' (K moves out of cells):
*Transcellular shift (K moves out of cells):
**'''Acidosis''' (metabolic acidosis shifts K extracellularly)
**Acidosis (metabolic acidosis shifts K extracellularly)
**'''Insulin deficiency''' / [[DKA]]
**Insulin deficiency / [[DKA]]
**Tissue destruction: [[rhabdomyolysis]], tumor lysis, hemolysis, burns
**Tissue destruction: [[rhabdomyolysis]], tumor lysis, hemolysis, burns
**Succinylcholine, beta-blockers, digitalis toxicity
**Succinylcholine, beta-blockers, digitalis toxicity
**Hyperkalemic periodic paralysis
**Hyperkalemic periodic paralysis
*'''Increased intake''': excessive supplementation, salt substitutes (KCl)
*Increased intake: excessive supplementation, salt substitutes (KCl)
*'''Pseudohyperkalemia''': hemolyzed sample, prolonged tourniquet, thrombocytosis, leukocytosis
*Pseudohyperkalemia: hemolyzed sample, prolonged tourniquet, thrombocytosis, leukocytosis
**'''Always repeat level if unexpected'''
**Always repeat level if unexpected


==Clinical Features==
==Clinical Features==
*Often '''asymptomatic''' until severe
*Often asymptomatic until severe
*'''Muscle weakness''', fatigue, paresthesias
*Muscle weakness, fatigue, paresthesias
*Ascending paralysis (may mimic [[Guillain-Barre]])
*Ascending paralysis (may mimic [[Guillain-Barre]])
*'''Cardiac dysrhythmias''' (most dangerous manifestation)
*'''Cardiac dysrhythmias''' (most dangerous manifestation)
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===ECG Changes (Progressive)===
===ECG Changes (Progressive)===
*'''Peaked T waves''' (earliest change, typically >5.5 mEq/L)
*Peaked T waves (earliest change, typically >5.5 mEq/L)
*'''Prolonged PR interval'''
*Prolonged PR interval
*'''Widened QRS'''
*Widened QRS
*'''Loss of P waves'''
*Loss of P waves
*'''Sine wave pattern''' (pre-arrest)
*Sine wave pattern (pre-arrest)
*'''Ventricular fibrillation''' / '''asystole'''
*Ventricular fibrillation / asystole
*'''ECG changes do NOT reliably correlate with K level''' — some patients arrest without warning
*'''ECG changes do NOT reliably correlate with K level''' — some patients arrest without warning


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==Evaluation==
==Evaluation==
*'''Stat ECG''' (most urgent — look for peaked T's, widened QRS)
*'''Stat ECG''' (most urgent — look for peaked T's, widened QRS)
*'''BMP''': potassium level, creatinine (renal function), glucose, bicarbonate
*BMP: potassium level, creatinine (renal function), glucose, bicarbonate
*'''Repeat K level''' if unexpected (rule out pseudohyperkalemia)
*Repeat K level if unexpected (rule out pseudohyperkalemia)
*VBG/ABG (acidosis evaluation)
*VBG/ABG (acidosis evaluation)
*'''Digoxin level''' if on digoxin (hyperkalemia potentiates digitalis toxicity)
*Digoxin level if on digoxin (hyperkalemia potentiates digitalis toxicity)
*Urinalysis (myoglobinuria if rhabdomyolysis)
*Urinalysis (myoglobinuria if rhabdomyolysis)
*Consider: CK, uric acid, phosphorus (tumor lysis), cortisol (adrenal insufficiency)
*Consider: CK, uric acid, phosphorus (tumor lysis), cortisol (adrenal insufficiency)
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==Management==
==Management==
===Step 1: Cardiac Membrane Stabilization===
===Step 1: Cardiac Membrane Stabilization===
*'''Calcium''' (does NOT lower K; protects myocardium from arrhythmia):
*Calcium (does NOT lower K; protects myocardium from arrhythmia):
**'''Calcium gluconate 10%: 10-20 mL IV over 2-3 minutes''' (preferred; less tissue necrosis if extravasates)
**Calcium gluconate 10%: 10-20 mL IV over 2-3 minutes (preferred; less tissue necrosis if extravasates)
**Calcium chloride 10%: 5-10 mL IV (via central line preferred; 3x more elemental calcium)
**Calcium chloride 10%: 5-10 mL IV (via central line preferred; 3x more elemental calcium)
**Onset: '''1-3 minutes'''; duration 30-60 minutes; may repeat in 5-10 min if ECG unchanged
**Onset: 1-3 minutes; duration 30-60 minutes; may repeat in 5-10 min if ECG unchanged
**'''Give immediately if ECG changes present or K >6.5'''
**'''Give immediately if ECG changes present or K >6.5'''
*'''Caution in [[digoxin toxicity]]''': calcium may worsen toxicity → use cautiously or consider digibind first
*Caution in [[digoxin toxicity]]: calcium may worsen toxicity → use cautiously or consider digibind first


===Step 2: Shift Potassium Intracellularly===
===Step 2: Shift Potassium Intracellularly===
*'''Insulin + Glucose''' (most reliable):
*Insulin + Glucose (most reliable):
**'''Regular insulin 10 units IV + D50W 25g (50 mL) IV'''
**Regular insulin 10 units IV + D50W 25g (50 mL) IV
**Onset: 15-30 min; duration 4-6 hours; lowers K by '''0.5-1.2 mEq/L'''
**Onset: 15-30 min; duration 4-6 hours; lowers K by 0.5-1.2 mEq/L
**'''Monitor glucose q30min x 4h''' (hypoglycemia occurs in up to 20%)
**Monitor glucose q30min x 4h (hypoglycemia occurs in up to 20%)
**Give D50 '''before or simultaneously''' with insulin
**Give D50 before or simultaneously with insulin
*'''Albuterol''' (nebulized):
*Albuterol (nebulized):
**'''10-20 mg nebulized''' (4-8x standard asthma dose)
**10-20 mg nebulized (4-8x standard asthma dose)
**Onset: 15-30 min; lowers K by '''0.5-1.5 mEq/L'''
**Onset: 15-30 min; lowers K by 0.5-1.5 mEq/L
**Additive with insulin; 40% of patients are non-responders
**Additive with insulin; 40% of patients are non-responders
*'''Sodium bicarbonate''':
*Sodium bicarbonate:
**'''50-100 mEq IV''' over 5-10 minutes
**50-100 mEq IV over 5-10 minutes
**Minimal effect as monotherapy; useful in setting of severe '''metabolic acidosis'''
**Minimal effect as monotherapy; useful in setting of severe metabolic acidosis
**'''Do NOT rely on bicarb alone''' to lower potassium
**'''Do NOT rely on bicarb alone''' to lower potassium


===Step 3: Remove Potassium from Body===
===Step 3: Remove Potassium from Body===
*'''Loop diuretics''' (furosemide 40-80 mg IV): if adequate renal function
*Loop diuretics (furosemide 40-80 mg IV): if adequate renal function
*'''Sodium polystyrene sulfonate (Kayexalate)''' 15-30g PO:
*Sodium polystyrene sulfonate (Kayexalate) 15-30g PO:
**Delayed onset (hours); controversial efficacy; risk of bowel necrosis
**Delayed onset (hours); controversial efficacy; risk of bowel necrosis
**'''Not recommended as acute treatment'''
**Not recommended as acute treatment
*'''Patiromer''' (Veltassa) or '''sodium zirconium cyclosilicate''' (Lokelma):
*Patiromer (Veltassa) or sodium zirconium cyclosilicate (Lokelma):
**Newer potassium binders; better tolerated than Kayexalate
**Newer potassium binders; better tolerated than Kayexalate
**Lokelma 10g PO may lower K within 1 hour
**Lokelma 10g PO may lower K within 1 hour
*'''Hemodialysis''' (most effective method of K removal):
*Hemodialysis (most effective method of K removal):
**'''Indicated for''': refractory hyperkalemia, severe renal failure, K >7 despite medical therapy
**Indicated for: refractory hyperkalemia, severe renal failure, K >7 despite medical therapy


===Cardiac Arrest from Hyperkalemia===
===Cardiac Arrest from Hyperkalemia===
*Standard ACLS + '''calcium 10-20 mL IV push'''
*Standard ACLS + calcium 10-20 mL IV push
*Insulin + glucose + bicarb + albuterol simultaneously
*Insulin + glucose + bicarb + albuterol simultaneously
*Avoid succinylcholine for intubation
*Avoid succinylcholine for intubation
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==Disposition==
==Disposition==
*'''Admit''' if K >6.0, ECG changes, renal failure, or ongoing cause
*Admit if K >6.0, ECG changes, renal failure, or ongoing cause
*'''ICU''' if severe (>7.0), ECG changes, or refractory to treatment
*ICU if severe (>7.0), ECG changes, or refractory to treatment
*'''Continuous telemetry''' for all admitted patients
*Continuous telemetry for all admitted patients
*'''Consider discharge''' if mild hyperkalemia (5.0-5.5), known chronic cause, normal ECG, correctable precipitant
*Consider discharge if mild hyperkalemia (5.0-5.5), known chronic cause, normal ECG, correctable precipitant


==See Also==
==See Also==

Revision as of 09:28, 22 March 2026

Background

  • Serum potassium >5.0 mEq/L (some define >5.5 mEq/L)
  • Life-threatening when >6.5 mEq/L or with ECG changes
  • Most common electrolyte disorder causing cardiac arrest
  • Potassium homeostasis:
    • 98% intracellular (maintained by Na/K-ATPase)
    • Renal excretion is primary mechanism of potassium regulation

Causes

  • Decreased excretion (most common mechanism):
  • Transcellular shift (K moves out of cells):
    • Acidosis (metabolic acidosis shifts K extracellularly)
    • Insulin deficiency / DKA
    • Tissue destruction: rhabdomyolysis, tumor lysis, hemolysis, burns
    • Succinylcholine, beta-blockers, digitalis toxicity
    • Hyperkalemic periodic paralysis
  • Increased intake: excessive supplementation, salt substitutes (KCl)
  • Pseudohyperkalemia: hemolyzed sample, prolonged tourniquet, thrombocytosis, leukocytosis
    • Always repeat level if unexpected

Clinical Features

  • Often asymptomatic until severe
  • Muscle weakness, fatigue, paresthesias
  • Ascending paralysis (may mimic Guillain-Barre)
  • Cardiac dysrhythmias (most dangerous manifestation)
  • Nausea, vomiting, diarrhea

ECG Changes (Progressive)

  • Peaked T waves (earliest change, typically >5.5 mEq/L)
  • Prolonged PR interval
  • Widened QRS
  • Loss of P waves
  • Sine wave pattern (pre-arrest)
  • Ventricular fibrillation / asystole
  • ECG changes do NOT reliably correlate with K level — some patients arrest without warning

Differential Diagnosis

Evaluation

  • Stat ECG (most urgent — look for peaked T's, widened QRS)
  • BMP: potassium level, creatinine (renal function), glucose, bicarbonate
  • Repeat K level if unexpected (rule out pseudohyperkalemia)
  • VBG/ABG (acidosis evaluation)
  • Digoxin level if on digoxin (hyperkalemia potentiates digitalis toxicity)
  • Urinalysis (myoglobinuria if rhabdomyolysis)
  • Consider: CK, uric acid, phosphorus (tumor lysis), cortisol (adrenal insufficiency)

Management

Step 1: Cardiac Membrane Stabilization

  • Calcium (does NOT lower K; protects myocardium from arrhythmia):
    • Calcium gluconate 10%: 10-20 mL IV over 2-3 minutes (preferred; less tissue necrosis if extravasates)
    • Calcium chloride 10%: 5-10 mL IV (via central line preferred; 3x more elemental calcium)
    • Onset: 1-3 minutes; duration 30-60 minutes; may repeat in 5-10 min if ECG unchanged
    • Give immediately if ECG changes present or K >6.5
  • Caution in digoxin toxicity: calcium may worsen toxicity → use cautiously or consider digibind first

Step 2: Shift Potassium Intracellularly

  • Insulin + Glucose (most reliable):
    • Regular insulin 10 units IV + D50W 25g (50 mL) IV
    • Onset: 15-30 min; duration 4-6 hours; lowers K by 0.5-1.2 mEq/L
    • Monitor glucose q30min x 4h (hypoglycemia occurs in up to 20%)
    • Give D50 before or simultaneously with insulin
  • Albuterol (nebulized):
    • 10-20 mg nebulized (4-8x standard asthma dose)
    • Onset: 15-30 min; lowers K by 0.5-1.5 mEq/L
    • Additive with insulin; 40% of patients are non-responders
  • Sodium bicarbonate:
    • 50-100 mEq IV over 5-10 minutes
    • Minimal effect as monotherapy; useful in setting of severe metabolic acidosis
    • Do NOT rely on bicarb alone to lower potassium

Step 3: Remove Potassium from Body

  • Loop diuretics (furosemide 40-80 mg IV): if adequate renal function
  • Sodium polystyrene sulfonate (Kayexalate) 15-30g PO:
    • Delayed onset (hours); controversial efficacy; risk of bowel necrosis
    • Not recommended as acute treatment
  • Patiromer (Veltassa) or sodium zirconium cyclosilicate (Lokelma):
    • Newer potassium binders; better tolerated than Kayexalate
    • Lokelma 10g PO may lower K within 1 hour
  • Hemodialysis (most effective method of K removal):
    • Indicated for: refractory hyperkalemia, severe renal failure, K >7 despite medical therapy

Cardiac Arrest from Hyperkalemia

  • Standard ACLS + calcium 10-20 mL IV push
  • Insulin + glucose + bicarb + albuterol simultaneously
  • Avoid succinylcholine for intubation
  • Consider emergent dialysis

Disposition

  • Admit if K >6.0, ECG changes, renal failure, or ongoing cause
  • ICU if severe (>7.0), ECG changes, or refractory to treatment
  • Continuous telemetry for all admitted patients
  • Consider discharge if mild hyperkalemia (5.0-5.5), known chronic cause, normal ECG, correctable precipitant

See Also

References

  • Palmer BF. Managing hyperkalemia caused by inhibitors of the renin-angiotensin-aldosterone system. N Engl J Med. 2004;351(6):585-592. PMID 15295051
  • Weisberg LS. Management of severe hyperkalemia. Crit Care Med. 2008;36(12):3246-3251. PMID 18936701
  • Montford JR, Linas S. How dangerous is hyperkalemia? J Am Soc Nephrol. 2017;28(11):3155-3165. PMID 28778861
  • Long B, et al. An emergency medicine approach to hyperkalemia. Am J Emerg Med. 2018;36(5):918-921. PMID 29548654
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