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Hyperkalemia
Aka: Hyperkalemia, Hyperkalemia Related EKG Changes
- See Also
- Hyperkalemia Causes
- Hyperkalemia Management
- Causes
- See Hyperkalemia Causes
- Findings: Signs and Symptoms
- Symptoms occur when Serum Potassium > 6.0 to 6.5 meq/L
- Neurologic Changes
- Weakness
- Paresthesias
- Areflexia
- Ascending paralysis
- Respiratory Failure
- Cardiovascular Changes
- Bradycardia to Asystole or Ventricular Fibrillation
- AV prolonged transmission to complete Heart Block
- Labs
- Chemistry Panel
- Serum Potassium
- Serum Electrolytes including serum bicarbonate
- Renal Function tests (BUN, Creatinine)
- Spot urine for Urine Potassium, Urine Sodium and Urine Creatinine
- Fractional Excretion of Potassium
- Transtubular Potassium Gradient
- Urine Sodium <25 mEq/L suggests decreased distal renal flow
- See Hyperkalemia Causes
- Other labs to consider (see evaluation below)
- Serum aldosterone
- Serum renin
- Diagnostics: Electrocardiogram
- EKG changes occur when Serum Potassium >6.0 meq/L
- Initial
- T Waves peaked or Tented (increased amplitude) in V2, V3, II, III
- Next
- ST depression
- First degree AV Block (PR interval increases)
- QT Interval shortening
- Next (ominous harbinger)
- QRS Duration widening (>110 msec)
- Loss of P Wave (Junctional Rhythm)
- Sine Wave appearance
- New Bundle Branch Block
- Final
- Biphasic wave (sine wave) QRS and T fusion
- Severe Bradycardia
- Imminent Asystole, Ventricular Tachycardia or Ventricular Fibrillation
- Changes exacerbated by
- Hyponatremia
- Hypocalcemia
- Metabolic Acidosis
- Hypermagnesemia
- Chronic Renal Failure with frequent, recurrent Hyperkalemia
- Change from normal EKG to Cardiac Arrest may be rapid in these patients
- Evaluation: Non-Renal Causes (transcellular shift, Potassium load, Pseudohyperkalemia)
- Serious signs of Hyperkalemia present (EKG, symptoms)
- Urgent Hyperkalemia Management
- Consider Pseudohyperkalemia
- Consider confirmatory testing (re-draw sample)
- Consider exogenous source or transcellular shift
- See Hyperkalemia Causes
- Eliminate causative factors
- Evaluation: Decreased renal excetion
- Urine Sodium <25 mEq/L suggests decreased distal renal flow
- See Hyperkalemia Causes
- Acute Kidney Injury or Chronic Kidney Disease
- Congestive Heart Failure
- Cirrhosis
- Urine Sodium >25 mEq/L with normal serum aldosterone
- Primary tubular defects (e.g. RTA-4)
- Obstructive uropathy
- Tubular unresponsiveness to aldosterone (e.g. SLE, Multiple Myeloma, Sickle Cell Anemia)
- Medications (e.g. Potassium sparing Diuretics, Lithium, Trimethoprim)
- Urine Sodium >25 mEq/L with low serum aldosterone and normal serum renin
- Primary Adrenal Insufficiency
- Medications (Heparin, Cyclosporine, ACE Inhibitor, ARB)
- Urine Sodium >25 mEq/L with low serum aldosterone and low serum renin
- Hyperglycemia
- Primary renal tubular defects
- Medications (e.g. NSAIDs, Beta Blockers)
- Management
- See Hyperkalemia Management
- References
- Gibbs in Marx (2002) Rosen's Emerg Med, p. 1730-1
- Klahr (2001) in Noble (2001) Primary Care p. 1359-62
- Viera (2015) Am Fam Physician 92(6): 487-95 [PubMed]