Section IV — Electrolyte Command

Electrolyte Abnormalities

Rapid identification and tiered treatment of common imbalances. Select an electrolyte to load its severity tiers, causes, clinical signs, and treatment ladder.

Hyperkalemia
High K⁺
Normal Range
3.5–5.0 mEq/L
1Mild
5.5–6.0 mEq/L

Dietary restriction; consider K⁺ binder

2Moderate
6.1–6.5 mEq/L

Shift K⁺ into cells; add binder

3Severe
> 6.5 or ECG changes

Emergent: stabilize, shift, remove

Causes

  • CKD/AKI with reduced excretion
  • ACEi/ARB, K⁺-sparing diuretics, NSAIDs
  • Tissue breakdown: rhabdo, tumor lysis, hemolysis
  • Metabolic acidosis (intracellular shift out)
  • Adrenal insufficiency (Addisonian crisis)

Clinical Signs

  • Muscle weakness progressing to paralysis
  • Paresthesias
  • Nausea, abdominal pain
  • Cardiac arrhythmias — potentially fatal
ECG Changes
Peaked T waves → PR prolongation → QRS widening → sine wave → arrest

Kidney-disease-specific workup steps for this imbalance. Tags indicate the renal context each step addresses.

1
Confirm true hyperkalemiaAll

Rule out pseudohyperkalemia (hemolysis, fist clenching, severe leukocytosis) on a free-flowing repeat sample.

2
ECG immediatelyAll

Peaked T waves, PR/QRS widening, or sine wave = emergent — stabilize myocardium before further workup.

3
Distinguish AKI vs CKDAKI

Compare creatinine to baseline, urine output, FENa/urine Na; abrupt rise + oliguria favors AKI.

4
Medication reviewCKD

Stop ACEi/ARB, K⁺-sparing diuretics, NSAIDs, beta-blockers, heparin, calcineurin inhibitors; reassess after K⁺ controlled.

5
Check acid-baseCKD

Metabolic acidosis (common in CKD/AKI) extrudes K⁺ from cells — correct with bicarbonate if HCO₃⁻ low.

6
Dialysis adequacy & accessESRD

Missed/inadequate sessions, high-K diet, constipation (colonic K⁺ absorption) — emergent hemodialysis if severe or refractory.

7
Endocrine screen if eGFR normalAll

Cortisol/ACTH for adrenal insufficiency; renin/aldosterone if hypertensive.

1
Stabilize myocardium
Onset: 3–5 min
Calcium gluconate 1g IV over 2–5 min
Note:Does NOT lower K⁺; protects the heart
2
Shift K⁺ into cells
Onset: 15–30 min
Insulin 10 units IV + 50% dextrose 25g IV
Note:Monitor glucose; effect lasts 4–6h
3
Adjunctive shift
Onset: 30 min
Albuterol 10–20 mg nebulized
Note:Beta-2 agonist; avoid in tachyarrhythmia
4
Remove K⁺
Onset: Hours
Loop diuretics; binders (patiromer, SZC); dialysis
Note:Dialysis if refractory or severe

Stage-specific treatment guidance for this imbalance across the renal disease spectrum.

AKI
  • Stabilize myocardium (Ca²⁺ gluconate) if ECG changes; shift with insulin/dextrose + albuterol.
  • Remove K⁺ with loop diuretics only if producing urine; reverse cause (rhabdo, TLS, acidosis).
  • Correct metabolic acidosis with bicarbonate (reduces extracellular K⁺ shift).
  • Emergent dialysis if oliguric/anuric, refractory, or severe with ECG changes.
CKD
  • Dietary K⁺ restriction (2–3 g/day); avoid salt substitutes and hidden K⁺ sources.
  • Patiromer or sodium zirconium cyclosilicate for chronic control; avoid chronic kayexalate.
  • Continue ACEi/ARB if tolerated with close monitoring; review trimethoprim/heparin.
  • Oral NaHCO₃ for metabolic acidosis; loop diuretics to enhance excretion if not anuric.
ESRD
  • Dietary restriction + treat constipation (colonic K⁺ excretion matters on dialysis).
  • Adjust dialysis prescription: K⁺ bath, longer/more-frequent sessions for chronic elevation.
  • Emergent hemodialysis for severe/refractory; peritoneal dialysis is inadequate for acute K⁺ removal.
  • Add binders (patiromer/SZC) between sessions; review missed or shortened treatments.
References & Further Reading
  1. 01KDIGO Dyskalemia Clinical Practice Guideline — Kidney International (2024)
  2. 02European Clinical Practice Guideline on Hyponatremia — Spasovski G et al., Eur J Endocrinol (2014)
  3. 03Hypernatremia — Adrogué HJ, Madias NE, N Engl J Med (2000)
  4. 04Hyponatremia — Adrogué HJ, Madias NE, N Engl J Med (2012)
  5. 05KDIGO Consensus on Metabolic Acidosis in CKD — KDIGO (2022)
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