Chart — Electrolytes
Potassium Disorders Comparison Chart
Hypokalemia vs hyperkalemia — causes, manifestations, ECG changes, treatment, nursing priorities, and patient safety considerations side-by-side.
Educational use only. IV potassium protocols and treatment thresholds vary by institution. Always follow facility policy and verify urine output before IV potassium administration. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
| Feature | Hypokalemia (K⁺ < 3.5 mEq/L) | Hyperkalemia (K⁺ > 5.0 mEq/L) |
|---|---|---|
| Definition | K⁺ < 3.5 mEq/L | K⁺ > 5.0 mEq/L |
| Common Causes | Loop/thiazide diuretics (most common in hospitalized patients), vomiting, diarrhea, NG suction, alkalosis, steroid use, hypomagnesemia, insulin excess | AKI/CKD (most common), ACE inhibitors/ARBs, K-sparing diuretics, metabolic acidosis, hemolysis, cell destruction, excessive supplementation |
| Clinical Manifestations | Muscle weakness (legs first), fatigue, cramps, constipation, paralytic ileus; severe: flaccid paralysis, respiratory failure | Muscle weakness, paresthesias, bradycardia; severe: flaccid paralysis, cardiac arrest |
| ECG Changes | Flat/inverted T waves → prominent U waves (deflection after T) → prolonged QT → dysrhythmias (PVCs, SVT, VT) | Peaked narrow T waves → widened QRS → loss of P waves → sine wave → VF/asystole |
| Cardiac Risk | Dysrhythmias (especially with digoxin); increases digitalis toxicity | Life-threatening — VF and asystole; peaked T waves = emergency |
| First-Line Treatment | PO KCl for mild–moderate; IV KCl for severe (never IV push; max 10 mEq/hr peripheral, 40 mEq/hr central with monitoring) | Calcium gluconate FIRST (stabilizes cardiac membrane); then insulin + D50W (shifts K into cells) |
| Additional Treatment | Correct hypomagnesemia; dietary potassium increase; address underlying cause (adjust diuretics) | Sodium bicarbonate (if acidotic); sodium polystyrene sulfonate or patiromer (eliminates K); dialysis for renal failure |
| Nursing Monitoring | Continuous ECG; muscle strength; bowel sounds; check Mg level; potassium level after each replacement dose | Continuous ECG; check ECG before and after treatment; monitor urine output; avoid all K-containing products |
| Key Patient Safety | IV K⁺ = NEVER IV push. Verify urine output ≥ 30 mL/hr before giving. Correct Mg first if not responding. | Verify specimen not hemolyzed before treating asymptomatic high K. First treatment = calcium gluconate if ECG changes present. |
| NCLEX Memory Aid | Think: DIURETICS → K⁺ goes down. U waves = hypoKalemia. "Low K = Ugly U waves." | Think: RENAL FAILURE → K⁺ goes up. Peaked T waves = hyperKalemia. "High K = Tall Tents." |
Hyperkalemia Treatment Sequence
| Order | Intervention | Purpose | Duration |
|---|---|---|---|
| 1st | Calcium gluconate | Cardiac membrane stabilization — does NOT lower K⁺ | Effect onset within minutes; lasts ~30–60 min |
| 2nd | Insulin (regular) + D50W | Drives K⁺ into cells; dextrose prevents hypoglycemia | Onset 15–30 min; temporary redistribution only |
| 3rd | Sodium bicarbonate | Corrects acidosis; drives K⁺ into cells | Most effective when acidosis is present |
| 4th | Kayexalate / Patiromer | Binds K⁺ in GI tract — eliminates from body | Hours — definitive but slow elimination |
| Definitive | Dialysis | Removes K⁺ from blood — most effective for AKI/CKD | Per access — requires consultation |
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Infusion Nurses Society (INS) Standards of Practice · Institute for Safe Medication Practices (ISMP) · Standard laboratory reference ranges. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →