Nursing care
Hyperkalemia nursing care: what to assess and what to do first
Written and reviewed by Dana Whitfield, RN, MSN · 5 min read · Updated September 2026
Short answer
Hyperkalemia nursing care starts with the ECG, not the patient's symptoms. Peaked T waves appear before the patient feels anything, so a potassium above 5.0 mEq/L demands an ECG and continuous cardiac monitoring first. If the ECG shows changes, calcium gluconate is given immediately to stabilise the cardiac membrane, then insulin with dextrose to shift potassium into cells.
The clinical picture
Hyperkalemia is a serum potassium above 5.0 mEq/L. It develops from three broad routes: the kidneys failing to excrete potassium, as in acute kidney injury or advanced chronic kidney disease; potassium shifting out of cells, as with metabolic acidosis, tissue breakdown, or tumour lysis syndrome; or excess intake, often from potassium-sparing diuretics, ACE inhibitors, ARBs, or salt substitutes in a patient with reduced renal clearance.
The danger is that the ECG changes before the patient does. A patient with a potassium of 6.2 mEq/L may report nothing more than mild fatigue while their rhythm strip already shows peaked T waves. That gap between how the patient looks and what the heart is doing is the entire reason hyperkalemia is treated as a cardiac emergency rather than a lab value to trend. Left uncorrected, the sequence progresses toward a widened QRS, a sine-wave pattern, and ventricular fibrillation or asystole.
Assessment: what to look for and in what order
Put the monitor before the checklist. On confirmation of a potassium above 5.0 mEq/L, or any level with symptoms, obtain a 12-lead ECG and place the patient on continuous cardiac monitoring before working through a symptom inventory. Peaked, narrow T waves are the earliest change and can appear at a potassium as low as 5.5 to 6.0 mEq/L, well before muscle weakness or cardiac symptoms are reported.
Once monitoring is in place, assess neuromuscular status: generalised weakness, paresthesias, and deep tendon reflexes, which diminish as potassium rises. Check for the underlying cause, renal function, urine output, current medications, and recent tissue injury, since treatment differs depending on whether the problem is excretion, shift, or intake. Review the full metabolic panel alongside potassium; concurrent acidosis or renal impairment changes the treatment sequence and the goals of care.
Immediate interventions
If ECG changes are present, calcium gluconate is given first, by slow IV push or infusion. It does not lower the serum potassium; it raises the threshold potential at the cardiac cell membrane and protects the heart from arrhythmia while other therapies work. Expect this distinction to be tested and to be explained to colleagues: calcium buys cardiac stability, it does not treat the underlying hyperkalemia.
Next comes insulin with concurrent dextrose, which drives potassium into cells within 15 to 30 minutes. Monitor blood glucose during and after administration, since hypoglycemia is the main complication. Nebulised albuterol can be added as a second shifting agent. Sodium bicarbonate is used selectively, mainly when acidosis is present. None of these shifting therapies remove potassium from the body; they buy time until elimination therapy, such as loop diuretics, sodium zirconium cyclosilicate, patiromer, or dialysis in renal failure or refractory cases, brings the total body potassium down.
Ongoing nursing management
Keep the patient on continuous cardiac monitoring until potassium trends down and the ECG normalises, not until symptoms resolve, since the two do not track together. Recheck potassium and glucose per protocol, typically one to two hours after insulin and dextrose, and again after any elimination therapy. Document trends rather than isolated values; a potassium moving from 6.8 to 6.1 mEq/L tells you the treatment is working even before it reaches the normal range.
Review the medication list for anything contributing to the hyperkalemia, ACE inhibitors, ARBs, potassium-sparing diuretics, NSAIDs, and hold them per orders pending resolution. Restrict dietary potassium if ongoing risk exists, and coordinate with the provider on the underlying cause; a patient with acute kidney injury needs a different long-term plan than one on a potassium-sparing diuretic with normal renal function.
Patient and family education
Explain why the patient is on a monitor even though they feel relatively well, since the disconnect between symptoms and cardiac risk is often what confuses families. Plain language works: the heart shows a problem on the tracing before the body feels it, so the monitor is protecting against a rhythm change, not just recording one.
For patients going home on a potassium-restricted diet, be specific rather than general. Salt substitutes are frequently potassium chloride and are an easy source of hidden intake. Bananas, oranges, potatoes, tomatoes, and dried fruit are common contributors worth naming directly. If the patient is on a potassium-sparing diuretic or an ACE inhibitor, reinforce which lab values will be rechecked and when, and instruct them to report muscle weakness or palpitations rather than waiting for the next scheduled draw.
How this appears on the NCLEX
NCLEX items on hyperkalemia usually test sequencing over recognition. Expect a stem with a potassium value and an ECG description, then a question asking what to do first; the answer is calcium gluconate when ECG changes are present, not insulin and dextrose, because stabilising the myocardium takes priority over correcting the level. A frequent distractor pairs a normal-looking patient with an abnormal ECG, testing whether the test-taker defaults to symptoms instead of the monitor.
Another common pattern is a select-all-that-apply item on foods or medications to avoid, or a prioritisation question comparing a hyperkalemic patient against another patient with a less urgent electrolyte abnormality. Know that calcium gluconate protects the heart without changing the potassium level; test items sometimes offer this as a distractor by implying it lowers potassium, and the correct answer requires ruling that out.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our renal and genitourinary practice questions are the closest set to what this page covers.
Common questions
Does calcium gluconate lower potassium levels?
No. Calcium gluconate stabilises the cardiac cell membrane and reduces the risk of arrhythmia, but it does not remove potassium from the body or shift it into cells. Insulin with dextrose, albuterol, and elimination therapies such as diuretics, binding resins, or dialysis are what actually lower the serum level.
What ECG change appears first in hyperkalemia?
Peaked, narrow T waves are typically the earliest change, sometimes visible at a potassium of 5.5 to 6.0 mEq/L. As potassium continues to rise, the PR interval prolongs, P waves flatten, the QRS widens, and untreated the pattern can progress to a sine wave and cardiac arrest.
Why does insulin lower potassium if the patient isn't diabetic?
Insulin activates the sodium-potassium ATPase pump, which drives potassium into cells regardless of the patient's glucose status. Dextrose is given alongside it to prevent hypoglycemia, since the insulin dose used for this purpose is not calibrated to blood sugar control.
What foods should a patient with hyperkalemia avoid?
Bananas, oranges, potatoes, tomatoes, avocados, and dried fruit are common high-potassium foods. Salt substitutes are also worth flagging specifically, since many are potassium chloride and are an easy source of unintentional intake for patients who don't realise they're a dietary source.