Hyperkalemia is a serum potassium above 5.0 mEq/L (normal is 3.5 to 5.0), and it is dangerous for one reason: potassium sets the heart’s electrical rhythm. The ECG changes are the most-tested part of the topic and the hardest to hold onto from a list. So here they are as the NurseSavvy hyperkalemia lesson teaches them: watch each one form, then recall it.
The first sign: peaked T waves
As potassium rises, the T wave grows tall, narrow, and pointed. It is the earliest ECG change, and any ECG change in a patient with hyperkalemia means calling the provider now.
Live card · Hyperkalemia lesson
Hyperkalemia causes peaked T waves
Any ECG change: call now
Potassium climbs on a live monitor and the T wave grows tall and pointed as the camera pushes in. You see the earliest ECG sign form instead of memorizing its name.
The recall card that follows it
Hyperkalemia, K⁺ 6.6. What does the monitor show?
If it keeps climbing: the full ECG progression
- Peaked (tall, narrow) T waves, the earliest sign
- A prolonged PR interval, then flattened and lost P waves
- A widened QRS complex
- A sine-wave pattern
- Ventricular fibrillation or asystole
That is why every patient with hyperkalemia goes on a cardiac monitor and a high potassium is reported right away, even when the patient feels fine. Feeling well does not lower the number.
Why calcium comes first, even though it does not lower potassium
IV calcium gluconate steadies the heart muscle within minutes, but it does not move the potassium at all, and it lasts only 30 to 60 minutes. Students mix this up constantly because “treat hyperkalemia” sounds like “lower the potassium.” The film makes the distinction visible: the T waves settle while the potassium readout does not budge.
Live card · Hyperkalemia lesson
Administer calcium to protect the heart
It does not lower the K⁺
The peaked T waves soften while the K⁺ readout stays at 6.8. Protection, not a fix, in one view.
The recall card that follows it
Hyperkalemia with peaked T waves. What does calcium do?
Protect, shift, remove
Treatment runs in a fixed order. Protect the heart with IV calcium. Shift potassium into the cells with insulin and dextrose (or albuterol). Remove it from the body with a potassium binder, a loop diuretic if the kidneys work, or dialysis if it is severe. After insulin, watch the blood glucose: the dextrose is there because insulin pulls glucose into the cells along with the potassium.
Live card · Hyperkalemia lesson
Treat in order: protect the heart, shift K⁺ in, remove it
The three steps play as three moves on the same heart and the same potassium, so the order is a sequence you watched, not a list you memorized.
The recall card that follows it
Hyperkalemia, K⁺ 6.8, peaked T waves. Give what first?
Why it happens, in one line each
- Kidney failure is the top cause: the kidneys are the main way potassium leaves the body.
- Potassium-holding drugs: spironolactone, ACE inhibitors, and ARBs.
- Acidosis pushes potassium out of the cells as hydrogen moves in.
- Broken cells (burns, crush injuries) spill their potassium into the blood.
Run the whole lesson
The flow below is the real NurseSavvy hyperkalemia lesson. It opens in Recall first, so the films appear when you miss; switch to Learn first to watch each stage before its questions.
Hyperkalemia · live lesson
Why we teach with short films you recall instead of videos you watch: visual learning without videos. For the low side of potassium, open the hypokalemia lesson.
Lock in the electrolytes
Free account, no card. Sodium, potassium, calcium, magnesium and acid–base all have visual lessons.
Common questions
What is the first ECG change in hyperkalemia?
Peaked (tall, narrow) T waves. As potassium keeps rising: a prolonged PR interval, lost P waves, a widened QRS, a sine-wave pattern, then ventricular fibrillation or asystole.
Why is calcium given first for hyperkalemia?
IV calcium gluconate steadies the heart muscle within minutes when the ECG shows changes. It does not lower potassium and lasts only 30 to 60 minutes, so insulin with dextrose (shift) and a binder, loop diuretic or dialysis (remove) follow.