Easy one for you this week. What's the problem?
It is, of course, hyperkalemia. The changes which occur, in approximate order as K+ increases:
- Peaked T waves
- P wave widens and flattens
- PR segment lengthens
- P waves eventually disappear
- Prolonged QRS interval with bizarre QRS morphology
- High-grade AV block with slow junctional and ventricular escape rhythms
- Any kind of conduction block (bundle branch blocks, fascicular blocks)
- Sinus bradycardia or slow AF
- Development of a sine wave appearance (a pre-terminal rhythm)
- Ventricular fibrillation
- PEA with bizarre, wide complex rhythm
I present this review because of an article I read this week which gives us some idea of what to expect:
Severe Hyperkalemia: Can the Electrocardiogram Risk Stratify for Short-term Adverse Events? (West J Emerg Med. 2017 Aug; 18(5): 963–971.)
You can read the whole article here.
Salient points: No relationship of adverse events to peaked T-waves!
All patients with an adverse event had an ECG abnormality.
Most important were QRS prolongation, junctional rhythm, bradycardia in order of importance (least to most)