In this video from Medcram, Dr. Seheult discusses recognition of hyperkalemia findings on ECG. He discusses the specific case of a patient with COVID-19 who came in with rhabdomyolysis.
What is rhabdomyolysis?
This is muscle breakdown which leads to the release of the contents of multiple cells in the body and can lead to a condition of hyperkalemia or high potassium. Hyperkalemia can be very deadly. It can lead to cardiac arrhythmias and cardiac arrest. Potassium in of itself is one of the most controlled electrolytes within the body. Dr. Seheult reviews a case report of rhabdomyolysis occurring after COVID-19. Rhabdomyolysis itself can occur after viral infections but can also occur in traumatic injuries such as crush injuries. It can even occur in prisons who have had a strenuous workout and even seen for example in marathon running. One thing people may notice is that their urine has turned a tea-color which is a potential signal that muscle is being broken down and being released into the urine. This case report that Dr. Seheult reviews states in its discussion that rhabdomyolysis is a known complication of viral and bacterial infections. It is characterized by the breakdown of skeletal muscle leading to the release of muscular components into the bloodstream including myoglobin, creatinine kinase, and lactate dehydrogenase. It is important to remember that cells are very rich in potassium and when these cells break down that’s going to lead to a significant release of potassium into the bloodstream which may be difficult for the body to regulate.
ECG findings of hyperkalemia
If you were to look at an ECG of somebody with severe hyperkalemia, you would see a lack of P waves followed by very peaked T waves. In some cases the peaked T waves are so tall that they may actually be taller than the QRS complex itself which should never be the case. Patients may come in with nonspecific symptoms with hyperkalemia. You will need a definitive test which is a basic metabolic panel also known as a chem-7. MedCram has a course on this for those who are interested in a more in depth dive into the basic metabolic panel. A normal potassium level should range from 3.5-5 meq/L; however, if you are starting to see peaked T waves, the potassium levels are generally at 6 meq/L or above. The EKG he goes over in this case is also showing some bradycardia. He explains how to calculate the heart rate based on the EKG. Medcram also has an extensive course on ECG interpretation as well.
Treatment of hyperkalemia
Depending on the level of the hyperkalemia, the treatment options range from immediate stabilization to those that will take several hours to work. For patients that have elevated T waves and appear to be going into possible cardiac arrest you can give albuterol, bicarbonate, insulin and glucose, furosemide, and even potassium binders that work in the gut. However, none of these are going to work within a few minutes and for a patient with impending cardiac arrest you need something that is going to stabilize the cardiac membranes immediately which is calcium.
It should be noted that you don’t necessarily need a 12 lead ECG to notice hyperkalemia changes. Smart watches use lead I from an ECG now have the ability to monitor your pulse. An ECG is basically a photograph of how electricity is moving throughout your heart. Medcram has video on smart watches and ECG.
The key to hyperkalemia, as in any disease, is early recognition and treatment.
LINKS / REFERENCES:
Rhabdomyolysis after COVID-19 Infection: A Case Report and Review of the Literature (Viruses) | https://www.ncbi.nlm.nih.gov/pmc/arti….