In this video from MedCram, Dr. Seheult discusses a case that almost resulted in cardiac arrest. He recalls he was asked to see a patient that he had never seen before. He walked into the room in the intensive care unit and the patient was on a ventilator and his mother was there at bedside. As he was obtaining history from the mother, he noticed out of the corner of his eye that the vitals monitor was initially showing heart rate in the 80s. As he continued speaking with the patient’s mother, the heart rate was slowly dropping. After a few minutes it was down to the 60s and when he looked at the labs he realized what was happening. He told the nurse to pull up a specific medication as soon as possible and when he went back into the room, the heart rate was now in the 30s and the patient was progressing towards cardiac arrest. As soon as the medication was given, within 5 to 6 seconds, the patient’s vitals stabilized and he was now back to normal sinus rhythm.
Complications of medications used in intubation
So what exactly was going on? As Dr. Seheult was looking at the monitor, he noted not only the heart rate but also the EKG strip that was running across the monitor. He noted that the T waves were very peaked. When you see something like this you need to consider hyperkalemia or elevated potassium level. How did he know that this may be the case? Besides the peaked T waves, he was aware that the patient had just been intubated and some medications used in the induction of anesthesia during intubation can cause hyperkalemia.
He reviewed the chart and found that the patient had been given etomidate and succinylcholine. Etomidate helps the patient go to sleep and succinylcholine helps relax the muscles as it is a paralytic. It does so by depolarizing the cell membranes and this causes more potassium to exit the cell and go into the peripheral blood stream. When this patient came into the hospital, his initial potassium was already at a level of 6 which is above the upper limits of 5 for potassium levels. So when he received succinylcholine, the levels went even higher. So what medication did Dr. Seheult give to the patient?
How do you treat hyperkalemia?
Normally in patients with hyperkalemia, options for medications to give include bicarbonate, glucose and insulin, albuterol. All of these strategies shift the potassium into the cells. Other medications include binders that help get rid of potassium. Another option is hemodialysis but this takes time. So all of the above strategies take some time but none of these medications work rapidly.
How does calcium chloride work?
In this case, Dr. Seheult had the nurse push calcium chloride. The way this works is that due to the high concentration of potassium outside of the cell, the potential across the cell membrane decreases and this causes a destabilized situation. So how do you cause the cell membrane to stabilize? Adding calcium chloride adds an additional positive charge to outside the cell which then increases the potential difference across the cell and stabilizes it. This is also very transient, but it acts extremely quickly and provides you time to initiate the other solutions for hyperkalemia.
MedCram does have an EKG course that can help in recognizing dangerous rhythms and help you possibly save someone’s life.
LINKS / REFERENCES:
ECG / EKG Interpretation Explained Clearly (MedCram) | https://www.medcram.com/courses/ekg-e…