Like a million times before, the tech thrust an ECG in front of you. This one, however, grabbed every neuron's attention. Who was this?
The tech says the patient is a 70ish-year-old diabetic, hypertensive man brought to the emergency department because he has been feeling weak from a couple days of diarrhea.
Where was he? Was he talking? What was his blood pressure?
The tech pointed at one of the back rooms, and said, "Oh, his blood pressure is good—138/71, and he is talking to his family."
He did look pretty good. His heart rate was 37 bpm as he chatted with his family. Staring back at the ECG, I think maybe I should rethink my initial thoughts of atropine and pacer. Maybe this guy needed a different drug or a different intervention. Maybe he needed calcium and perhaps a Foley.
The labs returned rather quickly confirming these thoughts. His potassium was 8.2 mEq/L, and the creatine was 7.0 mg/dL. This patient may well be on the way to a full-blown BRASH syndrome with four of the five components, which include:
R: Renal failure
A: AV nodal blocker
(PulmCrit. Feb. 15, 2016; http://bit.ly/2LVi6QD.)
BRASH occurs when poor renal perfusion leads to renal insufficiency or failure, which causes the AV nodal medication and potassium to build up in the bloodstream. They combine to produce the bradycardic picture, which ultimately will result in shock with potentially severe hypotension. This cascade is often set off by hypovolemia, such as the diarrhea this patient experienced. Often these patients may appear better than expected, and they may not exhibit the typical ECG findings of hyperkalemia beyond the bradycardia.
This patient was given calcium, D50, insulin, and fluids for his hypovolemia. It was noted that he had urinary retention with a Foley draining a liter for urine. By the next morning, his ECG had returned to normal. Looking back, he probably had more ECG stigmata of hyperkalemia. The QRS complex narrowed significantly, and now the T's in V2 seemed more peaked than initially appreciated.
Tip to Remember: Take a minute to think hyperkalemia with bradycardia.