Adenosine

#KYJ.  Adenosine.
Have you ever given this IV drug to a patient?
It is used to cause a complete block through the AV node, in patients experiencing a Junctional Tachycardia (previously and more commonly called Supraventricular Tachycardia (SVT)).

Its use is common, and when given correctly it is very effective.  In the past you may have been taught to give it as a neat push IV.  But more recently it has become popular to dilute the required dose up to a 20ml volume and rapidly push in a largish (18g) IV cannula in the antecubital fossa, and quickly flush with a 10-20 ml saline

This drug has the effect of stopping the heart.  Thankfully it has a very short half life of 4-7 seconds (requiring the rapid push). Like a computer that is playing up, you get the sense that this drug is like a cardiac "Reset button", like someone said "have you tried turning it off, then on again?"

Vials come in 6 mg but it is very common (almost expected) that we start at 9mg.
A common regimen is
3 x 2 minutely doses starting at
9mg - 9mg - 12 mg.

If it works on dose 1, the other two are not needed.

Doses are expected to work in 5-10 seconds so as you give the push, the patient needs to be attached to the cardiac monitor.  You are watching for the SVT to deteriorate into a severe bradycardia or asystole (flat line).

Their heart stops.... Then in 3-5 seconds it automatically restarts, hopefully into a normal sinus rhythm .... It's a reset button.

Patients often experience fear, and altered consciousness as their brain oxygenation ceases for that few seconds.  Many describe a sense of doom, or near death phenomenon like a Tunnel of light, out of body experiences or a peaceful place of comfort and warmth.  Some report an experience of meeting their deity or previously deceased loved ones.  Rarely this experience is one of terror, and there are documented case reports of Post traumatic stress disorder.  This drug is excellent but has some issues.

Nurses should comfort the patient and prepare them for a sensation of "passing out". Tell them that you will stay with them and keep them safe.  Hold their hand.  They are often very frightened.

Have you had a patient on this drug?  Tell us your story.