The success of adenosine depends as much on the administration technique as it does the mechanism of action. The 2010 Advanced Cardiac Life Support (ACLS) Guidelines recommend the following when administering adenosine
"6 mg IV as a rapid IV push followed by a 20 mL saline flush; repeat if required as 12 mg IV push"While most drugs are metabolized in the liver, adenosine doesn't even make it that far, being metabolized in the erythrocytes and vascular endothelial cells. With this extremely short half-life (10 seconds), it is important to help it reach the heart before it's metabolized and excreted without being effective.
There are a variety of methods to administer adenosine. Some will push it through a running IV line, followed by two 10-mL saline flushes.
Others will utilize a stopcock, where the adenosine is hooked up to one port and a 10-mL saline flush is hooked up to the other. After the adenosine is pushed, the swivel is switched and the 10-mL saline flush quickly follows.
Others, still, will use a hybrid of these two methods. The problem with all of these approaches is that it takes time to switch syringes. Even if utilizing the stopcock, nurse unfamiliarity with how to maneuver the port from OFF to ON may lead to some fumbling. With almost any other drug, a few seconds lost here or there wouldn't matter. But it can with adenosine.
Trick of the Trade: Combine the adenosine and flush solution in one syringe.
The major advantage to this approach is that it obviates the need for any syringe switching or stopcock swiveling. There's no need for additional flushes since your diluted adenosine syringe doubles as the flush. If you don't have 20-mL syringes, you can still add the adenosine to one of the two 10-mL saline flushes to get the same effect. Flush volumes as low as 5 mL have been effective .
Adenosine is stable in, and compatible with, normal saline [2, 3]. Even if you're giving a 12 mg dose, the adenosine will only take up 4 mL of volume, leaving 16 mL for the normal saline. The efficacy of diluted adenosine was demonstrated in a study by Lopez-Palop et al., albeit by the intracoronary route .
Read more about when to consider alternative doses of adenosine from my previous post.