Trick of the Trade: Combine Adenosine with the Flush

“6 mg IV as a rapid IV push followed by a 20 mL saline flush; repeat if required as 12 mg IV push”

This recommendation remained in the 2015 iteration.

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. In young pediatric patients, the stopcock method delivers lower-than-intended doses. [9]

Trick of the Trade:
Combine the adenosine and flush solution in one syringe.

• Grab a 20-mL (or 30-mL) syringe.
• Draw up the adenosine AND the normal saline in the same 20-mL syringe.
• Administer via fast IV push (can be through a running IV line).

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 10-mL syringe to get the same effect. Flush volumes as low as 5 mL have been effective [4].

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. A small study from Korea demonstrated the feasibility and effectiveness of this approach compared to the standard techniques [7]. The efficacy of diluted adenosine was also demonstrated in a study by Lopez-Palop et al., albeit by the intracoronary route [6].

One group reported successful conversion of SVT in an infant via the IO route with the mixing-adenosine-in-the-flush technique [8].

2019 Update – Technique success confirmed with new study

A group of pharmacist researchers at Advocate Christ Medical Center conducted a pilot study in 53 patients to determine if the single syringe method was non-inferior to the traditional techniques for administering adenosine in SVT [10].

What They Did

What It Means

This is the first U.S. study to evaluate the effectiveness of the single-syringe method first described in this ALiEM post. Though there are some limitations (eg, didn’t meet the enrollment goal of 75 patients and didn’t record which traditional technique was used in each case), this study confirms that the single-syringe method of adenosine is at least as effective as the traditional techniques. The authors should be commended for performing this study. They suggest that a larger study should be conducted to confirm the findings.

This is a wonderful example of an idea being generated in FOAMed and sparking a study to evaluate it.

Additional Reading

• Read ‘Is the 6-12-12 adenosine approach always correct?‘ from Dr. Bryan Hayes at ALiEM.
• Read ‘Calcium channel blockers for stable SVT: A first line agent over adenosine?‘ from Drs. Stephen Rappaport and Meghan Groth at ALiEM.
• Read ‘Would You Choose Adenosine?‘ from Dr. Justin Morgenstern at First 10 EM.
• Read ‘The REVERT Trial: A Modified Valsalva Maneuver to Convert SVT‘ from Dr. Salim Rezaie at REBEL EM.

Original: December 18, 2012
Last updated: November 1, 2019

References

1. Neumar RW, Otto CW, Link MS, et al. Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2010;122(18 Suppl 3):S729-67. [PMID 20956224]
2. Ketkar VA, Kolling WM, Nardviriyakul N, et al. Stability of undiluted and diluted adenosine at three temperatures in syringes and bags. Am J Health Syst Pharm 1998;55(5):466-70. [PMID 9522931]
3. Kaltenbach M, Hutchinson DJ, Bollinger JE, et al. Stability of diluted adenosine in polyvinyl chloride infusion bags. Am J Health Syst Pharm 2011;68(16):1533-6. [PMID 21817085]
4. Gausche M, Persse DE, Sugarman T, Shea SR, Palmer GL, Lewis RJ, Brueske PJ, Mahadevan S, Melio FR, Kuwate JH, et al. Adenosine for the prehospital treatment of paroxysmal supraventricular tachycardia. Ann Emerg Med 1994;24(2):183-9. [PMID 8037382]
5. Ng GA, Martin W, Rankin AC. Imaging of adenosine bolus transit following intravenous administration: insights into antiarrhythmic efficacy. Heart 1999;82(2):163-9. PubMed [PMID: 10409529] PDF
6. Lopez-Palop R, Saura D, Pinar E, et al. Adequate intracoronary adenosine doses to achieve maximum hyperaemia in coronary functional studies by pressure derived fractional flow reserve: a dose response study. Heart 2004;90(1):95-6. [PMID 14676256]
7. Choi SC, Yoon SK, Kim GW, et al. A convenient method of adenosine administration for paroxysmal supraventricular tachycardia. J Korean Soc Emerg Med 2003;14(3):224-7.
8. Helleman K, Kirpalani A, Lim R. A Novel Method of Intraosseous Infusion of Adenosine for the Treatment of Supraventricular Tachycardia in an Infant. Pediatric Emerg Care 2017;33(1):47-8. [PMID 28045841]
9. Weberding NT, et al. Adenosine Administration With a Stopcock Technique Delivers Lower-Than-Intended Drug Doses. Ann Emerg Med 2018;71(2):220-4. [PMID 29089171]
10. McDowell M, Mokszycki R, Greenberg A, et al. Single Syringe Administration of Diluted Adenosine. Acad Emerg Med. 2019 Oct 30. [ePub ahead of print]. [PMID 31665806]

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