ACMT Toxicology Visual Pearl – Along Comes a Spider

Spider

What is this pictured spider that can inflict a deadly bite?

  1. Black Widow Spider (Latrodectus mactans)
  2. Brown Recluse Spider (Loxosceles reclusa)
  3. Redback Spider (Latrodectus hasselti)
  4. Sydney Funnel Web Spider (Atrax robustus)

[Image from thebeachcomber, CC BY 4.0 https://creativecommons.org/licenses/by/4.0, via Wikimedia]

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Trick of the Trade: Ultrarapid adenosine push for SVT with a pressure bag

With some things in life, speed is everything. Adenosine is one of those things. With an ultrafast half-life estimated to be between 0.6 to 10 seconds [1], parenterally administered adenosine needs to reach the cells of the AV-node and cardiac pacemaker cells in an expedited fashion to facilitate the termination of supraventricular tachycardias (SVTs).

Known Techniques of Adenosine Administration

Currently, there are 2-syringe and 1-syringe methods that are widely accepted for the administration of adenosine. Recent data suggests that they are non-inferior to each other [2].

Adenosine flush 2 syringe method

Classic 2-syringe method: Benefit = undiluted adenosine to the heart; Limitation = limited by the syringe flush volume [3]

adenosine single syringe method

1-syringe method: Benefit = large volume; Limitation = dilution of adenosine with IV fluid. Read more about the single syringe trick of the trade.

Trick of the Trade: Pressure bag setup

We propose administering undiluted adenosine in an ultra-rapid fashion via an in-line, primed saline tubing with a pressure bag setup.

adenosine iv tubing in y-injection site port

The unique aspect of the trick is to incorporate a high-pressure, unidirectional IV fluid administration system. It is similar to the 2-syringe system except that the flush syringe is replaced with high-pressure IV fluids.

How to set-up

  1. Setup a pressure bag with a primed saline line in the standard fashion.
  2. Close the roller clamp so that no IV fluid is flowing through the tubing.
  3. Attach the IV line to the patient’s angiocatheter.
  4. Attach a syringe with undiluted adenosine to the Y-site port as close to the patient’s IV as possible.
  5. Open the roller clamp to start the high-pressure IV fluid administration.
  6. Rapidly push the adenosine into the tubing.

Video demonstration

In this video, adenosine is the colored fluid for demonstration purposes. Notice how quickly the adenosine reaches the patient.

References

  1. Parker RB, McCollam PL. Adenosine in the episodic treatment of paroxysmal supraventricular tachycardia. Clin Pharm. 1990 Apr;9(4):261-71. PMID: 2184971.
  2. Miyawaki IA, Gomes C, Caporal S Moreira V, et al. The Single-Syringe Versus the Double-Syringe Techniques of Adenosine Administration for Supraventricular Tachycardia: A Systematic Review and Meta-Analysis. Am J Cardiovasc Drugs. 2023;23(4):341-353. doi:10.1007/s40256-023-00581-w. PMID 37162718
  3. Kotruchin P, Chaiyakhan I, Kamonsri P, et al. Abstract 10470: Comparison between the double-syringe technique and the single-syringe diluted with normal saline technique of adenosine for a termination of supraventricular tachycardia: A pilot, randomized, single-blind controlled trial (DO-single trial). Circulation. 2021;144(Suppl_1). doi:10.1161/circ.144.suppl_1.10470
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