Adenosine

What is Adenosine?

Adenosine is a purine nucleoside that acts as a very useful ACLS Drug to often treat and diagnose stable narrow-complex SVT (Supraventricular Tachycardia). When administered, adenosine basically causes a short-term blockade of the AV node within the heart which with patients with SVT, can restore normal sinus rhythms.

Adenosine may help distinguish atrial flutter from SVT, but adenosine is not effective for atrial flutter, atrial fibrillation, or tachycardia that is not caused by AV nodal reentry. Thus it can act as a safe diagnostic tool to identify the etiology of the abnormal heart rate.

Adenosine Indications

• SVT/PSVT caused by re-entry at the AV node, which includes both accessory pathway and AV nodal re-entry mechanisms.
• Regular & monophasic wide QRS Tachycardia

Adenosine Dosage

• Initial Dose: Administer an initial dose of 6 mg rapid IV bolus followed by flush (20 ml Normal Saline Flush).
• Subsequent Dose: 12 mg via rapid IV Push followed by NS flush

Adenosine Administration

1. Insert a large cannula in the antecubital fossa.
2. Draw up 6 mg of adenosine in a 2 – 5ml syringe.
3. Draw up a 20 ml Normal Saline flush.
4. Connect the adenosine syringe to the top port of the cannula and the Saline flush to the back port.
5. Administer the adenosne syringe first and as fast as possible.
6. Immediately follow the adenosine with the NS Flush.
7. Observe the rhythm. If the drug is effective, the rhythm will convert to sinus within 1 to 2 minutes.
8. If no effect is observed, give a rapid IV push of 12 mg adenosine dose, followed by NS flush.

Throughout the whole process make sure to have continuous ECG monitoring. Usually, 90% of re-entry arrhythmias are terminated within 2 minutes.

Adenosine Precautions/Side Notes

• Must be administered as a bolus, followed by a flush
• May cause bronchospasm – use caution with asthmatics
• Flushing and/or chest tightness are common effects