Two cases of failed cardioversion of SVT after tibial intraosseous administration of adenosine in infants are described in this month’s Pediatric Emergency Care. Both cases were subsequently cardioverted by intravenous adenosine. The maximum intraosseous dose given was 0.25 mg/kg. The successful IV doses were not higher than the IO doses.
It has been noted before that infants may require relatively higher doses of adenosine than children and that 0.2 mg/kg might even be considered a starting dose in infancy. I wonder if a bigger IO dose would have been effective, or whether a proximal humeral insertion site would make a difference. IO adenosine has been successfully used in infants and piglets.
This interesting case series provides a helpful caution in the management of paediatric SVT.

ABSTRACT: Supraventricular tachycardia (SVT) is a common tachyarrhythmia in the pediatric population that can necessitate immediate treatment. Adenosine has been well studied as a mainstay treatment, but the methods of adenosine administration have not been very well delineated. The intraosseous technique has presented itself as a possible method of administration. We describe 2 cases in which adenosine was administered through bone marrow infusion to convert SVT without success. The cases we describe show that intraosseous is not a reliable method of administering adenosine to stop SVT. Both patients presented with SVT refractory to vagal maneuvers and difficult intravenous placement. Intraosseous access was achieved, but administration of adenosine at increasing doses was unable to successfully convert the arrhythmia.

Intraosseous Infusion Is Unreliable for Adenosine Delivery in the Treatment of Supraventricular Tachycardia
Pediatr Emerg Care. 2012 Jan;28(1):47-8