So you’ve gone ahead and diagnosed supra ventricular tachycardia. While getting ready to place an IV and draw up adenosine somebody (a seasoned RN perhaps) suggests that you try vagal maneuvers. Perhaps you’re feeling pessimistic that day, and wondering if they ever work. And, which one should you choose anyway? Let’s answer both questions.

How should vagal maneuvers be performed in children?

First of all, these should only be done in the child who is stable. In infants and young children (who can’t cooperate) apply a bag filled with ice and cold water to their face (the whole face) for 15-30 seconds. This will initiate the “diving reflex” whereby the child’s glottis closes, intrathoracic pressure increases and they valsalva. The EKG should be recording while this is done. You can also try inserting a rectal thermometer. In older children ask them to “bear down” like they are going to have a bowel movement, or have them blow hard on an occluded straw. Doing so for 15-20 seconds will potentially stimulate the vagus nerve. Do not perform carotid massage or orbital pressure.

Do vagal maneuvers work?

Surprisingly, at least according to a few studies the answer is yes. Garson et al. from J. Pediatrics in 1981 noted that 63% (12/19) of their SVT cases that had valsalva performed converted (at least for a short time). In a 1994 study form the American Journal of Cardiology Muller et al. saw that ice to the face terminated tachycardia in 9 of 46 episodes (20%). Note that both studies were pediatric only – which is rarer in the literature – and had very small numbers of patients. Nevertheless, in the stable patient you really have nothing to lose, even if you think that the likelihood of aborting SVT is low.