Response to Letter Regarding Article, “Hands-On Defibrillation: An Analysis of Electrical Current Flow Through Rescuers in Direct Contact With Patients During Biphasic External Defibrillation”
We are grateful for J.L. Sullivan’s interest in and comments regarding our article.1 Clearly, the use of polyethylene gloves is an important constraint to our experiments (We mention this in the article more than once). However, such gloves are a part of standard precautions during resuscitation. Moreover, we clearly demonstrate the safety of hands-on defibrillation in humans despite a direct bare-skin–to–bare-skin return current pathway between the patient and rescuer.
Should our findings be interpreted as the “go-ahead” to ignore guidelines and perform compressions while shocks are delivered? Obviously, they should not. As pointed out in the Discussion, we do not advocate that this maneuver be used clinically until proven safe by further testing. We must, however, address and clarify several points made by Mr Sullivan.
Mr Sullivan points out that the dielectric integrity of the gloves may break down when exposed to electric fields in the kilovolt range. For gloves to be exposed to this type of voltage, the defibrillator pads would essentially have to be applied directly to either side of the glove. Defibrillating the gloves instead of the patient is beyond the range of foreseeable medical error. In reality, we have found that the measured voltage on the skin surface of patients 15 cm from the pads is less than 1/20th the voltages proposed by Mr Sullivan (unpublished experiments). This is likely the reason that none of our experiments have shown evidence of dielectric breakdown.
There is no recommendation in resuscitation guidelines for the use of biphasic shock energies of >200 J. In 8 of our experiments, we included 360-J biphasic shocks to further test the safety margin of this maneuver. These measurements used energies beyond what would be used in cardiac arrest scenarios. Therefore, these measurements bolster, not hinder as Mr Sullivan would suggest, our conclusions.
In our continuing research regarding hands-on defibrillation, we recognize that the safety of rescuers is an absolute requisite. We remain confident that future resuscitation protocols will include streamlined, efficient maneuvers such as ours. Until that time, in the care of our patients, we and the remainder of clinicians should stick to the guidelines.