A 58 year old male arrives to the ED in cardiac arrest.  CPR is in progress and you are concerned about the amount of time needed prior to defibrillation to stop compressions, ensure all personnel are not touching the patient or the bed, delivering the shock, and then restarting CPR.  It occurs to you that the pads could deliver a shock while CPR is in progress, but wonder about the safety and efficacy.

Chest compression fraction (CCF) is a measure, represented by percentage, of the time spent performing compressions during a cardiac arrest. A high CCF promotes not just cerebral perfusion, but promotes coronary perfusion pressure (CPP) which takes several compressions to return back to optimal state following an interruption.  The practices of counting down from 10 seconds during pulse checks (to limit time spent searching for a pulse or obtaining ultrasound), deferring advanced airway management (using a BVM or LMA instead of moving to endotracheal intubation), and using TEE during CPR have all been shown to improve CCF.  

In VF/VT arrest, the clinician operating the defibrillator will ensure all members of the resuscitation team are not touching the patient or bed prior to delivering a defibrillation shock, often with a phrase “I’m clear, you’re clear, we’re all clear” or more dramatically shouting “CLEAR!”.  These few seconds represent an interruption of compressions and a fall in CPP. Some resuscitation researchers have proposed “hands on defibrillation”, where a shock is delivered while a clinician is compressing with shielding from the electrical current (either through an insulating blanket or with electrically insulated gloves), as an additional way to reduce compression interruptions.

From a safety perspective, basic nitrile exam gloves used during compressions have been shown to not have the requisite insulation to prevent accidental electric shock.  Other solutions such as standard electrical insulating gloves or thick polyethylene sheets covering the chest have been proposed. In terms of efficacy, manikin and animal models have shown significant increase in CCF with HOD, but it is unknown if this improvement yields better outcomes in actual patients.

While there is emerging evidence supporting HOD, this data has important limitations.  First, there is a publishing bias which tends to favor positive experiences or outcomes.  Secondly, because experience and research on HOD is lacking, the true safety picture isn’t really known.  Finally, it is always important to practice within the system you belong to. A cross disciplinary discussion and practice within a resuscitation group is needed to ensure everyone is on the same page to prevent errors and injuries. Ultimately, HOD isn't ready for use, but is worth watching to determine if it is found to be feasible, safe, and effective.

Reference: Kwak J, Brady WJ. The safety and efficacy of hands-on defibrillation in the management of adult cardiac arrest: A systematic review. Am J Emerg Med. February 2020. doi:10.1016/j.ajem.2020.02.020.