Wednesday, October 31, 2012

Double Gloving It - Hands-on Defibrillation

The Gist:  In the pursuit of minimally interruptive, excellent CPR, there has an increasing interest in hands-on defibrillation.  Mounting literature suggests that external, biphasic defibrillation, with a gloved individual providing chest compressions, is safe (but wear double gloves).  The literature isn't conclusive in either direction and this practice hasn't been endorsed by the American Heart Association,  allowing providers to make their own conclusions and practices.  




The recent paper: Sullivan J, Chapman F.  Will medical examination gloves protect rescuers from defibrillation voltages during hands-on defibrillation? Resuscitation. 2012 Aug 25.
  • Simulated (lab) study evaluated the voltage needed to cause current flow and breakdown in various exam gloves (latex, nitrile, etc).
  • Exam gloves performed differently based on composition (and variably within the composition group).  Double nitrile, vinyl, and latex performed best.
  • Some single gloves broke down in the biphasic defibrillator range.
  • Double gloves leak within the biphasic defibrillator range but only broke down when the voltage exceeded this range.
  • The leakage of current in these gloves often occurred at levels below 'the level of sensation.' I.e. a provider may not detect current when, in fact, it is passing through the glove.
    • Clinical significance of this is unknown but the authors make interesting points in their discussion, emphasizing that there is likely no ill health effect, by examining the duration of shock, amplitude of the voltage, likelihood of the current's path including the heart, and intrinsic health characteristics of the health care provider. 
  • There are limitations: these gloves weren't soaked in ultrasound jelly/patient sweat/condensation from cooling packs, weren't stretched out because there were no appropriate sized gloves available in the room, and were likely evaluated for rents.
  • Study performed by Physio-Control, producers of the LUCAS chest compression system (Read Dr. Weingart's comment below on this conflict of interest!).
The impetus:  About a week ago, the following video appeared, accompanied with lively discussion, on my Twitter feed. 

I thought this was neat because last year I heard about hands-on defibrillation on this ERCAST episode.  I gasped, as this opposed the "all clear" dogma I lapped up in BLS and ACLS.  I found the following articles and a good LITFL post.
Convinced, I was nervously excited to try it.  It took many charming smiles, print outs of references, and attempts with various attendings but I got my chance.  And, well, I really didn't feel anything.  Granted, I was wearing a couple sets of gloves and I ensured I wasn't touching any metal, but I felt good about it.  I've repeated my attempts in the various institutions I've rotated through recently, although most say "no."  After evaluating the paper above, I'll still try (double gloved).  We argue that interventions for our patients must be "clinically significant and, in a fit, healthy individual, I think that any current leakage is going to be insignificant.  

Why does this matter?
  • "Good quality CPR" depends on constant, consistent, adequate compressions as well as early defibrillation.  Guidelines, training programs, and leaders emphasize no interruptions while recommending defibrillation (a necessary interruption) - a somewhat contradictory set up.  
    • One of my favorite FOAM professors, Dr. Amal Mattu, brought the following to my attention in the following UMEM pearl: "For every 10 seconds of hands-off time during cardiac arrest, the patient's chances of successful return of spontaneous circulation decreases by 50% due to reductions in cerebral perfusion." (Edelson et al in Resuscitation 2010)
  • Chest compression interruptions during CPR are more common than we think.  This month's Resuscitation also ran a study by McInnis et al evaluating code leaders perception of error.  The most commonly unidentified error?  Interruptions in chest compressions (>10 sec), which occurred in 32/40 cases (pulse check and defibrillation were the most often cited reasons although, I think sometimes a lack of awareness/fatigue is more likely the culprit)
    • Hands-on defibrillation could aid us in achieving interruption-less CPR!  Even if you remove your hands for defibrillation, make an effort to minimize this.  
Dr. Scott Weingart's experience:  check out this article in Resuscitation, where Weingart discusses experiences with >20 hands-on defibrillations, including some cautionary stories.  Pearls:  possibly more safe with pads in anterior-posterior position, consider removing hands for brief instant at time of defibrillation.  

Note:  I recommend discussing hands-on defibrillation with others, particularly those who run codes or are often members of the code team.  The middle of a resuscitation is probably not the time to surprise people with your plan to do hands-on defibrillation.  Communication is key!

2 comments:

  1. Great post! Will be talking on this exact topic next week. One key point from the resus article is that the article is published by two authors directly employed by physiocontrol. Why is this relevant? They manufacturer one of the most popular automated compression systems; the automated compression system obviously allows compressions during shock. Conflict of interest?

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    1. Thanks, that's definitely an important part of the story (and something I failed to note!).

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