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M2E Too! Mellick's Multimedia EduBlog

The M2E Too! Blog by Larry Mellick, MD, presents important clinical pearls using multimedia.

By its name, M2E Too! acknowledges that it is one of many emergency medicine blogs, but we hope this will serve as a creative commons for emergency physicians.

Thursday, November 29, 2012

Hands On During Defibrillation: ‘I’m Not Clear!’
It’s a wonder that anyone survives — or survives neurologically intact — with all the interruptions that happen during the recognition, delivery, transfer, and treatment of a patient undergoing cardiopulmonary resuscitation.
The American Heart Association and the international resuscitation community have been constantly beating the drum in recent years about quality of chest compressions and the need to decrease interruptions that occur during cardiopulmonary resuscitation. (Circulation 2010;122[18 Suppl 3]:S706, 2010;122[18 Suppl 3]:S640, 2009;120[13]:1241; Resuscitation 2011;82[3]:263; Resuscitation 2010;81[10]:1219; Heart 2009;95[24]:1978.)
Animal studies have demonstrated that interruptions in chest compressions decrease coronary and cerebral blood flow and worsen survival outcomes. (Circulation 2001;104[20]:2465, 2007;116[22]:2525.) Even pausing a few seconds reduces the chances that the defibrillation shock will be successful. (Circulation 2002;105[19]:2270, Circulation 2004;110[1]:10; Resuscitation 2006;71[2]:137.)
Nevertheless, interruptions still continue to occur for intubation, ventilations, AED analyses, charging, and defibrillation shocks. The latest European guidelines recommend continued chest compressions while charging the defibrillator. Those guidelines, however, still recommend chest compressions be briefly paused and all rescuers cleared of the patient once the defibrillator is charged. (Resuscitation2010;81[10]:1219.) Lloyd et al analyzed electrical current flow through rescuers in direct contact with patients during biphasic external defibrillation. (Circulation 2008;117[19]:2510.)
They demonstrated that the amount of current that flows through the rescuer is minimal and clinically insignificant. Rescuers were instrumented during 43 hands-on shocks in 39 patients in the study. Forty-three shocks were delivered, four at 100 J, 27 at 200 J, and eight at 360 J. None of the 43 shocks was perceptible to the rescuers and the measured electrical currents were well within safe ranges. An accompanying editorial published in Circulation essentially stated that within appropriate guidelines the tradition of “I’m clear, you’re clear, everybody’s clear” is no longer relevant. (Circulation 2008;117[19]:2435.)
The guidelines, however, were that hands on during defibrillation should only occur with the use of adhesive, pregelled electrodes and a biphasic defibrillator, and the rescuer should be wearing gloves. Nevertheless, one researcher sounds the alarm for continued caution. (Circulation 2008;118[23]e712; Resuscitation 2012;83[12]:1467.)
The bottom line is that it is way too easy and there are far too many opportunities to allow precious seconds to slip by without cardiac compressions. Rescuers may even feel a sense of futility that leads to less caution and attention to those fleeting seconds for patients with a longer downtime or prolonged CPR prior to arrival. We all need to be reminded that continuous chest compressions should be our gold standard. We need to weigh our willingness for risk-taking and consider whether continuous compressions with no pause during defibrillation is the correct action for our patients. That specific discussion is ongoing in our emergency department.