A note of caution on the performance of hands-on biphasic defibrillation

Hands-on defibrillation during active chest compressions: eliminating another interruption

After decades of research, effective chest compressions have emerged as a key component of high-quality cardiopulmonary resuscitation (CPR) for cardiac arrest patients. Minimizing interruptions in chest compressions is garnering increasing attention as a method to improve CPR quality and outcomes. Hands-on defibrillation has been suggested as both a safe and effective means of reducing interruptions in chest compressions. This article discusses the safety and efficacy of a novel and controversial method to reduce interruptions: hands-on defibrillation.

Achieving safe hands-on defibrillation using electrical safety gloves--a clinical evaluation

INTRODUCTION

Safe hands-on defibrillation (HOD) will allow uninterrupted chest compression during defibrillation and may improve resuscitation success. We tested the ability of electrical insulating gloves to protect the rescuer during HOD using a 'worst case' electrical scenario.

MATERIALS AND METHOD

Leakage current flowing from the patient to the 'rescuer' during antero-lateral defibrillation of patients undergoing elective cardioversion was measured. The 'rescuer' maintained firm (20 kgf) contact with the patient during defibrillation, wearing Class 1 electrical insulating gloves while simulating an inadvertent contact with the patient, through an additional wired contact between 'rescuer' and patient.

RESULTS

Data from 61 shocks from 43 different patients were recorded. The median leakage current from all defibrillations was 20.0 μA, (range: 2.0-38.5). In total, 18 of the shocks were delivered at 360 J and had a median leakage current of 27.0 μA (range: 14.3-38.5).

CONCLUSION

When using Class 1 electrical insulating gloves for hands-on defibrillation, rescuer leakage current is significantly below the 1 mA safe threshold, allowing safe hands-on defibrillation if the rescuer makes only one other point of contact with the patient.

Electrical exposure risk associated with hands-on defibrillation

BACKGROUND

The use of hands-on defibrillation (HOD) to reduce interruption of chest compression after cardiac arrest has been suggested as a means of improving resuscitation outcomes. The potential dangers of this strategy in regard to exposing rescuers to electrical energy are still being debated. This study seeks to determine the plausible worst-case energy-transfer scenario that rescuers might encounter while performing routine resuscitative measures.

METHODS

Six cadavers were acquired and prepared for defibrillation. A custom instrumentation-amplifier circuit was built to measure differential voltages at various points on the bodies. Several skin preparations were used to determine the effects of contact resistance on our voltage measurements. Resistance and exposure voltage data were acquired for a representative number of anatomic landmarks and were used to map rescuers' voltage exposure. A formula for rescuer-received dose (RRD) was derived to represent the proportion of energy the rescuer could receive from a shock delivered to a patient. We used cadaver measurements to estimate a range of RRD.

RESULTS

Defibrillation resulted in rescuer exposure voltages ranging from 827V to ∼200V, depending on cadaver and anatomic location. The RRD under the test scenarios ranged from 1 to 8J, which is in excess of accepted energy exposure levels.

CONCLUSIONS

HOD using currently available personal protective equipment and resuscitative procedures poses a risk to rescuers. The process should be considered potentially dangerous until equipment and techniques that will protect rescuers are developed.