Do clinical examination gloves provide adequate electrical insulation for safe hands-on defibrillation? I: Resistive properties of nitrile gloves

Risk assessment of electric shock to the general public without Personal Protective Equipment during defibrillation shock delivery: A simulation study

Aim

This study aimed to elucidate the risk of electric shock when the general public, not wearing Personal Protective Equipment (PPE), is in contact with a patient, and a defibrillation shock is inadvertently delivered.

Methods

A simulation study was conducted simulating the following scenarios. 1) Both the rescuer and the patient were isolated from the ground, with the rescuer making single-point contact with the patient. 2) Both the rescuer and the patient were in contact with the common ground, and the rescuer made single-point contact with the patient. 3) The rescuer made contact at two different points to the patient. A mannequin with a towel saturated with 3% saline solution placed on the chest was used. Defibrillation shocks were delivered using a defibrillator three times at each of three energies: 150 J, 200 J, and 360 J. The voltage across the simulated rescuer was measured with an oscilloscope.

Results

In Scenario 1, all measurements were below the detection limit. In Scenario 2, the voltage and current across the rescuer increased with higher defibrillation shock energy, averaging 156.8 V and 156.8 mA at 360 J. In Scenario 3, voltage peaked at 326.0 V and current at 326.0 mA at 360 J.

Conclusion

In a simulated setting of defibrillation, over 300 mA of current could pass through the rescuer without PPE when having two contact points between the manikin and the rescuer. However, due to the brief duration and low energy, immediate danger to the rescuer is considered low.

Hands-on defibrillation with safety drapes: Analysis of compressions and an alternate current pathway

BACKGROUND

Hands-on defibrillation (HOD) could theoretically improve the efficacy of cardiopulmonary resuscitation (CPR) though a few mechanisms. Polyethylene drapes could potentially facilitate safe HOD, but questions remain about the effects of CPR on polyethylene's conductance and the magnitude of current looping through rescuers' arms in contact with patients.

METHODS

This study measured the leakage current through 2 mil (0.002 in.) polyethylene through two different current pathways before and after 30 min of continuous compressions on a CPR mannequin. The two pathways analyzed were the standardized IEC (International Electrotechnical Commission) leakage current analysis and a setup analyzing a current pathway looping through a rescuer's arms and returning to the patient. First, ten measurements involving the two pathways were obtained on a single polyethylene drape. 30 min of continuous compressions were applied to the drape on a CPR mannequin after which the ten measurements were repeated.

RESULTS

Twenty patients undergoing elective cardioversion for atrial fibrillation (18/20) or atrial flutter (2/20) at Emory University Hospital underwent analysis all receiving 200 J shocks (age 38-101, 35% female). Through the IEC measurement method the peak leakage current mean was 0.70 +/- 0.02 mA before compressions and 0.59 +/- 0.19 mA after compressions. Only three of the ten measurements assessing current passing through a rescuer's arms had detectable current and each was of low magnitude. All measurements were well below the maximum IEC recommendations of 3.5 mA RMS and 5.0 mA peak.

CONCLUSIONS

Polyethylene may facilitate safe HOD even after long durations of compressions. Current looping through a rescuer's arms is likely of insignificant magnitude.

[Adult advanced life support]

These European Resuscitation Council Advanced Life Support guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest.

European Resuscitation Council Guidelines 2021: Adult advanced life support

These European Resuscitation Council Advanced Life Support guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest.

Hands-on defibrillation with a safety barrier: An analysis of potential risk to rescuers

BACKGROUND

Interruptions in compressions reducethe efficacy of cardiopulmonary resuscitation (CPR) and are inevitable during hands-off periods for shocks. Clinical exam gloves were found to facilitate safe contact with patients during shock delivery but the safety of this practice has been questioned. Polyethylene is of interest because of its safety record in the medical arena and its electrical insulation properties.

METHODS

This study measured the current leak through 2 mil (0.002 inch) polyethylene drapes during shock delivery. The current leak was assessed by measurement of voltage changes in a circuit recommended by the International Electrotechnical Commission (IEC) for current leak safety testing. Current flowed off the drape, through the circuit and to electric ground in a manner consistent with standardized testing. Perceptibility was assessed in a subset with the investigator's bare hands pressed into the drape during shock delivery.

RESULTS

Thirty-three patients undergoing elective cardioversion at Emory University Hospital underwent analysis (age 23-90, 36% female). Biphasic energies were 200-360 J. The root mean square (RMS) current leak averaged 0.072 ± 0.022 mA and peak current leak averaged 0.67 ± 0.21 which is well below IEC recommendations of 3.5 mA RMS and 5.0 mA peak. Finally, no instances of dielectric breakdown occurred and no shocks were perceptible.

CONCLUSIONS

Polyethylene is a common medical material which may facilitate safe hands-on defibrillation. Our data illustrates that a thin, semitransparent layer of polyethylene is a safe and feasible adjunct to cardiac arrest kits to allow continued compressions and simplification of the CPR process.

Leakage current from transvenous and subcutaneous implantable cardioverter defibrillators (ICDs): A risk to the rescuer?

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are a well-established therapy for patients at risk of life-threatening ventricular arrhythmias. With rising implant rates, the risk of a rescuer performing chest compressions during discharge is increasing, leading to concerns over rescuer safety from the resultant leakage current. More recently, subcutaneous ICDs (S-ICD) have been developed, which utilise a higher energy and more superficial electrodes compared with transvenous ICDs (T-ICD), raising safety concerns further.

OBJECTIVE

We measured the current a rescuer would potentially receive from T-ICDs and S-ICDs if they were in contact with the patient at the time of ICD discharge to assess its magnitude in relation to international safety standards.

METHODS

Surface voltages adjacent to ICD electrodes were measured on patients undergoing defibrillation threshold checks. Rescuer current was then calculated assuming a total rescuer circuit impedance of 1696 Ω.

RESULTS

Twenty-five patients were recruited. Rescuer current from S-ICDs was significantly higher than those from T-ICDs (S-ICD: Median RMS 135 mA range 91 mA-164 mA, T-ICD: Median RMS 31 mA, range 9 mA-75 mA, P < 0.0001). Surface voltages (median RMS) to which the rescuer is likely to be exposed are higher when performing chest compressions from the patient's left side compared with the right (127 V vs 67 V respectively, 95% CI of difference -34 V to -67 V, P < 0.0001).

CONCLUSIONS

Rescuers performing chest compressions on ICD patients are at risk from leakage current, particularly from S-ICDs. Chest compressions should be performed from the opposite side to the ICD to reduce rescuer risk.

Hospital resuscitation teams: a review of the risks to the healthcare worker

Background

“Code blue” events and related resuscitation efforts involve multidisciplinary bedside teams that implement specialized interventions aimed at patient revival. Activities include performing effective chest compressions, assessing and restoring a perfusing cardiac rhythm, stabilizing the airway, and treating the underlying cause of the arrest. While the existing critical care literature has appropriately focused on the patient, there has been a dearth of information discussing the various stresses to the healthcare team. This review summarizes the available literature regarding occupational risks to medical emergency teams, characterizes these risks, offers preventive strategies to healthcare workers, and highlights further research needs.

Methods

We performed a literature search of PubMed for English articles of all types (randomized controlled trials, case-control and cohort studies, case reports and series, editorials and commentaries) through September 22, 2016, discussing potential occupational hazards during resuscitation scenarios. Of the 6266 articles reviewed, 73 relevant articles were included.

Results

The literature search identified six potential occupational risk categories to members of the resuscitation team—infectious, electrical, musculoskeletal, chemical, irradiative, and psychological. Retrieved articles were reviewed in detail by the authors.

Conclusion

Overall, we found there is limited evidence detailing the risks to healthcare workers performing resuscitation. We identify these risks and offer potential solutions. There are clearly numerous opportunities for further study in this field.

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.

Cardiac Arrest Resuscitation

Cardiac arrest is a dynamic disease that tests the multitasking and leadership abilities of emergency physicians. Providers must simultaneously manage the logistics of resuscitation while searching for the cause of cardiac arrest. The astute clinician will also realize that he or she is orchestrating only one portion of a larger series of events, each of which directly affects patient outcomes. Resuscitation science is rapidly evolving, and emergency providers must be familiar with the latest evidence and controversies surrounding resuscitative techniques. This article reviews evidence, discusses controversies, and offers strategies to provide quality cardiac arrest resuscitation.

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.