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DOuble SEquential External Defibrillation for Refractory VF

Not Applicable
Completed
Conditions
Out-Of-Hospital Cardiac Arrest
Ventricular Fibrillation
Interventions
Procedure: Double Sequential Defibrillation
Procedure: Vector Change Defibrillation
Registration Number
NCT04080986
Lead Sponsor
Sunnybrook Health Sciences Centre
Brief Summary

Despite significant advances in resuscitation efforts, there are some patients who remain in refractory ventricular fibrillation (VF) during out-of-hospital cardiac arrest. Double sequential external defibrillation (DSED) and vector change defibrillation have been proposed as viable options for patients in refractory VF. This cluster randomized trial will compare (1) continued resuscitation using standard defibrillation; (2) resuscitation involving DSED; or (3) resuscitation involving vector change defibrillation, in patients presenting with refractory VF during out-of-hospital cardiac arrest. The results of this study will provide high level evidence of the impact of both DSED and vector change defibrillation on ROSC and patient survival after OHCA.

Detailed Description

Double sequential external defibrillation (DSED) and vector change defibrillation have been proposed as viable options for patients in refractory ventricular fibrillation (VF) during out-of-hospital cardiac arrest. However, currently there is insufficient evidence to support widespread implementation of this therapy. As such, a well-designed randomized controlled trial (RCT) employing a standardized approach to alternative defibrillation strategies early in the treatment of refractory VF is required to determine whether these treatments may impact clinical outcomes. This cluster randomized trial will be conducted in the regions of Peel, Halton, Simcoe, and the cities of London, Ottawa, and Toronto, Ontario, Canada over a three year time period. All adult (≥ 18 years) patients presenting in refractory VF/pulseless ventricular tachycardia (pVT) (defined as patients presenting in VF/pVT and remaining in VF/pVT after three consecutive standard defibrillation attempts each separated by 2 minutes of CPR) during out-of-hospital cardiac arrest of presumed cardiac etiology will be assigned to be treated by one of three strategies: (1) continued resuscitation using standard defibrillation; (2) resuscitation involving DSED (two defibrillators, one using anterior-posterior pad placement and the second using anterior- anterior pad placement delivering two rapid sequential shocks for all subsequent defibrillation attempts); or (3) resuscitation involving vector change (change of defibrillation pads from anterior-anterior to an anterior-posterior pad position) defibrillation. All study arms will continue to receive antiarrhythmic use and epinephrine as per current provincial standards. The cluster units will be defined by emergency medical service (EMS) agency and each cluster will crossover at 6 month intervals throughout the duration of the study.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
405
Inclusion Criteria
  • ≥ 18 years of age
  • Non-traumatic cardiac arrest of presumed cardiac etiology
  • Presenting rhythm of ventricular fibrillation or pulseless ventricular tachycardia
  • No ROSC or non-shockable rhythm after three consecutive shocks by EMS or fire department.
Exclusion Criteria
  • Traumatic cardiac arrest
  • Patients with pre-existing do not resuscitate orders
  • Patients without VF or pulseless VT as presenting rhythm
  • Patients without three consecutive shocks delivered
  • Patients initially treated by non-participating fire or EMS agencies.

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Double Sequential DefibrillationDouble Sequential DefibrillationThe first three shocks will occur with defibrillation pads placed in the anterior-anterior position. For all further shocks, a second set of defibrillation pads (via a second on scene EMS or fire defibrillator) will be applied in the anterior-posterior position, and defibrillation will be carried out by sequential defibrillation shocks provided by the two defibrillators (i.e. with a short delay between the two defibrillators). The patient may also be administered antiarrythmic agents and epinephrine, as per current provincial standard.
Vector Change DefibrillationVector Change DefibrillationThe first three shocks will occur with defibrillation pads placed in the anterior-anterior position. All further shocks will occur with the pads placed in the anterior-posterior position. The patient may also be administered antiarrythmic agents and epinephrine, as per current provincial standard.
Primary Outcome Measures
NameTimeMethod
Survival to Hospital DischargeThrough study completion of three years

Binary outcome of whether the patient was discharged alive from hospital or died prior to discharge.

Secondary Outcome Measures
NameTimeMethod
Neurologic outcomeThroughout study completion of three years

Neurologic outcome as defined by the modified Rankin Scale at time of hospital discharge. mRS 0-2 will be considered a good neurologic outcome.

Return of Spontaneous Circulation1 Day

Binary outcome of whether or not a patient had a return of spontaneous circulation

VF termination after first interventional shock1 Day

Cessation of the VF waveform on defibrillator monitor at first rhythm analysis post interventional or standard shock. The interpretation will occur after three standard shocks have failed to terminate VF

VF Termination after all interventional shocks1 Day

Cessation of the VF waveform on defibrillator monitor at any rhythm analysis post interventional or standard shock. The interpretation will occur after three standard shocks have failed to terminate VF

Number of defibrillation attempts to achieve Return of spontaneous circulation1 Day

Total number of shocks required to achieve the first return of spontaneous circulation during resuscitation, inclusive of the first three standard shocks

Trial Locations

Locations (6)

Middlesex-London Paramedic Service

🇨🇦

London, Ontario, Canada

Peel Regional Paramedic Service

🇨🇦

Brampton, Ontario, Canada

Halton Region Paramedic Services

🇨🇦

Oakville, Ontario, Canada

County of Simcoe Paramedic Services

🇨🇦

Simcoe, Ontario, Canada

Ottawa Paramedic Service

🇨🇦

Ottawa, Ontario, Canada

Toronto Paramedic Services

🇨🇦

Toronto, Ontario, Canada

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