DOuble SEquential External Defibrillation for Refractory VF (DOSEVF)

Sunnybrook Health Sciences Centre

Status: Completed

Conditions: Out-Of-Hospital Cardiac Arrest; Ventricular Fibrillation

Treatments: Procedure: Vector Change Defibrillation; Procedure: Double Sequential Defibrillation

Study type: Interventional

Funder types: Other

Identifiers

NCT04080986

DOSEVF RCT

Details and patient eligibility

About

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.

Full 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.

Enrollment: 405 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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405 participants in 3 patient groups

Standard Arm

No Intervention group

Description:

All defibrillation attempts will occur using the standard defibrillation method, i.e. defibrillation pads will be placed in the anterior-anterior configuration. The patient may also be administered antiarrythmic agents and epinephrine, as per current provincial standard.

Double Sequential Defibrillation

Active Comparator group

Description:

The 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.

Treatment:

Procedure: Double Sequential Defibrillation

Vector Change Defibrillation

Active Comparator group

Description:

The 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.

Treatment:

Procedure: Vector Change Defibrillation