Out-Of-Hospital Cardiac Arrest, Ventricular Fibrillation
Conditions
Keywords
Resuscitation, Arrhythmia, Cardiac, Heart Diseases, Heart Arrest
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.
Interventions
PROCEDUREDouble Sequential Defibrillation
Defibrillation using pad placement in anterior-posterior position
PROCEDUREVector Change Defibrillation
Defibrillation using two defibrillators, one with pad placement in anterior-posterior position and the other with pad placement in anterior-anterior position delivering two rapid sequential shocks.
Sponsors
Peel Regional Paramedic Services
Toronto Paramedic Services
Halton Region Paramedic Services
County of Simcoe Paramedic Services
London Health Sciences Centre
Middlesex-London EMS
Ottawa Paramedic Service
Sunnybrook Health Sciences Centre
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
This is a cluster randomized trial, with cluster units defined by EMS agency. Each cluster will crossover at six month intervals for each EMS agency during the study.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Survival to Hospital Discharge | Through study completion of three years | Binary outcome of whether the patient was discharged alive from hospital or died prior to discharge. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Neurologic outcome | Throughout 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 Circulation | 1 Day | Binary outcome of whether or not a patient had a return of spontaneous circulation |
| VF termination after first interventional shock | 1 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 shocks | 1 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 circulation | 1 Day | Total number of shocks required to achieve the first return of spontaneous circulation during resuscitation, inclusive of the first three standard shocks |
Countries
Canada
Outcome results
None listed