The pilot study
The DoubleD pilot was an academically driven, prospective, randomised trial conducted in Sweden. The study was coordinated by the Centre for Resuscitation Science at Karolinska Institutet, Stockholm.
The aim of this pilot study was to evaluate the feasibility and safety of conducting a randomised controlled trial to compare double sequential defibrillation (DSD) as early as possible with standard defibrillation in patients with out-of-hospital cardiac arrest who remain in ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) after the first defibrillation.
The pilot study used 3:1 randomisation (3 DSD: 1 standard) and was planned to continue until 40 patients have been enrolled. Patients were randomised by specially trained EMS providers at the scene of cardiac arrest, to receive either DSD (intervention) or standard defibrillation (control). The pilot study was conducted within the ambulance services in Alingsås, Kungälv, and Sahlgrenska University Hospital.
Inclusion criteria
Out-of-hospital cardiac arrest (regardless of initial rhythm) and at least one defibrillation delivered with pads in standard antero-lateral position
Two study-specific defibrillators on scene
Exclusion criteria
- Age: under 18 years.
- Known or obvious pregnancy
- Known pre-existing Do Not Attempt Resuscitation order.
Outcomes
Feasibility:
- The number of defibrillations by the ambulance before randomisation (target: >80% before the third defibrillation).
- Among patients randomised to DSD, the proportion who received DSD (target: >80%).
- Among patients randomised to standard, the proportion who received DSD (target: <10%).
- The proportion of patients who met the inclusion criteria and were included and randomised (target: >80%).
Safety:
- Serious adverse events (such as defibrillator failure).
- Interruptions in chest compressions during CPR (defined as the proportion of time during CPR when chest compressions are being performed; target: >80% in both groups).
Patient outcomes:
- The proportion in each group who regained sustained circulation.
- Number of defibrillations before return of spontaneous circulation in each group.
- The proportion of patients who were alive upon arrival at the hospital.
- The proportion of patients who were alive at hospital discharge.
- 30-day survival.
- Neurological function 30 days after cardiac arrest.
- Neurological function and health-related quality of life at 90 and 180 days after cardiac arrest.
For detailed information, secondary and tertiary outcomes, as well as methodology, see CIP or CIP-summary.