Helen Pocock
Doctorate
Doctorate Title: A feasibility study for a randomised trial to assess prehospital optimal shock energy for defibrillation in cardiac arrest.
Doctorate Description:
Background: In the out-of-hospital setting up to 46% of patients who sustain a cardiac arrest will display a shockable rhythm during a resuscitation attempt. Defibrillation is an essential precursor to restoration of circulation in these patients but despite being a proven treatment there is currently no clear evidence for optimal shock energy or shock strategy. European Resuscitation Council guidelines indicate the acceptability of any energy between 120 and 360 joules for an initial shock and either a fixed or escalating strategy for subsequent shocks.
Methods
I performed a systematic review of first shock energy and shock strategy. I conducted a feasibility randomised controlled trial comparing three strategies in current UK ambulance service use. This study included testing a novel approach to informing relatives of non-surviving patients of study enrolment. I surveyed cardiac arrest researchers around the world to explore how others approach this issue.
Results
I found only one study, of very low certainty, comparing energy level strategies for defibrillation in out-of-hospital cardiac arrest. I demonstrated the feasibility of conducting a randomised controlled trial, recruiting 38 patients in 11 months in a single NHS ambulance service. Treatment adherence was 86% and data completeness 85.9%. The observed recruitment rate was 3.5 patients per month; modelling identified this would increase to 22.4 patients per month if all defibrillators in the ambulance service were randomised and available. Sample size calculations indicated that a definitive trial would require 3462 patients, achievable by 11 NHS Ambulance services in 20 months. I found wide variability across the world in the approach to informing the relatives of non-survivors. Writing to relatives appeared acceptable, although limited by availability of contact information.
Conclusions
I have established the need for a trial, ascertained recruitment rate and treatment adherence and suggested strategies for optimising the trial at multiple study sites.
Details:
Type: PhD
University: University of Warwick
Primary Supervisor: Professor Gavin Perkins
Category: Cardiac Arrest
Funding: NIHR ICA CDRF
Start Date: 2019
End Date: 2023
Status: Complete
Thesis
ThesisResearch Interests
Publications
Paramedic PhD is endorsed by:
