Cardiac ArrestVOCALISTNCT05926973
VectOr ChAnge defibriLlatIon in Refractory Shockable rhyThms
An observational study of Cardiac Arrest and Ventricular Fibrillation, run by Thames Valley Air Ambulance at 1 site in United Kingdom.
Trial summary
Management of cardiac arrest according to published guidelines has remained largely unchanged for a decade. Thames Valley Air Ambulance provide Critical Care Paramedic and Physician teams who respond to cardiac arrests and offer treatments beyond the scope of ambulance service clinicians. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Arrest, Ventricular Fibrillation, Ventricular Tachycardia
- What is being tested?
- Enhanced cardiac arrest bundle
- How many people
- 50 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 May 2023to Sep 2023
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Adult, Older adult
Study population: Adult patients with medical cardiac arrest attended by TVAA, in refractory shockable rhythms (defined as continuous VF or VT after 5 shocks).
Who may be able to join
- adult patients with medical cardiac arrest
- in refractory shockable rhythms (defined as continuous VF or VT after 5 shocks).
Who cannot join
- traumatic cardiac arrests
- cardiac arrests where the VF/VT was recurrent (could be terminated but then restarted) rather than refractory (unable to get the patient out of the shockable rhythm). Refractory VF refers to VF that persists despite shock delivery (i.e. shock-resistant VF). This is distinguished from recurrent VF, which is VF that re-appears after it has been terminated (2). In this study refractory would be defined as continuous VF or VT after 5 shocks.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site, 1 recruiting
- Recruiting
Thames Valley Air Ambulance
Oxford, Oxfordshire
James Raitt, MBChB, 0300 999 0135, james.raitt@tvairambulance.org.uk
About this study
Official title: Vector Change Defibrillation in Refractory Shockable Rhythms
Management of cardiac arrest according to published guidelines has remained largely unchanged for a decade. Thames Valley Air Ambulance provide Critical Care Paramedic and Physician teams who respond to cardiac arrests and offer treatments beyond the scope of ambulance service clinicians. Following a review of practice and appraisal of evidence the investigators developed an additional algorithm for cases of adult medical cardiac arrest with refractory shockable rhythms. This adds to but does not replace the Advanced Life Support algorithm and includes:
- Delivering shocks with the LUCAS mechanical CPR device running
- After 5 shocks have been delivered placing new pads in the Anterior Posterior (AP) position
- Delivering shocks using the TVAA Tempus Pro defibrillator rather than the Ambulance Service defibrillator.
This bundle was based on recommendations from ILCOR and the Resus Council (UK) Advanced Life Support manual and was launched in October 2021.
Read the detailed description
Study hypothesis An enhanced algorithm for refractory shockable rhythms terminates VF/VT and improves outcomes (ROSC at hospital) in out of hospital cardiac arrest.
Study design
PICOST Population - adult patients with medical cardiac arrest in refractory shockable rhythms (defined as continuous VF or VT after 5 shocks).
Intervention - application of the TVAA enhanced cardiac arrest bundle Comparison - 18 month period before the introduction of the bundle (if the COVID period has significantly different response times than the intervention group then the COVID period will be excluded).
Outcome - primary outcome measure is ROSC at hospital (as this represents the success of the pre-hospital phase of resuscitation).
Study design - Retrospective observational study using the TVAA HEMSBASE database Timeframe - 18 months of data since the bundle was introduced.
Exclusions - traumatic cardiac arrests, cardiac arrests where the VF/VT was recurrent (could be terminated but then restarted) rather than refractory (unable to get the patient out of the shockable rhythm). Refractory VF refers to VF that persists despite shock delivery (i.e. shock-resistant VF). This is distinguished from recurrent VF, which is VF that re-appears after it has been terminated (2). In this study refractory would be defined as continuous VF or VT after 5 shocks.
Data set to be collected All data is held within HEMSBASE Age, sex, witnessed arrest, bystander CPR, time from 999 call to TVAA on scene, first rhythm, number of shocks (total in before group; number of shocks pre and post vector change in the after group), outcome (ROSC at any stage; PLE, died on arrival to ED, ROSC in ED).
Statistical analysis Statistical support will be sought from the South Central Research Design Service https://www.rds-sc.nihr.ac.uk Fisher's test or Chi square tests may be appropriate.
Ethical approval The HRA decision tools indicate that the study does not require REC review.
Search strategy Two independent researchers will search HEMSBASE for the intervention period (Oct 21 to April 23) and the control period (19 months prior to Oct 21, excluding the COVID period if response times are significantly different in this period) using the following strategy.
HEMSBASE search
- Cardiac arrests
- Initial rhythm VF or VT
- Manual search looking for refractory shockable rhythms (defined as continuous VF or VT after 5 shocks with no change to ROSC or a non shockable rhythm at any stage).
This search strategy will deliver a list of cases of refractory shockable rhythms that can then be compared between the two reviewers to ensure all cases are included, any cases where there is not agreement will be adjudicated by a third reviewer. The cases will then be analysed for the data set above and entered into an excel spreadsheet.
Data security No patient identifiable data will be exported outside of HEMSBASE.
- Being tested
- Enhanced cardiac arrest bundle
- Keywords
- cardiac arrest, Refractory shockable rhythm, defibrillation
- Medical subject headings
- Heart Arrest, Ventricular Fibrillation, Tachycardia, Ventricular
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Enhanced cardiac arrest bundleOther
Also called Vector change defibrillation
- Delivering shocks with the LUCAS mechanical CPR device running
- After 5 shocks have been delivered placing new pads in the Anterior Posterior (AP) position
- Delivering shocks using the TVAA Tempus Pro defibrillator rather than the Ambulance Service defibrillator.
| Study group | Role | What they receive |
|---|---|---|
| Before intervention | Standard care as per ALS guidelines prior to October 2021 | |
| After intervention | Enhanced cardiac arrest management as per TVAA guideline from October 2021 onwards Receives: Other: Enhanced cardiac arrest bundle |
What is being measured
The primary outcome is the main question the study is designed to answer.
ROSC at hospital
ROSC at hospital
Measured: within 24 hours of arrest
Secondary outcomes (1)
PLE rate
PLE - death declared at scene
Measured: within 24 hours of arrest
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jul 2023
- Study start1 May 2023
- Primary completion30 Jun 2023 (estimated)
- Study completionSep 2023 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cardiac ArrestStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Thames Valley Air Ambulance
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, James Raitt, Thames Valley Air Ambulance
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05926973
- Sponsor's protocol ID
- TVAA02/23
- Acronym
- VOCALIST
- Status last verified
- Jun 2023
- First submitted
- 22 May 2023
- Last updated
- 3 Jul 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No individual patient data to be shared
Study at a glance
From the registry record, last updated by the sponsor on 3 Jul 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vector Change Defibrillation in Refractory Shockable Rhythms
- ClinicalTrials.gov ID
- NCT05926973
- Acronym / sponsor ID
- VOCALIST / TVAA02/23
- Keywords
- cardiac arrest, Refractory shockable rhythm, defibrillation
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Thames Valley Air AmbulanceUniversity, hospital or other
- Study start
- 1 May 2023 (actual)
- Primary completion
- 30 Jun 2023 (estimated)
- Study completion
- Sep 2023 (estimated)
- First posted
- 3 Jul 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Management of cardiac arrest according to published guidelines has remained largely unchanged for a decade. Thames Valley Air Ambulance provide Critical Care Paramedic and Physician teams who respond to cardiac arrests and offer treatments beyond the scope of ambulance service clinicians. Following a review of practice and appraisal of evidence the investigators developed an additional algorithm for cases of adult medical cardiac arrest with refractory shockable rhythms. This adds to but does not replace the Advanced Life Support algorithm and includes:
- Delivering shocks with the LUCAS mechanical CPR device running
- After 5 shocks have been delivered placing new pads in the Anterior Posterior (AP) position
- Delivering shocks using the TVAA Tempus Pro defibrillator rather than the Ambulance Service defibrillator.
This bundle was based on recommendations from ILCOR and the Resus Council (UK) Advanced Life Support manual and was launched in October 2021.
Detailed description
Study hypothesis An enhanced algorithm for refractory shockable rhythms terminates VF/VT and improves outcomes (ROSC at hospital) in out of hospital cardiac arrest.
Study design
PICOST Population - adult patients with medical cardiac arrest in refractory shockable rhythms (defined as continuous VF or VT after 5 shocks).
Intervention - application of the TVAA enhanced cardiac arrest bundle Comparison - 18 month period before the introduction of the bundle (if the COVID period has significantly different response times than the intervention group then the COVID period will be excluded).
Outcome - primary outcome measure is ROSC at hospital (as this represents the success of the pre-hospital phase of resuscitation).
Study design - Retrospective observational study using the TVAA HEMSBASE database Timeframe - 18 months of data since the bundle was introduced.
Exclusions - traumatic cardiac arrests, cardiac arrests where the VF/VT was recurrent (could be terminated but then restarted) rather than refractory (unable to get the patient out of the shockable rhythm). Refractory VF refers to VF that persists despite shock delivery (i.e. shock-resistant VF). This is distinguished from recurrent VF, which is VF that re-appears after it has been terminated (2). In this study refractory would be defined as continuous VF or VT after 5 shocks.
Data set to be collected All data is held within HEMSBASE Age, sex, witnessed arrest, bystander CPR, time from 999 call to TVAA on scene, first rhythm, number of shocks (total in before group; number of shocks pre and post vector change in the after group), outcome (ROSC at any stage; PLE, died on arrival to ED, ROSC in ED).
Statistical analysis Statistical support will be sought from the South Central Research Design Service https://www.rds-sc.nihr.ac.uk Fisher's test or Chi square tests may be appropriate.
Ethical approval The HRA decision tools indicate that the study does not require REC review.
Search strategy Two independent researchers will search HEMSBASE for the intervention period (Oct 21 to April 23) and the control period (19 months prior to Oct 21, excluding the COVID period if response times are significantly different in this period) using the following strategy.
HEMSBASE search
- Cardiac arrests
- Initial rhythm VF or VT
- Manual search looking for refractory shockable rhythms (defined as continuous VF or VT after 5 shocks with no change to ROSC or a non shockable rhythm at any stage).
This search strategy will deliver a list of cases of refractory shockable rhythms that can then be compared between the two reviewers to ensure all cases are included, any cases where there is not agreement will be adjudicated by a third reviewer. The cases will then be analysed for the data set above and entered into an excel spreadsheet.
Data security No patient identifiable data will be exported outside of HEMSBASE.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Before intervention | – | –Standard care as per ALS guidelines prior to October 2021 |
| After intervention | – | Other: Enhanced cardiac arrest bundleEnhanced cardiac arrest management as per TVAA guideline from October 2021 onwards |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Adult patients with medical cardiac arrest attended by TVAA, in refractory shockable rhythms (defined as continuous VF or VT after 5 shocks).
Key inclusion criteria (2 listed)
- adult patients with medical cardiac arrest
- in refractory shockable rhythms (defined as continuous VF or VT after 5 shocks).
Key exclusion criteria (2 listed)
- traumatic cardiac arrests
- cardiac arrests where the VF/VT was recurrent (could be terminated but then restarted) rather than refractory (unable to get the patient out of the shockable rhythm). Refractory VF refers to VF that persists despite shock delivery (i.e. shock-resistant VF). This is distinguished from recurrent VF, which is VF that re-appears after it has been terminated (2). In this study refractory would be defined as continuous VF or VT after 5 shocks.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Enhanced cardiac arrest bundleAlso: Vector change defibrillation* Delivering shocks with the LUCAS mechanical CPR device running * After 5 shocks have been delivered placing new pads in the Anterior Posterior (AP) position * Delivering shocks using the TVAA Tempus Pro defibrillator rather than the Ambulance Service defibrillator. | Other | After intervention |
Primary outcome
ROSC at hospital
Time frame: within 24 hours of arrest
ROSC at hospital
1 secondary outcome
PLE rate
Time frame: within 24 hours of arrest
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jul 2023.
- Individual participant dataSharing planned: No. No individual patient data to be shared
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cardiac Arrest and Ventricular Fibrillation, run by Thames Valley Air Ambulance at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 3 Jul 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact James Raitt, MBChB (0300 999 0135, james.raitt@tvairambulance.org.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
ROSC at hospital (time frame: within 24 hours of arrest). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Jul 2023.