The PRE-hospital Cooling to improvE carDiac arrEst Neurological outComEs (PRECEDENCE) study is a pilot feasibility trial evaluating the implementation of pre-hospital targeted temperature management (TTM) using a wearable surface cooling device (CarbonCool® vest) in adult out-of-hospital cardiac arrest (OHCA) patients with return of spontaneous circulation (ROSC). The study aims to assess feasibility, fidelity, acceptability, and safety of initiating cooling in the field by emergency medical services (EMS) prior to hospital arrival. Results will inform the design of a larger definitive trial to determine the clinical effectiveness of early pre-hospital TTM in improving neurological outcomes.
Background: Despite advances in resuscitation, neurological recovery after out-of-hospital cardiac arrest (OHCA) remains poor. Current hospital-initiated targeted temperature management (TTM) often begins several hours after ROSC, potentially missing the optimal neuroprotective window. Early or ultra-early cooling during the pre-hospital phase may mitigate ischemia-reperfusion brain injury, but evidence from real-world EMS settings is limited. Rationale: The PRECEDENCE study tests the operational feasibility of initiating TTM in the pre-hospital environment using a novel, power-free CarbonCool® cooling vest designed for rapid application by paramedics immediately after ROSC. The vest provides conductive surface cooling without interfering with resuscitation, transport, or diagnostics. Study Design: PRECEDENCE is a pilot feasibility trial conducted by the Singapore Civil Defence Force (SCDF) and collaborating hospital. Eligible OHCA patients attended by SCDF Division 4 paramedics will be allocated to either (a) pre-hospital TTM using the CarbonCool® vest or (b) standard pre-hospital care, depending on predefined eligibility and operational criteria. Both groups will be prospectively followed through hospital discharge. Outcomes: The primary outcome is feasibility of implementing pre-hospital TTM, evaluated through recruitment rates, intervention delivery, protocol fidelity, and provider acceptability. Secondary outcomes include hospital TTM uptake, time from ROSC to target temperature, neurological outcome at discharge (CPC 1-2), and predefined safety endpoints (overshoot cooling \< 33 °C, hemodynamically significant bradyarrhythmias, and skin injury). Significance: By assessing real-world feasibility and safety of early pre-hospital cooling, this pilot will provide critical implementation data and guide protocol refinements for a future multi-division or national randomized trial.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
50
The CarbonCool® vest is a power-free, thermoplastic polyurethane (TPU) surface cooling device containing a proprietary carbon-based cooling medium capable of high heat exchange (35 W/mK). It is designed for rapid pre-hospital application and continuous cooling during patient transport.
National University Heart Centre, Singapore (NUHCS)
Singapore, Singapore
Recruitment feasibility
Proportion of EMS-attended, eligible OHCA patients who received pre-hospital TTM
Time frame: Through study completion, anticipated to be one year
Intervention feasibility
Proportion of recruited OHCA patients receiving the TTM protocol as intended
Time frame: Through study completion, anticipated to be one year
Proportion of cases with complete adherence of workflow and case report forms
Adherence of paramedics to workflow and case report forms
Time frame: Through study completion, anticipated to be one year
Acceptability of Intervention Measure (AIM)
Paramedic acceptability of the intervention will be assessed using the validated Acceptability of Intervention Measure (AIM). The AIM consists of a 4-item questionnaire rated on a 5-point Likert scale, with higher scores indicating greater acceptability of the intervention. Range score between 4 to 20.
Time frame: Time frame within 3 months of case recruitment
Intervention Appropriateness Measure (IAM)
Perceived appropriateness of the intervention will be evaluated using the validated Intervention Appropriateness Measure (IAM). The IAM is a 4-item questionnaire rated on a 5-point Likert scale, with higher scores indicating greater perceived fit and relevance of the intervention for prehospital care. Range score between 4 to 20.
Time frame: Time frame within 3 months of case recruitment
Feasibility of Intervention Measure (FIM) scores
Feasibility of implementing the intervention in the operational prehospital setting will be assessed using the validated Feasibility of Intervention Measure (FIM). The FIM comprises 4 items rated on a 5-point Likert scale, with higher scores indicating greater perceived feasibility. Range score between 4 to 20.
Time frame: Time frame within 3 months of case recruitment
Proportion of Eligible OHCA Patients Receiving Hospital TTM
Percentage of out-of-hospital cardiac arrest (OHCA) patients who meet inclusion criteria and subsequently receive targeted temperature management (TTM) in hospital.
Time frame: 6 hours
Time to Achieve Target Core Temperature After ROSC
Duration (in minutes) from return of spontaneous circulation (ROSC) to achievement of target core temperature
Time frame: 12 hours
Good Neurological Outcome at Hospital Discharge
Proportion of patients with a Cerebral Performance Category (CPC) score of 1 or 2 at hospital discharge.
Time frame: To hospital discharge, with an average of 30 days
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.