Evaluation of the prehospital use of a Valsalva assist device in the emergency treatment of supraventricular tachycardia (EVADE SVT): study protocol for a stepped wedge cluster randomised controlled trial.

INTRODUCTION: Patients with episodes of supraventricular tachycardia (SVT), a common heart arrhythmia, are often attended by ambulance services. International guidelines advocate treatment with the Valsalva manoeuvre (VM), but this simple physical treatment has a low success rate, with most patients requiring conveyance to hospital. The Valsalva Assist Device (VAD) is a simple device that might help practitioners and patients perform a more effective VM and reduce the need for patients to be taken to hospital. METHODS AND ANALYSIS: This stepped wedge cluster randomised controlled trial, conducted within a UK ambulance service, compares the current standard VM with a VAD-delivered VM in stable adult patients presenting to the ambulance service with SVT. The primary outcome is conveyance to hospital; secondary outcomes measures include cardioversion rates, duration of ambulance care and number of subsequent episodes of SVT requiring ambulance service care. We plan to recruit approximately 800 patients, to have 90% power to detect an absolute reduction in conveyance rate of 10% (from 90% to 80%) between the standard VM (control) and VAD-delivered VM (intervention). Such a reduction in conveyance would benefit patients, the ambulance service and receiving emergency departments. It is estimated potential savings would pay for devices for the entire ambulance trust within 7 months. ETHICS AND DISSEMINATION: The study has been approved by the Oxford Research Ethics Committee (reference 22/SC/0032). Dissemination will be through peer-reviewed journal publication, presentation at national and international conferences and by the Arrhythmia Alliance, a patient support charity. TRIAL REGISTRATION NUMBER: ISRCTN16145266.

Factors that influence the administration of tranexamic acid (TXA) to trauma patients in prehospital settings: a systematic review.

OBJECTIVE: In the UK there are around 5400 deaths annually from injury. Tranexamic acid (TXA) prevents bleeding and has been shown to reduce trauma mortality. However, only 5% of UK major trauma patients who are at risk of haemorrhage receive prehospital TXA. This review aims to examine the evidence regarding factors influencing the prehospital administration of TXA to trauma patients. DESIGN: Systematic literature review. DATA SOURCES: AMED, CENTRAL, CINAHL, Cochrane Database of Systematic Reviews, Conference Proceedings Citation Index-Science, Embase and MEDLINE were searched from January 2010 to 2020; searches were updated in June 2022. CLINICALTRIALS: gov and OpenGrey were also searched and forward and backwards citation chasing performed. ELIGIBILITY CRITERIA: All primary research reporting factors influencing TXA administration to trauma patients in the prehospital setting was included. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers performed the selection process, quality assessment and data extraction. Data were tabulated, grouped by setting and influencing factor and synthesised narratively. RESULTS: Twenty papers (278 249 participants in total) were included in the final synthesis; 13 papers from civilian and 7 from military settings. Thirteen studies were rated as 'moderate' using the Effective Public Health Practice Project Quality Assessment Tool. Several common factors were identified: knowledge and skills; consequences and social influences; injury type (severity, injury site and mechanism); protocols; resources; priorities; patient age; patient sex. CONCLUSIONS: This review highlights an absence of high-quality research. Preliminary evidence suggests a host of system and individual-level factors that may be important in determining whether TXA is administered to trauma patients in the prehospital setting. FUNDING AND REGISTRATION: This review was supported by Research Capability Funding from the South Western Ambulance Service NHS Foundation Trust and the National Institute for Health Research Applied Research Collaboration South West Peninsula. PROSPERO REGISTRATION NUMBER: CRD42020162943.