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Clinical research

At EHAAT, we’re committed to improving the care and experience of our patients, harnessing the transformative power of clinical research to explore new ideas and enhance patient outcomes.

Clinical research

Clinical Research

Essex & Herts Air Ambulance (EHAAT) is committed to driving forward with new ideas and clinical innovations, continually looking for ways to improve – encouraging initiative, creativity and agility. We’re passionate about the transformative power of research, which plays a pivotal role in improving the service and care delivered to our patients.

Patient speaking with EHAAT Paramedic

Patient Involvement Forum

We set up a Patient Involvement Forum at EHAAT, comprising former patients and their family members. Together, they provide invaluable advice on our research projects to ensure we address issues that are important to patients, whose perspectives are represented in every stage of the research.

EHAAT is passionate about involving patients, their family members and the wider public in our research to ensure that it is relevant, acceptable and reflects the priorities of patients and their families. We are looking to expand this group, so if you are interested in finding out more, please contact our Patient Liaison Team at patientliaison@ehaat.org for further details.



Our Centre for Excellence Research Lead, Sarah McLachlan, works closely with our pre-hospital care doctors, critical care paramedics and charity staff, as well as colleagues at Anglia Ruskin University and in other pre-hospital care services. You can learn more about her work and our latest research projects below:

Predictors of post-intubation hypotension in trauma patients following prehospital emergency anaesthesia: a multi-centre observational study

James Price, Lyle Moncur, Kate Lachowycz, Rob Major, Liam Sagi, Sarah McLachlan, Chris Keeliher, Alistair Steel, Peter B. Sherren & Ed B. G. Barnard

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A multi-centre randomised controlled trial of the clinical and cost-effectiveness of pre-hospital whole blood administration versus standard care for traumatic haemorrhage.

Chief Investigators: Dr Laura Green (Barts Health NHS Trust) and Dr Jason Smith (Academic Department of Military Emergency Medicine); Primary sponsor: NHS Blood and Transplant; Funders: Air Ambulance Charities, NHS Blood and Transplant, Ministry of Defence.

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Trauma Emergency Thoracotomy for Resuscitation In Shock (TETRIS).

Leads: UK National Trauma Research and Innovation Collaborative, Pre-Hospital Trainee Operated Research Network, Trainee Emergency Research Network, National Helicopter Emergency Medical Service Research & Audit Forum. EHAAT Site Leads: Dr Charlotte Ashworth and Dr Sarah McLachlan.

Mental health and well-being of Helicopter Emergency Medical Service (HEMS) clinicians: a systematic literature review and national survey of current provision in UK HEMS.

Lead: Dr Sarah McLachlan (EHAAT, Anglia Ruskin University); Collaborators: Dr Ash Vasireddy (EHAAT), Professor Hilary Bungay (Anglia Ruskin University), Professor Chris Land (Anglia Ruskin University) and Mr Nigel Lang (Devon Air Ambulance); Funder: Health Performance and Wellbeing Research Innovation & Impact Strategic Research Theme Leadership Group, Anglia Ruskin University.

Determining the current top research priorities in UK pre-hospital critical care: a national modified Delphi study.

Lead: Dr Lisa Ramage (Pre-Hospital Trainee Operated Research Network); Collaborators: Dr Sarah McLachlan (EHAAT, Anglia Ruskin University), Mr Kristian Williams (Pre-Hospital Trainee Operated Research Network).

Recent Publications

The pre-hospital emergency anaesthetic in 2022.

Air Med J. 2022;00:1-6. doi: 10.1016/j.amj.2022.08.003

Morton S, Dawson J, Wareham G, Broomhead R, Sherren P.

A psychological resilience briefing intervention for Helicopter Emergency Medical Service observers.

Air Med J. 2022;00:1-7. doi: 10.1016/j.amj.2022.07.010

Walton M, McLachlan S, Nelson M, Skeffington P, Phillipson L, Christian MD.

Impact of enhanced personal protective equipment on safety and logistics of pre-hospital emergency anaesthesia during the COVID-19 pandemic: a retrospective crossover study.

Br J Anaesth. 2022;129(4):E102-E104. doi: 10.1016/j.bja.2022.07.006\

Dawson J, Humphrey J, Samouelle J, Sherren PB.

HEMS out of hospital cardiac arrests during the initial COVID-19 lockdown versus non-pandemic: a comparison.

Air Med J. 2022;41(1): 68-72. doi: 10.1016/j.amj.2021.10.012

Morton S, Dawson J, McLachlan S, McGuinness W.

Consensus on research priorities for Essex & Herts Air Ambulance: a Delphi study.

Scand J Trauma Resusc Emerg Med. 2021;29:25. doi: 10.1186/s13049-021-00835-z

McLachlan S, Bungay H.

Scoping the demand for night operation of Essex & Herts Air Ambulance: a prospective observational study.

Air Med J. 2021;40:28-35. doi: 10.1016/j.amj.2020.11.008

McLachlan S, Bungay H, Wallman S, Christian MD, Ley E, Fenton R.

A comparison of deliberate self-harm incidents attended by Helicopter Emergency Medical Services before and during COVID-19 in the East of England.

Emerg Med J. 2021;38:842-845. doi: 10.1136/emermed-2020-210393

Stevens J, Price J, Hazlerigg A, McLachlan S, Barnard, E.