Ambulance CPAP: Use, Treatment effect and Economics

ACUTE (Ambulance CPAP: Use, Treatment effect and Economics) feasibility study: A pilot randomised controlled trial of prehospital CPAP for acute respiratory failure.

ACUTE project logo


Acute respiratory failure (ARF) is a common and life-threatening medical emergency that often results in long hospital stays or expensive intensive care admissions. It occurs when heart or lung disease suddenly develops or worsens and leads to the patient being unable to maintain oxygen levels in their blood. When this happens the patient may be at high risk of death and needs emergency treatment.

Paramedics currently provide oxygen delivered at normal pressure by a loose fitting face mask. Continuous positive airway pressure (CPAP) is a potentially useful treatment that could be delivered by paramedics in an ambulance. It involves delivering oxygen under increased pressure through a close-fitting facemask. Its use in hospital can reduce the risk of death in people with lung disease and improve breathing in people with heart disease. Small studies undertaken outside the UK have suggested that using CPAP in an ambulance may save more lives than delaying its use until arrival at hospital. However, it is uncertain whether this treatment could work effectively in NHS ambulance services, and if it represents value for money.


The purpose of this study is to see whether it is possible and worthwhile to undertake a full-scale study comparing CPAP and standard oxygen treatment delivered by paramedics for acute respiratory failure, and if so, how we should do it.


Paramedics will identify adults with ARF when attending 999 emergency calls. One hundred and twenty such patients will be included in the study. Half will be randomly assigned to a group that will receive CPAP, while the other half will be treated with standard oxygen therapy. All the patients will then undergo normal hospital treatment and be followed up for a month to see if they survive. We will also measure each patient’s quality of life, need for admission to intensive care, length of stay in hospital, and health service use.

Additionally, we will look at how many adults are attended with ARF, how many are entered into study, the number who correctly receive CPAP treatment, and how many patients we can follow up to the end of the study. Paramedics will also be surveyed to understand their experience of delivering CPAP and being involved in the research. Together these results will tell us whether it is feasible and affordable to conduct a full -scale trial evaluating CPAP for acute respiratory failure, and will also inform us how to design such a study.


The proposed study will be designed and conducted in accordance with Good Clinical Practice (GCP), an international standard that ensures medical research is safe and ethical. The main ethical issue is that the trial will involve patients who are severely ill and potentially unable to decide whether they wish to participate. In these circumstances patients can be recruited to the trial and their consent sought later, provided important legal safeguards are followed. All research procedures will be reviewed by an independent NHS ethics committee and overseen by committees of independent statisticians and clinical experts in the field. Additionally, the research will conform to University of Sheffield Clinical Trials and Research Unit (CTRU) standard operating procedures. We will publish our results in scientific journals and publicise our findings through the Study website and on social media.

If you would like more information about the trial, please contact:

Dr Samuel Keating on +44 114 222 5156 or

Project team

  • Dr Gordon Fuller
  • Prof Steve Goodacre
  • Dr Sam Keating
  • Prof Cindy Cooper
  • Mike Bradburn
  • Sarah Gonzalez
  • Prof Gavin Perkins
  • Prof Tim Harris
  • Dr Praveen Thokala
  • Matt Ward
  • Dr Andy Carson
  • Andy Rosser
  • Imogen Gunson
  • Joshua Miller


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