Continuous Positive Airways Pressure

Acute pulmonary oedema (APO), most often due to heart failure, is potentially life-threatening. Fluid leaks into the lungs causing extreme breathlessness and distress. Continuous positive airways pressure (CPAP) applied by face mask is an integral part of hospital treatment but better patient outcomes may be achieved when CPAP is applied earlier by paramedics in the pre-hospital setting. This clinical trial aims to compare patient outcomes for patients with severe APO who receive CPAP to those who receive usual care in the pre-hospital setting. Ultimately this study aims to improve pre-hospital and emergency clinical management of patients who suffer APO.

Principal Researcher:

Dr Teresa Williams

Associate Investigators:

Professor Ian Jacobs (Curtin), Professor Judith Finn (Curtin), Associate Professor Glenn Arendts (UWA) and Dr Quentin Summers (RPH)

Year Commenced: 2012

Year Completed: In progress

Funding: UWA Research Development Grant – 2012 ($29,619)

Ethics Approval: RA/4/1/5065 – 27 January, 2012

Duration: 1 Year


Acute pulmonary oedema (APO) is a potentially life-threatening medical emergency. Fluid leaks from the pulmonary capillary network into the lung interstitium and alveoli. Severe APO requires immediate treatment. CPAP is an integral part of the hospital treatment of APO. This non-invasive medical therapy maintains positive airway pressure during spontaneous ventilation throughout the whole respiratory cycle and reduces the work of breathing. Applied by face mask, CPAP has been shown to improve outcomes. This non-randomised comparative clinical trial aims to:

  1. compare patient outcomes for patients with severe APO who receive CPAP and usual care (experimental group) to those who only receive usual care (control group) in the pre-hospital setting; and
  2. test the proof of concept to inform a larger, multicentre RCT. It is hypothesised that patients who receive CPAP will have improved patient outcomes.

The primary outcome is a 20% reduction in the respiratory rate immediately prior to arrival at the emergency department (ED). Secondary outcomes include improved arterial oxygen saturation, and decreased intubation rate in ED, number of ICU admissions, hospital length of stay (LOS) and in-hospital mortality.

Status: In progress

Contact Person: Dr Teresa Williams – email: