The Ventilation Accuracy in NEAS using Zoll feedback (VANZ2)

An out of hospital cardiac arrest (OHCA) occurs when the heart suddenly stops beating.  NHS ambulance services attend approximately 30,000 such incidents annually to provide a treatment called resuscitation.  Despite the efforts of the ambulance services, less than 1 in ten people survive.

When a patient’s heart stops their body becomes deprived of oxygen.  One of the treatments a paramedic will undertake during a cardiac arrest is to provide support for the patients breathing, which involves inserting a tube into the patient’s mouth, and squeezing a bag inflated with oxygen to assist or take over a patient’s breathing.   

When delivering oxygen, it is important to deliver the right amount.  The European Resuscitation Council (ERC) provides guidance about how much oxygen to deliver with each rescue breath, and how often each breath should be delivered, although it is very difficult for paramedics to adhere to this guidance as until recently it has been impossible to know exactly how much oxygen is being delivered.

Previous research suggests paramedics frequently deliver too much oxygen and this is known to be detrimental to survival and that paramedic compliance with guidelines can be improved with visual feedback. 

A new feedback device has been developed that attaches to the tube that is inserted into the patient’s mouth.  The other end of the device connects to the defibrillator screen used by paramedics.  When a paramedic squeezes the bag to deliver oxygen, the amount of oxygen delivered appears on the screen, so the paramedic can respond to any under or over delivery of oxygen.  A five second counter tells the paramedic when to squeeze the bag at the right time.

North East Ambulance is undertaking a research project involving paramedics from Blucher, Middlesbrough and Redcar ambulance stations to see if the feedback device improves the care patients receive.  

If you are aged 18 years or over, are not pregnant, not involved in a traumatic incident and suffer an OHCA, you may be involved in this research.  This means we may collect information about you and your care. 

If you would like more information about this research or if you decide you do not wish to participate, please contact the chief investigator Karl Charlton on, telephone 0191 430 2294, or write to Karl Charlton, North East Ambulance Service NHS Foundation Trust, Ambulance Headquarters, Bernicia House, Goldcrest Way, Newburn Riverside, Newcastle upon Tyne, NE15 8NY.

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