We commonly use filters in our airway circuits #AirwayNerds so what do we know about them?


Well the Yellow one on the LEFT is a Bacterial filter designed to protect the proximal parts of the ventilation circuit (Not needed in a BVM based circuit if all items used are disposable) or to protect an Entonox/Nitronox administration system ( The exhalation port of the Regulator which is reusable) from contamination carried by patient exhalation and for this purpose it is the right item BUT is often the ONLY one stocked by UK ambulance services.


If you wish to protect your Waveform ETCO2 Sidestream or Mainstream Adaptor from moisture AND prevent the drying and cooling effects of pressurised oxygen when ventilating a patient using a BVM or Mechanical Ventilator then the PATIENT needs the Green one on the RIGHT which is an HME (Heat and Moisture Exchange) Filter. I only know of ONE UK ambulance service that stocks both types for appropriate use but of course there may be more??


P.S If you were not aware of the above differences it is not necessarily your fault but is down to the people educating you and making decisions on clinical kit purchase on your behalf!


P.P.S Both dependent on the manufacturer in ADULT sizes ADD about 60 Mls of DEAD AIR SPACE which is VERY important knowledge for #AirwayNerds when it comes to Paediatrics.