single-patient use mouthpieces
those with a barrier filter
those with a one way valve
In order to prevent the equipment becoming a source of infection for subsequent patients to contract, there needs to be a barrier between the patient and the equipment.
Barrier filters have been used in ventilation equipment for many years to reduce infection risks but they have only recently been implemented into lung function mouthpieces.
There are two types of barrier filters used in mouthpieces:
Bacterial filters have been shown to trap 99.9% of micro-organisms up to flow rates of 750 litres per minute. However, there are no filters that are efficient enough to eliminate the need to clean the equipment beyond the filter.
Reusable mouthpieces must be cleaned appropriately to remove extraneous materials such as saliva and lipstick, then disinfected to remove micro-organisms and finally dried thoroughly to remove water marks. Disinfection methods depend on the material of the mouthpiece; chlorine based chemical disinfection or the use of a standard dishwasher is sufficient for plastic or rubber mouthpieces.
Where only an expiratory manoeuvre is required, such as in a peak flow meter or expiratory forced vital capacity measurement, a disposable mouthpiece with a one way valve allowing only expiration may be sufficient to prevent cross infection.