Tables
- TABLE 1
Spacer/valved holding chamber features or characteristics
Size/volume
Shape
Presence of valve(s)
Material of manufacture
Mode of interface with the patient
Presence of feedback devices or mechanisms
pMDI-specific or universally adaptablepMDI: pressurised, metered-dose inhaler.
- TABLE 2
Advantages and disadvantages of a spacer/valved holding chamber (VHC)
Advantages Slows down the aerosol cloud as it emerges from the pMDI Reduces impact of hand–breath (activation–inhalation) coordination problems Longer propellant evaporation time reduces particle size (increases respirable fine-particle fraction) and improves lung deposition Filters out larger aerosol particles Reduces oropharyngeal impaction/deposition and local side-effects (inhaled corticosteroids) Reduces fraction of swallowed drug, gastrointestinal absorption, systemic bioavailability and thus extrapulmonary unwanted effects (β-adrenergic agonists) VHCs can be used with tidal breathing, administered by a care giver For the very young (using a face mask) and any patient where coordination is a challenge During acute exacerbations (replacing nebulisers) Disadvantages Require regular cleaning Large-volume spacer/VHC devices are more bulky and less portable Electrostatic charge may reduce the respirable aerosol fraction More expensive (but may save medication) pMDI: pressurised, metered-dose inhaler.
- TABLE 3
Washing and cleaning a spacer/valved holding chamber (VHC)
1) Disassemble the spacer/VHC after the last dose of the day 2) Immerse the parts in lukewarm tap water containing a few drops of household detergent 3) Shake the parts in the water and rub them with a soft cloth 4) Leave the parts soaking for 15 min, then take them out of the water 5) Do not rinse or dry rub the inside of the parts 6) Rinse soapy water off the mouthpiece 7) Place the parts on a clean towel to air-dry overnight 8) Reassemble the parts the next morning and check that the valve is not stuck 9) Wash your spacer/VHC every week
