Figures
- FIGURE 1.
Diagrammatic scale contrasting ease of use with ease of preparation. pMDI: pressurised metered-dose inhaler; BA pMDI: breath-actuated pMDI; DPI: dry powder inhaler; SMI: soft mist inhaler.
Tables
- TABLE 1—
Correct techniques for different types of inhaler and the errors patients are known to make
Device Correct technique Errors in technique “Press and breathe” pMDI Remove mouthpiece cap Failure to remove mouthpiece cap* Shake inhaler (suspensions only) Inhaler not shaken Hold inhaler upright Inhaler upside down* Breathe out No exhalation Place mouthpiece between lips Fire while breathing in deeply and slowly Firing device before start of inhalation Firing device at or after end of inhalation* Inhaling through nose* Continue to inhale after firing Stopping inhalation as device is fired* Fast inhalation Hold breath (10 s) No/short breath-hold Breath-actuated pMDI Remove mouthpiece cap Failure to remove mouthpiece cap* Shake inhaler (suspensions only) Inhaler not shaken Hold inhaler upright Inhaler upside down* Prepare device (e.g. lift lever) Failure to prepare device correctly* Breathe out No exhalation Place mouthpiece between lips Poor seal around mouthpiece Using “open mouth” inhalation technique* Breathe in deeply and slowly Weak inhalation, failure to trigger device* Inhaling through nose* Continue to inhale after firing Stopping inhalation as device is fired* Fast inhalation Hold breath (10 s) No/short breath-hold “Press and breathe” pMDI plus spacer Inappropriate handling (static charge) Remove mouthpiece cap Failure to remove mouthpiece cap* Shake inhaler (suspensions only) Inhaler not shaken Hold inhaler upright Inhaler upside down* Insert pMDI into spacer Breathe out No exhalation Fire while breathing in deeply and slowly Long delay before inhalation Multiple actuation Weak inhalation, failure to open valve* Inhaling through nose* Continue to inhale after firing Stopping inhalation as device is fired* Fast inhalation Hold breath (10 s) No/short breath-hold DPIs Remove cover (device specific) Failure to remove cover* Load dose (device specific) Incorrect dose loading* Pierce capsule (single-dose devices) Failure to pierce capsule* Breathe out Breathing out into device* Place mouthpiece between lips Inhalation vents blocked¶ Poor seal round mouthpiece Using “open-mouth” inhalation technique* Inhale deeply and quickly Not inhaling quickly enough* Insufficient “acceleration” Inhaling through nose* Hold breath (10 s) No/short breath-hold Store in cool dry place Inappropriate storage Respimat® Soft MistTM Inhaler# Hold upright and turn base Failure to prime device/load dose* Open mouthpiece cap Failure to open mouthpiece cap* Breathe out No exhalation Put mouthpiece between lips Mouthpiece vents blocked¶ Press dose release button while breathing in deeply and slowly Firing device before start of inhalation Firing device at or after end of inhalation* Inhaling through nose* Continue to inhale after firing Stopping inhalation as device is fired* Fast inhalation Hold breath (10 s) No/short breath-hold pMDI: pressurised metered-dose inhaler; DPI: dry powder inhaler. *: crucial error, likely to result in zero lung deposition of drug; #: manufactured by Boehringer Ingelheim GmbH & Co. KG, Ingelheim, Germany; ¶: error that may be crucial.
- TABLE 2—
Advantages and disadvantages of different inhaler devices
Device Advantages Disadvantages “Press and breathe” pMDI Compact Contains propellants Portable Not breath-actuated 100+ doses Many patients cannot use it correctly (e.g. coordination difficulties, “cold Freon” effect) Convenient Usually low lung deposition/high oropharyngeal deposition Quick to use Relatively cheap Cannot contaminate contents Breath-actuated pMDI Compact Contains propellants Portable “Cold Freon” effect 100+ doses Usually low lung deposition/high oropharyngeal deposition Convenient Quick to use Breath-actuated (no coordination needed) Cannot contaminate contents “Press and breathe” pMDI plus spacer 100+ doses Contains propellants Quick to use Not very portable or convenient Easier to coordinate Not breath-actuated Tidal breathing often OK Plastic spacers may acquire static charge Less oropharyngeal deposition Usually higher lung deposition than a pMDI DPI Compact Work poorly if inhalation is not forceful enough Portable Many patients cannot use them correctly (e.g. capsule handling problems for elderly) Convenient (multi-dose devices) Most types are moisture sensitive Quick to use Breath-actuated (no coordination needed) Usually higher lung deposition than a pMDI Do not contain propellants Respimat® Soft MistTM Inhaler* Compact Not breath-actuated Portable Not currently available in most countries Multi-dose device (1 month's supply) Convenient Probably easier to use correctly than pMDI High lung deposition Does not contain propellants pMDI: pressurised metered-dose inhaler; DPI: dry powder inhaler. *: manufactured by Boehringer Ingelheim GmbH & Co. KG, Ingelheim, Germany.
- TABLE 3—
Crucial errors in inhaler use
Error Devices affected pMDI BA pMDI pMDI + spacer DPI Respimat® Soft MistTM Inhaler§ Failure to remove mouthpiece cap or device cover ✓ ✓ ✓ ✓ ✓ Incorrect preparation/priming of device or loading of dose* ✓ ✓ ✓ Failure to pierce capsule ✓# Inhaler upside down ✓ ✓ ✓ Breathing out into device* ✓ Firing device at or after end of inhalation* ✓ ✓ Open-mouth inhalation technique ✓ ✓ Weak or very slow inhalation* ✓¶ ✓+ ✓ƒ Inhaling through nose ✓ ✓ ✓ ✓ ✓ Stopping inhalation as device is fired* ✓ ✓ ✓ ✓ pMDI: pressurised metered-dose inhaler; BA pMDI: breath-actuated pMDI; DPI: dry powder inhaler. *: common errors; #: single-dose devices; ¶: failure to trigger device; +: failure to open spacer valve; ƒ: too slow to aerosolise the dose; §: manufactured by Boehringer Ingelheim GmbH & Co. KG, Ingelheim, Germany.
- TABLE 4—
Common requirements for all devices reviewed
Remove mouthpiece cap if present Orientate inhaler correctly (e.g. upright for pMDI) Breathe out Place mouthpiece between lips Breathe in deeply and slowly*,# Hold breath for 10 s pMDI: pressurised metered-dose inhaler. *: breathe in deeply and quickly for dry powder inhalers; #: for “press and breathe” pMDI, actuate inhaler while breathing in.
