An inhaler is a device for the administration of an inhalation. Various inhalers and formulations have been developed to help ensure the efficient delivery of drugs, simply and with minimal side-effects (Rees and Kanabar, 2006). Nurses are well placed to advise patients on how to use inhalers and to monitor their technique.
VOL: 103, ISSUE: 36, PAGE NO: 24
Phil Jevon, PGCE, BSc, RN, is resuscitation officer/clinical skills lead, Manor Hospital, Walsall, and honorary clinical lecturer, University of Birmingham Medical School
Nicola Humphrey, RN, is respiratory nurse specialist, Manor Hospital, Walsall
Types of inhalers
Pressurised metered dose inhalers (pMDIs) are the most commonly used inhaler. They are small, convenient, easy to carry and can be used to deliver a wide range of medications (Newell and Hume, 2006). However, the technique for using them can be difficult to master as it involves coordinating actuation and inhalation efficiently, and inhaling at the correct inspiratory flow rate (Pearce, 2000).
Some patients, particularly older people and small children, find pMDIs difficult to use (British Medical Association and Royal Pharmaceutical Society of Great Britain, 2007), as do some people with arthritis (Rees and Kanabar, 2006). Their use should therefore be restricted to patients who can consistently demonstrate the ability to use them correctly (Pearce, 2000).
With the exception of the Seretide Evohaler, pMDIs do not have a dose counter and some users find it difficult to estimate when they are nearly empty (Newell and Hume, 2006).
Breath-actuated inhalers (Autohaler and Easi-Breathe) are also small and easy to carry. As inhalation via the mouthpiece triggers the release of medication, they do not require actuation and inhalation to be coordinated - an obvious advantage over pMDIs (Newell and Hume, 2006). Dry power inhalers, for example Accuhaler and Diskhaler, deliver medication in the form of a dry powder. They are also automatically activated by the patient’s inspiratory effort. Although they are popular and generally easy to use, some require a fairly high respiratory flow rate in order to be activated (Newell and Hume, 2006).
Inhalers are designed to deliver the correct dose of an inhalation to an appropriate part of the airway. Even when a pMDI is used properly only 10% of the drug reaches the airways below the larynx; 50% is deposited in the mouth with close to 90% eventually being swallowed (Currie and Douglas, 2006; Rees and Kanabar, 2006).
Drugs administered using an inhaler
Drugs that can be administered using an inhaler include:
- Short-acting beta2 agonists, such as salbutamol, which causes bronchodilation, improving lung function and reducing breathlessness for up to six hours;
- Long-acting beta2 agonists, such as salmeterol, which are effective for up to 12 hours;
- Short-acting anticholinergics, such as ipratropium, which relax smooth muscle and cause bronchodilation, improving lung function and reducing breathlessness for up to six hours;
- Long-acting anticholinergics, such as tiotropium, which are effective for up to 24 hours (Currie and Lipworth, 2006).
Procedure for the use of a PMDI
Check the drug prescription sheet follows local policy.
- Explain the procedure to the patient.
- Ask the patient to remove the mouthpiece cover from the inhaler.
- Ask the patient to shake the pMDI and then breathe out.
- Advise the patient to place the mouthpiece into their mouth and close their lips and teeth around it.
- At the start of inspiration, ask the patient to press the canister down while inhaling slowly and deeply.
- Advise the patient to remove the mouthpiece from their mouth and then to close their lips.
- Ask the patient to hold their breath for up to 10 seconds and then breathe out normally.
- If a second dose is required, wait 30-60 seconds and repeat the above steps before replacing the cover.
- Document that the medication has been administered.
- The use of a pMDI with a spacer device is recommended for some patients.
It is not possible to describe the use of all the different inhalers that are currently available, so it is important to refer to manufacturers’ recommendations.
Teaching and monitoring
Patients should be carefully instructed on how to use their inhaler and it is important to ensure they continue to use it correctly as poor technique may be mistaken for a lack of response to the prescribed drug (BMA and RPSGB, 2007). Each patient’s technique should be reassessed at every available opportunity as many patients become less proficient over time (Currie and Douglas, 2006). Asthma UK’s website (www.asthma.org.uk) contains detailed advice on how to use inhalers, which patients may find helpful.
This article has been double-blind peer-reviewed.
This procedure should be undertaken only after approved training, supervised practice and competency assessment, and carried out in accordance with local policies and protocols.