Asthma: Why Inhaler Technique Matters More Than Which Inhaler
Studies of inhaler technique repeatedly find that a large majority of users make at least one error that substantially reduces the dose reaching the lungs. Before changing the drug, it is worth checking whether the drug is arriving.
What asthma is
Asthma involves chronic inflammation of the airways, which makes them hypersensitive. Triggers cause three things: the muscle around the airways tightens, the lining swells, and mucus production increases. The airway narrows and breathing becomes difficult.
The key insight for treatment is that the muscle tightening is the acute event, but the inflammation is the underlying disease. Treating only the tightening leaves the disease running.
The two kinds of inhaler
Reliever, usually blue. A short-acting bronchodilator such as salbutamol. It relaxes the airway muscle within minutes. It does nothing to the inflammation.
Preventer, often brown, orange or purple. Contains an inhaled corticosteroid, sometimes combined with a long-acting bronchodilator. It reduces inflammation over days and weeks. It does not help during an attack.
The most common and most dangerous pattern in asthma care is a person who relies on the reliever and skips the preventer because the reliever “works” and the preventer “does nothing”. The preventer is doing the work that prevents the attack from happening.
Warning sign: needing a reliever more than twice a week, or getting through more than about three reliever canisters a year, indicates poorly controlled asthma and is associated with increased risk of severe attacks. It is a reason to review treatment, not to buy more relievers.
Current guidance in many countries has moved away from reliever-only treatment entirely, towards combination inhalers containing a steroid plus formoterol used both as maintenance and as reliever, so that every rescue dose also delivers anti-inflammatory treatment.
Technique, step by step
Pressurised metered-dose inhaler, the standard canister:
- Remove the cap and shake well
- Breathe out fully, away from the inhaler
- Place the mouthpiece between your teeth and seal your lips around it
- Start to breathe in slowly and deeply, and press the canister once as you begin the breath
- Keep breathing in slowly for three to five seconds
- Hold your breath for ten seconds, or as long as comfortable
- Breathe out slowly
- Wait about 30 seconds before a second dose
- Rinse your mouth and spit after steroid inhalers
The commonest errors are not breathing out first, pressing before or after the breath rather than at its start, breathing in too fast, and not holding the breath.
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Use a spacer with a metered-dose inhaler whenever possible. It dramatically improves delivery, removes the need to coordinate press and breath, and reduces the amount deposited in the mouth and throat. With a spacer, children and anyone struggling with timing can take several normal breaths through it instead.
Dry powder inhalers need the opposite breath: a fast, forceful inhalation rather than a slow one. Using DPI technique on a metered-dose inhaler, or the reverse, wastes most of the dose. Know which type you have.
Why mouth rinsing matters
Inhaled steroid deposited in the mouth and throat causes oral thrush and hoarseness. Rinsing and spitting after each steroid dose prevents most of this. Using a spacer reduces it further.
Controlling triggers
Common ones: respiratory viruses, which cause most severe attacks; dust mites; pollen; pets; cold air; exercise; smoke, including incense and cooking smoke; air pollution; strong fragrances; NSAIDs in a subset of people; and stress.
Practical measures include treating associated allergic rhinitis, which worsens asthma control when untreated, managing reflux if present, annual influenza vaccination, avoiding smoking and second-hand smoke, and allergen-specific measures where allergy is confirmed.
Exercise-induced symptoms are usually a sign of inadequate control rather than a reason to stop exercising. Well-controlled asthma should permit normal activity and sport.
Recognising a severe attack
Seek emergency care for:
- Difficulty speaking in full sentences
- Reliever not helping, or wearing off within an hour or two
- Lips or fingertips turning blue
- Drowsiness, confusion or exhaustion
- Ribs visibly pulling in with each breath
- Peak flow below 50 per cent of personal best
- A silent chest on listening, which is an ominous sign rather than a reassuring one
While waiting for help: sit upright, do not lie down. Take one puff of reliever through a spacer every 30 to 60 seconds, up to ten puffs. Stay as calm as possible. Call for emergency help if there is no improvement after ten puffs.
Severe attacks sometimes build over days rather than minutes, with gradually increasing reliever use and worsening night symptoms. Those are the ones that get underestimated.
The asthma action plan
Everyone with asthma should have a written personalised action plan setting out daily medicines, what to do when symptoms worsen, when to start oral steroids if prescribed, and when to seek emergency care. Having one reduces hospital admissions. Many people have never been given one; asking for it at the next review is worthwhile.
Reasons control is poor
Before concluding the medicine has stopped working, check:
- Inhaler technique, demonstrated in front of a clinician rather than described
- Adherence, honestly
- Whether the preventer is being taken daily even when well
- Untreated nasal allergy
- Smoking, which reduces steroid responsiveness
- Reflux
- Obesity
- Exposure to a trigger at home or work
- Beta blockers or NSAIDs where relevant
The short version
The reliever treats the symptom, the preventer treats the disease, and using the reliever often is a sign the disease is not controlled. Use a spacer, breathe slowly for a metered-dose inhaler and fast for a powder one, rinse after steroids, and get a written action plan. If treatment seems to be failing, check the technique before changing the drug.