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What is asthma?

Asthma is a condition that affects the airways – the small tubes that carry air in and out of the lungs. People with asthma have airways that are almost always red and sensitive (inflamed) (see Fig 1). When a person with asthma comes into contact with an asthma trigger, the muscle around the walls of the airways tightens, the lining of the airways becomes inflamed and starts to swell, often sticky mucus or phlegm is produced. All these reactions cause the airways to become narrower and irritated – leading to the symptoms of asthma.

What are the symptoms?

The usual symptoms of asthma are:

  • Coughing
  • Wheezing or a whistling noise in the chest
  • Shortness of breath
  • Tightness in the chest

Not everybody will get all these symptoms. Some people experience them from time to time. A few people may experience these symptoms all the time.

What are the treatments?

Relievers and Preventers are most commonly used to manage asthma.

Relievers (short-acting bronchodilators)

Everyone with asthma should have a reliever inhaler. Relievers are medicines that are taken immediately to relieve asthma symptoms. They relax the muscles surrounding the narrowed airways (usually within 5 to 10 minutes) making it easier to breathe again. If a reliever inhaler needs to be used more than once a day an additional preventer treatment may be needed to keep asthma symptoms under control.

Preventers (inhaled corticosteroids – ICS)

Preventers control the swelling and inflammation in the airways, stopping them from being so sensitive to asthma triggers and reducing the risk of a severe attack. The protective effect of preventer treatments builds up over time so it is important that the treatment is taken every day. If the preventer is taken regularly (as prescribed) the chances of controlling asthma symptoms will improve and reduce the likelihood of permanently damaging the airways.


How do bronchodilators and ICS work?

Relievers (short-acting bronchodilators)

In asthma the muscles around the airways constrict reducing the opening of the airways and making it difficult to breathe.

Bronchodilators relax these constricted muscles and open the airways.

Preventers (inhaled corticosteroids – ICS)

In asthma the airways become inflamed and fill with mucus.

ICS work by reducing the inflammation and helping to decrease the amount of mucus, opening the airways.

How are treatments delivered?

Asthma medicine is most commonly delivered by breathing it into the lungs. The advantage of inhaled therapy is that it reaches the target organ (airways) with minimal side effects. Inhaled therapy can be given by:

  • Pressurised metered dose inhaler (pMDI) sometimes called an inhaler or ‘puffer’
  • Dry powder inhaler (DPI) – a range of different inhalers exist eg. Accuhaler, Turbuhaler
  • Nebulizer compressor systems

Not all drug treatments are available for administration in DPIs and nebulizer compressor systems in all delivery forms.

What is a metered dose inhaler?

A metered dose inhaler (MDI) is a device for delivering medicine directly to the lungs. It consists of a pressurised metal canister containing a drug solution placed within a plastic case with a mouthpiece. When the canister is pushed down, a valve delivers a measured dose of medicine in a fine mist, this is inhaled into the lungs via the mouthpiece.

Common mistakes when using an inhaler

  • Not shaking the inhaler – the medicine in the canister is mixed with a solution which helps it to become an aerosol. Sometimes the medicine and solution can separate out and if your inhaler is not shaken before use, your child may not get all their medicine.
  • Pressing the canister at the wrong time when breathing in – your child will need to press the canister down as they first start breathing in, not at the end of taking a breath, otherwise there is a risk that the drug will end up in their mouth or upper airways and not in the correct part of their lungs.
  • Pressing the canister more than once with each breath.

What is a chamber?

A chamber (also known as a spacer) is a plastic container which has a mouthpiece at one end and a hole at the other end for inserting the inhaler. The medicine from the inhaler is sprayed into the chamber and it can then be inhaled via the mouthpiece on the chamber.

What is the benefit of using a chamber?

It is often very difficult to use an inhaler correctly because the canister needs to be pressed at the same time as breathing in. The medicine comes out of the inhaler very quickly so, if a breath is not taken at the right time, it can end up in the mouth or throat where it can cause side effects such as a sore throat.

A chamber is a device designed to make an inhaler easier to use as there is no need to breathe and fire the cannister at the same time. A chamber helps to deliver more medicine directly into the lungs where it is needed.

How to use a chamber

The following is a guide to using a Philips Respironics OptiChamber Diamond valved holding chamber and LiteTouch facemask. Click here to find out more about your child’s chamber.

  1. We hope you found this ‘How to guide’ helpful. Feel free to download the PDF using the button below.

  2. 1

    Remove the caps from the inhaler and the Diamond chamber. Look for and remove any foreign objects in the chamber.

  3. 2

    Insert the mouthpiece of your inhaler securely into the back of the Diamond chamber.

  4. 3

    If a facemask is needed, place the facemask onto the mouthpiece end and gently twist until it fits securely.

  5. 4

    Shake the chamber and inhaler 4 – 5 times, this will help to mix the medication inside.

  6. 5

    Place your lips around the mouthpiece to form a tight seal. Exhale. Spray one puff of medicine into the chamber and immediately begin to inhale slowly, taking a full deep breath.*

    *If your doctor has instructed you to take more than one puff of medication, wait for one minute and then repeat steps 5–8.

  7. 6

    If the flow alert ‘whistle’ sounds, breathe in more slowly. Hold your breath for up to 8 seconds and then breathe out.

  8. 7

    Or if using a facemask, press and hold the facemask over the mouth and nose. Spray one puff of medicine into the chamber and breathe in and out for 6 breaths.*

    * If your doctor has instructed you to take more than one puff of medication, wait for one minute and then repeat steps 5 – 8.

  9. 8

    The exhalation valve will open when the user breathes out, which can help you to count the breaths.

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Should a facemask or a mouthpiece be used?

Babies and all young children, who cannot use a mouthpiece of the chamber, should be encouraged to use a facemask. It is important that the facemask fits comfortably on your child’s face, providing a good fit, to help them receive the proper dose of inhaler medication.

To use the mouthpiece effectively your child needs to be able to firmly close their teeth and lips around the mouthpiece and be able to take one full inhalation and breath hold. Young children, or children who cannot do this, will need to use a facemask.

Once your child is able to use the mouthpiece of the chamber correctly, the facemask can simply be removed.

Importance of a good fitting facemask

A comfortable, well fitting facemask is important to help the medication reach the lungs where it is most effective.

Asthma treatments can sometimes be unsettling for children and they may be frightened by a facemask being held over their nose and mouth. However, it is important that the facemask is held on the face to reduce medication leaking out during a treatment. Offering praise, encouragement and reassurance may help a child to take their asthma medication.

What is peak flow?

Peak flow is a measure of how fast you can blow air out of your lungs. People with asthma who are well, will have airways that are open, so they will be able to blow air out of their lungs quickly. They will have a high peak flow reading. If their asthma is not controlled, their airways will be narrowed so they will not be able to blow air out so fast. This will then mean that their peak flow readings will be lower.

How is Peak Flow measured?

Peak flow is measured using a small handheld device called a peak flow meter. There are two types – electronic ones and also mechanical ones (non-electronic). The non-electronic ones generally have a moveable marker alongside a scale. The scale is in units of litres per minute (lpm). When you blow into the mouthpiece the small marker will move depending on how fast you are blowing out. Where the marker ends up, is your peak flow reading. The highest reading from three attempts should be recorded as the peak flow reading.

How to use a Peak Flow Meter

The following is a guide for using a Philips Respironics PersonalBest peak flow meter.

  1. We hope you found this ‘How to guide’ helpful. Feel free to download the PDF using the button below.

  2. 1

    Remove top cover.

  3. 2

    Swing the bottom hinged cover down and click the two halves together to form a handle.

  4. 3

    Slide the red indicator to the bottom of the scale.

  5. 4

    Stand up and breathe in as deeply as you can. Place your mouth around the mouthpiece so your lips form a tight seal. Blow as hard and as fast as you can.

  6. 5

    The number where the indicator stops is your peak flow measurement. Repeat from step 3 and take 3 measurements.

  7. 6

    Record the highest measurement in your daily record chart, noting the time and date.

Download PDF

3 zone traffic light system

Your doctor will set the colour zone indicators based on your child’s personal best peak expiratory flow rate (the best peak flow measurement your child can achieve when their asthma is under control). Your child’s peak flow measurement will fall into one of three zones, as shown above.

What is nebulizer therapy?

Nebulizer therapy is a way of treating illnesses that affect the lungs and cause breathing problems, such as asthma. If your child has been prescribed liquid medications for inhalation, nebulizers are used in order to change the liquid into a fine mist which allows it to reach deep into the lungs where it can be most effective.

What is a nebulizer?

The nebulizer (sometimes called a medication cup) is the part of the system that changes the medication into a fine mist. The compressor provides a flow of air to the nebulizer, enabling it to create the mist.

Nebulizers come in a range of designs. Click here to find out more.

Girl using nebulizer with family

What is a compressor?

The compressor is a pump that draws in air and blows it out at high pressure into the nebulizer to produce a fine mist of medication that can be breathed in.

A compressor is electrically powered by the mains socket in your home or, if it is a portable compressor, it may also have a separate battery or a AC/DC charger.

How do nebulizers and compressors work together?

Nebulizers are designed to perform best when driven by a compatible compressor. This is called a ‘matched system’. Click on the image opposite to see how a nebulizer and a compressor system operates.

The importance of particle size

The fine mist created by a nebulizer is made up of thousands of particles – but they are not all the same size.

The particles that make up the mist are so small that they are measured in microns (µm) which is equal to a thousandth of a millimetre. To travel deep into the lungs, the particles that are breathed in need to be within the size range of 1 and 5 microns. This is extremely small when you consider that the average human hair is around 50 microns across. If the particles are not between 1 and 5 microns it is unlikely that they will reach the area of the lungs where they can be most effective.

How to use a nebulizer compressor system

The following is a basic guide for using a Philips Respironics compressor with a SideStream nebulizer.

Please refer to the instructions for use provided within your child’s nebulizer compressor system for more details.

  1. 1

    Remember to relax as much as possible. Sit upright in a chair or in bed. When you are ready, turn on the compressor using the on/off switch and take normal steady breaths.

  2. 2

    Should you need to stop midway through your treatment, turn off the compressor using the On/Off switch and place the nebulizer in its holder located on the compressor. This will prevent the nebulizer from falling over causing drug to spill out.

  3. 3

    Turn off the compressor when your nebulizer begins to make a ‘spluttering’ noise.

    Your treatment has now finished.

  4. 4

    Plug your compressor into the electrical supply, then connect one end of the long tubing onto the airflow outlet on your compressor.

  5. 5

    Push the other end of the long tubing onto the stem at the bottom of your SideStream nebulizer.

  6. 6

    Unscrew the two halves of the SideStream nebulizer.

  7. 7

    Remove the medication from the pack and pour into the bottom part of the SideStream nebulizer. Make sure all of the contents are emptied out.

    Please note: if you have been instructed to dilute the solution, add the amount of saline as instructed.

  8. 8

    Screw the two halves of the nebulizer back together.

  9. 9

    Connect either the mouthpiece or the mask to the top of the SideStream nebulizer.

    If using a facemask, hold it over your mouth and nose whilst placing the elastic strap around the back of your head.

    If using a mouthpiece, place it between your lips.

Download PDF

Should a facemask or a mouthpiece be used?

Babies and all young children, who cannot use the mouthpiece accessory on the nebulizer compressor system, should be encouraged to use a facemask. It is important that the mask fits comfortably on your child’s face, providing a good fit, to help them receive the proper dose of inhaler medication.

To use the mouthpiece effectively your child needs to be able to firmly close their teeth and lips around the mouthpiece and slowly breath in and out during the treatment. Young children, or children who cannot do this, will need to use a facemask.

Looking after the nebulizer

A small amount of drug always remains in the medication cup after treatment. This should be emptied and cleaned to prevent the medication from crystallizing and blocking the nebulizer jets. If not cleaned, the performance of the nebulizer will decline as it cannot work as efficiently.

  1. Remove the tubing and the mouthpiece or facemask from the nebulizer. Unscrew the nebulizer into two parts.
  2. If a facemask has been used, wipe it with a damp cloth.
  3. Wash the nebulizer and mouthpiece in warm, soapy water (dish washing liquid). Rinse under clean, cold running water and shake off any excess water.
  4. Please note that reusable nebulizers should be boiled with two drops of dish washing liquid for 10 minutes once a week to ensure optimum performance.
  5. It is essential that the nebulizer parts are completely dry before reassembly.
  6. Store the nebulizer parts between uses in a clean, dry, environment.
  7. Replace the accessories regularly, as specified in the instructions for use.
  8. Never use a cleaning brush or sharp objects when cleaning because this will damage the nebulizer.

Remember: make sure to clean the nebulizer after every use to maintain its performance.

Why is it important to replace the nebulizer?

The nebulizer should be replaced regularly to ensure that a good fast treatment is achieved. If the nebulizer is not replaced as required, the nebulizer will stop working efficiently. This will mean that the medicine cup may wear and produce larger aerosol particles that may not reach the lungs; treatment times may become longer; and germs may start to grow.

The instructions for use included in the current nebulizer will indicate when to replace it, but most disposable nebulizers should be replaced after one month, and most reusable nebulizers between 6 and 12 months.

Looking after the compressor

Always keep the compressor on a firm surface, such as a table, when in use. Do not place the compressor on the carpet, to avoid dust being drawn in. Be careful not to block the vents on the sides of the compressor, otherwise air cannot be drawn in. Keep the compressor clean and free from dust by wiping with a damp cloth.

The air inlet filter on the compressor gets dirty over time and should be changed at least every 3 months (more often if a member of the household smokes). If the filter is blocked, the compressor will be less efficient.

If the filter is a colour similar to, or darker than, the box on the right, it is time to change the filter. Please consult the instructions for use supplied with the compressor for more details on correct maintenance and cleaning procedures.

Please be aware that the information given within this website is only intended as general advice and should in no way be taken as a substitute for professional medical advice. Symptoms or conditions which are severe or persistent require professional medical assistance.