Inhaler Devices in Asthma

Asthma is caused by inflammation of the airways (breathing tubes). The swelling of the airways which is the result of inflammation causes the airways to be narrowed. During an acute asthma attack the airways are further narrowed by the contraction of the airway muscles (bronchospasm.) (see leaflet "What is asthma?"). Both the airway inflammation and muscle contractions are best treated by breathing the medicine into the airways. In this information sheet the best ways of delivering the medicines to the airways are discussed.

Why inhale medicine into the airways?

• It makes good sense to breath the drugs (medicine) into the airways (breathing tubes) of the lungs because this is where the problem is.
• Breathing the medicines into the airways is safe and faster because:
  • The medicine is delivered to where the problem is and starts to work more rapidly.
  • Only a tiny amount of the medicine is needed.

Which children can inhale medicines?

• Children of all ages can inhale medicines into the airways.
• It has been shown that even in babies and small children the best way of delivering the treatment is by inhalation into the airways.
• Babies and young children are unable to use the devices available without an adaptation of the technique or the use of a different device. When these adaptations are used all children and adults can successfully be treated by the inhalation techniques. The table below lists the techniques suitable for babies and children:

   

  Age-group	Inhaler
  Babies	Pressurised aerosol inhaler with spacer and mask Nebuliser.
  Children under 4 years old	Pressurised aerosol inhaler with spacer and mask Nebuliser.
  Children 4-8 years old	Pressurised aerosol inhaler with spacer. Dry powder inhaler Breath-activated inhaler.
  Children older than 8 years old	Pressurised aerosol inhaler Pressurised aerosol inhaler with spacer Dry powder inhaler Breath-activator inhaler

• Make sure that you or your child has received the correct inhalation device to ensure that the drugs reach the airways. Incorrect apparatus and incorrect use of the apparatus are important causes of poor control of asthma.

What are the different types of inhalers available?

1. Pressurised aerosol inhaler (asthma pump)
   • The medicine in a liquid form is forced into a holder (canister) under pressure.
   • The canister is supplied with a holder. When the inhaler is pressed down in the holder the medicine is released through the mouth piece of the holder as a gas or cloud. It is this cloud of medicine which has to be inhaled.
   • These inhalers (pumps) are inexpensive and effective if used correctly.
   • To be used correctly co-ordination is needed between activating the inhaler and breathing the medicine in. This requires instruction from your doctor, nursing sister or pharmacist. They should also check to see if you are using it correctly every time you re-visit them.
     
2. Pressurised aerosol inhaler and spacer.
   
   • For babies and children unable to correctly use an asthma pump an additional device is needed. This is called a spacer. They are plastic containers which make the asthma pump easier to use for babies and children as well as adults.
   • A spacer is a plastic holder into which the medicine is squirted. The spacer then holds the medicine until the child is ready to breathe out of it.
   • Spacers come in various shapes and sizes.
   • Some spacers are fitted with a mask which fits tightly over the babies/child's mouth (Aerochamber, Babyhaler).
   • Older children and adults use larger spacers (750 ml) (Volumatic, Fisionair). These larger spacers have mouth pieces with a valve through which the asthmatic breathes inhaling the medicine already deposited in the spacer.
   • Cheap spacers can also be made from polystyrene coffee cups and 500ml plastic cooldrink bottles.

     Spacers are more efficient than an inhaler alone. They are used to:

   • Give inhaled medicines to babies, small children and children unable to use an inhaler alone. They are also useful in patients unable to co-ordinate the breathing in effort with the puff of medicine and in old people with arthritis.
   • Reduce the unwanted effects of inhaled medicines. Less local side effects occur in the mouth and throat when spacers are used.
   • Enable asthmatics with an accute attack to use their inhalers to maximal effect. Spacers can be used in an emergency when co-ordinating with the inhaler is difficult. It is as effective as nebulised medicine.
   • Use the cheapest form of treatment (asthma pumps).
   • Increase the amount of medicine delivered to the airways. Spacers have been shown to double the amount of medicine delivered to the airways making it more cost effective.
     
3. Dry powder inhaler.
   
   • Dry powder inhalers make use of the medicine in a powder form which is then breathed into the airways of the lung.
   • The dry powder medicine is enclosed in a capsule (Spinhaler), in a circular disk (Diskhaler) or a special apparatus (Turbuhaler, Accuhaler).
   • When the child breathes in, very small particles are inhaled into the lung.
   • To use the dry powder inhaler the child must be able to breathe in fast enough to get the powder into the lungs and not in the mouth.
   • The great advantage that dry powder inhalers have over asthma pumps is that they do not need the co-ordination the aerosol inhalers need. They have very little advantage over aerosol inhalers if the inhalers are used with a spacer.
     
4. Breath activated inhalers.
   
   • These are the same as pressurised aerosol inhalers except that they have a special mechanism which automatically activates the inhaler when the asthmatic breathes in.
   • They have the same advantage as dry powder inhalers in that co-ordination between activating the aerosol inhaler and breathing in is not needed.
5. Nebuliser (see leaflet "Home nebulisers for asthma").
   
   • A nebuliser is a machine that works by blowing air or oxygen through a fluid (medicine) and turns it into a mist wihch is then breathed into the airways.
   • To nebulise fluid to the airways of babies and children is an expensive form of treatment which in nearly all cases is not more effective than other correctly used forms of therapy.
   • It should only be used after your doctor has supplied clear guidelines when to use it and what medicines should be used.

How do you correctly use the different inhalers?

1. Pressurised aerosol inhalers (asthma pump).
   Use the inhaler as follows
   
   1. Shake inhaler vigorously. After taking the cap off, hold the inhaler in the upright position. It is now ready for use.
   2. Sit or stand and tilt your head back slightly.
   3. Breathe out all the air in your lungs slowly. The more air that is breathed out the better the inhalation of the medicine will be.
   4. Place the inhaler in the upright position in your mouth.
   5. Breathe in slowly. Just after the start of the breath press the inhaler once. Breathe the medicine right down into the lungs by breathing in all the air you can.
   6. Hold your breath for between 5 to 10 seconds. This allows the medicine to settle in your airways.
   7. Breathe out slowly.

   Common mistakes with the use of the inhalers:

   • Not shaking the inhaler well enough.
   • Breathing out too fast or not completely.
   • Pressing the inhaler too early or too late.
   • Breathing in too fast.
   • Using an empty inhaler. An inhaler must be checked to see if there is still medicine in it. This can be done by shaking the inhaler. If there is still medicine in it you will hear it.
   • Checking How Much Medicine is Left in the Canister
     
     1. If the canister is new, it is full.
     2. An easy way to check the amount of medicine left in your metered dose inhaler is to place the canister in a container of water and observe the position is takes in the water.
        Note: This method does not work for all inhalers. Please ask your doctor if you can check your inhaler this way.
        
   • Always start a new inhaler before the old one is completely empty (have a spare on available).
   • The opening in the holding case gets blocked. This is easily seen if the inhaler is pressed and a good cloud of spray is not seen. The case should then be washed in warm soapy water and left to dry completely.
     
2. Dry powder inhalers
   There are many types of dry powder inhalers available. Each of them has a different operating method. Some have to be loaded each time they are used (Inhalator, Spinhaler, Rotahaler), others have disks which have a number of doses (4 or 8), while other dry powder inhalers have as many as 200 doses stored in the device (Turbuhaler, Accuhaler).

5 key points to remember

• The correct use of the inhalation device is as important as the medicines that are prescribed.
• You or your child's asthma may be poorly controlled because you are not using the inhalation device correctly.
• Inhaled medicine is the best method of treatment as the medicine is delivered directly to the lungs where it acts quickly and only requires very small amounts to achieve this. This ensures that the anti-asthmatic effect is achieved at the safest dose.
• There are devices that suite all asthmatics.
• Ensure your doctor, nurse or pharmacist teach you to use yours correctly.

Written by: Dr Robert Gie