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Tests and Services

Inhalation Therapy Instruction

What is a peak flow meter?

A peak flow meter (PFM) is a device used to measure how well your child's asthma is under control. The device measures air flowing out of the lungs, called peak expiratory flow rate (PEFR), as a child with asthma forcefully blows into the device. A peak flow meter, when used properly, can reveal narrowing of the airways well in advance of an asthma attack. Used mainly by children with moderate to severe and persistent asthma, peak flow meters can help determine:
  • when to seek emergency medical care.
  • the effectiveness of your child's asthma management and treatment plan.
  • when to stop or add medication, as directed by your child's physician.
  • what triggers the asthma attack (such as exercise-induced asthma).
Why should a peak flow meter be used?

The PFM removes a lot of guesswork out of managing your child's asthma. It can provide you, your child's physician, or even the school teachers with information about how open the airways are in your child's lungs.

The PFM can detect small changes in the large airways before your child starts to wheeze. Using a PFM every day will let you know when your child's peak flows are starting to drop. This allows you to make early changes in your child's medication or routine to help prevent your child's asthma symptoms from getting worse. The PFM can also identify the value at which you will need to call your child's physician or go to the emergency room.

How to use a peak flow meter:
  • Use the PFM once daily and whenever your child is experiencing early warning signs. Always use the PFM before taking reliever medication.
  • Hold the PFM by the handle.
  • Before each use, make sure the pointer is reset to zero.
  • Have your child stand up straight. Remove chewing gum or any food from your child's mouth.
  • Have your child take a deep breath and put the mouthpiece in his/her mouth. Seal his/her lips and teeth tightly around the mouthpiece.
  • Let your child blow out as hard and as fast as he/she can. Remember a fast blast is better than a slow blow.
  • Note the number where the pointer has stopped on the scale.
  • Reset the pointer to zero.
  • Repeat this routine three times. You will know your child has done the technique correctly when the numbers from all three tries are close together.
  • Record the highest of the three readings on a graph or in a notebook. Do not average these numbers together. This is called your peak flow.
  • Use the peak flow meter once a day. Measure peak flows about the same time each day. A good time might be when your child first wakes up or at bedtime.
What are peak flow zones?

Peak flow zones are based on the traffic light concept: red means danger, yellow means caution, and green means safe. These zones are different for each person. Your child's physician will help determine your child's peak flow zones. The three peak flow zones include:
  • Green: This is the GO zone! This zone is from 80 to 100 percent of your child's highest peak flow reading. This is the zone your child should be in every day. This is a signal that air moves well through the large airways and that your child can do the usual activities and go to sleep without trouble. When the peak flow readings are in this zone, your child should:
    • avoid asthma triggers.
    • use controller medications every day.
    • use the reliever medications 15 to 20 minutes before exercise if your child has exercise-induced asthma, as directed by your child's physician.
  • Yellow: This is the CAUTION or SLOW DOWN zone! This zone is from 50 to 80 percent of your child's highest peak flow reading. This is a clue that the large airways are starting to narrow. Your child may begin to have mild symptoms. Your child may be coughing, feeling tired, feeling short of breath, or feeling like his/her chest is tightening. These symptoms may keep your child from his/her usual activities or from sleeping well. To keep your child's peak flow numbers from getting worse and get your child's asthma back under control, you will need to:
    • continue to use the controller medication as your child's physician has ordered and avoid asthma triggers.
    • use the reliever medication as ordered by your child's physician.
    • make sure you are using the proper technique with your child's metered-dose inhaler and spacer.
  • Red: This is the STOP zone! This zone is less than 50 percent of your child's highest peak flow reading. Readings in this zone are a medical emergency and you will need to get help right away. This means severe narrowing of the large airways has occurred. Your child may now be coughing, very short of breath, wheezing both when breathing in and out, or having retractions. Your child may also have problems walking and talking. Have your child take his/her reliever medication now and call your child's physician.
The goal of the peak flow zones is to help recognize when the asthma may start to become uncontrolled.

How is a personal best peak flow measured?

Each child's peak flow zones are based on his/her personal best peak flow number. To establish your child's personal best peak flow, have your child take his/her peak flow measurement each day at the same time for two to three weeks, when the asthma is under control.

After recording your child's peak flow measurements for two to three weeks consistently, your child's physician may also measure the optimum lung function with a spirometer (a device that can check lung function by measuring both the amount of air expelled and how quickly the air was expelled). The spirometer measurement may then be compared with the peak flow meter record to help set up an asthma management and treatment plan.

Your child's personal best peak flow measurement may change over time. Consult your child's physician as to when to check for a new personal best peak flow measurement.

When should a peak flow meter be used?

Peak flow meters should be used regularly to check how well the asthma is being controlled. In addition, the peak flow meter may be a valuable tool during an asthma attack, because it can help determine how well the short-term, quick-relief asthma medication is working. The National Heart, Lung, and Blood Institute (NHLBI) recommends measuring lung function during the following times:
  • every morning, before taking asthma medications
  • during asthma symptoms or an asthma attack
  • after taking medication for an asthma attack
  • other times as recommended by your child's physician
The peak flow meter is a tool to help collect information. The key to successful asthma management is communicating this information (the peak flow meter recordings, the severity of your child's symptoms, and the effectiveness of your child's medications) to your child's physician.

How can I obtain a peak flow meter?

Consult your child's physician about obtaining a peak flow meter and for step-by-step instructions on how to use the device.

If you are using more than one peak flow meter, be sure they are the same brand.

What are oximeters?

An oximeter is a small machine that measures oxygen saturation (the amount of oxygen) in your child's blood.

To get this measurement, a small sensor (similar to an adhesive bandage) is taped onto your child's finger or toe. When the oximeter is on, a small red light can be seen in the sensor. The sensor is painless and the red light does not get hot.

What is a spirometer?

A spirometer is a device used by your child's physician that assesses lung function. Spirometry, the evaluation of lung function with a spirometer, is one of the simplest, most common pulmonary function tests and may be necessary for any of the following reasons:
  • to determine how well the lungs receive, hold, and utilize air
  • to monitor a lung disease
  • to monitor the effectiveness of treatment
  • to determine the severity of a lung disease
  • to determine whether the lung disease is restrictive (decreased airflow) or obstructive (disruption of airflow)
After taking a deep breath, your child forcefully breathes out into the spirometer as completely and forcefully as possible. The spirometer measures both the amount of air expelled and how quickly the air was expelled from the lungs. The measurements are recorded by the spirometer.

The normal, healthy values measured by the spirometer for the amount of air exhaled vary from child to child. Your results are compared to the average expected in someone of the same age, height, sex, and race, according to the National Heart, Lung, and Blood Institute (NHLBI). However, if the values fall below 85 percent of the average, it may indicate a lung disease or other airflow obstruction. If a child has abnormal spirometer measurements, he/she may be referred for other lung tests to establish a diagnosis.

Hand-Held Nebulizer Treatments

A nebulizer is a type of inhaler that sprays a fine, liquid mist of medication. This is done through a mask, using oxygen or air under pressure, or an ultrasonic machine (often used by persons who cannot use a metered-dose inhaler, such as infants and young children, and persons with severe asthma). A mouthpiece is connected to a machine via plastic tubing to deliver the medication.

The medications used in nebulizers help your child by loosening the mucus in the lungs so it can be coughed out more easily, and by relaxing the airway muscles so that more air can move in and out of the lungs. Breathing the medication straight into the lungs works better and faster than taking the medication by mouth. Nebulizer treatments take about 15 to 20 minutes to give the medication.

Giving a treatment:

The following steps are recommended when giving a treatment to your child. However, always consult your child's physician for specific instructions.
  • Gather supplies needed, including:
    • medication to be nebulized
    • nebulizer set (nebulizer cup, mouthpiece or mask, tubing to connect to nebulizer machine)
  • Find a quiet activity to do while your child sits up for the treatment (i.e., reading a book or playing a quiet game).
  • Place the nebulizer on a flat surface (i.e., table or the floor).
  • Plug the unit into a wall outlet.
  • Connect the air tubing to the nebulizer machine.
  • Put the medication into the nebulizer cup and screw the cap on securely.
  • Connect the other end of the air tubing to the nebulizer cup.
  • Connect the mouthpiece or face mask to the nebulizer cup.
  • Turn the machine on.
  • Check to make sure a fine mist of medication is coming through the face mask or mouthpiece.
    • Mouthpiece:
      • Place the mouthpiece in the child's mouth with the lips sealed around the mouthpiece.
      • Encourage your child to take slow deep breaths in and out of their mouth. The mist should disappear with each breath.
    • Face mask:
      • Place the mask over your child's mouth and nose. The adjustable elastic band may be used to hold the mask in place.
      • Encourage your child to take deep breaths in and out for the duration of the treatment.
  • Encourage your child to continue slow, deep breaths until all the medication in the nebulizer cup is gone. You may need to tap the sides of the nebulizer cup to ensure all medication is given.
  • Turn the nebulizer off.
  • If the child's treatment plan orders peak flow measurements, obtain these before the treatment starts and after the treatment is completed.
After each treatment:
  • Disconnect the nebulizer cup from the tubing.
  • Open the cup and wash all pieces in a mild dish soap and water. (Do not wash or rinse the tubing.)
  • Rinse all pieces.
  • Air dry on a clean towel.
  • Store the dried nebulizer cup and tubing in a plastic bag.
  • Once a week rinse the nebulizer cup in a vinegar/water solution, as directed by you physician, after washing.
Notes for parents:
  • Stay with your child throughout the nebulizer treatment.
  • If your child should vomit or have a severe coughing spell during the treatment, stop the treatment, let the child rest for a few minutes, then resume the treatment.
  • Check the filter on the nebulizer machine once a week. When it becomes discolored, replace with a new filter.
  • Always keep a spare nebulizer kit at home. When you are down to your last two kits, contact your medical equipment company to deliver more.

What medications are commonly used for children with asthma?

The use of medications in children is highly individualized, based on the severity of the child's symptoms, the age of the child, and the ability of the child to take inhaled medications. The following are the most commonly used medications:
  • bronchodilators
    These medications are used to help open the narrowed lungs and may relieve coughing, wheezing, shortness of breath, or difficulty in breathing. These are usually considered rescue medications for acute attacks of asthma. Types of bronchodilators are beta-agonists, theophylline, and anticholinergics. These medications come inhaled, in pill form, liquid, or injectables.

    The short-acting bronchodilators are used as needed as symptoms occur. Longer acting bronchodilators may be used for maintenance or on a daily basis to help control flare-ups from occurring.
  • anti-inflammatory medications
    These medications help to decrease the inflammation that is happening in the airways with asthma. These include two types of medications:
    • nonsteroidal anti-inflammatory medications (NSAIDs)
      Cromolyn and nedocromil are two types of nonsteroidal medications that are usually inhaled by the child.
    • corticosteroids
      These medications can be given in a variety of ways. Some of them are inhaled, while others may be taken as a pill or liquid, or even as an injection. The steroids taken by mouth can have more side effects than those that are inhaled. Inhaled steroids are safe and effective controller medications and should be taken every day. Consult your child's physician about the best choice for your child.
  • anti-leukotrienes
    These are a relatively new type of medication being used to help control the symptoms of asthma. These medications help to decrease the narrowing of the lung and to decrease the chance of fluids in the lungs. These are usually given by mouth.

Inhalation Therapy Instruction - Departments & Programs - Children's National Medical Center