Peak Flow Meter
Peak Flow Meter
Your peak flow meter is a like a portable pulmonary function machine. It reflects the size of the airways (the breathing tubes to the lungs) and asthma status (determine the level of inflammation or disease). It is easy to use, is done twice daily and gives helpful information about your asthma.
The doctor uses peak flow readings to determine if a patient is responding to treatment or to see if certain conditions or environments aggravate the asthma. Once a peak flow pattern is established, and a patient has few or no symptoms the doctor can set peak flow zones. With these zones we can create an individual action plan. There is no normal range for a patient from a chart. Each patient’s peak flow zones are determined individually and correlated with their pulmonary function tests (spirometry).
Your best number is the key to zone values. It represents your maximal airflow and airway diameter. With any inflammation or constriction of the airways, the diameter is smaller and therefore a lower peak flow number. The degree of constriction, from asthma, determines what action should be taken. Children need to be re-evaluated and change their peak flow zones every six months. This is because the child’s height and lung capacity will increase with growth. If you live with old numbers there can be a false sense of security. Peak flow values drop 24 to 48 hours before any clinical symptoms are perceived. That is why they must be done every day. Early warning and intervention mean a lesser degree of sickness, quicker recovery, shorter medicine course and less damage to the airways.
All is well and no intervention is needed.
This is 80% or better of your best value (Best number x 0.8).
Caution! There is constriction and possible airway inflammation.
This is a number between 50% and 80% of your best value (Best number x 0.5 to Best number x 0.8).
When you have a peak flow reading in the yellow zone you must take 2 puffs from your rescue inhaler (albuterol, Proventil, Ventolin, Maxair), wait 5 minutes and repeat a peak flow. If the new value is in the green zone all is well. It was just some constriction, but remain cautious, it could be the beginning of something. If the new value is in the yellow zone then take 2 more puffs from your rescue inhaler (albuterol, Proventil, Ventolin, Maxair), wait 5 minutes and repeat a peak flow. If the second value is in the green zone all is well, but remain cautious, there is a chance an asthma attack will be coming. If the second reading is still in the yellow zone you must call the doctor. This means there is constriction and inflammation and we need to listen, look and evaluate to see if extra medicine is needed.
There is an asthma attack present, even without symptoms!
This is less than 50% of your best value (Best number x 0.5). Take 2 puffs of your rescue inhaler or preferably a treatment with your nebulization machine. After the treatment call the doctor immediately, medical evaluation and treatment will be necessary.