Peak expiratory flow rate is a very helpful measurement for achieving better control of asthma
and earlier detection of asthma attacks. As the asthma symptoms worsen the peak expiratory flow rate will go down. This can be assessed with a simple handheld device which you can keep at home, in your purse, etc.
Ideally, your doctor
or asthma educator should measure your daughter's peak expiratory flow rate in the office when her symptoms are really well controlled. This will serve as her baseline value (alternatively a baseline value can be calculated based on her size). Then your asthma educator will help you define what decline in peak expiratory flow rate should be concerning for an asthma attack. These cut off values will go into your asthma action plan. When your daughter is feeling well, should should measure her peak flow at least a few times a week. When she is having symptoms, she should take these measurements multiple times a day and make decisions about whether to intensify her home medications or seek medical care (as directed by her asthma action plan).
Talk to your doctor or your asthma provider for more information about managing your daughter's asthma.