What is a Peak Flow Meter Chart?

A peak flow meter chart is one of the tools used in monitoring asthma. A peak flow meter is a small handheld instrument that measures a person’s ability to exhale. Measurements taken at regular intervals are recorded on a peak flow meter chart and are used to predict and treat acute asthma attacks.

Asthma is a chronic inflammatory disease of the airways that afflicts more than 300 million people worldwide. It is characterized by airflow obstruction and spasms of the bronchi that cause the patient to experience coughing, wheezing, tightness in the chest and shortness of breath. With medications and proper monitoring, asthma is a treatable and controllable disease.

A person’s maximum rate of exhalation is called peak expiratory flow rate. Healthy patients will have higher peak flow rates, with lower rates indicating breathing distress. By monitoring changes in rates over time with a peak flow meter chart, patients can determine the severity of asthma symptoms and work with their physicians to devise effective treatment plans. The use of peak flow meters and peak flow meter charts can be an important part of an asthma patient’s treatment plan, but only when used in conjunction with appropriate doctor supervision, medications and other diagnostic tools. A peak flow meter is not an appropriate tool for diagnosing asthma.

Patients take three peak flow meter measurements, and the best measurement is recorded on the peak flow meter chart. The measurements can be plotted over time on graph paper along with anecdotal information about a patient’s symptoms. This provides a patient with useful information to bring to his or her doctor, and it also can indicate when to take prescribed medication. By analyzing the readings on a peak flow meter chart, patients can determine what triggers an asthma attack, assess the effectiveness of current medications and decide whether emergency care is needed. Common asthma triggers include airborne allergens, exercise, cigarette smoke, colds, viruses and emotional distress.

Typically, peak flow readings are categorized into three areas of measurement: green, yellow and red. A green categorization indicates that asthma symptoms are under control, and the yellow and red categories indicate varying levels of distress. In partnership with a healthcare team, a patient's asthma treatment plan can be developed to handle situations when peak flow meter readings are in the danger zones.