The peak expiratory flow rate measures how fast a person can breathe out (exhale) air. It is one of many tests that measures how well the lungs are working.
Alternative NamesPeak flow
How the test is performedThis test requires a peak expiratory flow monitor: a small handheld device with a mouthpiece at one end and a scale with a moveable indicator (usually a small plastic arrow).
To perform this test:
Loosen any tight clothing that might restrict your breathing. Sit up straight or stand while performing the tests.
How the test will feelThere is usually no discomfort. Rarely, repeated efforts may cause some light-headedness.
Why the test is performedThe test is commonly used to diagnose and monitor lung diseases such as:
Home monitoring can help determine whether treatments are working or detect when your condition is getting worse.
Normal ValuesNormal values vary based on a person's age, sex, and size. Peak flow measurements are most useful when a person compares the number on a given day to his or her "personal best."
A fall in peak flow can signal the onset of a lung disease flare, especially when it occurs with symptoms such as:
Early treatment may be needed to prevent complications.
What abnormal results meanPeak air flow during exhalation decreases when the airways are blocked (obstructed).
Many patients can use peak expiratory flow monitoring to monitor their lung function at home. This can be very helpful, especially in asthma patients whose peak flow reading sometimes gets low before they develop breathing symptoms. If the fall in peak flow is treated early, symptoms can be avoided.
If you note that your peak flow is decreasing, tell your health care provider.
What the risks areThere are no significant risks.
Special considerationsPeak expiratory flow rate measurements are not as accurate as the spirometry measurements performed in a health care provider's office. Small changes in your peak flow may not mean significant changes in your lung function.
ReferencesNational Asthma Education and Prevention Program Expret Panel Report 3: Guidelines for the Diagnosis and Management of Asthma. Rockville, MD. National Heart, Lung, and Blood Institute, U.S. Dept. of Health and Human Services; 2007. NIH publication 08-4051.
Peak expiratory flow rate (PEFR)
Averaging peak expiratory flow rate readings is not recommended because it may mask fluctuations that could be important for diagnosing and managing conditions such as asthma. It is more beneficial to monitor the peak flow variability to better understand how the condition is progressing and to tailor treatment accordingly. Individual peak flow readings can provide valuable insights into a person's respiratory health that may be obscured by averaging.
Averaging the readings of the peak expiratory flow rate is not recommended because it may not accurately reflect the variability in lung function throughout the day. It is important to track the peak flow rates at different times to get a better understanding of how lung function changes over the course of the day. Averaging the readings may mask important fluctuations that can impact treatment decisions.
The average peak expiratory flow rate for a healthy 46-year-old male typically ranges between 400 to 700 liters per minute, depending on factors such as height, weight, and overall health. Peak flow can vary significantly among individuals, and it's important to consider personal health conditions, such as asthma or other respiratory issues, that may affect these values. For precise assessment, a peak flow meter can be used to measure an individual's specific rate.
The inside of a peak flow meter typically consists of a tapered tube that narrows at one end, allowing air to flow through it. As a patient exhales forcefully into the device, the airflow causes a movable indicator or piston to slide along a scale, measuring the peak expiratory flow rate. The scale is usually marked in liters per minute, enabling users to easily read their airflow measurements. The design is simple and portable, making it easy for individuals to monitor their lung function at home.
Wheezing, coughing, chest tightness, shortness of breath. A reduction in peak expiratory flow rate (PEFR) by around 20% or a Forced expiratory volume reduction in one second (FEV1) of 15%. I have Asthma and its hard to breathe, and your throat feels like its going to squash up. So choking, coughing,tightness of your chest and your throat closing up to make you choke. TRUST ME: YOU DO NOT WANT ASTHMA. ITS HORRIBLE.
Increasing flow rate typically leads to narrower peak widths in chromatography. This is because higher flow rates reduce the time that analytes spend interacting with the stationary phase, resulting in faster elution and narrower peaks. However, excessively high flow rates can also lead to peak broadening due to increased dispersion and reduced resolution.
Averaging the readings of peak expiratory flow (PEF) is not recommended because it can mask significant fluctuations in a patient's respiratory function. PEF can vary considerably throughout the day and under different conditions, so averaging may obscure acute changes that indicate worsening asthma or other respiratory conditions. Instead, monitoring should focus on the highest and lowest values to accurately assess variability and ensure timely intervention. Additionally, individual day-to-day comparisons are more informative for managing respiratory health.
Spirometry, including graphic record, total and timed vital capacity, expiratory flow rate measurement(s), with or without MVV. Essentially .. it's a pulmonary function test (lung function test)
Wheezing, coughing, chest tightness, shortness of breath. A reduction in peak expiratory flow rate (PEFR) by around 20% or a Forced expiratory volume reduction in one second (FEV1) of 15%. I have asthma and its hard to breathe, and your throat feels like its going to squash up. So choking, coughing,tightness of your chest and your throat closing up to make you choke. TRUST ME: YOU DO NOT WANT ASTHMA. ITS HORRIBLE.
Firstly an attenuation is the reduction in the peak of a hydro-graph as it movesdownstream, resulting in a more broad, flat hydro-graph.Therefore the attenuated peak is the highest point before it attenuates.
yes it does in many ways such as Exercise will effect your breathing and your heart rate by making them both faster. It does this because you need more oxygen to your muscles so you are breathing faster to get in more o2 and your heart beats faster to circulate that o2 to the muscles in your body.