Peak flow
The peak flow (peak flow), actually peak expiratory flow (PEF, expiratory peak flow English literally Ausatmungsspitzenfluss), is a measure of the medicine , which measures the maximum Ausatmungsgeschwindigkeit a person. The peak flow is measured with a peak flow meter , a small hand-held device, or a spirometer . These devices measure the air flow through the bronchi and are therefore a measure of lung function .
history
The pioneer in measuring peak flow was the bio-engineer Martin Wright , who developed the first measuring device to measure peak flow as an index of lung function. The first measuring device was introduced in the late 1950s. With the subsequent development of portable and cheaper versions, other designs and copies of the meter were developed ( Mini-Wright ).
functionality
The peak flow readings are higher when the patient is healthy and lower when the airway is narrowed. From relative changes compared to recorded values, patients and physicians can draw conclusions about lung function, the severity of asthma symptoms and treatment options.
A precaution would be to monitor the patient for signs and symptoms of hypervolaemia asthma. This would indicate whether the peak flow measurement can be used. Measuring the peak flow rate requires practice to use the peak flow meter correctly and the normal expectation depends on the sex, age, and size of the patient.
Due to a large interval of "normal" values and a high degree of variability, the peak flow test is not suitable for identifying an asthma disease.
Some of the people with asthma can benefit from regular peak flow measurements to check asthma symptoms and to control the frequency of reliever medication. A recommended procedure for peak flow measurements is to take two measurements in the morning and two in the evening, before taking the drug to combat chronic inflammation, and 30 minutes apart after taking it. Sometimes it is also recommended to determine the peak flow at noon. As a rule, the device exhales three times in bursts and records the peak value of the three measurements.
If the peak flow is monitored regularly, the values can be entered in a peak flow table. It is important to use the same measuring device for every measurement.
Standards
There are a number of non-equivalent scales that can be used when measuring peak flow.
Graphs, tables, and calculators are available that predict expected values based on the person's gender, age, and height . Apps are now also available for smartphones that allow web-based recording of peak flow values and certain evaluations.
The following three metrics are commonly used:
- Wright scale
- EN 13826 or EU scale
- American Thoracic Society scale
Web links
Individual evidence
- ↑ salin-medicair.de: Keeping an asthma diary with a peak flow table ( memento of the original from March 17, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Martin R. Miller: Peak expiratory flow meter scale changes: implications for patients and health professionals . In: The Airways Journal . tape 2 , no. 2 , June 2004, p. 80–82 ( online PDF, 41 kB [accessed on April 3, 2015]).
- ↑ dynamicmt.com: Basic Peak Expiratory Flow Calculator
- ^ A. Nunn, I. Gregg: New regression equations for predicting peak expiratory flow in adults . In: BMJ . tape 298 , no. 6680 , 1989, pp. 1068-1070 , doi : 10.1136 / bmj.298.6680.1068 , PMID 2497892 , PMC 1836460 (free full text). - Predicted peak expiratory flow in normal adults using Wright-scale
- ↑ S. Godfrey, PL Kamburoff, JL Naim: Spirometry, lung volumes and airway resistance in normal children ages 5 to 18 . In: Br J Dis Chest . tape 64 , no. 1 , 1970, p. 15-24 , doi : 10.1016 / S0007-0971 (70) 80045-6 , PMID 5438753 . - Predicted peak expiratory flow in normal children using Wright-scale
- ^ Clement Clarke International: Predictive Normal Values (Nomogram, EU scale). Clement Clarke International, 2004, accessed June 6, 2006 . - Downloadable PDF charts for adults and children using EU scale
