呼气流量峰值
| 呼氣流量峰值 Peak expiratory flow | |
|---|---|
 A peak flow meter issued in the UK. | |
| MeSH | D010366 |
峰值呼氣流量（英文：peak expiratory flow，PEF），也稱峰值呼氣流量測定（英文：peak expiratory flow rate, PEFR）是一個人的最大呼氣速度，用峰值流量計測量，一個用於監測一個人呼吸空氣的能力的測定器。它測量通過支氣管的氣流，從而測量氣道中的阻塞程度。
為了解釋峰值呼氣流量測量的意義，根據從普通人群獲得的測量結果，對參考值（正常值，預測值）進行比較。在文獻中已經出版了各種參考值，並且根據患者的人口，種族，年齡，性別，身高和體重而變化。因此，使用表格或圖表來確定特定個人的正常值。最近，已經開發了醫用計算器來計算呼氣峰流量的預測值。
測定值的正常範圍 Scales or reference values
Normal values, shown on EU scale.[1]
Measurement
The highest of three readings is used as the recorded value of the Peak Expiratory Flow Rate. It may be plotted out on graph paper charts together with a record of symptoms or using peak flow charting software. This allows patients to self-monitor and pass information back to their doctor or nurse.[2]
Peak flow readings are often classified into 3 zones of measurement according to the American Lung Association;[3] green, yellow, and red. Doctors and health practitioners can develop an asthma management plan based on the green-yellow-red zones.
| Zone | Reading | Description |
|---|---|---|
| Green Zone | 80 to 100 percent of the usual or normal peak flow readings are clear. | A peak flow reading in the green zone indicates that the asthma is under good control. |
| Yellow Zone | 50 to 79 percent of the usual or normal peak flow readings | Indicates caution. It may mean respiratory airways are narrowing and additional medication may be required. |
| Red Zone | Less than 50 percent of the usual or normal peak flow readings | Indicates a medical emergency. Severe airway narrowing may be occurring and immediate action needs to be taken. This would usually involve contacting a doctor or hospital. |
History
The measurement of peak expiratory flow was pioneered by Martin Wright, who produced the first meter specifically designed to measure this index of lung function. Since the original design of instrument was introduced in the late 1950s, and the subsequent development of a more portable, lower cost version (the "Mini-Wright" peak flow meter), other designs and copies have become available across the world.[4]
參見 See also
- Spirometry
- Metered dose inhaler
- 沙丁胺醇 Salbutamol
- 慢性阻塞性肺病 Chronic obstructive pulmonary disease (COPD)
- 哮喘 Asthma
- 呼吸監控 Respiratory monitoring
References
- ^ Nunn, A. J., and I. Gregg. 1989. New regression equations for predicting peak expiratory flow in adults. Br. Med. J. 298: 1068-1070. Adapted by Clement Clarke for use in EU scale - see Peakflow.com > Predictive Normal Values (Nomogram, EU scale)
- ^ Scottish Intercollegiate Guidelines Network; The British Thoracic Society. British Guideline on the Management of Asthma - Annex 8: Personal Asthma Action Plan (PDF). Thorax. July 2007, 58: Suppl I [2011-10-27]. doi:10.1136/thx.58.suppl_1.i83. - for recording chart of PEFR readings
- ^ American Lung Association. How can I determine a normal peak flow rate for me?.
- ^ WRIGHT BM, McKERROW CB. Maximum forced expiratory flow rate as a measure of ventilatory capacity: with a description of a new portable instrument for measuring it. Br Med J. November 1959, 2 (5159): 1041–6 [2014-06-02]. PMC 1990874
. PMID 13846051. doi:10.1136/bmj.2.5159.1041.
