PEFR_estimated v.1
Peak expiratory flow (peak expiratory flow rate, PEFR) is the maximum flow rate of air generated during forceful exhalation from fully inflated lungs. It is a measure of flow through large airways and though traditionally measured by a portable peak flow meter or by spirometry, in their absence a baseline expected value can be estimated using various formulae that generally include the individual's age, height and sex. PEFR is measured in litres per minute (L/min) and is invaluable in assessing and monitoring the degree of airway obstruction in patients with asthma and chronic obstructive pulmonary disease (COPD).
To estimate the baseline expected peak expiratory flow for patients where previously unknown.
To record the estimated expected peak expiratory flow for different age groups and sexes. Many equations exist for estimating PEF and some examples for chidren and adults are as below: Children: PEFR (L/min) = ((Height in cm - 100) * 5) + 100 Adult males: PEFR (L/min) = (((Height in metres * 5.48) + 1.58) - (Age * 0.041)) * 60 Adult females: PEFR (L/min) = (((Height in metres * 3.72) + 2.24) - (Age * 0.03)) * 60 This application accepts height input in cm or inches.
Only for use if patient's baseline PEF is not known.
Knudson RJ, Lebowitz MD, Holberg CJ, Burrows B. Changes in the normal maximal expiratory flow-volume curve with growth and aging 1–3. American Review of Respiratory Disease. 1983 Jun;127(6):725-34. Nunn AJ, Gregg I. New regression equations for predicting peak expiratory flow in adults. BMj. 1989 Apr 22;298(6680):1068-70. Balasubramanian S, Ravikumar NR, Chakkarapani E, Shivbalan SO. Peak expiratory flow rate in children-A ready reckoner. Indian pediatrics. 2002 Jan 24;39(1):104-5.
OBSERVATION.basic_demographic.v1, OBSERVATION.height.v2, OBSERVATION.peak_expiratory_flow_estimated.v1
