PubMed ID: 15065839 The ratio of FEV1 to FVC as a basis for establishing Chronic Obstructive Pulmonary Disease. In other words...it is a measurement of how many LITERS you can blow in 1 second. Eur Respir J. The machine predicted a person your age, height, and gender could blow 2.57 liters. The normal value for the FEV1/FVC ratio is 70% (and 65% in persons older than age 65). The predicted FEV1 is calculated using the formula FEV1{litres} = 4.30*height{metres} - 0.029*age{years} - 2.49. Y-axis is expressed in Litres for FVC and FEV1, and in Litres/second for FEF25–75%. Hi you need to divide the bigger number (predicted) into your actual FEV1 2.77 to work out the percentage. Vaz Fragoso CA, Concato J, McAvay G, Van Ness PH, Rochester CL, Yaggi HK, Gill TM. The normal volume time curve has a rapid upslope and approaches a plateau soon after exhalation. Normal lung capacity is between 4 and 6 liters, and the average human total lung capacity is approximately 5.8 liters, according to The Physics Factbook. Similarly, if the patient is being evaluated for lung resection, you like them to end up with an FEV1 > 0.8 or 1.0 liters. If the FVC and the FEV1 are within 80% of the reference value, the results are considered normal. The higher the percentage derived from your FEV1/FVC ratio, in the absence of restrictive lung disease that causes a normal or elevated FEV1/FVC ratio, the healthier your lungs are. Lung capacity varies widely depending on a person’s age, sex, weight and activity level. What you scored is divided into the predicted number for a percentage. The formula for the predicted FEV1 is published by the Association for Respiratory Technology and Physiology (www.artp.org.uk). FEV 1 PREDICTED VALUES MALE CAUCASIAN Figures based on prediction equations from Hankinson et al. FeV1/FVC ratio is important as this ratio is decreased in obstructive lung diseases. "Reference ranges for spirometry across all … x In your case, you blew 2.15 liters in one second. Peak expiratory flow rate: Normal 500 to 600 liter… FEV1 stands for Forced Expiratory Volume in 1 second. Falaschetti E, Laiho J, Primatesta P, Purdon S. Prediction equations for normal and low lung function from the Health Survey for England. The formula for the predicted FEV1 is published by the Association for Respiratory Technology and Physiology (www.artp.org.uk). Thorax 2008; 63: 1046-1051. It is based on a regression model from a cohort of subjects aged 18-60, and included height, age and gender. Normal person can exhale 83 to 85%of FVC in 1 second (so FeV1 is 83 to 85%), 93% in 2 seconds (FeV2 is 93%) and 97% in 3 seconds (FeY3 is 97%). Using the lower limit of normal for the FEV1/FVC ratio reduces misclassification of airway obstruction. Stanojevic S, Wade A, Stocks J, et al. It is based on a regression model from a cohort of subjects aged 18-60, and included height, age and gender. It is expressed as percentage. English: Normal values for Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second (FEV1) and Forced Expiratory Flow 25–75% (FEF25–75%). volume (FEV1). For example if your fev1 is 2.15 litres and the predicted for your group is 2.77 then you divide the 2.77 into 2.15 and the result would be 83.66%. (February 2008). See main article: Wikipedia:Spirometry Reference. 2004 Mar;23(3):456-63. The predicted FEV1 is calculated using the formula FEV1{litres} = 3.95*height{metres} - 0.025*age{years} - 2.60. 1999. I hope you can work it out from this. Therefore, a patient with an FEV1 of 1.2 liters would be very high risk for a pneumonectomy (predicted post-op FEV1 = 0.6 L) but only moderate risk for a lobectomy (predicted post-op FEV1 = 1.0 L). When compared to the reference value, a lower measured value corresponds to a more severe lung abnormality.