Spirometry – technique, normal values, interpretation
Spirometry is an evaluation techinique of the breathing capacity that measures the air quantity that a person can inspire or expirate. It is very useful in order to diagnose and follow the evolution of certain breathing affections such as: COPD chronic obstrutive pulmonary disease that can be emphysematic or bronchitical, bronchic astma, chronic asmatiform bronchitis.
The spirometer is a simple device, in which you expire after you had stainedly inspired. With these devices you evaluate how fast and efficient your lungs can be filled in with air or emptied of air.
For the results to be correct, the pacient is sitting on a chair and under the correct guidelines of a pulmonary doctor or an allergy doctor, takes a deep breath, sticks the lips around the tube and profoundly expires until the lungs are emptied. Without sticking the lips from the device, s/he inspires once more and then slowly expires until all the air comes out of the lungs.
The technique is accesible inclusively to the children that are big enough to cooperate (older than 4 years old).
Laboratory tests interpretation and normal values:
The ventilating function is measured in static conditions in order to determine the pulmonary volumes and in dinamic conditions in order to determine the forced expiration flows. The expiratory reserve volume and the insiratory capacity are measured by asking the pacient to inspire and expire with a spirometer, a device that can measure the inspired or expired volume, and also defining their time dependence. Nomal values are individualised according to age, sex, weight and ethny. That is why you have to discuss with the doctor the interpretation of the results. 80% of the reference values are normal vales.
The price of the spirometry varies between 10 and 30 dollars at private cabinets, and in the hospitals if you have medical reference the laboratory tests are free.