I. Parameteres Signalizing Respiratory Problems
One of the main parameters, which indicates respiratory problems, is a (FORCED) VITAL CAPACITY (FVC).
FVC represents the volume of air maximally fiercely breathed out after the deep inhalation.
The healthy, non-smoker human's FVC is defined by TABLES.
If the patient's FVC is different from the table - predicted value, it can signalize a disease.
Why do we need this information?
Our first task is to FIND PATIENT'S FORCED VITAL CAPACITY and to COMPARE IT with a table (predicted) value. If there is nearly no difference between these two values, we can expect, that our patient does not have any breathing problems.
A piece of history
There were many famous doctors studying human Vital Capacity during the last centuries.
One of the first was Galen, well-known famous Greek doctor (2th century).
Later, Giovannin Alfonso Borelli (1679) rapidly increased the measurement accuracy, using the patient's nose blocking.
John Hutchinson (1849) created the first fully functional spirometer (water spirometer). Later, based on 4000 measurements, found a linear dependence between the vital capacity and a human height.
The first patient
Our first patient is a MAN, 56 years old, 171 centimeters tall. The result of his spirometry assessment is in the right picture.
(The volume represented on a graph is an air volume, inhaled and exhaled into/out of the patient's lung.)
What is the patient's Forced Vital Capacity?
Is there a difference between our patient's measured forced vital capacity and a forced vital capacity of a healthy, 56 years old, 171 cm high man?
(Predicted FVC values are avilable HERE )
II. Respiratory System Diseases
Solution of the Problem 1.2 showed us, that our patien's FVC (FORCED VITAL CAPACITY) is decreased/reduced.
But, what does it mean? What kind of a disease can our patient have?
To answer this question we need to know, what kind of pulmonary diseases exist. The list of existed pulmonary diseases and their description is available HERE.