Pulmonary Function Tests

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Pulmonary function tests (PFT’s) are analytical tools that aid in the diagnosis and monitoring of patients with, or at risk, for respiratory diseases. PFT’s measure the functionality of one’s lungs, measuring: quantity and speed of air flow and volume in/out of the lungs. This is the responsibility of the respiratory system, in taking oxygen and expelling carbon dioxide. The process of respiration/ventilation is comprised of 2 parts: inhalation and exhalation. At rest, the Dorsal respiratory group, located in the medulla, sets the rhythm of breathing (eupnea)1. Stimulating inhalation, an active process, which causes the rib cage to elevate causing the lungs to expand. This creates a drop in the intrapulmonary pressure (-1 mm Hg), generating …show more content…
PFT’s help classify lung disorders into 2 categories: Obstructive or Restrictive. Obstructive disorders (i.e. Asthma, COPD, Bronchiectasis) are classified when the flow of air is hindered resulting significant increases in reserve volume and tidal volume 1. Where as restrictive lung disorders (i.e. Tuberculosis, Pneumonia) decrease all lung volumes and capacities. Pulmonary function tests are traditionally done using a spirometer. This assess mechanical functionality of the lungs, chest wall, and respiratory muscles3. Physicians compare the results derived from the spirometry technique to the guideline norms, this aids in the classification of the disorder as obstructive or restrictive. PFTs are also used prior to any pulmonary operations to analyze operative risks, used as continuous measure to see the effects of medication. This experiment observed an individual’s pulmonary volume and capacities. A pulmonary function test was carried out using an airflow transducer software that converted airflow to volume, thus approximating the readings of a spirometer. Individual findings were then compared to average values; this methodology was applied to evaluate for a broad ranges of lung …show more content…
During exercise ventilation occurs in a range where the total lung compliance is at maximal performance providing the oxygen demand 7. The increased O2 consumption and CO2 production, results in a increase in the breathing frequency and tidal volume, resulting in breaths per minute as well as larger volumes of air per breath . All measures are taken to speed up the elimination of increased CO2 concentrations. If a pulmonary funciton test was performed at this point in the homeostatic control , the measurements of lung volumes would differ from rest. With exercise there is a increase in tidial volume and is accomodated for by the decrease in IRV. IRV is a set resevoir space, when there is a increase in tidal volume, it takes over this resevoir. The expiratory resevoir (ERV) is also forfeited, larger volumes of air are expelled out to remove the excess CO2 (Question F). This experiment looked at volume measurements and capacites. Volume measurements were the variables that were determined using the air flow transducer, these represented the lung volumes (TV, IRV and ERV). Where as the capacites calculations (TLC, IC, EC, FRC) were based on the sum of two or more lung volumes. (Question

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