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WVC pulmfunctest
WVC pulmonary function tests IGGY
Question | Answer |
---|---|
Ideal normal pulse oximetry values are | 95% to 100% |
Pulse oximetry can detect desaturation before | manifestations (e.g., dusky skin, pale mucosa, pale or blue nail beds) occur |
Causes for low SaO2 readings include | patient movement, hypothermia, decreased peripheral blood flow, ambient light (sunlight, infrared lamps), decreased hemoglobin, edema, and fingernail polish |
When the Spo2 is below _______body tissues have a difficult time becoming oxygenated. | 85%, |
Changes in PETCO2 reflect | changes in breathing effectiveness and may occur before hypoxia can be detected using pulse oximetry. Norm is 20-40 |
Capnometry and capnography are methods | that measure the amount of carbon dioxide present in exhaled air, which is an indirect measurement of arterial carbon dioxide levels. |
When performed while the patient exercises, PFTs help determine | whether dyspnea is caused by lung or cardiac dysfunction or by muscle weakness. |
FVC (forced vital capacity) records the maximum amount of air | that can be exhaled as quickly as possible after maximum inspiration. |
FVC gives an indication of respiratory | muscle strength and ventilatory reserve. FVC is often reduced in obstructive disease (because of air trapping) and in restrictive disease. |
FEV1 (forced expiratory volume in 1 sec) records the maximum amount of air that can be | exhaled in the first second of expiration. |
FEV1 is effort dependent and declines | normally with age. It is reduced in certain obstructive and restrictive disorders. |
FEV1/FVC is the | ratio of expiratory volume in 1 sec to FVC. |
FEV1/FVC ratio provides a much more sensitive indication of | obstruction to airflow. This ratio is the hallmark of obstructive pulmonary disease. It is normal or increased in restrictive disease. |
FEF(25%-75%) records the | forced expiratory flow over the 25%-75% volume (middle half) of the FVC. |
FEF measure provides a more sensitive index of obstruction in the | smaller airways. |
FRC (functional residual capacity) is the amount of | air remaining in the lungs after normal expiration. |
FRC test requires use of the | helium dilution, nitrogen washout, or body plethysmography technique. |
Increased FRC indicates hyperinflation or air trapping, which may result from | obstructive pulmonary disease. |
FRC is normal or decreased in | restrictive pulmonary diseases. |
TLC (total lung capacity) is the amount of air in the lungs at the | end of maximum inhalation. |
Increased TLC indicates air trapping associated with | obstructive pulmonary disease. |
Decreased TLC indicates | restrictive disease. |
RV (residual volume) is the amount of air remaining in the lungs | at the end of a full, forced exhalation. |
RV is increased in obstructive pulmonary disease such as | emphysema. |
DlCO (difusion capacity of carbon monoxide) reflects the | surface area of the alveolocapillary membrane. |
How is DICO performed | The patient inhales a small amount of CO, holds for 10 sec, and then exhales. The amount inhaled is compared with the amount exhaled. |
DlCO is reduced whenever the | alveolocapillary membrane is diminished, such as occurs in emphysema, pulmonary hypertension, and pulmonary fibrosis. |
DICO is increased with exercise and in conditions such as | polycythemia and congestive heart disease. |