-
Where does gas exchange occur?
Acinus - anatomic unit of the lung made of structures supplied by terminal bronchiole
-
What is the dead space?
Area that doesn't exchange gases
-
Understand the reasons pulmonary function tests (PFTs) are performed.
- Determine the cause of breathing problems
- Dx certain lung diseases (asthma, COPD)
- Evaluate a person's lung function before surgery
- Monitor the lung function of a person who is regularly exposed to substances such as asbestos that can damage the lungs
- Monitor the effectiveness of tx for lung diseases
-
Understand the technique and basic interpretation of spirometry. What volumes can and cannot be measured?
- First lung function test done
- Measures how much and how quickly you can move air out of your lungs
- Can - Tidal volume and vital capacity
- Cannot - TLC, FRC, RV
-
What is Total Lung Capacity?
Inspiratory Reserve Volume (IRV) + Tidal Volume (TV) + Expiratory Reserve Volume (ERV) + Residual volume (RV)
-
What is Vital Capacity?
Inspiratory Reserve Volume (IRV) + Tidal Volume (TV) + Expiratory Reserve Volume (ERV)
-
What is Inspiratory Capacity?
Inspiratory Reserve Volume (IRV) + Tidal Volume (TV)
-
What is Functional Residual Capacity?
Expiratory Reserve Volume (ERV) + Residual Volume (RV)
-
What is Tidal Volume and what is the average value?
- Volume of air entering or leaving lungs during a single breath
- 500 mL
-
What is Inspiratory Reserve Volume (IRV) and what is the average value?
- Extra volume of air that can be maximally inspired over and above the typical resting tidal volume
- 3000 mL
-
What is Inspiratory Capacity and what is the average value?
- Maximum volume of air that can be inspired at the end of a normal quiet expiration (IC = IRV + IV)
- 3500 mL
-
What is Expiratory Reserve Volume (ERV) and what is the average value?
- Extra volume of air that can be actively expired by maximal contraction beyond the normal volume of air after a resting tidal volume
- 1000 mL
-
What is Residual Volume and what is the average value?
- Minimum volume of air remaining in the lungs even after a maximal expiration
- 1200 mL
-
What is the Functional Residual Capacity (FRC) and what is the average value?
- Volume of air in lungs at end of normal passive expiration (FRC = ERV + RV)
- 2200 mL
-
What is Vital Capacity (VC) and what is the average value?
- Maximum volume of air that can be moved out during a single breath following a maximal inspiration (VC = IRV + TV + ERV)
- 4500 mL
-
What is Total Lung Capacity and what is the average value?
- Maximum volume of air that the lungs can hold (TLC = VC + RV)
- 5700 mL
-
What is Forced Expiratory volume in 1 second (FEV1)?
Volume of air that can be expired during the 1st second of expiration in a VC determination
-
What is obstructive lung disease?
- Airways are narrowed (usually causing an ↑ in the time it takes to empty the lungs)
- Ex. emphysema, bronchitis, infection, asthma, cystic fibrosis
-
What is restrictive lung disease?
- Loss of lung tissue, ↓ in the lungs' ability to expand, or a ↓ in the lungs' ability to transfer oxygen to the blood
- Ex. pneumonia, lung cancer, scleroderma, pulmonary fibrosis, sarcoidosis, MS, chest injuries, obesity, pregnancy, loss of lung tissue during surgery, interstitial fibrosis, scoliosis, cystic fibrosis
-
Predict changes in the flow-volume curves in obstructive disease.
- Volume - same but takes a longer time
- Flow - decreased
-
Predict changes in the flow-volume curves in restrictive disease.
- Volume - plateaus half of normal
- Flow - Quick flow and little less and short compared to normal
-
What is the whole body plethysmograph and how is it used?
- Measures:
- Functional residual capacity (FRC) - volume in lungs when the muscles of respiration are relaxed
- Total lung capacity
-
What is FVC and FEV1, FEV2, and FEV3? Why is this information useful?
- FVC - Forced expiratory volume
- FEV1 - volume of gas exhaled in 1 sec by a forced expiration from a full inspiration
- FEV2 - end of 2 sec
- FEV3 - end of 3 sec
-
How can these parameters FEV1, FEV2, FVC be used to aid in dx of pulmonary disease?
- FVC - 80-120% normal. Lower means reduction
- FEV1 - >75% normal. Lower means obstruction
|
|
