Term
| What instrument is used to measure lung volumes? |
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Definition
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Term
| What is a Forced Expiratory Maneuver? |
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Definition
| Patient is instructed to perform maximal inspiration to Total Lung Capacity (TLC) and then forcefully exhale to Residual Volume (RV). |
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Term
| What is Forced Vital Capacity (FVC)? |
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Definition
| The amount of air expired during the Forced Expiratory Maneuver. |
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Term
| T/F: In normal individuals FVC is usually larger than VC. |
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Definition
| False. In healthly normal individuals, FVC = VC. |
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Term
| What is Forced Expiratory Volume in One Second (FEV1)? |
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Definition
| The volume of air that is forcefully exhled in the first one second. |
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Term
| What is the normal value for FEV1/FVC? |
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Definition
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Term
| What is Forced Mid-Expiratory Flow (FEF25-75)? |
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Definition
| Expiratory flow over the mid-portion of the FVC (25-75% of the FVC). |
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Term
| What volumes cannot be measured by spirometery? |
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Definition
Residual Volume - Volume remaining in the lungs after complete expiration
Functional Residual Capacity - Volume remaining in lungs after passive expiration |
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Term
| Can Total Lung Capacity be measured with conventional spirometery? |
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Definition
| No. Since TLC would need a measurement of RV which cannot be measured by spirometry. |
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Term
| How can TLC be measured with spirometry? |
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Definition
| With the addition of helium, FVC can be measured to find TLC. |
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Term
| What is a Restrictive Ventilation Defect? |
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Definition
| A disease that makes the lung tissue less compliant. (eg. Fibrosis, sarcoidosis, interstitial edema, pneumonia) |
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Term
| How can you use spirometry to diagnose restrictive lung disease? |
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Definition
| There is reduced lung volume so FVC is reduced to <80% of predicted value. |
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Term
| What is can Obstructive Ventilation Defect? |
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Definition
| Diseases that create increased airway resistance and destroy lung elastic tissue. (eg. Asthma, bronchitis, emphysema) |
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Term
| How can you diagnose Obstructive Ventilation Defects with spriometry? |
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Definition
There is a markedly reduced FEV1/FVC ratio. This shows there is a defect with expiration.
Mild - 65 - 75%
Moderate - 55 - 65%
Severe - <55% |
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Term
| T/F: Obstruction to ventilation will decrease the RV. |
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Definition
| False. There is more air trapping and RV will increase. |
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Term
| Flow is more tubulent in large or small airways? |
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Definition
| Large. This is why breath sounds originate from the large airways. (eg. Trachea, bronchi) |
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Term
| What must occur in order to small airways in order to have total airway resistance affected? |
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Definition
| There must be a 50% reduction in small airway cross sectional area. Before this, increase in small airway resistance has little effect. |
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Term
| Small airways have less resistance when lung volumes are large or small? |
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Definition
| When lung volumes are larger, lumens are spread wider due to small airways being in the elastic tissue. Thus large lung volumes create less resistance. |
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Term
| When does airway collapse occur? |
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Definition
| When pleural pressure is greater than the airway lumen pressure |
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Term
| What are the determinants of Expiratory Flow? |
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Definition
1. Lung Elastic Recoil - Expiratory flow will be higher at larger lung volumes and lower at smaller lung volumes
2. Airway Resistance - Airway resistance will be lower in larger lung volumes than smaller lung volumes |
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Term
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Definition
| The maximum expiratory flow that can be achieved at a specific lung volume. Flow is proportional to lung elastic recoil and inversely proportional to upstream airway resistance. |
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Term
| What is the effect on air flow in an emphysematous lung? |
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Definition
| The airflow will be decreased since there is a lower amount of elastic tissue which in turn reduces the amount of recoil. |
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Term
| What will patients with restrictive lung disease do with their breathing in order to minimize the amount of work performed? |
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Definition
| They will take shorter, shallower breaths. |
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Term
| How is respiration affected in Obstructive Lung Diseases? |
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Definition
| Inflow and outflow are both affected so patients must increase the amount of work performed during both cycles of respiration. Patients with COPD will adopt a slower, deeper, pattern of breathing. |
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Term
| What is COPD and how is it characterized? |
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Definition
| Chronic Pulmonary Obstructive Disease is collectively asthma, bronchitis, and emphysema. It is characterized by fixed and reversible bronchoconstriction, airway edema, increased mucous production, and decreased mucous clearance. |
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