1. How do you determine ERV?
2. What is a normal ERV?
1. FRC - RV = ERV
2. about 1500mls
1. What is a normal IRV?
1. 2.5 - 3L
1. What Lung capacities and volumes can not be measured by spirometry?
1. TLC, FRC, RV
1. What is a normal RV?
2. How will this change for lung dz states such as emphysema?
2. Residual volume will be greater
1. The addition of all lung volumes = what measurement?
2. What is another way to calculate this measurement?
1. Total Lung Capacity = TLC
2. Vital capacity + Residual Volume
1. What is a normal TLC?
1. about 6 Liters
1. What is FRC and how is it calculated?
2. What does a health FRC prevent?
3. Pts with low FRC such as obesity/pregnant will exhibit what O2 symptoms?
1. ERV(1.5L) + RV(1.5L) = FRC (3000mls)
2. Normal FRC is MUCH larger than TV. Therefore prevents dramatic O2 and PO2 with each breath.
3. Fluctuations in PO2 - UP during inspiration and DOWN during expiration.
1. What is the Inspiratory capacity?
1. VT + IRV = 3000mls
1. Define Vital capacity and the amnt of air contained.
2. What does vital capacity assess?
3. What things increase vital capacity and what things decrease vital capacity?
1. Amt of air maximally exhaled after a maximal inspiration. about 4.5L
2. the strength of thoracic muscles and Pulm fx.
3. - Body size, male, Physical condition
- Smoking, obesity, supine, posture
1. What is FEV1
2. About how much of the VC does this account?
1. Forced Expiratory Volume in 1 second.
1. Spirometry cannot measure?
1. RV, FRC, TLC
1. What are 2 ways to measure FRC, RV, TLC?
1. - Helium-dilution
1. What is body Plethysmography and what Law does it utilize?
1. Pt placed in a closed chamber and makes inspiratory effort against a closed airway.
2. Utilizes Boyles law to measure pressure and volume changes.
1. What is Closing Volume?
2. What is Closing Capacity?
3. An increase in CV and CC occur with?
1. volume where airway closure begins to occur
2. Lung capacity where small airways begin to close
3. Age, smoking, lung dz, body position (supine > upright)
1. How is closing capacity calculated?
2. Closing capacity increases or decreases with age?
3. during Middle age, CC = FRC?
4. Neonates CC>FRC
5. What is probably responsible for decline of PaO2 in elderly
1. Closing volume + RV = Closing capacity
5. Increase in CC prob responsible to decline of PaO2.
1. Lung volume is below the CC what happens?
1. Shunt. Perfused but not ventilated alveoli.
1. What are some states that cause increased closing capacity?
increased lft atrial pressures
decreased plasma oncotic pressure
1. What is the difference in pleural pressure in the apex and the base of the lungs.
2. what is the implication for the alveoli in the base of the lungs.
1. The apex has more negative pressure d/t gravity and the base of the lungs are less negative.
2. At end expiration, FRC, they are less inflated than those in non-dependent zones
What is the concept called: The lung vol. at which airways in the lower dependent parts of the lung begin to close off.
1. closing volume
1. Which area of the lung has the greatest minute ventilation, Apex of Base?
2. Blood flow is greater in the Apex or Base?
3. Which alveoli in the lungs are more susceptible to collapse and therefore greater contributors to V/Q mismatch.
1. What is Ventilation?
1. The process by which O2 and CO2 are transported to and from the lungs.
1. What is anatomical dead space?
2. What is an easy way to calculate this?
1. Vol of air in conductive zone
2. ~ to pt wt in LBS ~ 150mls
1. What is Physiological dead space?
2. What is the symbol?
3. In healthy ppl, Anatomical dead space is = to physiological deadspace.
1. Anitomical deadspace + Alveolar Deadspace
1. Minute ventilation is also know as?
2. T/F - minute ventilation is equal to alveolar ventilation?
1. Total ventilation
2. False. It is not equal 500x15RR = 7500mls
1. What is Alveolar Ventilation?
3. How is this determined?
4. First you must determine______ by using what equation?
1. The vol that actually reaches respiratory zone and involved in gas exchange
3. VA = (VT-VD) x RR
4. VD - Bohrs equation
1. What is Bohrs equation
1. Figures the proportion of TV that is VD
VD = VT x (PaCO2 - PECO2/PaCO2)
1. VA is inversely or proportional to PaCO2?
1. Inversely proportional - increasing Ventilation x2 will decrease PaCO2 in half. The opposite is true.
1. Alveolar Ventilation equation?
2. What 2 assumptions are made by the Alveolar ventilation equation.
3. Additionally is assumed that the PP drop of O2 = PP drop of CO2. This is completely true, therefore a fudge factor is used.
1. Determines alveolar PAO2 levels
2. - PIO2 = PaO2
- PACO2 = PaCO2
1. We can determine then that as Alveolar PACO2 increases, PAO2 decreases.
1. What is Alveolar Deadspace?
2. Give examples
3. How do you know if there is Alveolar Deadspace present?
1. When air is in the Alveoli but no blood passing by.
2. PE, low Venous Return, High PEEP
1. What is a normal VD/VT ratio or percent?
1. 0.3 or 30%
1. What are the 2 ways to calculate deadspace?
2. Fowlers method uses?
1. Fowlers method and Bohr's method
2. Plotting N2 conc. agianst expired volume
1. What are situations that would alter Anatomical dead space?
- Traction - increase VD
- compression - decrease VD
1. Alveolar deadspace is calculated?
1. Measuring physiological deadspace (PaCO2-ETCO2) and subtracting Anatomical Deadspace