Chapter # 3 Lung Volume Lab Flashcards
What are the most significant volumes for evaluating the effects of pulmonary disorders on Lung Volume Testing
VC, FRC, RV, and TLC
How we determine RV and TLC ON lung Volume
RV= FRC-ERV or RV= (FRC+IC) - VC
TLC= FRC + IC or TLC= (FRC+ERV) + VC
Restrictive patterns demostrate reduction on how many lung volumes?
In all of them
IRV,Vt,ERV, and RV
In obstructive patterns how many lung volumes are increased?
Only some of them..
the exception is VC that may be normal or decreased
On Obstructive Patterns If FRC values are more than 120% predicted, What does it represent?
Air Trappping
(Like Emphysema, Asthma, and Bronchitis patiens)
What happen to VC when RV increases on Obstructive Patterns
a) VC decreases Proportionally (Equivalent)
b) VC Increases as RV
c) VC does not do anything
A) VC decreases Equivalent
What disease condiction can increase RV
- Emphysema
- Bronchitis
- Obstruction
(Any condiction that causes air trapping)
True Or False
In Obstructive Pattern RV and FRC Usually increased together?
True
In Obstructive Pattern, if RV increases what will happen to patient ventilation?
More ventilation is needed to adequately exchange O2 and CO2.
(By increasing Vt or Respiratory rate)
What are the two types of Obstructive Patterns?
Air Trapping [Increased RV with proportionally reduction on VC; TLC remains constant (80% -120%)]
Hyperventilation [RV increases with little or not change in VC; TLC Increases proportionally to RV(TLC>120% of predicted)]
What type of Pattern is this when, Lung Volume are usually reduced equally.
Restrictive Patterns
When we say there is a restrictive Pattern?
When TLC is less than 80%
What pathophysiology significant can produce restrictive pattern?
- Asbestosis
- Sarcoidosis
- Complicated Silicosis
- Neuromuscular Disorders
- Respiratory Depression
What is the RV/TLC ratio?
Is the percentage of total lung volume that must be ventilated by tidal breathing
How we get RV/TLC ratio?
RV/TLC x 100
(and in normal young healthy adults the RV/TLC ratio should be between 20% - 35%)
RV/TLC% >35% + Normal TLC, this is?
A) AIR TRAPPING
B) HYPERVENTILATION
C) NONE OF THE AVOBE
AIR TRAPPING
because TLC ramain between normal range 80% - 120%
Interprete this, explain why.
RV/TLC >35% + > Normal TLC
HYPERINFLATION
Because TLC is greater than 120%
TLC ↓
VC ↓
FRC ↓
RV ↓
RV/TLC% Normal
Restrictive Pattern
TLC Normal
VC ↓
FRC ↑
RV ↑
RV/TLC% hight (>35%)
Air Trapping
Normal TLC (80% - 120%)
RV/TLC% > 35%
TLC ↑
VC normal
FRC ↑
RV ↑
RV/TLC% ↑
Hyperinflation
why? because TLC is out of range (80% - 120%) more than 120% and RV/TLC% is > 35%
What can cause an overstimate on FRC ?
Any leack during the test causes overstimation of the FRC (Bigger)
True or False
Patients with increased RV often display gas exchange abnormalities such a Hypoxemia or CO2 retention. Because RV is effort-dependent, elevated RV may also be caused by muscle weakness or suboptimal effort.
TRUE
