Respiratory physiology 4 Flashcards
What are the 5 lung volumes?
inspiratory reserve volume
tidal volume
expiratory volume
residual volume
closing volume
What is the inspiratory reserve volume for a 70 kg male?
3000 mL
What is the tidal volume for a 70 kg male?
500 mL
What is the expiratory volume for a 70 kg male?
1100 mL
What is the residual volume for a 70 kg male?
1200 mL
What is the closing volume for a 70 kg male?
variable
What are the five lung capacities?
total lung capacity
vital capacity
inspiratory capacity
functional residual capacity
closing capacity
What makes up total lung capacity?
residual volume + expiratory reserve volume + tidal volume + inspiratory reserve volume
What is the total lung capacity for a 70 kg male?
5800 mL
What makes up vital capacity?
expiratory reserve volume + inspiratory reserve volume + tidal volume
What is the vital capacity for a 70 kg male?
4600 mL
What makes up inspiratory capacity?
tidal volume + inspiratory reserve volume
What is the inspiratory capacity for a 70 kg male?
3,500 mL
What makes up the functional residual capacity?
residual volume + expiratory reserve volume
What is the functional residual capacity for a 70 kg male?
2300 mL
__________ cannot measure residual volume, TLC, FRC, closing capacity, or closing volume
Spirometry
What is the inspiratory reserve volume?
volume of gas that can be forcibly inhaled after a tidal inhalation
What is the tidal volume?
volume of gas that enters and exits the lungs during tidal breathing
What is the expiratory reserve volume?
volume of gas that can be forcibly exhaled after a tidal exhalation
What is the residual volume?
volume of gas that remains in the lungs after a complete exhalation
What is the closing volume?
the volume above residual volume where the small airways begin to close
Tidal volume is
6-8 mL/kg
Vital capacity is
65-75 mL/kg
FRC is
35 mL/kg
Lung volumes are ____ in females
~25% smaller
Patients with asthma, emphysema, and bronchitis have an increased
residual volume, closing capacity and total lung capacity
What conditions reduce FRC? (select 2).
a. advanced age
b. pulmonary edema
c. COPD
d. obesity
b. pulmonary edema
d. obesity
Functional residual capacity is the
volume of air in the lungs at end-expiration
FRC is the reservoir of oxygen that
prevents hypoxemia during apnea
Conditions that decrease FRC include
general anesthesia
obesity
pregnancy
supine position
upright position
neuromuscular blockers
surgical displacement of the lung
neonates
high FiO2
fluid overload
Conditions that increase FRC include
PEEP
advanced age
sigh breaths
prone & sitting positions
At FRC, the inward elastic recoil of the lungs is balanced by
the outward elastic recoil of the chest wall- this is called static equilibrium
FRC can be measured indirectly by
nitrogen washout
helium wash-in
body plethysmography
How can you calculate the time until a patient desaturates?
time until desaturation= FRC/oxygen consumption
These two factors can be used to restore FRC:
alveolar recruitment maneuvers
PEEP
Closing capacity is the sum of closing volume and:
a. residual volume
b. expiratory reserve volume
c. functional residual capacity
d. tidal volume
a. residual volume
Closing volume is the volume above
residual volume where the small airways begin to close during expiration
Factors that increase closing volume include
COPD
LV failure
obesity
surgery
extremes of age
pregnancy
When closing capacity is greater than FRC, airway closure occurs
during tidal breathing
Early airway closure during tidal breathing contributes to
intrapulmonary shunting and hypoxemia
Closing capacity increases as
we age
At age 30, closing capacity~FRC when
under general anesthesia
At age 44, closing capacity~FRC when
supine
At age 66, closing capacity~FRC when
standing
Factors that increase closing volume mnemonic:
CLOSE-P
COPD
Left ventricular failure
obesity
surgery
extremes of age
pregnancy
