MECHANICAL VENTILATION EXAM 1 EXPECTED
QUESTIONS WITH VERIFIED ANSWERS
Question 1.
Ventilation
ANSWER
Movement of air into and out of the lungs
Question 2.
External respiration
ANSWER
Exchange of O2 and CO2 between alveoli and pulmonary capillaries (breathing)
Question 3.
Internal respiration
ANSWER
Transfer of O2 between the blood and the cells (cellular level)
Question 4.
Transpulmonary pressure
ANSWER
Pressure difference between alveolar space and pleural space. Pressure required to maintain
alveolar inflation.
Question 5.
Transrespiratory pressure
ANSWER
Pressure difference between airway opening and body surface. Pressure required to inflate
the lungs and airways during positive pressure ventilation.
,Question 6.
Transairway pressure
ANSWER
Pressure difference between airway opening and alveolus. Pressure gradient required to
produce airflow in conductive airways. Pressure that must be generated to overcome airway
resistance.
Question 7.
Transthoracic pressure
ANSWER
Pressure difference between the alveolar space or lung and the body's surface. Pressure
required to expand or contract lungs and chest wall at the same time.
Question 8.
Elastance
ANSWER
Tendency of a structure to return to its original form after being stretched or acted on by an
outside force.
Question 9.
Compliance
ANSWER
The relative ease with which the structure distends.
Question 10.
Resistance
ANSWER
Measurement of the frictional forces that must be overcome during breathing.
Question 11.
, Value for intraalveolar pressure thoughout inspiration and expiration during normal, quiet
breathing
ANSWER
0 cm H2O
Question 12.
Formula for compliance
ANSWER
C = Vt/(Pplateau-EEP or PEEP)
Question 13.
Formula for resistance
ANSWER
Raw = (PIP-Pplateau)/flow Raw = Pta/flow
Question 14.
How changes in lung compliance affect peak pressure measured during inspiration with a
mechanical ventilator
ANSWER
Thoracic compliance generally doesn't change significantly in a ventilated patient; BUT, if a
patient actively inhales or exhales during measurement of plateau pressure, the resulting
value will be inaccurate.
Question 15.
Changes in airway conditions that can lead to increased resistance
ANSWER
Airway resistance is increased when an artificial airway is inserted. Smaller internal diameter
of tube = greater resistance to flow. Decrease in diameter of the airways can also cause
airway resistance. Results of increased resistance: less pressure is available to expand the
alveoli; smaller volume of gas available for gas exchange; more force must be exerted to
maintain adequate gas flow.
QUESTIONS WITH VERIFIED ANSWERS
Question 1.
Ventilation
ANSWER
Movement of air into and out of the lungs
Question 2.
External respiration
ANSWER
Exchange of O2 and CO2 between alveoli and pulmonary capillaries (breathing)
Question 3.
Internal respiration
ANSWER
Transfer of O2 between the blood and the cells (cellular level)
Question 4.
Transpulmonary pressure
ANSWER
Pressure difference between alveolar space and pleural space. Pressure required to maintain
alveolar inflation.
Question 5.
Transrespiratory pressure
ANSWER
Pressure difference between airway opening and body surface. Pressure required to inflate
the lungs and airways during positive pressure ventilation.
,Question 6.
Transairway pressure
ANSWER
Pressure difference between airway opening and alveolus. Pressure gradient required to
produce airflow in conductive airways. Pressure that must be generated to overcome airway
resistance.
Question 7.
Transthoracic pressure
ANSWER
Pressure difference between the alveolar space or lung and the body's surface. Pressure
required to expand or contract lungs and chest wall at the same time.
Question 8.
Elastance
ANSWER
Tendency of a structure to return to its original form after being stretched or acted on by an
outside force.
Question 9.
Compliance
ANSWER
The relative ease with which the structure distends.
Question 10.
Resistance
ANSWER
Measurement of the frictional forces that must be overcome during breathing.
Question 11.
, Value for intraalveolar pressure thoughout inspiration and expiration during normal, quiet
breathing
ANSWER
0 cm H2O
Question 12.
Formula for compliance
ANSWER
C = Vt/(Pplateau-EEP or PEEP)
Question 13.
Formula for resistance
ANSWER
Raw = (PIP-Pplateau)/flow Raw = Pta/flow
Question 14.
How changes in lung compliance affect peak pressure measured during inspiration with a
mechanical ventilator
ANSWER
Thoracic compliance generally doesn't change significantly in a ventilated patient; BUT, if a
patient actively inhales or exhales during measurement of plateau pressure, the resulting
value will be inaccurate.
Question 15.
Changes in airway conditions that can lead to increased resistance
ANSWER
Airway resistance is increased when an artificial airway is inserted. Smaller internal diameter
of tube = greater resistance to flow. Decrease in diameter of the airways can also cause
airway resistance. Results of increased resistance: less pressure is available to expand the
alveoli; smaller volume of gas available for gas exchange; more force must be exerted to
maintain adequate gas flow.
