EGAN’S FUNDAMENTALS OF RESPIRATORY CARE QUESTIONS AND ANSWERS 2025
When is the Transpulmonary Pressure P(TP) difference the same as the Transaveoloar pressure P(TA)
difference? - (ANSWER)When the movement of air into and out of the lungs is static the
Transpulmonary Pressure difference is the same as the Transaveolar Pressure difference.
If a person is on a mechanical ventilator, how can you obtain the Transpulmonary Pressure difference. -
(ANSWER)By performing an inspiratory or expiratory hold maneuver.
What is Elastance - (ANSWER)A measure of the distensibility of the lungs and the thorax
How do we calculate the Elastance? - (ANSWER)Elastance = change in Pressure/change in Volume
How do we measure compliance? - (ANSWER)Compliance = change in Volume/ change in Pressure
What is Resistance? - (ANSWER)A measure of airflow and tissue resistance
How do we calculate Resistance? - (ANSWER)Resistance = change in Pressure / change in flow
How do we measure flow? - (ANSWER)Flow = change in volume / unit of time
What does the equation delta pressure = (Elastance x delta volume) + (Resistance x delta flow) -
(ANSWER)both values on the right side of the equation reduce to changes in pressure. When these
changes in pressure are added, they represent the loads against which the respiratory muscles and/or
ventilator must work to achieve gas movement.
What is the consequence of a patient that has a high elastance or a high resistance? - (ANSWER)The
pressure needed to move gas will need to be high.
Using your own words describe the equation of motion for the respiratory system. - (ANSWER)It is a
measure of the pressure difference required to move air into or out of the lungs in a single breath.
, EGAN’S FUNDAMENTALS OF RESPIRATORY CARE QUESTIONS AND ANSWERS 2025
Provide the formula for the simplified equation of motion - (ANSWER)delta Pressure = (Elastance * delta
Volume) + (Resistance * delta Flow)
Describe the model of the respiratory system used to create the simplified equation of motion. -
(ANSWER)a single airway connected to a single alveoli surrounded by the pleural space
1) The Pressure measured at the opening of the airway is the Pressure at airway opening (abbreviation:
AO).
2) The Pressure measured in the alveoli is the Pressure Alveolar (abbreviation: A).
3) The Pressure measured at the body surface is the Pressure Body Surface (abbreviation: BS)
4) The Pressure measured in the pleural space (abbreviated: pl)
Define the Transrespiratory Pressure - (ANSWER)The pressure difference between the pressure
measured at the airway opening and the pressure measured at the body surface (abbreviation: TR)
In the Transrespiratory Pressure equation why does P(AO) come before P(BS) - (ANSWER)In order to
dictate the direction of flow at the end of inspiration
What is the equation for Transrespiratory Pressure - (ANSWER)P(TR) = P(AO) - P(BS)
What is the term that defines the pressure difference between the Airway Opening and the Alveoli in
Fg11.1. - (ANSWER)The Transairway pressure P(TAW)
What is the equation used to calculate the Transairway pressure? - (ANSWER)P(TAW) = P(AO) - P(A)
What does airways does the P(TAW) represent - (ANSWER)All the airway both physiological and artificial
In the model of the respiratory system pictured in fig 11.1 where does the alveolar region exist? -
(ANSWER)Between the pressure measured in the alveolus and the pressure measured in the pleural
space.
When is the Transpulmonary Pressure P(TP) difference the same as the Transaveoloar pressure P(TA)
difference? - (ANSWER)When the movement of air into and out of the lungs is static the
Transpulmonary Pressure difference is the same as the Transaveolar Pressure difference.
If a person is on a mechanical ventilator, how can you obtain the Transpulmonary Pressure difference. -
(ANSWER)By performing an inspiratory or expiratory hold maneuver.
What is Elastance - (ANSWER)A measure of the distensibility of the lungs and the thorax
How do we calculate the Elastance? - (ANSWER)Elastance = change in Pressure/change in Volume
How do we measure compliance? - (ANSWER)Compliance = change in Volume/ change in Pressure
What is Resistance? - (ANSWER)A measure of airflow and tissue resistance
How do we calculate Resistance? - (ANSWER)Resistance = change in Pressure / change in flow
How do we measure flow? - (ANSWER)Flow = change in volume / unit of time
What does the equation delta pressure = (Elastance x delta volume) + (Resistance x delta flow) -
(ANSWER)both values on the right side of the equation reduce to changes in pressure. When these
changes in pressure are added, they represent the loads against which the respiratory muscles and/or
ventilator must work to achieve gas movement.
What is the consequence of a patient that has a high elastance or a high resistance? - (ANSWER)The
pressure needed to move gas will need to be high.
Using your own words describe the equation of motion for the respiratory system. - (ANSWER)It is a
measure of the pressure difference required to move air into or out of the lungs in a single breath.
, EGAN’S FUNDAMENTALS OF RESPIRATORY CARE QUESTIONS AND ANSWERS 2025
Provide the formula for the simplified equation of motion - (ANSWER)delta Pressure = (Elastance * delta
Volume) + (Resistance * delta Flow)
Describe the model of the respiratory system used to create the simplified equation of motion. -
(ANSWER)a single airway connected to a single alveoli surrounded by the pleural space
1) The Pressure measured at the opening of the airway is the Pressure at airway opening (abbreviation:
AO).
2) The Pressure measured in the alveoli is the Pressure Alveolar (abbreviation: A).
3) The Pressure measured at the body surface is the Pressure Body Surface (abbreviation: BS)
4) The Pressure measured in the pleural space (abbreviated: pl)
Define the Transrespiratory Pressure - (ANSWER)The pressure difference between the pressure
measured at the airway opening and the pressure measured at the body surface (abbreviation: TR)
In the Transrespiratory Pressure equation why does P(AO) come before P(BS) - (ANSWER)In order to
dictate the direction of flow at the end of inspiration
What is the equation for Transrespiratory Pressure - (ANSWER)P(TR) = P(AO) - P(BS)
What is the term that defines the pressure difference between the Airway Opening and the Alveoli in
Fg11.1. - (ANSWER)The Transairway pressure P(TAW)
What is the equation used to calculate the Transairway pressure? - (ANSWER)P(TAW) = P(AO) - P(A)
What does airways does the P(TAW) represent - (ANSWER)All the airway both physiological and artificial
In the model of the respiratory system pictured in fig 11.1 where does the alveolar region exist? -
(ANSWER)Between the pressure measured in the alveolus and the pressure measured in the pleural
space.
