Blood Gas Flashcards
What is tidal volume?
The volume of gas displaced during normal breathing
What is the functional residual capacity (FRC)?
The gas left in the lung after quiet expiration
What is the inspiratory reserve volume (IRV)?
The extra gas involved in forced inspiration, as opposed to quiet inspiration
What is the expiration reserve volume?
The has involved in forced expiration as opposed to quiet expiration
What is the vital capacity?
The amount of gas in the tidal volume, IRV & ERV combined
What is the ‘residual volume’?
The amount of gas left in the respiratory system after maximum expiration.
(Gas left in the dead space and the alveoli)
What is the total lung capacity?
The tidal volume, IRV, ERV and the Residual volume combined.
What is the conducting zone?
The parts of the respiratory system where there is no gas exchange
What is ‘alveolar ventilation’ (VA)?
VA = (tidal volume - dead space) x rate
Is it better to increase depth or rate in order to increase ventilation?
Depth, because fresh air has to get through the conducting zone to get to the alveoli to allow gas exchange.
Which is higher: the PO2 in the lungs or the PO2 in the atmosphere? Why?
In the atmosphere. The air is diluted with water when it is humidified upon inspiration.
What is the respiratory quotient?
CO2 production / O2 consumption.
Normally 0.8
What is the alveolar gas equation for?
T calculate the partial pressure of O2 in the alveoli
What is the alveolar gas equation?
PAO2 = PIO2 - (PaCO2/R)
Where PIO2 is the partial pressure of inspired air.
PaCO2 is the arterial pressure of CO2
R is the respiratory quotient
What is a VQ mismatch?
A ventilation perfusion mismatch is where there is reduced ventilation to part of the lung, so the blood here is not being oxygenated.
