Partial Pressure Of O2 Inspired

Question 1

Partial pressure of 02 inspired

Answer 1

0.21 X (760-47) = 150mmHg

760 = atmospheric pressure or barometric pressure 
47= water vapor pressure

Question 2

Total ventilation

Answer 2

Minute ventilation = TV x RR (min)

*35% anatomical dead space

E.g. TV is 500ml
RR(min) is 10 breaths/min
Hence minute vol. = 500 X 10 = 5000ml/min
*35% anatomical dead space= 0.35X500 = 175mls
Hence alveolar ventilation = 500-175= 325mls X 10= 3250mls

Question 3

End tidal CO2 monitoring

Answer 3

All expired CO2 is directly related to the alveolus ~40mmHg = also equal to PaO2 of patient’s blood

Question 4

Oxyhemoglobin dissociation curve

Answer 4

PaO2 of > or equal to 60mmHg = O2 stat of 90-100%