Respiratory physiology 5 Flashcards
Calculate the patient’s arterial oxygen content from the data set:
Hgb 9 g/dL
HR: 100 bpm
Stroke volume: 70 mL
SaO2: 90%
PaO2: 60 mmHg
a. 10.641 mL O2/dL
b. 11.034 mL O2/dL
c. 11.894 mL O2/dL
d. 12.002 mL O2/dL
b. 11.034 mL O2/dL
CaO2= (1.34 x Hgb x SaO2) + (PaO2 x 0.003)
Oxygen content is a measure of how much
oxygen is present in 1 deciliter (100 mL) of blood
What is the oxygen content equation?
CaO2= (1.34 x Hgb x SaO2) + (PaO2 x 0.003)
Oxygen delivery tells us
how fast a quantity of O2 is delivered to the tissues
What is the oxygen delivery equation?
DO2= CaO2 x cardiac output x 10
Oxygen consumption is the
difference between the amount of O2 that leaves the lungs and the amount of O2 that returns to the luns
What is the oxygen consumption equation?
VO2= cardiac output x (CaO2-CvO2) x 10
After oxygen diffuses through the alveolar capillary membrane, it is transported by the blood in 2 ways:
- reversibly binds with hemoglobin (97%)
- dissolves in the plasma (3%)
Each gram of hemoglobin molecule can carry a theoretical maximum of
1.39 mL of molecular oxygen
VO2 equals
3.5 mL/kg/min
Vo2 is about ___________ in a 70 kg male
250 mL/min.
P50 is reduced by: (select 3) a. hgb f
b. hyperthermia
c. hypocarbia
d. increased 2,3 DPG
e. acidosis
f. carboxyhemoglobin
a. hgb F
c. hypocarbia
f. carboxyhemoglobin
P50 is the
PaO2 where hemoglobin is 50% saturated with oxygen
The oxyhemoglobin dissociation curve tells us the
tendency of hemoglobin to bind oxygen
A right-shifted oxyhemoglobin curve means
right= release
hemoglobin has a lower affinity for oxygen
A left-sided oxyhemoglobin curve means
left= love
hemoglobin has a higher affinity for oxygen
A lower P50 reflects
a left shift (left= love)
A higher P50 reflects a
right shift (right= release)
A left shift (decreased P50) is caused by
alkalosis, decreased temperature
decreased 2,3-DPG
A right shift (increased P50) is caused by
acidosis
increased temperature
increased 2,3-DPG