Oxygen Delivery

Question 1

What is the definition of atmospheric pressure?

Answer 1

The total downward force of all the gases in the atmosphere.

Question 2

What is the value of atmospheric pressure?

Answer 2

760mmhg

Question 3

What is partial pressure?

Answer 3

Partial pressure, also referred to as the tension of a gas is the pressure a single gas in the atmosphere.

Question 4

What is Dalton’s law?

Answer 4

The total pressure of a gas mixture is equal to the sum of the partial pressures of the component gases.

Question 5

How do you calculate the partial pressure of a gas?

Answer 5

Multiple the total pressure (760mmhg) by the fraction of the gas you are trying to find.

I.e oxygen is 20.93%

760 x 0.2093 = 159.1mmhg

Question 6

What are the 3 main components of atmospheric air?

Answer 6

Nitrogen, oxygen, carbon dioxide

Question 7

What % of atmospheric air is nitrogen?

Answer 7

79.03%

Question 8

What % of atmospheric air is oxygen?

Answer 8

20.93%

Question 9

What % of atmospheric air is CO2?

Answer 9

0.0004%

Question 10

What is the atmospheric pressure of nitrogen?

Answer 10

600.60mmhg

Question 11

What is the partial pressure of oxygen in the atmosphere?

Answer 11

159.10mmhg

Question 12

What is the atmospheric pressure of CO2?

Answer 12

0.3mmhg

Question 13

What is the alveolar pressure of nitrogen?

Answer 13

569.24mmhh

Question 14

What is the alveolar pressure of oxygen?

Answer 14

104mmhg

Question 15

What is the alveolar pressure of CO2?

Answer 15

40.28mmhg

Question 16

What is the alveolar pressure of water?

Answer 16

47.12mmhg

Question 17

What is the % of nitrogen in alveolar air?

Answer 17

74.9%

Question 18

What is the % of carbon dioxide in alveolar air?

Answer 18

5.3%

Question 19

What area of the lung does gas exchange occur?

Answer 19

The alveoli. Gas diffuses across the alveolar and capillary membrane.

Question 20

What are the 5 factors that affect diffusion across the alveolar capillary membrane.

Answer 20

Thickness of membrane

Surface area

Concentration of gases

Solubility of the gas in the fluid

Temperature of the fluid

Question 21

What is the average partial pressure of oxygen in VENOUS blood (PVO2)

Answer 21

40mmhg

Question 22

What is the average partial pressure of CO2 in venous blood?

Answer 22

46mmhg

Question 23

What are the 3 major factors that affect oxygen affinity to hemoglobin?

Answer 23

PH, CO2, temperature.

Question 24

What are 2 main ways Oxygen is carried in the body?

Answer 24

Hemoglobin, and transported in blood plasma.

Question 25

What are the 3 ways CO2 is transported in blood?

Answer 25

Carried as bicarbonate (65-70%) Combined with hemoglobin (23-25%) Dissolved in blood plasma (7-10%)

Question 26

What enzyme assists CO2 and H2O to create carbonic acid?

Answer 26

Carbonic anhydrase

Question 27

What does carbonic anhydrase do?

Answer 27

It joins CO2 and H2O together to create carbonic acid.

Question 28

What is the chemical name of carbonic acid?

Answer 28

H2CO3

Question 29

What does H2CO3 dissociate into?

Answer 29

Hydrogen + bicarbonate H + HCO3

Question 30

What chemical moves into cells when bicarbonate moves in? And why?

Answer 30

Chloride. To maintain electrochemical neutrality within the cell.

Question 31

What happens to bicarbonate in the lungs?

Answer 31

It becomes H2O and CO2 and is expelled

Question 32

What is the Bohr effect

Answer 32

During exhalation CO2 is exhaled causing the body to become alkaline (creates a stronger O2 affinity at lung level). When blood reaches the tissue level CO2 diffuses from tissue to capillary blood making blood more acidotic (creates less O2 affinity). Bohr effect occurs on a breath by breath basis.

Question 33

What are the 4 types of hypoxia?

Answer 33

Hypoxic hypoxia Hypemic hypoxia Stagnant hypoxia Histotoxic hypoxia

Question 34

What is hypoxic hypoxia?

Answer 34

Hypoxia due to breathing air with less than normal PO2. Or due to decreased pulmonary ventilation from, pneumonia, pneumothorax, respiratory depression. Anything that reduces the amount of oxygen available.

Question 35

What is hypemic hypoxia?

Answer 35

Hypoxia as a result of hemoglobin disruption or dysfunction. Carbon monoxide poisoning, anemia

Question 36

What is stagnant hypoxia?

Answer 36

Hypoxia due to inadequate tissue perfusion. Can be caused by any shock state, blood flow deficit, thrombosis, embolus, vasoconstriction.

Question 37

What is histotoxic hypoxia?

Answer 37

When the body is able to acquire oxygen, transport oxygen adequately, but is unable to use it at the cellular level due to cellular disruption. Example: cyanide poisoning

Question 38

Where are the CENTRAL chemoreceptors located?

Answer 38

Located on the Centerolateral surface of the medulla oblongata as well as other areas of the brainstem

Question 39

What chemical excites the central chemoreceptor causing increased respiration?

Answer 39

Hydrogen, produced from the break down of H2CO3.

Question 40

What are 7 things to consider when trouble shooting low SpO2? Fick principle

Answer 40

Adequate FiO2 Adequate diffusion across alveolar membrane Adequate affinity for O2 Adequate O2 carrying capacity Adequate perfusion Adequate O2 release at tissues Adequate ability to use O2

Question 41

What are the % O2 concentrations in a nasal cannula?

Answer 41

1Lpm = 24% 2 Lpm = 28% 3 Lpm = 32% 4 Lpm = 36% 5 Lpm = 40% 6 Lpm = 44%

Question 42

What are the O2 % in an NRB at 6-10lpm?

Answer 42

6 LPM = 60% 7 LPM = 70% 8 LPM = 80% 9 LPM = 90% 10 LPM = 95%+

Question 43

What is the calculation for oxygen tank duration?

Answer 43

PSI - safe residual pressure / flow rate x constant

Question 44

What are the constant factors for D, E, M tanks

Answer 44

D = 0.16 E = 0.28 M = 1.56