RESP 1340 50-107

Question 1

What should be done when using therapeutic agents that can cause metHb? what can be used to treat?

Accepted Answer

Methylene blu, Ascorbic acid

Question 2

What is the normal O2 saturation range of Hb?

Accepted Answer

95-100%

Question 3

What formula is used to calculate the amount of dissolved O2 in blood?

Accepted Answer

PaO2 x 0.003

Question 4

Define hypoxia?

Accepted Answer

When O2 delivery falls short of cellular needs

Question 5

What is the affinity of Hb for carbon monoxide compared to oxygen?

Accepted Answer

200 times greater than O2

Question 6

What is the normal form of iron in hemoglobin?

Accepted Answer

Fe2+

Question 7

How does decreased 2,3 DPG shift the OHb curve? How does this affect affinity of Hb for O2?

Accepted Answer

Shifts to the left

Question 8

What happens to the oxyhemoglobin dissociation curve when pH lowers?

Accepted Answer

Decrease Hb affinity for O2, Right shift

Question 9

What is methemoglobinemia (metHb)?

Accepted Answer

Abnormal iron (Fe3+) cannot bind with oxygen, Alters HbO2 affinity (left shift)

Question 10

What happens to Hb saturation for O2 when the OHb curve shifts to the left?

Accepted Answer

Need a lower pressure

Question 11

Define saturation as it pertains to Hb?

Accepted Answer

Saturation means that the hemoglobin is actively carrying O2

Question 12

In the upright lung, where is the majority of perfusion?

Accepted Answer

At the base

Question 13

Define hypoxemia?

Accepted Answer

When the PaO2 is decreased to lower than the predicted normal

Question 14

What is the movement of chloride ions into the RBC in exchange for the movement of bicarbonate ions out to the plasma?

Accepted Answer

Chloride shift, Hamburger phenomenon

Question 15

What is the formula for calculating total O2 content (CaO2)?

Accepted Answer

(0.003 X PO2)+ (Hbtotal X 1.34 X SO2)

Question 16

When can a decrease in alveolar ventilation occur?

Accepted Answer

Decreased tidal volume

Question 17

40-50-60 PO2 corresponds with ___-___-___- SaO2

Accepted Answer

70-80-90

Question 18

What is the most common cause of hypoxemia in patients with respiratory diseases?

Accepted Answer

V/Q imbalances

Question 19

Calculate the CaO2 for a patient with Hb 15g/dl, PaO2 100 mmHg, SaO2 97%?

Accepted Answer

19.797mL/dL of O2

Question 20

In what direction does the oxyhemoglobin dissociation curve shift when body temp decreases?

Accepted Answer

Shifts left, Oxyhemoglobin holds onto O2 more

Question 21

What enzyme is responsible for accelerating the reaction between CO2 and H2O?

Accepted Answer

Carbonic Anhydrase (CA)

Question 22

How much dissolved O2 is there in blood for a person with a PaO2 of 100mmHg?

Accepted Answer

0.3 mL/dL of dissolved O2

Question 23

What is the formula used to calculate expected PaO2 based on age?

Accepted Answer

Expected PaO2= 100- (0.323 x age in years)

Question 24

What can impaired CO2 removal by the lungs cause?

Accepted Answer

1.V/Q mismatch, Decreased VE, Increased VD

Question 25

What is caroxyhemoglobin (HbCO)?

Accepted Answer

hemoglobin combined with carbon monoxide

Question 26

How much more blood do the bases receive compared to the apexes?

Accepted Answer

20 times more

Question 27

What happens to Hb saturation for O2 when the OHb curve shifts to the right?

Accepted Answer

Need a higher pressure.

Question 28

What are the V/Q ratios for the middle?

Accepted Answer

V is about equal to Q (about 1) causing an equal V/Q

Question 29

How does pH affect the loading and unloading of O2?

Accepted Answer

Low pH, more O2 is unloaded Hb’s affinity for O2 decreases, High pH, less O2 is unloaded, because Hb’s affinity for O2 is increased

Question 30

Define dysoxia?

Accepted Answer

Abnormal cellular function prevents proper uptake of O2

Question 31

What is the normal value for P50?

Accepted Answer

26.6 mmHg

Question 32

What are the three forms of transport of CO2?

Accepted Answer

Chemically combined with protein (hemoglobin), Dissolve in physical solution, Ionized as bicarbonate

Question 33

What are the two ways O2 is carried in blood?

Accepted Answer

Dissolve in plasma and Red Blood Cells (RBC) fluid., Reversible chemical combination with hemoglobin.

Question 34

What shape is the oxyhemoglobin dissociation curve?

Accepted Answer

S-curve / sigmoid curve

Question 35

What is the significance of the steep part of the oxyhemoglobin dissociation curve?

Accepted Answer

A small change in PaO2, PaO2 is less than 60mmHg, Changes SaO2 significantly when we are less than 90%,

Question 36

What are causes of hypoxia?

Accepted Answer

dysoxia (abnormal cellular function prevents proper uptake of O2), Hypoxemia (low arterial O2), Cardiac output or diffusion is decreased (shock or ischemia)

Question 37

Of the two methods, which carries more O2?

Accepted Answer

Reversible chemical combination with hemoglobin.

Question 38

What can cause dysoxia?

Accepted Answer

When tissue O2 consumption becomes dependent on O2 delivery….. Lactic acid

Question 39

How much more ventilation is received in the bases compared to the apexes?

Accepted Answer

4 times more

Question 40

In what direction does the oxyhemoglobin dissociation curve shift when body temp increases?

Accepted Answer

Shifts right, cells need O2 to meet metabolic demands

Question 41

Define the Bohr effect?

Accepted Answer

Defines the effect of pH on hemoglobin (Hb) affinity for O2

Question 42

What does it mean when the P50 is decreased?

Accepted Answer

The HG curve shifts to the left if P50 increased

Question 43

What are the V/Q ratios for the top?

Accepted Answer

V>Q causing a high V/Q about 3

Question 44

How does increased 2,3 DPG shift the OHb curve? How does this affect affinity of Hb for O2?

Accepted Answer

Shifts to the right

Question 45

What does it mean when the P50 is increased?

Accepted Answer

The HG curve shifts to the right if P50 increased

Question 46

How much O2 can 1 gram of Hb carry?

Accepted Answer

1.34 mL of O2

Question 47

What does 2,3 DPG do to deoxygenated Hb? How does it affect the affinity of Hb for O2?

Accepted Answer

It stabilizes deoxygenated Hb, and decreases oxygen’s affinity for Hb

Question 48

What is the name of a fully saturated hemoglobin molecule?

Accepted Answer

Oxyhemoglobin

Question 49

What does the upper flat portion of the oxyhemoglobin dissociation curve represent?

Accepted Answer

greater than 100mmHg has a strong affinity for oxygen, small changes in PaO2 don’t affect SaO2 as much, Occurs with SaO2 >90 PaO2

Question 50

What is the Haldane effect?

Accepted Answer

CO2 is unloaded, HbO2 decreases and facilitates CO2 transport to the lungs, HbO2 increases and CO2 content decreases, Relationship between PaCO2 and CO2 content

Question 51

What is the reaction formula for hydrolysis of CO2? carbonic acid) which then dissociates into HCO3 + and H+ ions.

Accepted Answer

CO2 + H20= H2CO3

Question 52

What is P50 used for?

Accepted Answer

Partial pressure of O2 at which hemoglobin is 50% saturated, standardized at pH of 7.40

Question 53

What are the V/Q ratios for the base?

Accepted Answer

V<Q, causing a low V/Q of about 0.6.

Question 54

Calculate the CvO2 for a patient with Hb 15g/dl, PvO2 40 mmHg, SvO2 75%

Accepted Answer

15.195

Question 55

What is the normal range for CaO2 in arterial blood?

Accepted Answer

16-20mL/dL

Question 56

If a person has 15 grams of Hb, how much O2 can it carry?

Accepted Answer

20.1 mL/dL of O2

Question 57

What happens to the oxyhemoglobin dissociation curve when pH raises?

Accepted Answer

Left shift, increases Hb affinity for O2

Question 58

What are common causes of metHb?

Accepted Answer

nitroglycerin, lidocaine, NO (nitric oxide)

RESP 1340 50-107

Questions 58

RESP 1340 50-107

Questions 58