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Flashcards in Pulmonary Diagnostic Testing Deck (55):
0

What is the calculation for the partial pressure oxygen (PO2) in the alveoli?

PAO2= (PB-PH20)FIO2-PaCO2/.8

1

What is the purpose of A-aDO2 (the A-a Gradient)?

This equation measures the difference between alveolar and arterial PO2

2

What is the formula to the A-a Gradient?

A-aDO2= PAO2-PaO2

3

What is the interpretation of an A-a Gradient of 25-65 mm Hg on 100%?

Normal Value

4

What is the interpretation of an A-a Gradient of 66-300 mm Hg?

V/Q Mismatch

5

What is the interpretation of an A-a Gradient greater than 300 mm Hg?

Shunting

6

What is the difference between the P/F Ratio and the A-a Gradient?

P(A-a)O2 : 300 means Shunting

7

Which Pulmonary Diagnostic Testing of 300 signifies ALI?

P/F Ratio

8

Which Pulmonary Diagnostic Testing of 300 signifies V/Q Mismatch?

P(A-a)O2 Gradient

9

What is CaO2?

Arterial Oxygen Content

10

What does measuring CaO2 mean?

It is the best measurement of oxygen delivered to the tissues, or the best index of oxygen transport; oxygen carried by the hemoglobin and dissolved in the plasma.

11

What is the formula for CaO2?

CaO2= (Hb x 1.34 x SaO2) + (PaO2 x .003)

12

What is the normal value for CaO2?

17-20 vol% or 19 vol%

13

What is CvO2?

Mixed venous oxygen content

14

What does the CvO2 mean?

It tells about the total amount of oxygen carried in the mixed venous blood

15

How is the CvO2 measured?

The blood is drawn from the Pulmonary Artery via the balloon-tip, flow directed (Swanz-Ganz) catheter

16

What is the formula for CvO2?

CvO2= (Hb x 1.34 x SvO2) + (PvO2 x .003)

17

What is the normal value for CvO2?

14 vol% (12-16 vol%)

18

When cardiac output decreases , what else decreases?

CvO2 and SvO2

19

Normally, what is the pressure on the left ventricle?

120/0

20

What is the mean arterial pressure (MAP) in the systemic arteries?

90 mm Hg (120/80)

21

What is the normal value for the Central Venous Pressure (CVP)?

2-6 mm Hg (<10)

22

What are the normal values of the Pulmonary Artery Pressure (PAP)?

25/8 mm Hg (teens)

23

What are the normal values for the Pulmonary Capillary Wedge Pressure (PCWP)?

8 mm Hg

24

What is the normal values for Cardiac Output (QT)?

4-8 L/min

25

What is Cardiac Index?

Cardiac Output divided by the Body Surface Area

26

What is the Cardiac Output divided by the Body Surface Area?

Cardiac Index

27

What is a normal adult cardiac index (CI)?

2-4 L/min/m2

28

If the PCWP is high, where is the problem?

In the left heart

29

What pressures will be affected if there is a problem in the capillaries?

Mean Arterial Pressure (systemic)

30

If CVPs are high, where is the problem?

In the right heart

31

What pressures will be affected if the problem is in the lungs?

Pulmonary Artery Pressures (PAP)

32

What is the C(a-v)O2 (or arterial-venous oxygen content difference)?

It is CvO2 subtracted from CaO2, and measures the oxygen consumption of the tissues

33

What indicates a decreasing cardiac output when referring to the C(a-v)O2?

An increase in the C(a-v)O2; which means a decreasing CvO2

34

What P/F ratio signifies ALI?

A ratio less than 300 torr

35

What P/F ratio signifies ARDS?

A ratio less than 200 torr

36

If O2 Consumption (VO2) and O2 Content Difference (C(a-v)O2) are known, what equation will be used?

QT (Cardiac Output)

37

What is the QT (Cardiac Output) equation formula?

VO2/
C(a-v)O2 (10)

38

What is the normal value for QT (Cardiac Output)?

4-8 L/min (5)

39

What is QS/QT?

The shunt equation

40

What does the QS/QT (shunt equation) mean?

It is the portion of the cardiac output (QT) that is shunted (QS)

41

What is the QS/QT (shunt equation) formula?

(A-aDO2)(.003)/
(A-aDO2).003 + C(a-v)O2

42

Calculate the percent (%) shunt when A-aDO2 is 300 torr and the C(a-v)O2 is 3.6 vol%

.20 or 20% shunt

43

What are the normal values for the QS/QT (shunt equation)?

3-5%

44

How can the PaO2 value be estimated from the SaO2?

Subtract 30 from the SaO2

45

If SaO2 values are 70, 80, or 90, what are the estimated PaO2 values?

40, 50, and 60 PaO2

46

What is the Deadspace to Tidal Volume Ratio?

It is the percentage of tidal volume that is deadspace (areas of the lung that do not participate in gas exchange) ventilation without perfusion

47

What are normal values for the VD/VT (deadspace to tidal volume ratio)?

20-40%, (up to 60% for ventilator patients).

48

What is PaCO2-PECO2 x 100/
PaCO2 ?

The VD/VT (deadspace to tidal volume ratio) formula

49

What indicates a deadspace producing disease (pulmonary embolism) when it comes to the deadspace to tidal volume ratio?

An INCREASE in the VD/VT ratio

50

Calculate the VD/VT ratio for a patient who has a PaCO2 of 40 torr and a PECO2 of 30 torr.

.25 or 25%

51

What is the formula for the Desired Minute Volume equation?

(Current VE x Current PaCO2) = (Desired VE x Desired PaCO2)

52

With a minute volume of 8 L/min, the patient has a PaCO2 of 50 torr. What minute volume is required to achieve a PaCO2 of 40 torr?

VE = 10 L/min

53

What is the formula for the Desired PaO2 equation?

FIO2 x Desired PaO2/
Current PaO2

54

What is the normal value for DLCO?

25 ml CO/min/mm Hg (STPD)