Pulmonary Diagnostic Testing

Question 1

What are the three primary sites for obtaining an ABG?

Answer 1

• Radial
• Brachial
• Femoral (only if BP is low; 60/40)

Question 2

In how many seconds should the hand pink up when doing a modified Allen’s test?

Answer 2

1-2 seconds after releasing the ulnar artery

Question 3

If there is bleeding after drawing an ABG, how long should you hold pressure?

Answer 3

At least 5 minutes

Question 4

When a patient is on Anticoagulant Therapy (Heparin), you should…

Answer 4

Apply pressure longer

Question 5

What happens if there are air bubbles in the ABG sample?

Answer 5

• PaCO2 decreases to 0 torr
• PaO2 increases/decreases toward 150 torr
• pH increases

Question 6

What happens if the ABG sample isn’t iced?

Answer 6

• PaCO2 increases
• PaO2 decreases
• pH decreases

Question 7

What happens to the ABG sample if there is too much liquid heparin?

Answer 7

• PaCO2 decreases toward 0 torr
• PaO2 increases/decreases toward room air (150 torr)
• pH decreases down to 7.0

Question 8

How is a capillary sample arterialized?

Answer 8

Wrapped in a wet, warm cloth at 45 Celsius for 5-7 minutes

Question 9

Capillary gases shouldn’t be used to monitor what?

Answer 9

Oxygen therapy

Question 10

Who are capillary samples or heel sticks commonly used on?

Answer 10

Infants

Question 11

Who are umbilical arterial lines commonly used on?

Answer 11

Newborns

Question 12

What is the umbilical artery’s PO2 used to regulate?

Answer 12

FiO2

Question 13

What does an Arterial Line provide?

Answer 13

Continuous monitoring of systemic blood pressure and access for arterial blood sampling

Question 14

If the transducer is above the catheter, the pressure is…

Answer 14

Lower than actual

Question 15

If the transducer is below the catheter, the pressure is…

Answer 15

Higher the actual

Question 16

When the blood gas machine is functioning properly, the measured control values will be close to the mean and within…

Answer 16

+/- 2 standard deviations

Question 17

Alveolar Air Equation, Alveolar PO2 (PaO2)

Answer 17

(Pb - PH2O) x FiO2 - PaCO2/R

Question 18

A-a Gradient Equation (A-aDO2, P A-aO2)

Answer 18

PAO2 - PaO2

Question 19

What is a normal value for A-a Gradient?

Answer 19

25-65 torr on 100%

Question 20

What value for A-a Gradient means V/Q Mismatch?

Answer 20

66-300 torr

Question 21

What value for A-a Gradient means Shunting?

Answer 21

> 300 torr

Question 22

P/F ratio Formula

Answer 22

PaO2/FiO2

Question 23

What is a normal P/F ratio?

Answer 23

Above 380 torr

Question 24

What does a P/F ratio less than 300 mean?

Answer 24

Acute Lung Injury

Question 25

What does a P/F ratio less than 200 mean?

Answer 25

ARDS

Question 26

Arterial Oxygen Content (CaO2) Formula

Answer 26

(Hb x 1.34 x SaO2) + (PaO2 x 0.003)

Question 27

What is normal CaO2?

Answer 27

17-20 vol %

Question 28

Mixed Venous Oxygen Content (CvO2)

Answer 28

(Hb x 1.34 x SvO2) + (PvO2 x 0.003)

Question 29

What is normal CvO2?

Answer 29

12-16 vol %

Question 30

CvO2 and SvO2 values will decrease when cardiac output...

Answer 30

Decreases

Question 31

Arterial-Venous Oxygen Content Difference (C(a-v)O2) Formula

Answer 31

CaO2 - CvO2

Question 32

What is normal (C(a-v)O2)?

Answer 32

4-5 vol %

Question 33

(C(a-v)O2) difference will increase when the CvO2 is...

Answer 33

Decreasing, meaning cardiac output is also decreasing

Question 34

Cardiac Output Formula

Answer 34

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

Question 35

What is normal Cardiac Output

Answer 35

4-8 L/min

Question 36

Shunt Equation Qs/Qt Formula

Answer 36

(A-aDO2)(0.003) / (A-aDO2)(0.003) + (C(a-v)O2)

Question 37

What is normal Shunt?

Answer 37

3-5%

Question 38

What is normal SaO2?

Answer 38

95-100%

Question 39

Oxygenation Index, OI, Formula

Answer 39

( Paw x FiO2 / PaO2 ) x 100

Question 40

What is normal Oxygenation Index?

Answer 40

< 10

Question 41

When a newborn's OI is > 40, what should you recommend?

Answer 41

ECMO

Question 42

What does an increased oxygenation index mean?

Answer 42

The patient's condition is worsening

Question 43

Deadspace to Tidal Volume (Vd/Vt) Formula

Answer 43

( PaCO2 - PeCO2 / PaCO2 ) x 100

Question 44

What is normal Vd/Vt?

Answer 44

20-40% - Up to 60% for ventilator patients

Question 45

Deadspace formula (if tidal volume is known)

Answer 45

Vd/Vt x Vt

Question 46

Desired Minute Volume Formula

Answer 46

(Current Ve x Current PaCO2) = (Desired Ve x Desired PaCO2)

Question 47

What does it mean if the PaCO2 is ABOVE 45 torr?

Answer 47

Patient is NOT ventilating - Remove/decrease deadspace - Increase ventilation

Question 48

What does it mean if the PaCO2 is BELOW 35 torr?

Answer 48

Patient IS ventilating too MUCH - Decrease ventilation

Question 49

What is a PaO2 below 80, with an FiO2 between 21-59% mean?

Answer 49

Hypoxemia caused by: - High PaCO2 - V/Q Mismatch What to do? Increase FiO2 or ventilation

Question 50

What is a PaO2 below 80, with an FiO2 over 60% mean?

Answer 50

Hypoxemia caused by: - Shunt - Venous Admixture What to do? Increase PEEP

Question 51

What does a PaO2 above 100, with an FiO2 between 22-100% mean?

Answer 51

Hyperoxemia - Overoxygenation What to do? Decrease FiO2 or PEEP

Question 52

Normal ABG for newborn

Answer 52

Are slightly acidotic - pH > 7.30 - PaCO2 < 50 - PaO2 > 60

Question 53

What does a shift to the left mean for the O2-Hb Dissociation Curve?

Answer 53

Increased oxygen affinity; higher O2 content

Question 54

What does a shift to the right mean for the O2-Hb Dissociation Curve?

Answer 54

Decreased oxygen affinity; lower O2 content

Question 55

What do spirometers measure?

Answer 55

Volume and Flow Rates

Question 56

What does the turbine device (Wright respirometer) measure?

Answer 56

Flow and may display Volume

Question 57

What does the pressure differential (Fleisch) pneumotachometer measure?

Answer 57

Flow

Question 58

What do Peak Flow Meters measure?

Answer 58

measure and monitor PEFR for asthma patients

Question 59

Typical Peak Flow for a healthy adult

Answer 59

10 L/sec or 600L/min

Question 60

What does the Body Box measure?

Answer 60

FRC and Airway Resistance

Question 61

Normal MIP

Answer 61

80 cmH2O

Question 62

What MIP value indicates inspiratory muscle weakness?

Answer 62

Less than 20, INTUBATE IMMEDIATELY

Question 63

Normal MEP

Answer 63

160 cmH2O

Question 64

What MEP value indicates poor ability to clear airway secretions?

Answer 64

Less than 40

Question 65

How to calculate Vital Capacity

Answer 65

IRV + ERV + VT

Question 66

What is Vital Capacity?

Answer 66

Patient is instructed to take a maximal inspiration and maximal exhalation without force

Question 67

What does decreased volume indicate?

Answer 67

Restrictive disease

Question 68

What is the BEST indicator for restrictive

Answer 68

Decreased Vital Capacity

Question 69

What is Forced Vital Capacity?

Answer 69

Patient is instructed to take a maximal inspiration and maximal expiration as forcefully and as fast as possible

Question 70

If FVC is not completed in 3 seconds, that indicates...

Answer 70

Obstruction

Question 71

What is FEV1

Answer 71

Volume expired in the first second of FVC

Question 72

What is the minimal acceptable FEV1/FVC (FEV1%)

Answer 72

70%

Question 73

What is the BEST indicator for obstructive

Answer 73

Decreased FEV1/FVC

Question 74

If the FEV1 is decreased but the FEV1/FVC ratio is normal that means...

Answer 74

Restrictive disease only

Question 75

What does decreased FEF 200-1200 mean

Answer 75

Large airway obstruction

Question 76

Typical value for FEF 200-1200

Answer 76

6.0 L/sec

Question 77

What does decreased FEF 25-75 mean

Answer 77

Early stage of obstructive disease

Question 78

Typical value for FEF 25-75

Answer 78

4.7 L/sec

Question 79

Minute Volume Formula

Answer 79

RR x Vt

Question 80

Minimum ET tube size for flexible bronchoscopy

Answer 80

8.0 mm ID