Quiz 7 - Pulmonary Function Tests (PFT's)

Question 1

What are the ABG normal values?

Answer 1

pH = 7.4 Bicarb - 24 CO2 - 40 PO2 - 75-100 Base excess = -3 to 3

Question 2

What pH is considered acidemic?

Answer 2

< 7.35

Question 3

What pH is considered alkalotic?

Answer 3

> 7.45

Question 4

How can you tell if the alteration in pH is respiratory?

Answer 4

CO2 will be the most affected in a resp problem

Question 5

How can you tell is the pH alteration is metabolic?

Answer 5

HCO3 will be the most affected in a metabolic problem

Question 6

An increase or decrease in PCO2 by _________mm Hg causes a a decrease or increase in pH by _______.

Answer 6

10mmHg and pH 0.08

Question 7

What is the A-a gradient?

Answer 7

It is a measure of lung efficiency

Question 8

What is the equation for PAO2?

How do you find the A-a gradient?

Answer 8

PAO2 = (PB * PH2O) (FIO2) - PaCO2/0.8)
PB = 760, PH2O = 47

To find A-a gradient, subtract PAO2 from PaO2 measured on ABG

Question 9

What is a rough estimate of a NORMAL A-a gradient?

Answer 9

approximately your age/3

or less than 20mmHg difference

Question 10

What would cause a widened A-a gradient?

Answer 10

pneumothorax, PE, shunt, VQ mismatch, diffusion problems

Question 11

How would you treat an abnormal A-a gradient?

Answer 11

tx underlying cause - supplemental O2, adjust ventilation, tx atelectasis, add PEEP,

Question 12

An increase or decrease in bicarb by _________mmoles will increase or decrease the pH by __________.

Answer 12

10 mmoles, pH 0.15

Question 13

What is the equation for TOTAL BODY bicarb deficit?

Answer 13

base deficit x wt in kg x 0.4 = answer is in mEq/L

Question 14

How much of the total body bicarb deficit would you replace?

Answer 14

half of the deficit

Question 15

What is an acute cause of low pH and high PCO2?

Answer 15

hypoventilation with hypercarbia

Question 16

What is a chronic cause of low pH and high PCO2? (resp acidosis)

Answer 16

COPD, Asthma

Question 17

How long does it take the kidneys to help compensate the pH in acidosis?

Answer 17

1-2 days

Question 18

________ ions are excreted by the kidneys and _________ is reabsorbed into blood to PARTIALLY correct the pH

Answer 18

hydrogen, HCO3

Question 19

What can cause a HIGH pH and LOW PaCO2? (resp alkalosis)

Answer 19

Hyperventilation with hypocarbia

Question 20

What are some causes of resp alkalosis?

Answer 20

Pregnancy, artificial ventilation, hypoxic resp, CNS dzs, encephalitis, anxiety, withdrawal, early septic shock

Question 21

What are some causes of LOW pH and LOW HCO3? (met acidosis)

Answer 21

Lactic acidosis, Diarrhea, ASA ingestion, high protein intake, DKA,

Question 22

What are some causes of HIGH pH and HIGH HCO3? (met alkalosis)

Answer 22

Loss of H+ from vomiting or excessive NG tube suctioning

Question 23

What is the most important clinical tool in assessing the severity of airway disease?

Answer 23

FEV-1

Question 24

What is FEV-1? What are the normal values?

Answer 24

After max inspiration, the volume of air that can be forcefully exhaled in 1 second Normal - 3-5 liters

Question 25

How else can FEV-1 be reported?

Answer 25

Can also be reported as a percent of FVC. FEV-1/FVC

Question 26

What is a normal FEV1/FVC?

Answer 26

\> 75%

Question 27

What is a moderate and extreme FEV1/FVC and what would it indicate?

Answer 27

Mod = 45-60% Extreme = \< 35% Degree of risk of obstructive lung disease

Question 28

what is FEF 25-75 and how is it different from FEV1?

Answer 28

Reflects collapse of small/peripheral airways and It is a sensitive indicator of early airway obstruction. It is different because it is effort independent

Question 29

What is the nickname for Maximal Voluntary Ventilation (MVV) or Maximal Breathing Capacity (MBC)?

Answer 29

the "will to live" test - it is the maximal amount of air a pt can exhale in one minute at maximal effort (hyperventilation) tests motivation, mechanics, strength and endurance

Question 30

What patient are at risk for post-op pulmonary complications?

Answer 30

-Hx of pulmonary disease -Thoracic/abdominal(upper) surgery -Obesity -Long-term smoker -Elderly patients (\>70 yrs)

Question 31

Why get a pulmonary functioning Test preoperative?

Answer 31

Have a better plan and predict pre-, inta-, and post-operative pulmonary care requirements.

Question 32

What is the normal inspiration:expiratory (I:E)?

Answer 32

1:2

Question 33

What is the inspiration:expiratory (I:E) of a COPD patient?

Answer 33

1:3

Question 34

T/F: CO2 retainers: EtCO2 should be keep near the patient's baseline, a rapid correction will lead to metabolic alkalosis.

Answer 34

True

Question 35

What class of drugs should be avoided during bronchospasm?

Answer 35

Histamine releasing drugs

Question 36

What drugs release histamine?

Answer 36

-Pentothal (STP) -Morphine (MSO4) -Atracurium -Mivacurium -Neostigmine

Question 37

The extubation criteria are:

Answer 37

- VSS, awake and alert, resp. rate\<30 - ABG on FIO2 40% --\> PaO2\>70 and PaCO2\<55 - MIF is more negative than -20cm H2O - VC \> 15cc/kg

Question 38

Mechanic intubation criteria are:

Answer 38

RR\>35, VC \<10cc/Kg in child or 15cc/kg adult, MIF more neg. than -20cmH2O

Question 39

Oxygenation intubation criteria are:

Answer 39

PaO2 \< 70mmHg on FiO2 of 40%, A-a gradient \> 350mmHg on 100% O2

Question 40

Ventilation intubation criteria are:

Answer 40

PaCO2 \> 55 (except in chronic hypercarbia), Vd/Vt \> 0.6 (remember normal dead space is 30%)

Question 41

Clinical intubation criteria are:

Answer 41

airway burn, chemical burn, epiglottis, mental status change, rapidly deteriorating pulmonary status, fatigue

Question 42

An arterial blood gas must be measured within 15 minutes or ________ will occur.

Answer 42

glycolysis (The sample can be placed on ice for 1 to 2 hours)

Question 43

What MAY heparin due to a small arterial blood gas sample?

Answer 43

Lower PCO2

Question 44

What results would indicate high risk PFT's on FEV1 and FEV1/FVC?

Answer 44

FEV1 \<2 liter/second