PFT

Question 1

What pts are at risk for PPC?

Answer 1

Hx of significant pulmonary disease
Obesity
Aortic, thoracic, abdominal surgery
Long term smokers
Elderly (>70)

Question 2

High risk PFT results: FEV1, FEV1/FVC, VC

Answer 2

<2L
<.5
< 40-50% predicted (15cc/kg in adults, 10cc/kg in children)

Question 3

What % improvement in PFT is good?

Answer 3

15

Question 4

How to treat bronchospasm and infections preoperatively

Answer 4

Bronchodilators
ABX, culture and senstivity

Question 5

IE ratio for COPD pt

Answer 5

BIGGER
1:2 to 1:3!

Question 6

What level to keep etco2 in co2 retainers? What if you dont?

Answer 6

Baseline, if not, you will cause metabolic alkalosis

Question 7

What drugs to avoid in bronchospasm?

Answer 7

Histamine releasing drugs
STP (penthotal, barbituate for induction),
ABX,
neostigmine,
morphine/meperdine,
atracurium/succ/mivacurium,
Possibly aspirin, and if so then ketoralac

Only use albuterol, ketamine

Question 8

If FEV1 is less than ___% of predicted, extubation will not be effected

Answer 8

50

Question 9

If FEV1 is __% - __% of predicted, with some hypoxemia and hypercarbia, prolonged extubation is probably

Answer 9

25-50

Question 10

If FEV1 is less than 25% what procedures should be done?

Answer 10

only life saving procedures
use regional if possible
Risk: inability to wean ventilator, trachestomy

Question 11

Extubation criteria; RR, PaO2, PaCO2, MIF, VC

Answer 11

<30
>70 (on fio2 .4)
<55
less than -20cmH2o
>15cc/kg

Question 12

Intubation criteria for acute respiratory failure; rr, vc, MIF, pao2, paco2, vd/vt, aa gradient, and clinical diagnosis’

Answer 12

> 35
<15cc/kg or 10cc/kg
-20cm h20
<70 on fio2 .4
55 (unless chronic)
.6
350mmHg on fio2 1.0
burns, AMS, rapid deterioration, fatigue

Question 13

ABCs if CXR

Answer 13

airway
bone
cardiac
diaphragm
equal fields of lungs
gastric
hilum
invasive lines

Question 14

How soon does an ABG need to be measured? What will happen if not?

Answer 14

15 minutes, glycolysis with lactic acid production, decreased ph, increased pco2

Question 15

How long can i store abg on ice?

Answer 15

2h

Question 16

What will heparin do to abg

Answer 16

lower PCO2 by dilution, especially in children with small samples

Question 17

ABG normal values, ph, pco2, po2, hco2, base excess

Answer 17

7.35-7.45
35-45
70-105
22-27
-3 - 3

Question 18

How does PCO2 effect ph

Answer 18

pco2 increase by 10, ph drop by .08
vice verse

Question 19

Alveolar gas equation/ AA gradient equation

Answer 19

PAO2=(Pb-Ph2o)x(fio2)-(paco2/rq)
PaO2= from abg

Question 20

What increases AA gradient?

Answer 20

GA
PTX
PE
shunt
VQ MM

Question 21

When is AA gradient normal? in disease processes

Answer 21

hypoventilation, low fio2

Question 22

How to treat high Aa?

Answer 22

fio2
PEEP

Question 23

How does bicarb effect ph?

Answer 23

Increase in bicarb by 10mmoles increases ph by .15 (stronger than pco2)

Question 24

What causes respiratory acidosis?

Answer 24

CNS depression from trauma or drugs
Obesity PF
COPD asthma

Question 25

Causes of respiratory alkalosis

Answer 25

hypoxic respiration encephalitis anxiety pregnancy mech ventilation

Question 26

Metabolic alkalosis causes

Answer 26

bicarb infusion excessive vomiting NGT suctioning

Question 27

FRC in ml

Answer 27

2300

Question 28

IC in ml

Answer 28

3500

Question 29

vc in ml

Answer 29

4600

Question 30

TLC in ml

Answer 30

5800

Question 31

what % of TLC is FRC?

Answer 31

40%

Question 32

FEV1 normal range

Answer 32

4L or 75% (if fev1 frc ratio)

Question 33

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

Answer 33

FEV1 will decrease to below 20% with acute asthma

Question 34

Most sensitive marker of small airway disease?

Answer 34

FEF 25 75

Question 35

Degree of risk in OLD, FEV1FRC

Answer 35

Normal- >75 Mild- 60-75 moderate- 45-60 severe- 35-40 extreme- <35

Question 36

What is the use of flow volume loops?

Answer 36

Helps distinguish extrathoric/ intrathoracic diseases ALSO Helps distinguis from OLD vs RLD

Question 37

FV loop normal

Answer 37

Semi circle on bottom (inspiration right to left) Line up and angled right, and start line back to starting point (expiration)

Question 38

What PFT has been shown to predict increased mortality in pts undergiong thoracic surgery?

Answer 38

MMV/ MBC Maximum voluntary ventilation

Question 39

What % fef 25 75 is considered confirmation of airway obstruction?

Answer 39

60 WITH FEV1 FVC low or normal

Question 40

FV loops intrat vs extra thoracic

Answer 40

Extra thoracic- top heavy Intrathoracic- bottom heavy (extra- you can see, it, intra, underground, cant see)

Question 41

FV loops L or R shift

Answer 41

L shift- OLD R shift- RLD

Question 42

PFTs that indicate airway obstructions

Answer 42

FEF 25 75- less then 60% predicted AND FEV1:FVC- low (or normal)

Question 43

What PFT, when decreased, has a high correlation with mortality and morbidity?

Answer 43

MMV max minute ventilation MBC mac breathing capacity

Question 44

Patho of extra vs intrathoracic disease? what do each mean?

Answer 44

Extra- obstruction Intra- lung disease

Question 45

Most important PFT for assessment of severity of OLD?

Answer 45

FEV1

Question 46

How to differentiate OLD from RLD (PFT)

Answer 46

FEV1 FVC ratio

Question 47

What conditions (bad) dont stimulate HPV?

Answer 47

Anemia/ CO poison PaO2 stays normal

Question 48

Extrathoracic vs intrathoracic obstruction effect on inspiratory vs expiratory flow

Answer 48

Extra- inspra Intra-extra Extra blocks inspiration Intra block expiration

Question 49

Fixed FV loop shape and cause

Answer 49

Its a small rectangle around the line Tracheal stenosis

Question 50

Metabolic acidosis causes

Answer 50

Lactic acidosis DKA ASA high protein intake Bicarb loss from diarrhea

Question 51

When (how soon) does renal compensation occur after respiratory acidosis

Answer 51

1-2 days after