Abgs & Pfts

Front 1

The sum of Dalton's partial pressures should equal..

Back 1

1 atm; 760 mmHg

Front 2

Two most important gases for life?

Back 2

CO2 & O2

Front 3

How do you calculate blood's oxygen carrying capacity?

Back 3

(1.39 * Hgb * O2 Sat) + (0.003 * PO2)

Front 4

How do you calculate PaO2 based on someone's age?

Back 4

PaO2 = 102 - Age/3

(i.e. 30 y/o would have estimated PaO2 of 92)

Front 5

1) Oxygen transport is dependent upon _____ and _____.

2) Also upon ______, supply and _____.

Back 5

1) "Cardiac and circulation"
(I assume he meant 'cardiac funtion and circulation')

2) diffusion, supply and demand.

Front 6

4 causes of hypoxemia affecting blood gases?

Which is easiest to correct?

Back 6

1) hypoventilation**

2) shunt

3) Diffusion

4) V/Q mismatch


**easiest to correct

Front 7

CO2 is not limited by _____ under most circumstances?

Back 7

diffusion

Front 8

CO2 is carried mainly as _______ that is converted to __________ to be transported to the lung for O2 exchange.

Back 8

Carried mainly as BICARB

converted to CARBONIC ACID

Front 9

What does PAO2 - PaO2 mean?

Back 9

Alveolar - arterial gradient

Front 10

What is normal shunting %?

What is "acceptable" shunting %?

What % is compatible with life and spontaneous ventilation?

What % is incompatible with spontaneous ventilation?

Back 10

5% normal

<20% acceptable

20-30% compatible with spont ventilation

>30% incompatible with spont vent.

Front 11

Shunting from _ to _ does NOT cause hypoxemia.

Back 11

Left to Right does NOT cause hypoxemia.

Front 12

In a shunt, blood reaches arterial system without being...

Back 12

...ventilated by lung. Does not undergo gas exchange.

Front 13

2 intrapulmonary causes of shunting...

1 extrapulmonary cause of shunting...

Back 13

Intrapulm:
1) fistulas
2) lung disease (ARDS, PNA)

Extrapulm:
1)Congenital heart defects

Front 14

Shunt fraction...

Back 14

Qs / Qt

Qt = total CO
Qs = % CO not undergoing gas exchange.

Front 15

Diffusion is impaired ______ _______ between the _______ & ______.

Back 15

Impaired GAS EXCHANGE between the alveolus & pulm capillaries.

Front 16

Impaired diffusion seen with what 3 disease states?

Back 16

Asthma

Bonchitis/PNA

Cystic Fibrosis

Front 17

Normal V/Q mismatch?

Back 17

0.8

200/250
(CO2 produced over O2 consumed)

Front 18

Avg physiologic dead space?

Back 18

150 mL or 2 mL/kg

*Or, weight of pt in lbs ~ mL dead space

Front 19

Describe difference between alveolar DS and anatomic DS.

Back 19

Alveolar DS - alveoli not being perfused.

Anatomic DS - trachea, non-resp airway

Front 20

Base excess allows for ....

Back 20

additional HCO3 to correct and maintain homeostasis.

Front 21

Base excess: if more negative, pt will become more...

Back 21

acidotic.

Front 22

PO2 < __ is respiratory failure.

Back 22

< 60 = resp failure

Front 23

Causes of Resp Acidosis

Back 23

1) Acute intoxication

2) COPD

3) Airway obstruction

4) Neuromusc disorders (ALS, Guillan Barre)

Front 24

Causes of Resp Alkalosis

Back 24

1) Anxiety Attack

2) Pregnancy

3) cirrhosis

4) salicylate intox

5) central nervous system disease

Front 25

Causes of Metabolic Acidosis

Back 25

1) Diarrhea

2) Carbonic Anhydrease Inhib

3) Renal Tubular Necrosis

Front 26

Causes of Metabolic Alkalosis

Back 26

1) Vomiting

2) NGT suctioning

3) Diuretics

Front 27

How do you calculate Anion Gap?

Back 27

Anion Gap =

w/ K+ (normal <11)
=(Na + K) - (Cl + HCO3)

w/o K+ (normal 8-16)
=(Na - Cl - HCO3)

Front 28

What does an anion gap identify?

Back 28

IDs the cause of metabolic acidosis.

Front 29

_ lung volumes

_ lung capacities

(How many of each?)

Back 29

4 LVs

4 LCs

Front 30

Tidal Volume (TV) = ??

Back 30

Volume of air moved during normal breathing.

Front 31

Inspiration: _____ process.

Expiration: _____ but can be _____ during exercise.

Back 31

Insp = active

Exp = passive; active w/ exercise

Front 32

6 pt groups in which PFTs are "extremely helpful"

Back 32

1) >65 y/o

2) h/o smoking, wheezing, cough

3) Undergoing abdominal or thoracic surgery

4) obese

5) scholiosis, kyphosis

6) undergoing anesthesia for a period of time

Front 33

Diameter of an alveoli...

What maximizes surface area?

Back 33

1/3 mm

(1/3 of a dot)

Surfactant

Front 34

How do you calculate pt's TV?

Back 34

8 mL/kg

Front 35

What is IRV ?

What is ERV ?

Back 35

IRV = max volume that can be inspired after normal TV.

ERV = max volume that can be expired from resting expiration.

Front 36

What is residual volume?

Back 36

Volume of air left in lungs after maximum expiration (end of ERV).

Front 37

What is vital capacity?

Back 37

Volume of air that can be expired after max inspiration.

VC = IRV + TV + ERV

Front 38

What is Inspiratory Capacity?

Back 38

Maximum volume of air that can be inhaled from expiration of TV.

IC = IRV + TV

Front 39

Functional Residual Capacity (FRC) =

Back 39

Total volume of air in the lungs at the end of TV exipration.

FRC = ERV + RV

Front 40

Total lung capacity =

Back 40

Volume of air in lungs after max inspiration.

TLC = IRV + TV + ERV + RV

Front 41

PFTs evaluate 3 things to provide insight into effective anesthesia mgmt.

Back 41

1) Lung volumes

2) Airway function

3) Gas exchange

Front 42

Airway PFTs (5)

Back 42

1) Spirometry

2) FVC

3) Maximal ventilation

4) Inspiratory/expiratory pressures

5) Airway resistance

Front 43

Volume PFTs

Back 43

1) FRC **Most important**

2) TLC/RV

3) Minute ventilation

4) Alveolar ventilation

5) Dead space

Front 44

Compliance

Give explanation and equation

Back 44

change in volume for any given applied pressure at any given time during actual movement of air (indicates how easy/difficult it will be to ventilate pt)

Compliance = Volume / Pressure = L/cm H2O

Front 45

Static compliance (Cs) =

What does it indicate?

What is normal value?

Back 45

Reflects stiffness of lung and chest wall.

Cs = TV / (plat. press. - PEEP)

Normal = 50 - 100 ml / cm H2O

Front 46

High Cs indicates what?

Low Cs?

Back 46

Increased Cs = emphysema, re-expansion of lung with relief of abdominal distension

Decreased Cs = Pulm edema, atelectasis, pneumothorax, anesthesia, ascites, obesity, kyphoscoliosis

Front 47

Define and give equation for Dynamic Compliance...

Normal values?

Back 47

Def: The elastic and resistive forces opposing lung inflation.

Cd = TV / (pk press. - PEEP)

Normal value 40-80 mL/cm H2O

Front 48

Cd decreased by 3 things...

Back 48

1) bronchospasm

2) mucous plug

3) kinked ETT

Front 49

5 factors affecting lung volumes...

Back 49

1) Age

2) Height

3) Weight

4) Sex

5) Diseases

Front 50

Spirometry helps evaluate many things. Name 4.

Back 50

1) FVC

2) FEV1

3) FEV1/FVC ration

4) FEF

Front 51

Forced Vital Capacity (FVC) =

Back 51

Amount of air that can be exhaled after a full inspiration.

Normal: >= 80% of predicted value

Front 52

Decreased FVC is associated with potential...

Back 52

... increased post-op complications.

Front 53

Foreced Exp Volume in 1 Sec (FEV1) =

Back 53

Volume exhaled during the first second of a forced expiratory maneuver started from level of total lung capacity (TLC)

Normal: >= 80% FVC

Mild 65 - 80%, Moderate 50 65%, Severe <50%

Front 54

What is the most valuable test for obstructive lung disease (COPD)?

Back 54

FEV1

Front 55

FEV1 / FVC ratio

Back 55

a.k.a. Tiffaneau Ratio

"Percentage of VC exhaled in one second."

Used in diagnosis of obstructive AND restrictive lung diseases.

Normal: 75-80%

Mile 60-75%, Moderate 45-60%, Severe <45%

Front 56

FEF/MMEF is sensitive for ....

Back 56

... small airway disease

Front 57

FEF/MMEF

Back 57

Avg expiratory flow over the middle half of the FVC (25-75%)

Independent of pt effort

Normal: >= 65%

Front 58

Volumes/capacities in restrictive diseases are all decreased but two may remain slightly normal...

Back 58

1) FEF/MMEF

2) FEV1/FVC

Front 59

What values increase with obstructive airway disease?

Back 59

1) TLC

2) FRC

Front 60

3 steps for flow-volume loop

Back 60

1) Inhale to TLC

2) exhale to RV

3) inhale to TLC

Front 61

A flow-volume loop that resembles a baby carriage is indicative of...

Back 61

Obstructive disease

Front 62

Big upside down ice cream cone flow-volume loop indicative of...

Back 62

Normal lung function

Front 63

Small upside down ice cream cone flow-volume loop indicative of...

Back 63

Restrictive disease

Front 64

T/F: with regards to flow-volume, the ratios will be the same when comparing normal lungs to restrictive disease.

Back 64

True. Ratios will be the same. Volumes will be smaller.

Front 65

Tracheal stenosis will show on flow-volume loop as...

As CRNA how do you prevent the above?

Back 65

"Big 'O'"

or rock looking thing.

Prevent by knowing your ETT cuff pressure.

Front 66

Fixed obstruction will result in decreased...... flow

Back 66

decreased inspiratory and expiratory

Front 67

Extra-thoracic obstruction will result in decreased...

Back 67

decreased inspiratory flow only

Front 68

Intra-thoracic obstruction will result in decreased...

Back 68

decreased expiratory flow only

Front 69

Quitting smoking > 2 weeks before surgery restores...

Back 69

... normal mucociliary function

Front 70

Quitting smoking for >24 hr before surgery reduces...

Back 70

reduces airway/bronchial reactivity.

Front 71

Pregnancy in PFTs

Back 71

Can show restrictive lung patterm, usu not significantly affected.

15-20% decrease in FRC

Front 72

Obesity and PFTs

Back 72

Restrictive pattern

Decreased: ERV, VC, FRC, PO2, pulmonary compliance

Increased: CO2 production

Front 73

FRC is decreased ____% by GA

Back 73

15-20%

Front 74

What happens in OR that decreases FRC?

Back 74

1) Light anesthesia

2) supine position

3) paralysis

4) change thoracic muscle tone (hurts to take deep breath)

Front 75

Every pregnant woman is RSI... why? and what drug?

What TV and RR?

Back 75

RSI because of possible full stomach (vomit, aspirate)

Use Roc (no Sux d/t K+?)

Low TV, High RR

Front 76

If pt can't tell you when they last ate, what type of induction?

Back 76

RSI

Front 77

Pt with FEV1/FVC ratio <0.7 has _______ disease.

Requires what TV? RR? PEEP?

Back 77

Normal to big TV

Normal to high RR

NEEDS PEEP

Front 78

Pt with kyphosis presents for surgery? What might you suspect regarding her lung function?

Back 78

Suspect restrictive lung disease.

Front 79

FEV1 = 2.8

FVC = 3.1

Explain what's going on here...

Back 79

Low volumes --> restrictive disease

Normal ratios