Anesthesiology Exam 2 - Swanson

Front 1

Arterial Blood

Back 1

Sample used for definitive analysis of hypoxemia

Front 2

Metabolic acidosis

Back 2

Acidic blood + Decreased HCO3-

Front 3

Respiratory acidosis

Back 3

Acidic blood + Increased PaCO2

Front 4

Metabolic alkalosis

Back 4

Alkaline blood + increased HCO3-

Front 5

Respiratory alkalosis

Back 5

Alkaline blood + decreased PaCO2

Front 6

Compensation

Back 6

When acid-base imbalance is chonic, this occurs:

Front 7

2-4 mEq/L

Back 7

For every 10 mmHG +/- change in PaCO2, there is a _____ change in HCO3-

Front 8

Respiratory alkalosis

Back 8

A secondary condition to hypoxemia can be:

Front 9

Increase Minute Volume

Back 9

Treatment for respiratory acidosis?

Front 10

Decrease Minute Volume

Back 10

Treatment for respiratory alkalosis?

Front 11

Metabolic ONLY (not in respiratory...they have too much CO2 already, even in respiratory acidosis)

Back 11

In which acidosis/alkalosis etiologies would you consider giving NaHCO3? (Respiratory or Metabolic)

Front 12

When pH < 6.9

Back 12

What is the critical acidic pH boundary value?

Front 13

Body weight(kg) X 0.3 X B.E.(mEq/L)

Back 13

Equation for calculating amount of HCO3- (in mEq) to give a patient in correcting a base deficit? (to bring pH back to 7.4 @ 40mmHg)

Front 14

Mixed acidosis. (Respiratory acidosis & metabolic acidosis since paCO2 > 60 AND pH < 7.3)

Back 14

Diagnosis? pH (7.35-7.45)= 7.06, PaO2 (80-100) = 85, PaCO2 (35-45) = 70, HCO3-(22-27) = 22, BE (0) = -5

Front 15

Hypoxemia

Back 15

Defined as subnormal oxygenation of arterial blood

Front 16

Hemoglobin (binds H+ ions)

Back 16

Acts as an important non-carbonate buffer in the body

Front 17

Anemia

Back 17

NOT a cause of hypoxemia, condition marked by decreased RBC count/decreased hemoglobin

Front 18

Hypoxemia

Back 18

Reduces the oxygen content in blood, not its capacity to hold oxygen

Front 19

1.) Abnormal inspired O2 concentration (FIO2 < 0.2) 2.) Abnormal ventilation (Hypoventillation where PaCO2 > 45 mmHg), 3.) Abnormal V/Q distribution, 4.) Decreased cardiac output, 5.) Anatomic right to left shunts, 6.) Diffusion impairments (rarely a problem)

Back 19

Clinical Etiologies of Hypoxemia

Front 20

Hypoventilation

Back 20

Which etiology of hypoxemia? (Difference between calculated PAO2 and measured PaO2 is <= 15 mmHg)

Front 21

V/Q abnormality

Back 21

Which etiology of hypoxemia? (Difference between calculated PAO2 and measured PaO2 is > 15 mmHg)

Front 22

Tetralogy of Fallot, reversed PDA, VSD w/ Eisenmenger's physiology

Back 22

Examples of Right to Left shunts?

Front 23

1.) What is the patient's FIO2? 2.) Is the sample arterial or venous?

Back 23

Two key questions to ask when interpreting blood gas analysis?

Front 24

Relative Hypoxemia

Back 24

Type of hypoxemia (not etiology)? (PaO2 is less than expected for a given FIO2, but still > 80 mmHg)

Front 25

Absolute Hypoxemia

Back 25

Type of hypoxemia (not etiology)? (PaO2 is < 80 mmHg)

Front 26

Blood Gas Analysis

Back 26

What test determines partial pressure of O2 in whole blood?

Front 27

Non-invasive pulse oximetry

Back 27

What monitoring determines percent saturation of hemoglobin in a patient?

Front 28

H2O + CO2 <--> H2CO3 <--> H+ + HCO3-

Back 28

What is the carbonic acid equilibrium equation?

Front 29

Use alveolar gas equation

Back 29

How do you derive an expected PaO2?

Front 30

Should be 5 times the inspired oxygen concentration

Back 30

What is the rule of thumb for expected PaO2?

Front 31

PaCO2 goes up, PaO2 goes down

Back 31

Relationship between PaCO2 and PaO2 during hypoventilation?

Front 32

Dead Space Ventilation

Back 32

Term for V/Q abnormality (V/Q > 1)

Front 33

Pulmonary emboli, high inflation pressure during positive pressure ventilation

Back 33

Clinical etiologies of dead space ventilation (V/Q > 1)

Front 34

Physiologic right to left shunt

Back 34

Term for V/Q abnormality (V/Q < 1)

Front 35

alveolar pneumonia, alveolar edema, space occupying masses, persistent atelectasis

Back 35

Clinical etiologies of physiologic right to left shunt (V/Q < 1)

Front 36

<= 15 mmHg

Back 36

What is the normal difference between PaO2 and PAO2 at FIO2 = 0.2?

Front 37

Intermittent Positive Pressure Ventilation (IPPV)

Back 37

What is cyclic inhalation/exhalation produced through intermittent introduction of fresh gas(es) into a patient's conducting airways under pressure?

Front 38

1.) Decreased CNS sensitivity to CO2-evoked alterations in CSF acid/base changes 2.) Neuromuscular weakness 3.) Surgical/traumatic disruption of diaphragmatic function or chest wall integrity

Back 38

Most anesthesized patients hypoventilate. What are 3 reasons why?

Front 39

Obesity

Back 39

What is neuromuscular weakness exacerbated by?

Front 40

Thoracotomy

Back 40

What is a surgical disruption of diaphragmatic function/chest wall integrity?

Front 41

Diaphragmatic hernia

Back 41

What is a traumatic disruption of diaphragmatic function/chest wall integrity?

Front 42

1.) Patient ventilation is impaired to the point of significant acid/base imbalance 2.) When alveolar hypoventilation becomes a limiting factor in maintaining inhalation anesthesia

Back 42

When is IPPV instituted? (two reasons)

Front 43

1.) Normalize the respiratory component of acid/base balance 2.) Optimize cardiac output

Back 43

What is the main clinical objective of IPPV? What is a secondary objective?

Front 44

Tidal volume (Vt) X respiratory rate (R)

Back 44

What defines a patient's minute volume?

Front 45

Difference reflects amount of physiologic dead space (to include anatomical and alveolar dead space)

Back 45

Why is a patient's end-tidal CO2 partial pressure less than the PaCO2?

Front 46

Venous return to the heart

Back 46

Introduction of IPPV alters the normal trans-diaphragmatic pressure gradient. What does this impede?

Front 47

Stroke volume is reduced (leads to hypotension/hypoperfusion)

Back 47

Why does decreased ventricular filling lead to decreased cardiac output?

Front 48

10-15 cc/kg

Back 48

What is tidal colume (Vt) for all mammals estimated at?

Front 49

8-12 breaths/min

Back 49

What is the respiratory rate in IPPV usually set at for dogs?

Front 50

6-10 breaths/min

Back 50

What is the respiratory rate in IPPV usually set at for horses?

Front 51

Maximum airway pressure achieved during positive pressure ventilation

Back 51

Define peak inspiratory pressure (PIP).

Front 52

12-30 cm H2O (although would like to limit alveolar pressure greater than 20 mmHg)

Back 52

Concerning PIP, what is the recommended range of pressure values?

Front 53

Normal mean pulmonary arterial pressure is 15-20 mmHg, so when alveolar pressure > pulmonary arterial pressure, perfusion suffers (hard for CO2 to perfuse into lungs against pressure gradient).

Back 53

Why do we want to limit alveolar pressure to values below 20 mmHg?

Front 54

Arterial PaCO2

Back 54

What defines global ventilation?

Front 55

1.) capnometry 2.) Arterial blood gas analysis

Back 55

What are two methods we can use to assess the patient's respiratory acid/base component?

Front 56

PIP

Back 56

Increasing or decreasing the tidal volume (Vt) during IPPV affects what?

Front 57

Inspiratory time

Back 57

Increasing or decreasing the respiratory rate (R) during IPPV affects what?

Front 58

Duration of positive airway pressure

Back 58

Negative effects of IPPV on venous return becomes more apparent with increasing _______ (Duration of positive airway pressure OR absolute value of pressure?)

Front 59

Increased breaths/min INCREASES time of positive airway pressure which leads to DECREASED venous return.

Back 59

Regarding IPPV, increased breaths/min causes _______ (increased or decreased) time of positive airway pressure, which can contribute to _________ (increased or decreased) venous return.

Front 60

Ratio of inspiratory time to entire expiratory pause between breaths.

Back 60

Define I:E ratio.

Front 61

4 seconds

Back 61

I:E should be 1:2 (or less). In the case of I:E = 1:2, if inspiratory time is set at 2 seconds, what is the expiratory time?

Front 62

6 seconds (2 seconds inspiratory + 4 seconds expiratory)

Back 62

I:E should be 1:2 (or less). In the case of I:E = 1:2, how many seconds are there for each CYCLE?

Front 63

Max 10 cycles (6 seconds per cycle, only 10 cycles will fit in 60 seconds)

Back 63

I:E should be 1:2 (or less). In the case of I:E = 1:2, how many cycles are there per minute?

Front 64

Optimize venous return

Back 64

Why should I:E be set to 1:2 or less (eg. 1:3, 1:4, etc)?

Front 65

Compliance

Back 65

What term defines the relationship of pressure and volume during inflation?

Front 66

Adjust tidal volume (have direct control over Vt)

Back 66

How can you adjust minute volume in a patient using a volume-limited ventilator?

Front 67

You do not have direct control over minute volume, however, adjust PIP (assumed to directly correlate to Vt)

Back 67

How can you adjust minute volume in a patient using a pressure-limited ventilator?

Front 68

Adjustable bellows

Back 68

What is the control mechanism for volume in a volume-limited ventilator?

Front 69

Compliance changes

Back 69

In pressure-limited ventilators, actual Vt will change as a result of what in the patient?

Front 70

Controlled Ventilation

Back 70

What defines ventilation solely at a user-defined rate and PIP/volume setting with no activation by patient effort?

Front 71

Assist-Control Ventilation

Back 71

What defines ventilation at a user-defined rate and PIP/volume setting with a trigger pressure at which the ventilator will cycle in response to a patient's breathing efforts?

Front 72

Taking over control of patient ventilation

Back 72

What does "capture patient" mean when initiating mechanical ventilation?

Front 73

Desired is 45 mmHg, above 60 mmHg is critical

Back 73

What is the desired upper limit of PaCO2 in a mechanically ventilated patient? What is the critical level?

Front 74

Patient should begin spontaneous ventilation.

Back 74

Allowing the PaCO2 to rise above 45 mmHg, but not 60 mmHg, may help to wean patient from mechanical ventilation. How?

Front 75

carp/o

Back 75

wrist bones
(carpals)