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CoreConcept_Practice > Pulmonary > Flashcards

Pulmonary Flashcards

1
Q

Normally, the respiratory quotient is:

  • 1.0
  • 0.6
  • 0.3
  • 0.8
A

0.8

The normal respiratory quotient is 0.8 and probably reflects utilization of a combination of both fats and carbohydrates a fuel sources.

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2
Q

In the upright position, the largest alveoli are found:

  • at the lung bases
  • in the lingular lobe
  • in zone 2
  • at the apices
A

at the apices

In the upright position, the largest alveoli are at the pulmonary apex, whereas the smallest tend to be at the base

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3
Q

Referring to the spirogram below, the vital capacity is best represented by:

A
B
C
D

A

B

The vital capacity is the maximum volume of gas that can be exhaled following maximal inspiration.

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4
Q

The amount at which airways in the dependent portions of the lung begin to close is referred to as the:

closing volume
closing capacity
functional residual capacity
residual volume

A

closing capacity

Small airways lack cartilaginous support and depend on radial traction caused by the elastic recoil of surrounding tissue to keep them open. Patency of these airways is highly dependent on lung volume. The volume at which these airways begin to close is called the closing capacity.

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5
Q

The flow-volume loop below that best represents normal lung function is:

A
B
C
D

A

B

flow-volume loop B demonstrates both normal volumes and flows.

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6
Q

In a patient receiving general anesthesia with controlled ventilation with a tidal volume of 600 mL, the PaCO2 was 42 mmHg and the mixed expired CO2 was 35. From this information, the dead space can be estimated to be:

  • 100 mL
  • 150 mL
  • 200 mL
  • cannot be determined from this information
A

100 mL(?)

Dead space can be estimated using the Bohr equation:
VD/VT = (PACO2 - PECO2)/PACO2

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7
Q

During the administration of general anesthesia, the airway pressures from graph A below were obtained. One hour later, the airway pressures in graph B were noted. Possible explanations for the change include:

  • increased compliance
  • increased dead space
  • kinked endotracheal tube
  • increased tidal volume
A

kinked endotracheal tube

Causes of increased peak inspiratory pressure and unchanged plateau pressure include decreased I:E ratio, increased airway resistance, bronchospasm, kinked endotracheal tube, secretions and foreign body aspiration.

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8
Q

Pulmonary vascular tone is most profoundly affected by:

  • alveolar hypoxia
  • mixed venous hypoxemia
  • a-adrenergic stimulation
  • cholinergic stimulation
A

alveolar hypoxia

Local factors are more important than the autonomic system in influencing pulmonary vascular tone. Both pulmonary arterial and alveolar hypoxia induce vasoconstriction, but alveolar hypoxia is a more powerful stimulus.

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9
Q

While receiving PCA after a lumbar fusion, an 21-year-old male was found to have a PaCO2 of 80 mmHg while breathing room air. From this information, his expected PaO2 would be:

  • 55 mmHg
  • 85 mmHg
  • 100 mmHg
  • 150 mmHg
A

55 mmHg

Large increases in PaCO2 (> 75 mmHg) readily induce hypoxia at room air, but not at high inspired oxygen concentrations.

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10
Q

β-2 stimulation results in:

  • bronchodilation and decreased secretions
  • bronchodilation and increased secretions
  • bronchoconstriction and decreased secretions
  • bronchoconstriction and increased secretions
A

bronchodilation and decreased secretions

Sympathetic activity mediates bronchodilation and decreased secretions via the β-2 receptors. α-1 receptors stimulation also decrease secretions, but may cause bronchospasm.

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11
Q

In patients with decreased lung volume, increasing lung volume with PEEP will:

  • decrease dead space
  • have little effect on airway resistance
  • increase airway resistance
  • decrease airway resistance
A

decrease airway resistance

At low lung volumes, loss of radial traction increases the contribution of small airways to total resistance; airway resistance becomes inversely proportional to lung volume. Increasing lung volume with PEEP can reduce airway resistance.

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12
Q

Hypoxic vasoconstriction has been shown to be inhibited by:

  • desflurane
  • nitroprusside
  • nitrous oxide
  • all of the above
A

all of the above

Inhalation agents, including nitrous oxide can inhibit hypoxic pulmonary vasoconstriction. For volatile agents, the ED50 is about 2 MAC.

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13
Q

Pulmonary capillary oxygen tension corresponds best with:

  • alveolar oxygen tension
  • PaO2
  • mixed venous O2
  • FiO2
A

alveolar oxygen tension

For all practical purposes, pulmonary end-capillary oxygen tension may be considered identical to alveolar oxygen tension; the gradient is normally minute.

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14
Q

The predicted PaO2 in a healthy 90-year-old patient is:

  • 72 mmHg
  • 83 mmHg
  • 94 mmHg
  • 100 mmHg
A

72 mmHg

Arterial oxygen tension can be approximated by the formula:
PaO2 = 102 - (Age/3)

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15
Q

In the adult at rest, oxygen consumption is approximately:

  • 150 mL/min
  • 250 mL/min
  • 500 mL/min
  • 1000 mL/min
A

250 mL/min

In the adult, oxygen consumption is approximately 250 mL/min with carbon dioxide production being 200 mL/min resulting in a respiratory quotient of 0.8.

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16
Q

Surfactant is produced by:

  • type I pneumocytes
  • type II pneumocytes
  • goblet cells
  • the basement membrane
A

type II pneumocytes

Type II pneumocytes are round cells that contain prominent cytoplasmic inclusions. These inclusions contain surfactant, an important substance necessary for normal pulmonary mechanics.

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17
Q

Upper abdominal procedures are associated with a reduction in FRC of approximately:

10 - 15%
20 - 30%
40 - 50%
60 - 70%

A

60 - 70%

Upper abdominal procedures consistently decrease FRC by 60 - 70%. This effect is maximal on the first postoperative day and usually lasts 7 - 10 days.

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18
Q

Most airway resistance comes from:

  • the trachea and vocal cords
  • large bronchi
  • medium-sized bronchi(before the 7th generation)
  • small bronchi)after the 7th generation)
A

medium-sized bronchi (before the 7th generation)

Normal total airway resistance is about 0.5 - 2 cm H2O/L/s, with the largest contribution coming from medium-sized bronchi (before the 7th generation).

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19
Q

The most sensitive pulmonary function test indicating the presence of increased airway resistance is the:

  • FEV1
  • FVC
  • FEV1/FVC ratio
  • FEF25-75%
A

FEF25-75%

Whereas both FEV1 and FVC are effort dependent, FEF25-75% is effort independent and a more reliable measurement of obstruction. In early obstructive disease the FEF25-75% is often the only abnormality.

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20
Q

Stimulation of vagal afferents and efferents of the bronchi is associated with:

  • an increased responsiveness to carbon dioxide
  • a decrease in hypoxic drive
  • bronchoconstriction
  • decreased bronchial secretions
A

bronchoconstriction

Vagal afferents in the bronchi are sensitive to histamine and multiple noxious stimuli. Vagal activation results in bronchoconstriction, which is mediated by an increase in cGMP.

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21
Q

During general anesthesia in healthy individuals, venous admixture (shunting) usually:

  • decreased to 1 - 4%
  • increases to 5 - 10%
  • increases to over 20%
  • remains unchanged from the unanesthetized state
A

increases to 5 - 10%

General anesthesia commonly increases venous admixture to 5 - 10%, probably as a result of atelectasis and airway collapse in dependent areas of the lung.

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22
Q

The effects of inhalation anesthesia at 1 MAC and greater are to:

  • decrease tidal volume and rate
  • increase tidal volume and rate
  • decrease tidal volume and increase rate
  • increase tidal volume and decrease rate
A

decrease tidal volume and increase rate

At 1.2 MAC, inhalation agents increase ventilatory rate and decrease tidal volume.

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23
Q

Pulmonary function tests that do not depend on patient effort include:

  • FVC
  • FEV
  • FEF25-75%
  • FEV1
A

FEF25-75%

Whereas both FEV1 and FVC are effort dependent FEF25-75% is effort independent and may be a more reliable measurement of obstruction.

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24
Q

Laminar flow in the airways is found:

  • in the trachea
  • in the mainstem bronchi
  • in bronchioles
A

in bronchioles

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25
Q

β2-adrenergic agonists produce bronchodilation by:

  • increasing intracellular cAMP
  • increasing intracellular cGMP
  • stabilizing mast cells
  • blocking histamine and serotonin receptors
A

increasing intracellular cAMP

Activation of β2-adrenergic receptors on bronchiolar smooth muscle activated adenylate cyclase, which results in the formation of intracellular cAMP.

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26
Q

The lung volume remaining after normal exhalation is the:

  • residual volume
  • expiratory reserve volume
  • functional residual capacity
  • closing capacity
A

function residual capacity

The lung volume at the end of a normal exhalation is called the functional residual capacity (FRC). At this volume, the inward elastic recoil approximates the outward elastic recoil. The FRC is the sum of the expiratory reserve volume and the residual volume and is approximately 2.5 L in volume.

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27
Q

The flow-volume loop below that best represents chronic obstructive pulmonary disease is:

A
B
C
D

A

A

Loop A demonstrates the elevated lung volumes and diminished expiratory flow associated with COPD.

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28
Q

Capnographic evidence of bronchospasm includes:

  • increased slope of phase I
  • increased slope of phase II
  • increased slope of phase III
  • increased slope of phase IV
A

increased slope of phase III

In the normal capnogram, phase III is nearly flat with a slope approaching zero. With obstruction, the slope of phase III increases.

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29
Q

Patients with long-standing COPD often develop:

  • decreased responsiveness to carbon dioxide
  • decreased pulmonary artery pressures
  • decreased right ventricular pressures
  • decreased red cell mass
A

decreased responsiveness to carbon dioxide

In patients with COPD, chronic hypoxia leads to erythrocytosis, pulmonary hypertension and right ventricular failure (cor pulmonale). Patients gradually develop CO2 retention and loss of sensitivity to arterial CO2 tension.

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30
Q

The dichotomous division of the tracheobronchial tree is estimated to involve:

  • 10 divisions
  • 17 divisions
  • 23 divisions
  • 31 divisions
A

23 divisions

Dichotomous division, starting with the trachea and ending in alveolar sacs, is estimated to involve 23 divisions. Gas exchange can occur only across the flat epithelium, which begins to appear on pulmonary bronchioles (generations 17 - 19).

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31
Q

The diaphragm is innervated by:

  • C1 - C2
  • C3 - C5
  • C7 - T2
  • T3 - T5
A

C3 - C5

The diaphragm is innervated by the phrenic nerves, which arise from the C3 - C5 nerve roots.

32
Q

Factors that favor ventilation in the non-dependent lung during thoracotomy in the lateral decubitus position include:

  • controlled positive-pressure ventilation
  • neuromuscular blockade
  • use of a bean bag
  • all of the above
A

all of the above

Controlled ventilation favors the upper lung in the lateral position because it is more compliant. Neuromuscular blockade enhances this effect. Using a rigid “bean bag” to maintain the patient in the lateral position further restricts movement of the dependent hemithorax.

33
Q

Referring to the spirogram below, the expiratory reserve volume is best represented by:

A
B
C
D

A

C

The expiratory reserve volume is the volume of gas that can be forcibly exhaled after exhalation of a normal tidal volume. In the adult, the ERV is 1.1 - 1.5 L.

34
Q

Cromolyn and nedocromil are effective in preventing asthmatic bronchoconstriction as a result of their:

  • directly bronchodilating properties
  • ability to stabilize mast cells
  • anticholinertic effects
  • B2 adrenergic effects
A

ability to stabilize mast cells

Cromolyn sodium and nedocromil are effective for preventing bronchospasm. Although devoid of direct bronchodilating properties, both agents block the degranulation of mast cells.

35
Q

During pulmonary function testing, it was found that the FEV1/FVC ratio was 0.72. This suggests:

  • normal pulmonary function
  • increased airway resistance
  • restrictive lung disease
  • increased dead space
A

increased airway resistance

The ratio of the FEV1 / FVC is proportional to the degree of airway obstruction. Normally this ratio is greater than 0.8.

36
Q

In the lung diagram below, the area of optimal ventilation/perfusion ratio is:

A
B
C
C if the patient is supine

A

B

Non-dependent apical areas (A) have higher V/Q ratios and therefore represent a greater area of deadspace. Conversely, low V/Q areas can be found at the bases (C) and represent areas of shunting. Optimal V/Q ratios are found in West zone II (B).

37
Q

α-1 stimulation results in:

  • bronchodilation and decreased secretions
  • bronchodilation and increased secretions
  • bronchoconstriction and decreased secretions
  • bronchoconstriction and increased secretions
A

bronchoconstriction and decreased secretions

Sympathetic activity (T1 - T4) mediates bronchodilation and also decreases secretions via β2 receptors. α1-adrenergic receptor stimulation decreases secretions, but may cause bronchospasm.

38
Q

During the administration of general anesthesia, the airway pressures from graph A below were obtained. One hour later, the airway pressures in graph B were noted. Possible explanations for the change include:

  • increased compliance
  • increased dead space
  • kinked endotracheal tube
  • increased tidal volume
A

increased tidal volume

Causes of increased peak inspiratory pressure (PIP) with increased plateau pressure (PP) include increased tidal volume and any cause of decreased pulmonary compliance, e.g. pulmonary edema, ascites and endobronchial intubation.

39
Q

The flow-volume loop below that best represents restrictive pulmonary disease is:

A

D

Loop D demonstrates the decreased volumes and flows associated with restrictive lung disease.

40
Q

Evidence of intraoperative brochospasm includes all of the following EXCEPT:

  • wheezing
  • increased plateau pressures
  • increased peak airway pressure
  • slowly rising waveform on the capnograph
A

increased plateau pressure

Intraoperative brochospasm is usually manifested as wheezing, increased peak inflation pressures, decreased exhaled tidal volumes and a slowly rising waveform on the capnograph. Plateau pressure should remain unchanged.

41
Q

The effect of general anesthesia on the closing capacity in the anesthetized patient is to:

  • cause a decrease of approximately 5%
  • cause a decrease of approximately 15 - 20%
  • cause little to no change
  • cause an increase of approximately 5%
A

cause a decrease of approximately 15 - 20%

Both FRC and CC are consistently reduced with the induction of general anesthesia by approximately 15 - 20%. Since both FRC and CC are reduced to a similar extent, the risk of increased intrapulmonary shunting under anesthesia is similar to that in the conscious state.

42
Q

Referring to the spirogram below, the inspiratory capacity is best represented by:

A
B
A + E
A + C + E

A

A + E

Inspiratory capacity is the sum of the tidal volume and the inspiratory reserve volume.

43
Q

In the lung diagram below, the area where pulmonary venous pressure exceeds pulmonary arterial pressure is:

A
B
C
none of the above

A

none of the above

Pulmonary venous pressure exceeding pulmonary arterial pressure would result in reversed blood flow and does not occur under normal conditions.

44
Q

The effect of neuromuscular blockade on the functional residual capacity (FRC) in the anesthetized patient is to:

  • cause an additional decrease of approximately 5%
  • cause an additional decrease of approximately 15 - 20%
  • cause little to no change
  • cause an additional increase of approximately 5%
A

cause little to no change

Induction of anesthesia consistently produces a 15 - 20% reduction in both FRC and CC. However, muscle paralysis does not appear to change the FRC further.

45
Q

Dead space ends and gas exchange begins at the:

  • carina
  • terminal bronchiole
  • respiratory bronchiole
  • alveolus
A

respiratory bronchiole

Gas exchange can occur only across the flat epithelium, which begins to appear on the respiratory bronchiole (generations 17 - 19).

46
Q

Sympathetic innervation of the lung originates at:

  • C1 - C2
  • C6 - C8
  • T1 - T4
  • T5 - T7
A

T1 - T4

Sympathetic innervation to the lung originates at T1 - T4. Sensory and parasympathetic innervation of the lung is provided by the vagus nerves.

47
Q

In the lung diagram below, alveolar dead space is best represented by:

A
B
C
B and C

A

A

Apical areas (zone I) have the highest V/Q ratios.

48
Q

The flow-volume loop below that best represents upper airway obstruction is:

A
B
C
D

A

C

Loop C demonstrates normal lung volumes with decreased flow rates consistent with upper airway obstruction.

49
Q

Closing capacity:

  • increases with age
  • declines with age
  • exceeds the FRC after the first year of life
  • is a significant component of dead space
A

increases with age

Closing capacity is normally well below FRC, but rises steadily with age. At an average age of 44 years, closing capacity equals FRC in the supine position; by age 66, closing capacity equals or exceeds FRC in the upright position. Unlike FRC, closing capacity is unaffected by posture.

50
Q

At the end of inspiration and the end of expiration, the alveolar pressure is:

  • -5 cm H20
  • 0 cm H20
  • +5 cm H20
  • +25 cm H20
A

0 cms H2O

Alveolar pressure is normally atmospheric (zero for reference) at end inspiration and end expiration.

51
Q

In a healthy individual with a cardiac output of 5.0 L/minute, oxygen delivery is approximately:

  • 200 mL/min
  • 250 mL/min
  • 1000 mL/min
  • 5000 mL/min
A

1000 mL/minute

Normal O2 delivery is the product of the oxygen content (20 mL/dL) and the cardiac output (50 dL/min).

52
Q

In the adult, carbon dioxide stores are approximately:

  • 10L
  • 40L
  • 80L
  • 120L
A

120 L

Carbon dioxide stores in the body are large (approximately 120 L in adults) and primarily in the form of dissolved carbon dioxide and bicarbonate.

53
Q

In a healthy patient with a PaO2 of 200 mmHg, the amount of dissolved oxygen in 100 mL of plasma is approximately:

  • 0.3 mL
  • 0.6 mL
  • 3.0 mL
  • 6.0 mL
A

0.6 mL

The solubility coefficient for O2 at normal body temperature is 0.003 mL/dL per mmHg. This is very small compared to the amount of oxygen carried by hemoglobin.

54
Q

The peripheral ventilatory response to hypoxemia can be abolished with:

  • phenothiazines
  • volatile anesthetic agents
  • bilateral carotid surgery
  • all of the above
A

all of the above

Anti dopaminergic drugs, most commonly used anesthetics and bilateral carotid surgery abolish the peripheral ventilatory response to hypoxemia.

55
Q

As compared to the diffusion rate of oxygen, the diffusion rate of CO2 across the alveolar membrane is approximately:

  • equal
  • 5 times greater
  • 20 times greater
  • 20 times less
A

20 times greater

56
Q

Methylxanthines produce bronchodilation by:

  • inhibiting phosphodiesterase
  • causing catecholamine release
  • blocking histamine release
  • all of the above
A

all of the above

Traditionally, methylxanthines are thought to produce bronchodilation by inhibiting phosphodiesterase, but their effects appear to be much more complex. Additional pulmonary effects include increased catecholamine release, histamine blockade and diaphragmatic stimulation.

57
Q

In a healthy adult patient breathing room air, apnea is induced with an induction dose of propofol. In the absence of ventilation, hypoxemia can be expected to occur in approximately:

  • 30 to 60 seconds
  • 90 to 120 seconds
  • 180 to 240 seconds
  • 300 seconds are more
A

90 - 120 seconds

Apnea in a patient previously breathing room leaves about 480 mL of oxygen in the lungs (FRC x 21%). With a normal oxygen uptake of 250 mL/min, hypoxemia should result in less than 2 minutes.

58
Q

Ipratropium:

  • produces bronchodilation through cholinergic blockade
  • causes significant systemic anticholinergic effects
  • blocks histamine release
  • all of the above
A

produces bronchodilation through cholinergic blockade

ipratropium is a congener of atropine that can be given by a metered-dose inhaler. It produces bronchodilation through an anticholinergic effect without appreciable systemic effects.

59
Q

The inhibition of ventilation, preventing over-inflation of the lung, is controlled by the:

  • pneumotaxic center
  • apneustic center
  • mid brain
  • basal ganglia
A

pneumotaxic center

Two pontine areas influence the dorsal (inspiratory) medullary center. A lower pontine (apneustic) center is excitatory, whereas an upper pontine (pneumotaxic) center is inhibitory.

60
Q

A reduction in cardiac output is usually results in:

  • increased shunting
  • decreased shunting
  • increased mixed venous oxygen content
  • leftward shift of the hemoglobin dissociation curve
A

decreased shunting

A reduction in venous admixture is usually observed with low cardiac output states secondary to accentuated pulmonary vasoconstriction from a lower mixed venous oxygen tension.

61
Q

Patients with long-standing emphysema commonly have:

  • decreased carbon monoxide diffusion studies
  • severe hypoxemia
  • significantly elevated carbon dioxide levels
  • decreased dead space
A

decreased carbon monoxide diffusion studies

Destruction of pulmonary capillaries in the alveolar septa decreases the carbon monoxide diffusion capacity. However, arterial oxygen tensions are usually normal or slightly reduced; carbon dioxide tension is also typically normal.

62
Q

During repair of an quadriceps tendon under general anesthesia, the following blood gas was obtained: pH - 7.55, PaO2 - 265 mmHg, PaCO2 - 25 mmHg, saturation - 99%. If the preoperative bicarbonate level was 24 mEq/L, the predicted bicarbonate level is:

  • 15 mEq/L
  • 20 mEq/L
  • 30 mEq/L
  • 35 mEq/L
A

20 mEq/L

A derivation of the Henderson-Hasselbalch equation allows the calculation of bicarbonate. The formula is:
[H+] = 24 x (PaCO2 / [HCO3-])
As a general rule, plasma bicarbonate decreases about 2 mEq/L for each 10 mmHg acute decrease in PaCO2.

63
Q

During a hip replacement in a 78-year-old patient, the following mixed venous blood gas is obtained: pH - 7.31, PaO2 - 30 mmHg, PaCO2 - 47 mmHg, saturation - 52%. From this information, it can be expected that the patient:

  • has arterial hypoxemia
  • is inadequately ventilated
  • has reading of 92% by pulse oximetry
  • has a depressed cardiac output
A

has a depressed cardiac output

Normal mixed venous oxygen tension is 40 mmHg with a saturation of 70%. These depressed numbers imply increased oxygen extraction and reduced cardiac output.

64
Q

Sub-anesthetic doses of inhalational agents have been shown to severely depress or ablate the:

  • effect of hypoxia on ventilation
  • effect of hypercarbia on ventilation
  • uptake of carbon dioxide by hemoglobin
  • all of the above
A

effect of hypoxia on ventilation

The peripheral response to hypoxemia is even more sensitive to anesthetics than the central CO2 response and is nearly abolished by even subanesthetic doses of most inhalation agents, including nitrous oxide.

65
Q

In healthy patients, a PaCO2 of 40 mmHg corresponds to a minute alveolar ventilation of:

  • 3500 mL
  • 3800 mL
  • 4200 mL
  • 5800 mL
A

3800 mL
Alveolar ventilation inversely affects the PaCO2 levels:

VA= VCO2/PaCO2 x 760

66
Q

A 28-year-old female with a history of sarcoidosis is scheduled for excision of a neck mass. Pulmonary function testing is expected to demonstrate:

  • increased FRC
  • increased diffusing capacity
  • increased airway resistance
  • increased inspiratory reserve volume
A

increased airway resistance

Sarcoidosis can cause both obstructive and restrictive lung disease. Parenchymal infiltration and fibrosis result in a decrease in lung compliance, diffusing capacity and lung volumes. Many patients also have an obstructive component with a reduced FEV1 and increased airway resistance.

67
Q

A sample of blood is found to have a P50 of 31 mmHg. Possible explanations for this include:

  • respiratory acidosis
  • metabolic alkalosis
  • decreased erythrocyte 2,3-DPG levels
  • presence of fetal hemoglobin
A

respiratory acidosis

The normal P50 is 27 mmHg. Causes for an elevated P50 include acidosis, hyperthermia and increased 2,3-DPG.

68
Q

Bronchodilating effects have been associated with the use of:

  • propofol
  • etomidate
  • ketamine
  • thiopental
A

ketamine

Ketamine is the only intravenous agent with bronchodilating properties.

69
Q

The largest fraction of carbon dioxide in the blood is in the form of:

  • carbamino compounds
  • dissolved gas in the plasma
  • attachement to the hemoglobin molecule
  • bicarbonate
A

bicarbonate

Bicarbonate represents the largest fraction (87.2%) of the carbon dioxide in blood.

70
Q

In healthy patients, the mixed venous blood has a:

  • PvO2 = 40 mmHg and 70% saturation
  • PvO2 = 30 mmHg and 60% saturation
  • PvO2 = 40 mmHg and 50% saturation
  • PvO2 = 70 mmHg and 90% saturation
A

PvO2 = 40 mmHg and 70% saturation

Normal mixed venous oxygen tension is about 40 mmHg and represents the overall balance between oxygen consumption and oxygen delivery.

71
Q

Paradoxical respiration can occur in patients:

  • in the lateral decubitus position, with an open pneumothorax and spontaneous ventilation
  • in the lateral decubitus position, with an open pneumothorax and controlled ventilation
  • in the lateral decubitus position, with a closed thorax and spontaneous ventilation
  • receiving controlled ventilation and PEEP
A

in the lateral decubitus position, with an open pneumothorax and spontaneous ventilation

Spontaneous ventilation in patient with an open pneumothorax results in to-and-fro gas flow between the dependent and nondependent lung (paradoxical respiration).

72
Q

The angles of the right and left mainstem bronchi bifurcating from the trachea are:

  • right 45’, left 25’
  • right 25’,left 45’
  • right 35’, left 35’
  • right 45’, left 85’
A

Right - 25o, Left - 45o

73
Q

Difficulties with right-sided double-lumen endotracheal tubes arise because:

  • the angle of the right bronchus is too acute for tube placement
  • the right lower lobe bronchus may not communicate with the right bronchus
  • the right upper lobe bronchus is often occluded by the tube
  • the tube gets caught in the surgical ligature of the bronchus
A

the right upper lobe bronchus is often occluded by the tube

Problems with right-sided double-lumen tubes arise because the orifice of the right upper lobe is close to the carina. It is very easy to occlude the right upper lobe orifice with the bronchial tube cuff.

74
Q

Prior to pneumonectomy, preoperative laboratory criteria necessitating split lung function testing includes:

  • PaO2 - 53 mmHg
  • PaCO2 - 44 mmHg
  • FEV1 - 1.86 L
  • all of the above
A

FEV1 - 1.86 L

Split lung function testing is indicated if pneumonectomy is contemplated in a patient not meeting any of the following criteria:
• PaCO2 > 45 mmHg
• FEV1

75
Q

Consistently effective measures of treating hypoxemia during one-lung anesthesia include:

  • application of PEEP to the dependent lung
  • increasing the tidal volume to the dependent lung
  • periodic inflation of the non-dependent lung with oxygen
  • decreasing the tidal volume and increasing the rate to the dependent lung
A

periodic inflation of the non-dependent lung with oxygen

Consistently effective measures in treating hypoxemia during one-lung anesthesia include:
• Periodic inflation of the collapsed lung with oxygen
• Early ligation of the ipsilateral pulmonary artery
• CPAP to the collapsed lung

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