Chapter 28, Part 2, Review Exam #3

Front 1

Which blade may be preferred for DLT placement?

Back 1

Mac, because it offers greater clearance for the tube and may decrease the chance of balloon rupture from the teeth

Front 2

Describe the placement of the DLT

Back 2

a. advanced with the distal curve concave anteriorly until the vocal cords are passed (curved tip points to the anterior chest when inserted)
b. Remove the stylet, rotate the tube 90 degrees toward the bronchus to be intubated.
d. Inflate tracheal cuff with 5-10 mL of air, inflate bronchial cuff with 1-2 mL of air
e. Attach adapters to the two lumens.
f. Verify placement: auscultation is unreliable- flexible fiberoptic bronchoscopy is essential
g. After positioning, verify placement again

Front 3

What can overinflation of the bronchial cuff lead to? 2
When should the cuff be deflated? and why?

Back 3

a. cause the lumen to be narrowed or occluded
b. increased risk of tearing the bronchus
c. this cuff is a low volume, high pressure cuff – for this reason, the cuff should be deflated when OLV is no longer needed

Front 4

What size bronchoscope is appropriate for verification of DLTs?

Back 4

a. 4.9mm external diameter can pass through a 37F or larger
b. use a 3.6mm scope for a 35F tube

Front 5

Describe the proper steps of auscultation of breath sounds after DLT placement

Back 5

a. Inflate the tracheal cuff
b. Verify bilaterally equal breath sounds
c. Inflate the endobronchial cuff
d. Clamp the endobronchial lumen and open its lumen cap
e. Verify breath sounds in the correct lung and absence in the other lung
f. Verify breath sounds are equal at the apex and the lateral lung (if diminished, withdraw slightly)
g. Verify absence of air leakage through the opposite lumen cap
h. Unclamp the endobronchial lumen and verify bilateral breath sounds
i. Clamp the tracheal lumen and open its cap
j. Verify breath sounds on the side opposite the lung with the endobronchial lumen and absence of breath sounds on the other side

Front 6

When the fiberoptic bronchoscope is inserted into the right lumen to verify left-sided DLT position, what should be seen?

Back 6

a. a clear straight-ahead view of the carina
b. the left lumen going off into the left mainstem bronchus
c. upper surface of the left endobronchial cuff 1-2 mm below the carina (most important)

Front 7

Complications of DLTs (6)

Back 7

a. risk of hypoxemia with malpositioning
b. rupture of thoracic aneurysm with a left DLT if it compresses the left mainstem bronchus
c. damage to the vocal cords or arytenoids with a carinal hook
d. bronchial rupture d/t overinflation of the bronchial cuff
e. barotrauma
f. vocal cord paralysis

Front 8

What is the average blood flow distribution to the nondependent and dependent lungs?

Back 8

non:dep is 40%:60%

Front 9

if the left lung is nondependent, the ratio is?

Back 9

35%:65% during 2LV

Front 10

if the right lung is nondependent, the ratio is?

Back 10

45%:55% during 2LV

Front 11

What is the average blood flow % to the dependent lung during 2LV?

Back 11

60%

Front 12

When one lung is deflated, what happens to blood flow? What would be anticipated?

Back 12

a. any blood flow to the deflated lung becomes shunt flow, causing the PaO2 to drop
b. without autoregulation of pulm blood flow, a 40% shunt would be anticipated

Front 13

Describe HPV

Back 13

vascular resistance of the pulmonary arteries is increased in hypoxic areas of the lung, diverting some blood flow to areas of better ventilation and perfusion
-this is the opposite effect of hypoxemia in the general circulation

Front 14

Cellular mechanism of HPV

Back 14

redox-based O2 sensor in smooth muscle cells of the pulmonary arteries

Front 15

Describe the effectiveness of HPV

Back 15

b. shunt flow changes from 10% during 2LV to 27% during OLV
c. this increase in shunt decreased the mean PaO2 from greater than 400 mmHg during 2LV to less than 200 mmHg during OLV

Front 16

HPV is effective in decreasing the CO to the nonventilated lung to?

Back 16

20-25%

Front 17

Overall, HPV can decrease the shunt fraction during OLV by?

Back 17

50%

Front 18

When is HPV ineffective?

Back 18

a. If the amount of hypoxic lung is < 20%, total amount of shunt flow is insignificant
2, >80%, HPV increases PVR, but the amount of well-perfused lung is not sufficient to accept shunt flow to maintain arterial oxygenation

Front 19

HPV increases?

Back 19

PVR, but the amount of well-perfused lung is not sufficient to accept shunt flow to maintain arterial oxygenation

Front 20

The increase in PVR can cause?

Back 20

RV strain or failure

Front 21

What events interfere with HPV? How can they be prevented?

Back 21

hypervolemia or high CO
hypovolemia

Front 22

To prevent interference with HPV what should be done? 3

Back 22

maintain normovolemia, use moderate Vt (6mL/kg), and avoid excessive PEEP

Front 23

What decreases shunt flow? 3

Back 23

Hypocapnea, alkalosis, and acidosis

Front 24

What causes pulmonary vasoconstriction and can shunt blood away from the ventilated lung?

Back 24

hypothermia

Front 25

What drugs can interfere with HPV? 2

Back 25

vasodilators, vasoconstrictors

Front 26

What drugs have no effect on HPV? 8

Back 26

fentanyl, pentazocine, ketamine, droperidol, diazepam, thiopental, pentobarbital, propofol

Front 27

What are pulmonary side effects of GA? 5

Back 27

a. impairment of HPV
b. disruption of V/Q matching
c. neural and pain-induced hypoventilation
d. postoperative residual curarization (residual relaxation)
e. atelectasis

Front 28

Benefits of GA during thoracic surgery. 4

Back 28

a. allow use of a high FiO2 to prevent hypoxemia
b. produce bronchodilatory effects
c. decrease airway irritability in directly manipulated lung tissue
d. do not depress postop airway reflexes or ventilation like narcotics, allowing for early extubation

Front 29

Describe the rationale for not using N2O? 2

Back 29

1. To prevent hypoxia and increases in PVR
2. In patients with bullous or emphysematous lungs

Front 30

Which neuromuscular blockers are best to use for these patients?

Back 30

a. short acting, fast offset relaxants
b. conservative dosing and reversal practices

Front 31

What place does regional anesthesia have in thoracic surgery?

Back 31

Beneficial in reducing atelectasis, pneumonia, respiratory failure and other pulmonary complications

Front 32

What are the 2 primary goals of OLV?

Back 32

a. maintaining adequate arterial oxygenation
b. providing a surgical field favorable for visualization and manipulation of the lung

Front 33

What are the current recommendations on VT size, use of PEEP, and PIP values?

Back 33

6 ml/kg, adding PEEP to pts without auto-PEEP, and limiting PIP to 25 cmH2O

Front 34

Most patients during OLV develop?

Back 34

auto-PEEP and have an increased FRC, in which case volutrauma can occur if the Vt is too large

Front 35

What role does FiO2 play in thoracic surgery?

Back 35

using as high as 100% FiO2 may be necessary to maximize PaO2, but should be lessened after 30 minutes to minimize the effects of absorptive atelectasis

Front 36

What should be avoided b/c it causes vasoconstriction?

Back 36

hypocapnea

Front 37

A high FiO2 induces?

Back 37

vasodilation in the dependent lung, improving blood flow

Front 38

Is the relationship between PaCO2 and EtCO2 altered in OLV?

Back 38

not altered

Front 39

If hypoxemia occurs during OLV, what are your options?

Back 39

1. Assess for physiologic causes
2. Assess for tube malposition/adequate lung separation

Front 40

During OLV, what is almost 100% efficacious in increasing PaO2 in the nondependent lung?

Back 40

CPAP

Front 41

During OLV, what can you apply to the dependent lung?

Back 41

PEEP

Front 42

If PaO2 wont' increase during OLV what may you have to do?

Back 42

Intermittent reinflation of the dependent lung

Front 43

What could be the last intervention for increasing PaO2?

Back 43

early ligation of the pulmonary artery in pneumonectomy patients may be used to improve oxygenation

Front 44

What are the causes of hypoxemia during OLV? 3

Back 44

a. shunt flow
b. atelectasis
c. reduced FRC in dependent lung

Front 45

How can PEEP be detrimental?

Back 45

a. excessive PEEP may reduce CO
b. combined with a fast RR, may impair adequate exhalation, leading to a net volume increase through auto-PEEP and the potential for volutrauma to the dependent lung

Front 46

Overdistention of alveoli with excessive PEEP may increase the?

Back 46

areas of zone 1 effect (alveolar pressure > capillary pressure) and create more dead space ventilation

Front 47

What are the desired PIPs used to reinflate the operative lung at the end of the procedure?

Back 47

a. 30-40 cmH2O, allows the surgeon to check for leaks
b. use slow breaths

Front 48

Describe some options for postop analgesia? 5

Back 48

1. PCA (less desirable)
2. thoracic epidural
3. intercostal/paravertebral blocks
4. cryoanalgesia
5. Catheter in intrapleural space

Front 49

Where is a thoracic epidural placed?

Back 49

at T6-T8, and infused with epidural opioids or dilute local

Front 50

What is cryoanalgesia?

Back 50

cooled to -60 degrees C and applied to nerves in intercostal spaces 2-3 spaces above and below the incision, disrupting nerve activity

Front 51

What are the significant factors associated with acute lung injury (ALI) after resection? 4

Back 51

a. right pneumonectomy
b. intraop overhydration with high vascular volume
c. high intraop airway pressure during OLV
d. preop alcohol abuse

Front 52

What are some lesser factors?

Back 52

a. female gender
b. poor postop predicted lung function
c. trauma
d. infection
e. chemotherapy
f. mediastinal lymphatic drainage
g. transfusion and admin of FFP
h. serum cytokines
i. O2 toxicity
j. prolonged OLV >100 minutes
k. increased postop UOP

Front 53

Why is normovolemia important?

Back 53

a. minimizes pulmonary intravascular pressures
b. prevents pulmonary edema
c. avoids respiratory dysfunction and pulmonary injury postoperatively
d. prevents stretching of capillaries, impairing venous return

Front 54

What patient comorbidities are associated with increased susceptibility to ALI? 2

Back 54

alcoholism and respiratory diseases

Front 55

What events during surgery induce the release of inflammatory mediators? 4

Back 55

a. lung hyperinflation
b. surgical trauma
c. ischemia
d. reperfusion

Front 56

What are some risk-reduction strategies for the occurrence of ALI? 3

Back 56

a. withdrawal of ETOH
b. intraop application of pressure-controlled ventilation with small Vts and air-O2 mixtures to prevent barotrauma, volutrauma, and oxidative damages
c. limitation of fluid intake for the first 24-48 hours after surgery while maintaining tight control of hemodynamics

Front 57

What are the treatments for pulm HTN and interstitial lung edema? 3

Back 57

a. diuretics
b. inhaled nitric oxide (NO)
c. noninvasive positive pressure ventilatory devices

Front 58

What can cause low cardiac output in the early postop period? 4

Back 58

a. blood loss
b. herniation of the heart through a pericardial defect
c. right sided heart failure
d. dysrhythmias

Front 59

What is the normal chest tube output?

Back 59

a. less than 500 mL/day
b. greater than 200 mL/hr requires re-exploration

Front 60

What are other signs of bleeding? 3

Back 60

a. hypotension
b. unexplained tachycardia
c. decreasing Hct

Front 61

What are the possible negative effects on the heart after lung resection? 2

Back 61

a. increased PVR and right sided heart failure
b. reduction in the EF is greater following pneumonectomy than lobectomy

Front 62

What conditions increase the likelihood of right heart failure? 3

Back 62

a. postop pneumonia
b. hypercarbia
c. acidosis

Front 63

What agents can be used to decrease PVR postoperatively?

Back 63

a. NTG, nitroprusside, CCBs, hydralazine
b. if an inotrope is needed, amrinone or dobutamine can be administered

Front 64

What causes post-thoracotomy dysrhythmias?

Back 64

a. hypoxemia
b. vagal irritation
c. atrial inflammation
d. pre-existing cardiac disease
e. pulm HTN
f. right atrial or ventricular dilation
g. Atrial fibrillation or SVTs are serious complications
h. no correlation between incidence of dysrhythmias and preop pulmonary function or age
i. admin of > 2 L fluids intraop may increase the risk of pulm infiltration and dysrhythmias
j. beta-blockers can help prevent atrial dysrhythmias
h. digitalis, adenosine, CCBs and beta-blockers are useful to treat SVTs

Front 65

What are the complications if a patient has a PFO?

Back 65

increased PVR and right sided heart pressures can cause a right-to-left shunt

Front 66

What is the treatment for a patent PFO?

Back 66

correct hypoxemia, acidosis, and hypercarbia

Front 67

What are the respiratory complications in the early postop period?

Back 67

a. atelectasis
b. pneumonia
c. respiratory failure
d. bronchopleural or bronchocutaneous fistula
e. pneumothorax
f. torsion of remaining lobes
g. pulmonary edema

Front 68

What are the consequences of disruption of the bronchial stump repair site?

Back 68

a. creates a communication between the bronchus and the pleural space
b. a large portion of the Vt can be lost to this low-resistance pathway, compromising gas exchange
c. any fluid present in the pleural space can enter the defect and contaminate the healthy lung

Front 69

What should you do if the bronchopleural fistula leak interferes with adequate ventilation?

Back 69

a. place DLT with endobronchial lumen in the healthy lung; PPV
b. until placement, patient should be position so that the lung with the fistula is dependent, and maintain spontaneous respiration

Front 70

How can a chylothorax develop?

Back 70

a. thoracic duct injury, possible during a left thoracotomy or placement of left sided central lines
b. may occur in either thorax after removal of lymph nodes during thoracotomy

Front 71

What is a late sign of a chylothorax?

Back 71

weight loss and recurrent sepsis

Front 72

What is treatment for a chylothorax?

Back 72

ligation of the duct or pleuroperitoneal shunting

Front 73

What nerves may be injured?

Back 73

a. phrenic nerve: as it passes through the mediastinum
b. RLN: vulnerable during dissection of aortopulmonary lymph nodes and mediastinal procedures
c. spinal cord injury is possible if an intercostal artery supplying a major radicular artery is injured, or if an epidural hematoma is created by surgical dissection between the pleura and epidural spaces

Front 74

Describe complications from masses in the mediastinum

Back 74

a. compression of vital structures
b. changes in CO
c. obstruction to airflow
d. atelectasis
e. CNS changes

Front 75

What are some examples of mediastinal masses?

Back 75

a. benign or cancerous tumors
b. thymomas
c. substernal thyroid masses
d. vascular aneurysms
e. lymphomas
f. neuromas

Front 76

Common tumors of the anterior mediastinum (the 4 T’s)

Back 76

a. thymoma
b. thyroid
c. teratoma
d. “terrible” lymphoma

Front 77

How can GA worsen effects of mediastinal masses?

Back 77

supine position, induction, and PPV can cause collapse of the airway with total obstruction

Front 78

GA problems associated with mediastinal masses

Back 78

a. total airway obstruction can occur at any time
b. PPV may be impossible if the mass encroaches on the airway distal to the ETTT

Front 79

What should the goal be in GA with mediastinal masses?

Back 79

to maintain spontaneous respirations

Front 80

Symptoms of mediastinal masses

Back 80

a. can be asymptomatic
b. vague symptoms like dyspnea, cough, hoarseness, chest pain
c. wheezing may represent airflow past a mechanical obstruction rather than bronchospasm
d. SOB or DOE, sweats, syncope, orthopnea, chest pain, chest fullness, SVC syndrome, cough (especially when supine)
e. symptoms may be positional, often worse in supine

Front 81

Subclinical airway obstruction may be revealed by?

Back 81

flow-volume loops, which demonstrate changes in flow rates at different lung volumes

Front 82

Decreased maximal inspiratory or expiratory flow rates alerts the anesthetist to?

Back 82

increased risk of obstruction perioperatively

Front 83

If any sign of respiratory obstruction is present, what should be done?

Back 83

a. perform surgery or biopsy under local anesthesia whenever possible
b. radiation to decrease mass bulk in radiosensitive tumors
c. awake fiberoptic bronchoscopy and intubation
d. maintain spontaneous respiration as long as possible or throughout if possible
e. guarantee the ability to provide PPV prior to administering muscle relaxants

Front 84

heliox can?

Back 84

improve airflow during partial obstruction (low density gas decreases turbulence past a stenotic area, improving flow and decreasing the WOB)

Front 85

In patients at high risk for requiring CPB during surgery, what should be done?

Back 85

cannulation of the femoral vessels should be performed prior to induction

Front 86

What are some emergent strategies that may help in the case of airway compromise?

Back 86

a. repositioning or awakening the patient
b. rigid bronchoscopy to establish a patent airway beyond the obstruction
c. sternotomy with manual decompression of the mass off the airway

Front 87

What are the consequences of compression of the great vessels or cardiac chambers by a mass?

Back 87

sudden hypoxemia, hypotension, cardiac arrest

Front 88

Why is compression of the pulmonary artery rare?

Back 88

it is a higher pressure vessel than the pulmonary vein and is protected by the aortic arch

Front 89

Describe SVC syndrome

Back 89

venous engorgement of the upper body caused by compression of the SVC by a mass

Front 90

What are the s/s of SVC?

Back 90

dilation of collateral veins of the upper part of the thorax and neck, edema and rubor of the face, neck, and upper torso and airway, edema of the conjunctiva with or without proptosis, SOB, headache, visual distortion, altered mentation

Front 91

Where are IV lines preferred in a patient with SVC?

Back 91

lower extremities

Front 92

What can worsen symptoms in SVC?

Back 92

large volumes of fluid

Front 93

Describe mediastinoscopy

Back 93

passing a scope into the mediastinum via an incision above the suprasternal notch

Front 94

During a mediastinoscopy where should you place the pulse ox and why?

Back 94

compression of innomiate artery

Front 95

What is a thorascopy?

Back 95

trocar introduced at the 4th to 5th or 5th to 6th intercostal spaces to allow passage of the thoracoscope

Front 96

What are the advantages of using GA for thoracoscopy?

Back 96

a. DLT is used
b. airway is secured before lateral positioning
c. allows for deflation of the lung before trocar introduction
d. CPAP and PEEP can be applied as needed to improve oxygenation
e. controlled ventilation helps prevent paradoxical respiration and mediastinal shift
f. lung can actively be reinflated at the end of the procedure

Front 97

What is a thoracoscopic sympathectomy done for?

Back 97

for hyperhidrosis (excessive sweating)

Front 98

Is a DLT used for a thoascopic sympathectomy?

Back 98

yes, procedure is bilateral
-no nitrous to be used

Front 99

What are bullae?

Back 99

air-filled spaces of lung tissue resulting from the destruction of alveolar tissues and consolidation of alveoli into large pockets

Front 100

Bullae allow low resistance to inspiration or expiration?

Back 100

inspiration

Front 101

Bullae increase in size with?

Back 101

PPV

Front 102

With a bullae, what causes air trapping on expiration?

Back 102

a valvelike mechanism

Front 103

overdistended bullae can rupture and cause?

Back 103

pneumothorax or tension pneumothorax with cardiopulmonary collapse, requiring a chest tube

Front 104

After excision of bullae, what occurs?

Back 104

normal lung tissue rapidly reexpands and compliance and gas exchange rapidly improve

Front 105

Why is a DLT indicated for bullae?

Back 105

allows for separate ventilation and the use of adequate Vts on the healthy lung without risk of rupturing bullae

Front 106

What type of ventilation is best for reducing the risk of rupturing bullae?

Back 106

spontaneous until the chest is opened