Thoracic Anesthesia I Flashcards
1
Q
Number of lobes on the right lung?
A
3 lobes
2
Q
Number of lobes on the left lung?
A
2 lobes
3
Q
Number of segments on the right lung?
A
22 segments
4
Q
Number of segments on the left lung?
A
20 segments
5
Q
Define FEV1
A
- Forced expiratory volume in 1 second
- Amount of expired air in the first second after full inspiration
6
Q
What is FEV1% Predicted?
A
Compares the actual total volume breathed out during the test to an average of the normal total volume for a person of the same gender, height, and age.
7
Q
What is the normal range of FEV1% Predicted?
A
80-120%
FEV1% Predicted has a strong correlation with post-op outcomes
8
Q
How is Predicted Postoperative FEV1% (PPO FEV1%) Calculated?
A
Preop FEV1% X (1- % of lung tissue removed/100)
9
Q
What would be the PPO FEV1% if FEV 1% is 70% and 25% of lung tissue is surgically removed?
A
52%
10
Q
What PPO FEV1% correlates with an increased risk of pulmonary complication?
What PPO FEV1% is considered high risk?
A
- <40% → Increased risk
- <30% → High risk
11
Q
What PaO2 and PCO2 are associated with poor surgical outcomes?
A
- PaO2 < 60 mmHg
- PCO2 > 45 mmHg
12
Q
What is the most useful pulmonary test for determining gas exchange capacity?
A
Diffusing Lung Capacity for Carbon Monoxide (DLCO)
13
Q
How is the DLCO PFT performed?
A
- Carbon Monoxide has a high affinity for Hgb
- A small amount of CO is inhaled with a tracer gas (helium or methane)
- After inhalation of the gas, the patient will exhale into an analyzer
- The analyzer will determine how much CO was picked up by the lungs
- This will correlate with total functioning surface are of alveolar/capillary interference
14
Q
What is the absolute minimum value of FEV1 or DLCO for a successful outcome in thoracic surgery?
A
No less than 20%
15
Q
What is the ideal V/Q ratio?
What is typically the V/Q ratio?
A
- 1.0 (ideal)
- 0.8 (typical)
16
Q
What 3 factors is the V/Q ratio dependent on?
A
- Position (gravity)
- Pathology
- Situation
17
Q
Blood flow in the lungs is ____________ dependent
A
Gravity
18
Q
Pulmonary ___________ pressure is always greater than Pulmonary ________pressure
A
Pulmonary artery pressure is always greater than Pulmonary venous pressure
19
Q
Absolute pressure of Pa and Pv is greater in the dependent portion of the lung due to _____________
A
Hydrostatic gradients
20
Q
The base of the lung has a ________ mmHg increase in blood flow relative to the apex of the lung in an upright position.
A
20 mmHg
21
Q
Rank PA, Pa, and Pv in Zone 1
A
PA > Pa > Pv
22
Q
Rank PA, Pa, and Pv in Zone 2
A
Pa > PA > Pv
23
Q
Rank PA, Pa, and Pv in Zone 3
A
Pa > Pv > PA
24
Q
How many cm above the heart is Zone 2?
A
3 cm
25
Which zone will have the alveoli maximally distended?
Zone 1
26
Which zone will have complete compression of the capillary?
Zone 1
27
Which zone will have the most dead space?
Zone 1
28
In Zone 2, _________ pressure is greater than PA and ________ pressure is less than PA
In Zone 2, **systolic** pressure is greater than PA and **diastolic** pressure is less than PA
29
This zone will have less distended alveoli, but greater intrapleural pressure.
Zone 3
30
This zone will have continuous blood flow and is not affected by the cardiac cycle?
Zone 3
31
Which zone is most affected by the cardiac cycle?
Zone 2
32
This zone is absent in healthy patients
Zone 1
33
How is Zone 1 developed?
* Positive Pressure Ventilation (↑ PEEP/ ↑Alveolar Pressure)
* Decrease Arterial Pressure (Hemorrhage, Shock, Hypovolemia)
34
For an accurate measurement of PCWP, which zone must the pulmonary artery catheter be placed in?
Zone 3, where there is a continual column of blood
35
Which PFT is used to determine whether lungs are obstructive, restrictive, or normal?
FEV1/FVC Ratio
36
What is normal FEV1/FVC?
70-85%
37
FEV1/FVC Ratio of Obstructive Pattern
Decreased
38
FEV1/FVC Ratio of Restrictive Pattern
Normal
39
TLC of Obstructive Pattern
Normal or Increased d/t air trapping
40
TLC of Restrictive Pattern
Decreased
41
Patho of Obstructive Lung Disease
Damage to the lung tissue or narrowing of the airways causes air trapping and difficulty expelling air from the lungs
42
What are the most common Obstructive Lung Diseases
* COPD (chronic bronchitis, emphysema)
* Asthma
* Cystic Fibrosis
43
What is the most common comorbidity in thoracic surgical patients?
COPD
44
Clinical presentation of COPD
* Compromised pulmonary mechanics
* Hypercapnia
* Dyspnea
* Hypoxia
* O2 therapy commonly required
45
Patho of Restrictive Lung Disease
* Stiffness in lung tissue, chest wall, or weak muscles.
* Cannot fully fill lungs with air
46
What are the most common Restrictive Lung Disease?
* Interstitial Lung Disease
* Pulmonary Fibrosis
* Sarcoidosis
* Obesity (hypoventilation syndrome)
* Neuromuscular diseases
47
What is the leading cause of cancer deaths?
Lung Cancer
48
Causes of lung cancer
* Smoking
* Environmental factors (asbestos, gas, metals)
49
What are the two types of lung cancer?
* Small cell lung cancer
* Non-small cell cancer
50
Characteristics of Small Cell Lung Cancer
* Fast growing
* Aggressive
* Commonly caused by smoking
* Usually starts in the bronchi
* Frequently metastasized
51
Characteristics of Non-Small Cell Lung Cancer
* Less aggressive
* Affects both smokers and non-smokers
* More common
* Better prognosis
52
Lung Cancer Signs and Symptoms
* Cough
* Hemoptysis
* Wheezing
* Stridor
* Dyspnea
* Airway obstruction
* Hoarseness
* Superior vena cava syndrome
* Pleural effusion
* Congestive heart failure
53
How are central/endo-bronchial lesions diagnosed?
Cytology analysis of sputum using flexible fiberoptic bronchoscopy
54
How are peripheral/pleural lesions diagnosed?
* CT scan
* Percutaneous fine needle aspiration
* VATS
55
Lung Cancer Treatment Options
* Radiation
* Chemo +/- radiation
* Surgical resection
56
What treatment is effective for small-cell lung cancer?
Radiation (small cell very radiosensitive)
57
Procedure where the entire lung is removed
Pneumonectomy
58
Procedure where one lobe is removed
Lobectomy
59
Procedure where there is partial lobe removal
Resection (sleeve, wedge, segment)
60
What is Pleurodesis?
A medical procedure that treats fluid or air buildup in the pleural space, the space between the lung and chest wall
61
Indications for a thoracotomy
* Pneumonectomy
* Lobectomy
* Advanced malignancy
* Hemorrhagic complications
62
What are the different approaches to a thoracotomy? Which one will be the most common?
* Sternotomy
* Anterolateral (Most Common)
* Posterolateral
63
Indications for Video-Assisted Thoracic Surgery (VATS)
* Pleural surgery
* Undiagnosed nodules
* Interstitial disease
* Lobectomy
64
VATS Benefits
* Reduced hospital stay
* Less blood loss
* Less pain
* Better postop pulmonary function
* May be done robotically
65
Purpose of One Lung Ventilation
* Immobile Surgical Field
* Access/ Visibility
* Prevent fluids/secretions from contaminating non-operative lung
66
What is lung separation
ADEQUATE lung deflation
67
What is lung isolation
COMPLETE lung deflation
68
What type of tube is typically used for OLV?
A Double Lumen Endotracheal Tube (DLT), usually left-sided to avoid obstructing the right main bronchus.
69
When is a right-sided DLT preferred?
When a left pneumonectomy or left upper lobe surgery is planned or if the left bronchus has structural issues like a tumor or aneurysm.
70
Typical DLT size for women
35 or 37 Fr
71
Typical DLT size for men
39 Fr
72
What are the key steps in placing a DLT?
Lubricate the tube, insert under direct vision or with a scope, rotate 90° as needed, advance into the trachea, inflate cuffs, and verify placement.
73
How much air is inflated into the tracheal cuff?
5-7 mL
74
How much air is inflated into the bronchial cuff?
2-3 mL
75
How is DLT placement confirmed?
Placement is confirmed with fiberoptic bronchoscopy to ensure the bronchial cuff is below (5-10 mm) the carina in the target bronchus.
76
What is a bronchial blocker, and when is it used?
A catheter with an inflatable balloon that occludes a bronchus, used for selective lung isolation, especially if DLT placement is challenging.
77
Name a specific case where a bronchial blocker would be used.
In patients with difficult airways or when nasotracheal intubation with OLV is necessary.
78
When should you confirm the placement of DLT?
* Immediately after placement
* Immediately after positioning
79
What should be clamped when deflating one side of the DLT?
Adaptor
80
What can be used to deflate the lung completely?
Suction catheter
81
What should be the tidal volume of the non-operative lung during OLV?
4-6 mL/kg
82
How should FiO2 be administered during OLV?
Judiciously, aiming to avoid hyperoxemia, with a target oxygenation of 88-95% to minimize absorption atelectasis.
83
If the patient is on this medication, do not administer 100% FiO2 because of O2 toxicity.
Bleomycin
84
What are ways to increase O2 saturation during OLV?
* CPAP to non-dependent lung
* PEEP to dependent lung (5cm H2O)
* Recruitment manuevers
85
What physiological change occurs during OLV?
A right-to-left shunt occurs, potentially causing relative hypoxemia due to blood bypassing the deflated lung.
86
How is the right-to-left shunt lessened during thoracic surgery?
* Surgical manipulation, obstruct flow to operative lung
* Lateral positioning, increase perfusion to ventilated lung
* Hypoxic pulmonary vasoconstriction in the operative lung
87
What is Hypoxic Pulmonary Vasoconstriction (HPV)?
A response where hypoxic alveoli trigger vasoconstriction, directing blood to better-ventilated areas, enhancing V/Q matching.
88
What factor increases perfusion in the dependent lung?
Gravity
89
What factors decrease ventilation in the dependent lung?
* Expansion of dependent lung limited by weight of mediastinum
* Expansion limited by non-compliance of thoracic wall pressed on OR bed
## Footnote
increase risk of atelectasis
90
Do you want to decrease HPV in the operative lung?
* No
* Decrease HPV to the operative lung will increase shunt and worsen oxygenation
91
What factors can decrease HPV during anesthesia?
* Volatile anesthetics >1 MAC
* Hypocapnia
* Alkalosis
* Hypothermia
* Vasodilators
92
What are common OLV complications?
* Hypoxemia
* Bronchospasm
* Hypoventilation
* Malpositioning
* Airway trauma from the large DLT
93
How is hypoxemia managed intraoperatively during OLV?
* Increase FiO2
* Perform alveolar recruitment maneuvers
* Resume two-lung ventilation if necessary.
94
What steps are taken if hypoxemia persists during OLV?
* Communicate with the surgical team
* Resume two-lung ventilation
* Manage hemodynamics
* Possible pulmonary artery ligation
95
What is the best predictor of difficult DLT placement?
Preoperative CXR
96
What is the gold standard for measuring physical activity?
VO2 Max
97
What is the ideal minimum for VO2max in thoracic surgery patients?
What VO2 max will have an increased risk of complications?
* VO2 max >20 ml/kg/min
* VO2 max <15 ml/kg/min will have an increased risk
98
Complications will decrease with smoking sessions of _______ weeks
4 weeks
99
Carboxyhemoglobin concentration decreases after ______ hours of smoking cessation.
12 hours
100
Smoking causes prolonged tissue _________
hypoxemia
101
Who will be high-risk thoracic surgery patients and have increase possibility of postop ventilatory support?
* Advanced age
* Malnutrition/frail/poor general health
* COPD
* Pulmonary HTN
* Obesity
* Low FEV1
* Low VO2Max/Low exercise tolerance
* Dyspnea
* Smoking
102
How long should thoracic surgery be delayed after bare metal stenting?
4-6 weeks
103
How long should thoracic surgery be delayed after drug-eluting stenting?
6 months
104
What is the most common concurrent disease with thoracic surgery?
COPD
105
Considerations for COPD patients undergoing thoracic surgery
* Assessment of severity made with FEV1 predicted
* ABG analysis to monitor hypercapnia
* Supplemental O2 to maintain PaO2 60-65
106
Why will patients with RV failure not tolerate positive pressure ventilation?
Can not tolerate a sudden increase in RV afterload
107
What arrhythmia will most likely develop within the first week after thoracic surgery?
Atrial Fibrillation
108
Causes of Atrial Fibrillation
* Increased Pulmonary Vascular Resistance
* Right heart strain
* Increased sympathetic stimuli
* Transient hypoxemia
* O2 demand increased
* Blood loss
109
Why is an arterial line typically used during thoracic surgery?
* Monitor transient compression of heart/great vessels
* Beat-to-beat assessment
* Serial ABG’s
110
Central lines are typically reserved for these thoracic surgeries.
Pneumonectomies/redo thoracotomies
111
What anesthetic agent should be avoided in thoracic surgery due to the risk of absorption atelectasis?
Nitrous Oxide
112
What nerve injury is common in thoracic surgery?
Brachial plexus injury
113
What are 2 ways to avoid acute lung injury in thoracic surgery?
* Avoid fluid overload
* Avoid hyperinflation
114
Postoperative Analgesic Options for Thoracic Surgery Patients
* Ketamine
* Precedex
* PCA pump
* Opioids
* Paravertebral/Intercostal blocks
* Anti-inflammatories
* Thoracic epidural
115
Pulmonary complications from thoracic surgery
* Atelectasis
* Pneumonia
* Respiratory failure (15-20% of pts)
116
How does one-lung ventilation impact the right ventricle (RV)?
↑ RV Pressure → RV Dysfunction
117
Which ventilation mode is less inflammatory? PCV or VCV?
PCV
118
The benefit of using a thoracic epidural for thoracic surgery
Loss of vasomotor tone and peripheral venous pooling will significantly decrease RV preload.
