Thoracic Surgery I

Question 1

How do we determine if a patient is fit for thoracic surgery?

Answer 1

Usually, CV, thoracic, and anesthesia are involved in this decision. It needs to be determined how much lung can be removed without rendering the person a pulmonary cripple. There is certain testing that can be done to determine this.

Question 2

Characteristics of small cell carcinoma

Answer 2

Represents about 25% of diagnosed lung CAs
Poor prognosis
Usually metastatic on presentation
Survival is 3 months after diagnosis d/t extensive metastasis
Often neuroendocrine in nature

Question 3

Patients with small cell lung CA may present with one of these neuro-endocrine diagnoses

Answer 3

1) Eaton Lambert Syndrome
- Autoimmune reaction against pre-synaptic voltage gated Ca++ channels
- Results in weakness of the extremities
- Weakness of the respiratory muscles may occur late in the disease process
- Patients will have prolonged responses to NMBs

2) SIADH
- Excessive release of ADH
- Results in dilutional hyponatremia

Question 4

Characteristics of Non-Small Cell Lung CA

Answer 4

Represents about 75% of diagnosed lung CAs
Often linked to cigarette smoking
Surgery is considered in all these patients
Prognosis is variable. Better than small cell, but still very aggressive. Less than 50% will survive 5 years.

Question 5

Acronym of TNM for tumor staging

Answer 5

T (Tumor)
- Describes the tumor. The size and extent of the primary tumor.

N (Nodes)
- Degree of spread to regional lymph nodes

M (Metastasis)
- Presence of distant metastasis beyond the lymph nodes

Question 6

Why is diagnosis of non-small cell lung CA often delayed?

Answer 6

Because the symptoms of the tumor (like coughing) are very similar to symptoms that smokers experience already. So they often don’t seek medical treatment until something like hemoptysis happens.

Often, patients experience 7 months of symptoms before they present to the ED. Usually they complain of a cold that they can’t get rid of.

Question 7

Demographics of typical lung CA patients

Answer 7

Usually in the 6th or 7th decade of life
Usually a male with history or heavy smoking, recent weight loss (d/t the cancer), and lives in an urban area.
Chemical industrial workers have a higher incidence of lung CA (asbestosis, chromates, nickel, and uranium).

Question 8

Non-smokers make up less than __% of lung cancers

Answer 8

less than 10%

Question 9

Specific and non-specific symptoms of lung CA

Answer 9

Specific:

• Cough (recently worsened)
• Dyspnea
• Chest pain
• Unilateral wheezing (d/t tumor site and obstruction)

Non-specific:

• Weight loss
• Anemia
• Lethargy
• Malaise
• Vague cold-like symptoms

Question 10

Possible tumor sites and their symptoms

Answer 10

Bronchopulmonary

• Involvement of the lung
• Cough, dyspnea

Extrapulmonary Intrathoracic

• Tumor that extends beyond the confines of the lung
• Pleural effusion, chest wall pain, dysphagia

Extrathoracic Metastatic

• Tumor spread outside of the thorax
• May invade brain, skeletal, kidney, and cause symtoms related to those sites

Extrathoracic Nonmetastatic

• Paraneoplastic syndrome
• Causes endocrine or endocrine-like syndromes (Cushing’s disease, hypercalcemia, etc)

Question 11

Labs/testing done to evaluate the patient’s lungs prior to surgery

Answer 11

Physical exam
- Inspection, palpation, auscultation, percussion
Lab Tests
- Routine labs, sputum gram stain, C&S, cytology, LFTs, BUN/Cr
CXR
- If you can see a tumor on CXR, then it has been there for a long time
PFTs
- Help determine how functional the remaining lung tissue will be after resection
Pre-op Bronchoscope

Question 12

What is the most useful common test before thoracic surgery?

Answer 12

CXR

Helps look at respectability, existence of pleural effusions, cardiac disease, risk for venocaval obstruction with mediastinal masses, etc.

Question 13

PFTs help answer this question

Answer 13

How operational or functional will the remaining lung tissue be after resection?

Question 14

PFTs should be considered in these 3 phases

Answer 14

Phase 1
- Whole lung test (ABGs and spirometry)

Phase 2
- Single lung testing (Individual lung split function test)

Phase 3
- Mimic post-op conditions (temporary unilateral balloon occlusion of the right or left main stem bronchus or right or left pulmonary artery

Question 15

CXR findings and their anesthesia implications

Answer 15

Tracheal deviation and obstruction
- Difficulty with intubation or ventilation

Mediastinal mass

• Difficulty with ventilation
• SVC syndrome
• Compression of PA

Pleural effusions
- Decreased VC and FRC

Cardiac enlargement
- High susceptibility to depressant effects on the heart

Bullous cyst
- Risk of rupture. Avoid PEEP!

Parenchymal reticulation consolidation
- Prone to atelectasis and edema

Question 16

What is the major factor associated with post-op pulmonary problems?

Answer 16

Pre-existing pulmonary problems!

Question 17

Who needs PFTs?

Answer 17

• Patients with evidence of COPD
• Patients with restrictive lung disease (chest wall or spinal deformities)
• Morbidly obese (affects 30% of this surgical population –> restrictive lung disease)
• Patients with history of wheezing or DOE
• Smokers with history of persistent cough
• Candidates for upper abdominal surgery
• Candidates for thoracic surgery**
• Patients of 70 years of age!*

Question 18

Why bother performing PFTs?

Answer 18

• They identify patients with abnormal lung function
• They answer questions about resectability
• They improve the outcome of patients at risk
• They reduce the risk of post-op rest and ventilatory compromise

Question 19

Phase I PFTs

Answer 19

Whole Lung Testing!

Two components to this phase:

1) Detect abnormalities of gas exchange
2) Detect abnormalities the mechanical aspects of ventilation (lungs and chest wall)

Question 20

What values can be measured with spirometry?

Answer 20

TV, VC, IRV, ERV, and IC

Question 21

What is the normal value of VC?

Answer 21

Remember that values vary with HEIGHT and AGE
Normally, VC is about 60mL/kg
Normal is considered >/= 80% of the predicted value of VC for that person’s age and height

Question 22

When is vital capacity (VC) decreased?

Answer 22

• Moving from sitting to supine
• Restrictive lung disease (everything decreases with this)
• Loss of distensible lung tissue
• Whenever the patient is unable to obtain maximum inhalation or exhalation (Post-op pain, abd distention, or muscle weakness)

Question 23

A patient is a high risk for PPCs if VC is less than __%

Answer 23

50%.

VC should be >50% and over 2L total

Question 24

What is FVC?

Answer 24

Forced vital capacity.
Reflects resistance to flow in the airway
Rapid, forced exhalation after maximal inspiration.
Exhalation is measured in time, and must not be interrupted by cough, closure of the glottis, or mechanical obstruction.

Question 25

What reduces FVC?

Answer 25

The same things that reduce VC, because they are essentially the same thing.

Question 26

What is FEV1?

Answer 26

Forced expiratory volume in 1 second. | The volume expelled in the first second of a FVC measurement (forceful, rapid exhalation after maximal inhalation)

Question 27

Tell me about the FEV1/FRC ratio?

Answer 27

Three spirograms are generated, and the best FVC and FEV1 values are used to create the ratio. FEV1 alone isn't all that useful, you get the most information from looking at it as a ratio with FVC. Normal FEV1/FVC ratio is 75-80%

Question 28

What value is MVV closely related to?

Answer 28

FEV1 This is because they both require a high rate of air flow and little airway resistance. Changes in airway resistance will decrease both. In general, MVV = FEV1 x 35

Question 29

These factors affect MVV

Answer 29

- Patient effort (requires a lot of work in 1 minute) - The elastic properties of the lung - Chest wall abnormalities (need good mechanics to generate that much airflow in a short amount of time) - Strength of respiratory muscles

Question 30

What is closing volume?

Answer 30

The lung volume at which airways begin to close or stop contributing to expired gas. On exhalation, the lung volume continues to get smaller and smaller. The volume will decrease to a point that some airway begin to close. These airways will no longer contribute to the gas expelled in expiration.

Question 31

For healthy individuals, normal closing volume in the sitting position is _____

Answer 31

15-20% of the VC

Question 32

Is closing volume lower or higher in smokers?

Answer 32

Higher! This means, their airways will begin to close sooner than those will healthy lungs. This is due to the loss of elastic recoil and/or small airway pathology. The small airways become floppy and close easily.

Question 33

Patients with increased operative risk for pneumonectomy

Answer 33

If: - ABG shows hypercapnia on room air - FEV1/FVC ratio is

Question 34

Patients presenting for pneumonectomy are more likely to tolerate it if:

Answer 34

- FEV1/FVC ratio is >50% - FEV1 > 2L - MVV > 50% predicted - RV/TLC ratio

Question 35

What is Phase II of PFTs?

Answer 35

Split lung testing! Looks at the function of each lung separately (compared to phase I testing, which looks at lung function as a whole) To do this, ventilation and perfusion of each lung is measured using radio isotope. Combines right and left fractional lung perfusion with conventional spirometry. Based on this, predicted FEV1 should be greater than 850mL. If a FEV1 of 850mL is NOT met, then dyspnea and CO2 retention will result. For example: - If perfusion to the lung to be removed has been calculated to be 40%, and the pre-op FEV1 is 1.4L This means that 60% of lung perfusion is going to the non-operative lung. 1.4L x 0.6 = 0.84L --> the Predicted FEV1 is 0.84L, so the patient should move on to phase II testing.

Question 36

What is Phase III Testing?

Answer 36

- Simulates post-op conditions the patient will experience - Done via temporary balloon occlusion of the major pulmonary artery to the operative lung. - The procedure is done with and without exercise - Compliance of the remaining pulmonary vascular bed is tested

Question 37

These values during Phase III testing indicate an inability to tolerate removal of this amount of lung

Answer 37

PAP > 40mmHg PaCO2 > 60mmHg PaO2

Question 38

Why is a thorough CV workup important in thoracic surgery?

Answer 38

Because cardiac complications are the SECOND most common cause of peri-op morbidity and mortality. Many people presenting for thoracic surgery are probably smokers. This can contribute to CAD and ischemia.

Question 39

The cardiovascular system has this response to COPD and CAD (often inter-related)

Answer 39

- Increased PVR - Pulmonary HTN - RV hypertrophy and dilation - LV dysfunction d/t CAD, HTN, and possible prior MI - EKG may be needed to determine severity of associated CV disease - Measurements obtainable by PAC may be required (PAP, PCWP, CO, SVR, etc)

Question 40

What is our overall goal of our pre-op testing for thoracic surgery?

Answer 40

To decrease post-op pulmonary complications (PPCs) like atelectasis and pneumonia

Question 41

What are some reasons for post-op pulmonary complications?

Answer 41

1) Patient likely has high pre-op pulmonary dysfunction (degree of dysfunction correlates to risk of PPCs) 2) Resulting surgical impairment of the lung - The operative (non-dependent) lung had tissue resected or traumatized - The dependent (non-operative lung) experienced compression that may result in edema and atelectasis - Incisional pain inhibiting deep breathing. Adequate pain management is essential!

Question 42

Pre-op methods to reduce PPCs

Answer 42

- Encourage smoking cessation - Dilate the airways (B2 agonists, PDE inhibitors, inhaled anticholinergics and steroids) - Loosen and remove secretions (hydrate!) - Increase patient motivation and to encourage proper post-op care - Possible digoxin therapy

Question 43

Benefits of smoking cessation over time

Answer 43

12-24 hours --> decreased CO and nicotine levels 48-72 hours --> COHb levels normalize and ciliary function improves 1-2 weeks --> Decreased sputum production 4-6 weeks --> PFTs improve 6-8 weeks --> Immune function improves and metabolism normalizes *****8-12 weeks --> Decreased overall post-op morbidity and mortality******

Question 44

Ways to dilate the airways and treat bronchospasm

Answer 44

Sympathomimetics (increase cAMP production, resulting in bronchodilation) PDE Inhibitors (decrease breakdown of cAMP) Steroids (decrease mucosal edema) Cromolyn (mast-cell stabilization, but must be on board at least 7 days prior to surgery)

Question 45

Ways to loosen and remove secretions

Answer 45

Hydration Treating existing infection Postural drainage Chest PT Forced expiration technique GE reflux prophylaxis Humidify and warm inspired gases Suctioning (prevents increased airway resistance and alveolar collapse) Mucolytics (mucomyst 2-5mL 5%-20% solution Q6-8 hours) Therapeutic bronchoscopy to remove mucus plugs

Question 46

These factors can reduce mucociliary flow

Answer 46

ETT inflation, high FiO2, and cold inspired gases,

Question 47

Education and patient motivation that should be given to the patient preoperatively

Answer 47

``` Importance of deep breathing Weight loss (restrictive lung pattern and OSA) Use of home O2 Realistic post-op expectations Post-op respiratory care Chest PT Importance of ambulation ```

Question 48

Prevention of arrhythmia in thoracic surgery

Answer 48

A-fib and a-flutter are common d/t atrial stretch. Occurs d/t increased right sided heart pressures. More common in patients > 60 years old and those presenting for L pneumonectomy. How to prevent arrhythmia: - Digoxin - BBs - Diltiazem - Amiodarone

Question 49

These are factors that place the patient at risk for PPCs

Answer 49

- Dyspnea - Cough and sputum production (lots of shit in there just begging to get infected) - Recent URI************ - Hemoptysis - Wheezing and/or use of bronchodilators and steroids - History of smoking - Age, general PMH and other significant comorbidities - Breathing pattern - Body habits - Site of the proposed surgery - Emergency surgery

Question 50

Characteristics of emphysema

Answer 50

``` PINK PUFFER PaO2 > 60, PaCO2 normal Thin, anxious, pursed lips (puffer) Dyspnea and use of accessory muscles Scant secretions VERY diminished breath sounds Respiratory infections can result in R sided heart compromise CXR shows hyperinflation with a low diaphragm ```

Question 51

Characteristics of chronic bronchitis

Answer 51

BLUE BLOATER (bronchitis = BB!) PaO2 45 (all these secretions lead to ineffective mechanics and shit, so labs are more off) Often overweight and cyanotic with a dusky appearance (blue and bloated) Cough with copious amount of secretions (the secretions are irritating to the airways) Diminished breath sounds Can result in R sided heart failure / or pulmonale CXR shows bronchovascular markings

Question 52

Anesthesia considerations for obstructive disease

Answer 52

- We want controlled ventilation at a slower RR (6-10) - Longer expiratory time to minimize VQ mismatch - The worse a patient/s FEV1, the more CO2 the patient will retain if the patient is permitted to SV during GETA - Regional techniques with spread above T6 is not recommended because accessory muscles will be wiped out, and many (especially emphysema --> pink puffer) depend on accessories for ventilation

Question 53

Mediators of airway hyper-responsiveness in asthma

Answer 53

A lot of dumb shit we probably don't have to know. Eosinophils, mast cells, neutrophils, macrophages, basophils, and T lymphocytes. Other dumb shit that probably causes it includes cytokines, interleukins 3,4,&5, metabolites of arachidonic acid (leukotrienes and prostaglandins), kinins, histamine, adenosine, and platelet activating factor

Question 54

These are various classes of bronchoactive drugs used

Answer 54

``` Beta agonists Corticosteroids Methylxanthines Anticholinergics Cromolyn ```

Question 55

Anesthesia considerations for asthma

Answer 55

- Consider regional techniques | - GA technique should be individualized to depress airway reflexes, and to blunt hyperactivity/bronchoconstriction

Question 56

Characteristics of restrictive lung disease

Answer 56

- Decreased lung compliance and impaired lung/chest wall expansion - Increased work of breathing - Decreased spirometry values - VC

Question 57

S/S of PE in general

Answer 57

Acute dyspnea and tachypnea, pleuritic chest pain (pain that occurs with breathing), coughing, accentuation of pulmonic 2nd heart sound, rales, tachycardia, fever, and hemoptysis ABG shows decreased PaO2 and PaCO2

Question 58

S/S of PE during general anesthesia

Answer 58

Arterial hypoxia, hypotension, tachycardia, and bronchospasm

Question 59

Diagnosis of PE

Answer 59

Diagnosed by VQ scan and/or pulmonary ateriography

Question 60

Management and treatment of PE

Answer 60

Management: - Monitor cardiac filling pressures, avoid drugs that increase PVR, give PPV Definitive treatment: - PA embolectomy, IVC filter placement, anticoagulants, pain control

Question 61

What is pneumonia and what are the symptoms?

Answer 61

Inflammatory process usually caused by gram negative bacilli and staph aureus S/S include fever, chills, productive cough, and tachypnea. Usually treated with antibiotics.

Question 62

Anesthetic considerations for the pt with pneumonia

Answer 62

Elective surgery is not recommended Consider regional technique (want to avoid introducing anything else into the lungs that can cause infection, and PPV which could spread infection) Inform the pt that they may need to be intubated and ventilated after the procedure.

Question 63

What causes TB and how is it spread?

Answer 63

Caused by mycobacterium tuberculosis and is transmitted via droplets

Question 64

Anesthesia considerations for the patient with TB

Answer 64

``` Special masks (N95 or PAPR) Follow institutional policies for cleaning the equipment, changing circuit, CO2 absorbent, etc. Remember things from previous semesters like doing the procedure when fewer personnel are present, do the case later in the day, close the OR down afterwards for the air to be recirculated, etc. ``` The breathing circuit should be COMPLETEY changed!

Question 65

S/S of for pulmonale

Answer 65

Dyspnea, syncope, mean PAP > 20, prominent "a" wave on CVP (atrial contraction) Overt right heart failure may be present

Question 66

Treatment/anesthesia considerations for for pulmonale

Answer 66

We want to decrease the workload of the RV - Digoxin - Diuretics - Supplemental O2 - Vasodilators - Antibiotics - Anticoagulants

Question 67

Considerations for URI

Answer 67

Usually viral in nature Recommendation is to AVOID elective procedures that require intubation --> Higher risk for airway hyperactivity, bronchospasm, and laryngospasm during URI*** Airway irritability may persist for weeks after URI Routine case cancellation is controversial, especially in the pediatric ENT population

Question 68

What is sarcoidosis?

Answer 68

Sarcoidosis is a systemic granulomatous disorder. This is a multi system disease that involving abnormal collections of inflammatory cells (granulomas). These granulomas are mostly found in the lungs or lymph tissue, but can be found anywhere.

Question 69

S/S of sarcoidosis

Answer 69

Depends on where the sarcoid is located. Cor pulmonale, heart block, dysrhythmias, and restrictive cardiomyopathy may develop. Hypocalcemia occurs rarely BP may increase d/t increased ACE activity

Question 70

How is sarcoidosis usually treated?

Answer 70

Steroids Does the patient need a stress dose?

Question 71

Anesthesia considerations for sarcoidosis

Answer 71

Look at co-existing disease book

Question 72

Hallmark symptoms of hemothorax

Answer 72

Hypotension Hypoxemia Tachycardia Increased CVP

Question 73

Anesthesia considerations for hemothorax?

Answer 73

Look in coexisting book

Question 74

Hallmark symptoms of tension pneumothorax

Answer 74

Hypotension Hypoxemia Tachycardia Increased CVP Symptoms for hemothorax and pneumothorax are the same Other symptoms include unilateral decrease in breath sounds, increase in vent pressures, progressive tracheal deviation, wheezing, and CV changes.

Question 75

What is an empyema and what is a classic cause?

Answer 75

Accumulation of pus in the pleural space with or without abscess formation. Classic Cause: Aspiration when drunk Other causes: Substance abuse, prior pneumonia, lung CA, steroid-induce immunosuppression, DM, COPD, and infection at another site

Question 76

Anesthetic considerations for empyema

Answer 76

Lung isolate in an absolute requirement because PPV may result in contamination of the healthy lung. Look in book for other considerations

Question 77

An increase in headspace will have this effect on PaCO2

Answer 77

PaCO2 will increase

Question 78

Physiologic effects of acidosis

Answer 78

CNS - Anxiety - Confusion - CO2 narcosis - Cerebral vasodilation and increased ICP CV - HTN - Tachycardia - Increased catecholamine activity - Increased PVR - HYPERKALEMIA

Question 79

Physiologic effects of alkalosis

Answer 79

CNS - Lightheadedness - Confusion - Coma - NM irritability - Paresthesias - Tetany, Sz (related to decreased Ca++) - Cerebral vasoconstriction CV - HYPOKALEMIA - Ventricular dysrhythmias - Hypotension - Decreased CO - Impaired O2 delivery to tissues (shift to the left)

Question 80

What is base excess/base deficit

Answer 80

A calculated value that illustrates the deviation from normal bicarbonate levels, using the normal bicarb level of 24

Question 81

How to dose your bicarb based on base deficit levels

Answer 81

mEq of bicarb = base deficit x weight in kg x 0.3 This is the dose for full correction. Try 1/2 of the dose at first and recheck your ABG in 5 minutes.