Module 9

Question 1

Module 9
Anesthetic Management of Patients with Respiratory Disease

Objectives
- By the end of this lecture, the students will be able to:
- Perform a preoperative assessment on a patient with _______(1).
- Identify patients at risk for _______(2) complications during anesthesia.
- Differentiate between _______(3) and _______(4) pulmonary diseases.
- Create an anesthetic care plan for a patient with _______(5).
- Discuss the anesthetic techniques for monitoring and management of patients with _______(6).

Respiratory diseases
- Patients with _______(7) are at increased risk of _______(8) respiratory complications.
- Pulmonary complications occur in up to _______(9) of patients and lead to increased morbidity and mortality and increased hospital length of stay.
- Postoperative pulmonary complications are very costly and can average increased healthcare costs of _______(10) per patient.

Risk factors for pulmonary complications
- Chronic obstructive pulmonary disease
- _______(11)
- Interstitial lung disease
- Pulmonary HTN
- Heart failure
- Functional status
- Hypoalbuminemia
- _______(12)
- Age
- OSA
- _______(13)
- Nutrition Status

Answer 1

Answers:
1. pulmonary disease
2. pulmonary
3. obstructive
4. restrictive
5. pulmonary disease
6. pulmonary disease
7. respiratory diseases
8. perioperative
9. 25%
10. $52,466
11. Asthma
12. Smoking
13. Obesity

Question 1

The site of surgery is an important risk factor for developing postoperative pulmonary complications
- Pulmonary complications _______(1) the closer the incision is to the _______(2).
- _______(3) surgery (13-33%) vs. lower abdominal surgery (0-16%)

Surgeries lasting longer than 3 hours are associated with increased risk of pulmonary complications
- Neurosurgery
- Head and neck surgery
- Trauma surgery
- Cardiac surgery with CPB
- Esophagectomy
- Lung resection

Preoperative Evaluation
- History and Physical
- Pulmonary Function Testing (Look to see if they have a _______(4))
- Arterial Blood Gas (ABG) Analysis
- Chest X-ray (Can see pleural effusions, _______(5), infiltrates etc.)

Pulmonary Function Tests
- Forced Expiratory Volume (FEV)
- the volume of gas exhaled in 1 second by forced expiration from full inspiration
- Vital Capacity
- the total volume of gas that can be exhaled after a _______(6) inspiration

Answer 1

Answers:
1. increase
2. diaphragm
3. Upper abdominal
4. pulmonologist
5. rails
6. full

Question 2

Pulmonary Function Test

• The lungs and thorax can be regarded as a simple air pump
  
  • The output of the pump depends on the stroke volume, the resistance of the airways, and the force applied to the _______(1).
• The forced vital capacity (FVC) is a measure of the _______(2).
  
  • Causes of stroke volume (FVC) reduction
    
    • Diseases of the thoracic cage such as scoliosis
    • Acute lung injuries
    • Diseases that affect the nerve supply to the respiratory muscles such as muscular dystrophy
    • Abnormalities of the pleural cavity such pneumothorax
    • Diseases of the lungs such as fibrosis
    • Space occupying lesions
    • Increased pulmonary blood volume such as left heart failure
• The forced expiratory volume (FEV) is affected by airway resistance during forced expiration
  
  • _______(3), chronic bronchitis, obstruction, _______(4) (i.e thyroid goiter)
• Any increase in resistance reduces the ventilatory capacity
  
  • Bronchoconstriction such as with _______(5)
  • Structural changes in the airway such as with chronic bronchitis
  • Obstruction of the airways
  • Destructive process in the lung parenchyma

Answer 2

Answers:
1. piston
2. stroke volume
3. Asthma
4. masses
5. asthma

Question 3

Pulmonary Function Test

• Forced expiratory volume in 1 sec (FEV₁): The volume of air that can be forcefully exhaled in 1 sec. Values of between _______(1) of the predicted value are considered normal.
• Forced vital capacity (FVC): The volume of air that can be exhaled with maximum effort after a deep inhalation. Normal values are ~_______(2) in females and ~_______(3) in males.
• Ratio of FEV₁ to FVC: This ratio in healthy adults is _______(4) to _______(5).
• Forced expiratory flow at 25%-75% of vital capacity (FEF₅₂₅₋₇₅): A measurement of airflow through the midpoint of a forced exhalation.
• Maximum voluntary ventilation (MVV): The maximum amount of air that can be inhaled and exhaled within 1 min. For the comfort of the patient, the volume is measured over a _______(6) time period and the results are extrapolated to obtain a value for 1 min expressed as liters per minute. Average values for males and females are _______(7) and _______(8) L/min, respectively.
• Diffusing capacity (DLco): The volume of a substance (carbon monoxide, or CO) transferred across the alveoli into blood per minute per unit of alveolar partial pressure. CO is rapidly taken up by hemoglobin. Its transfer is therefore limited mainly by diffusion. A single breath of _______(9) CO and _______(10) helium is held for 20 sec. Expired partial pressure of CO is measured. Normal value is _______(11).

Answer 3

Answers:
1. 80% and 120%
2. 3.7 L
3. 4.8 L
4. 75%
5. 80%
6. 15-sec
7. 140-180
8. 80-120
9. 0.3%
10. 10%
11. 17-25 mL/min/mm Hg

Question 4

Expiratory Flow-Volume Curve
- Recorded from a maximal forced expiration
- It records flow rate and volume
- Expiratory and Inspiratory Flow-Volume Curves
- It measures _______(1) and expiration
- Obstructive: _______(2) Shift
- Restrictive: _______(3) shift

The diagram on the right side of the image shows typical curves for normal, obstructive, and restrictive patterns. The obstructive pattern is associated with conditions like asthma, chronic bronchitis, and emphysema, showing a characteristic “left shift.” Restrictive patterns can be due to conditions such as pulmonary fibrosis, alveolar hyaline membranes, intralobular hemorrhage, or atelectasis, showing a “right shift.” The illustration provides visual representations of changes in flow rates with respect to lung volume during forced expiration and inspiration.

Answer 4

Answers:
1. inspiration
2. Left
3. Right

Question 5

Blood Gasses
- Arterial PaO2
- Partial pressure of oxygen in arterial blood
- Normal value _______(1) mmHg
- This image will likely be a board question

Causes of Hypoxemia
Hypoventilation
- The volume of fresh gas going to the alveoli per unit time is reduced
- Two cardinal features of hypoxemia:
- It ALWAYS causes a rise in _______(2)
- It can be abolished by increasing the PaO2 by delivering oxygen to the patient
- Causes of hypoventilation
- Depression of the respiratory center (narcotics)
- Diseases of the medulla (encephalitis, hemorrhage)
- Abnormalities of the spinal cord (high dissection)
- Anterior horn cell disease (poliomyelitis)
- Diseases of the nerves to the respiratory center (Guillain-Barre syndrome)
- Diseases of the myoneural junction (myasthenia gravis)
- Diseases of the respiratory muscles (muscular dystrophy)
- Thoracic cage abnormalities (crushed chest)
- Upper airway obstruction (tracheal compression by neoplasm)

Answer 5

Answers:
1. 85-100
2. PaCO2

Question 6

Diffusion Impairment
- Equilibration does not occur between the PaO2 in the pulmonary capillary blood and the alveolar gas.
- In a disease state, if the blood-gas barrier is thickened and diffusion is slowed, the equilibration may be incomplete
- Fick’s Law of Diffusion correlates the diffusion capacity
- Thickness of the membrane (e.g. _______(1))
- Surface area for diffusion (e.g. _______(2))

Diseases that cause diffusion impairment
- Asbestosis
- Sarcoidosis
- Interstitial fibrosis
- Scleroderma
- Rheumatoid lung
- Lupus
- Alveolar cell carcinoma

Shunt
- A shunt allows some blood to reach the arterial system without passing through ventilated regions of the lung.
- If a patient with a shunt is given pure oxygen to breathe, the arterial PaO2 fails to rise compared to normal patients.

Ventilation-Perfusion Inequality

• Ventilation and blood flow are mismatched in various regions of the lung, it results in inefficient gas transfer
• It occurs in most patients with COPD, interstitial lung disease, and vascular disorders such as PE
• Can be Vascular or Air-Exchange issue

Answer 6

Answers:
1. fibrosis
2. emphysema

Question 7

Study Figure 1 - Intrapulmonary Shunting
Study West three zone model

Increased Arterial PaCO2
- Arterial PaCO2
- The normal PaCO2 is _______(1) mmHg
- Outside of this range, pt becomes acidic or basic
- Causes of increased arterial PaCO2
- _______(2)
- Ventilation-perfusion inequality

Arterial pH
- Respiratory acidosis
- Caused by CO2 retention
- Depresses pH
- Acute vs chronic respiratory acidosis

• Respiratory alkalosis
  
  • Seen in acute _______(3)
• Metabolic acidosis
  
  • Caused by a fall in _______(4)
  • Acidosis stimulates peripheral chemoreceptors to increase ventilation
• Metabolic alkalosis
  
  • Seen in disorders such as severe vomiting
  • Usually no respiratory compensation

Acid-base Disturbance
- Acidosis
- Respiratory: PCO2 ↑ HCO3- ↑
- Metabolic: HCO3- ↓ PCO2 ↓
- Alkalosis
- Respiratory: PCO2 ↓ HCO3- ↓
- Metabolic: HCO3- ↑ Often none

Answer 7

Answers:
1. 37-43
2. Hypoventilation
3. hyperventilation
4. HCO3

Question 8

Chest X-Ray Interpretation

Lesson 1 https://www.youtube.com/watch?v=PDaRNPUNc10

Lesson 2 https://www.youtube.com/watch?v=L6bnD2wOEmg

Lesson 3 https://www.youtube.com/watch?v=iEjTY5PeVTg

Lesson 4 https://www.youtube.com/watch?v=9J8rcmCVoes

Lesson 5 https://www.youtube.com/watch?v=bU0Nm7JFJtU

Lesson 6 https://www.youtube.com/watch?v=wOpDvUO5sD8

Lesson 7 https://www.youtube.com/watch?v=mNLd4DKtGs4

Lesson 8 https://www.youtube.com/watch?v=fiGgpY2GXsk

Lesson 9 https://www.youtube.com/watch?v=OcIxL56an3c

Lesson 10 https://www.youtube.com/watch?v=rOzyJwH7szE

Obstructive Diseases

• Airway Obstruction
• Chronic Obstructive Pulmonary Disease
  
  • Emphysema
  • Chronic Bronchitis
• Asthma
  
  • COPD, Types A & B
• Localized Airway Obstruction
• Tracheal obstruction
• Very common disease in the US, second only to heart disease as a cause of disability benefits from Social Security Administration
• It’s difficult to distinguish among the various types of obstructive disease
• One common theme is that they are characterized by airway _______(1).

Airway Obstruction
- Increased airway resistance can be caused by conditions:
- Inside the _______(2)
- In the wall of the _______(3)
- In the peribronchial region

Chronic Obstructive Pulmonary Disease (COPD)
- COPD is a common condition often related to smoking or industrial toxins
- It’s projected that by 2020, COPD will rank _______(4) among diseases worldwide
- COPD can lead to increased length of hospital stay and mortality
- The care of these patients poses a challenge to the anesthesia provider
- COPD is a term that is applied to patients with either emphysema, chronic bronchitis, or a combination of both

Answer 8

Answers:
1. obstruction
2. lumen
3. airway
4. 5th

Question 9

COPD

• COPD is characterized by the progressive development of airflow limitation that is not fully reversible
• Causes loss of _______(1), which normally maintains the airways open
• There is decreased rigidity of the of the _______(2) that leads to collapse during exhalation
• An increase in the air velocity in narrowed bronchioles, lowers the pressure in the bronchiole that leads to airway collapse
• Active bronchospasm and obstruction results from increased _______(3)
• The patient has a destruction of lung parenchyma, enlarged air sacs, and development of _______(4)
• Risk Factors
  
  • Cigarette smoking
  • Respiratory infection
  • Occupational exposure to dust
  • Genetic factors such as _______(5)
• Signs and Symptoms
  
  • Varies with the severity of COPD
  • As expiratory airway obstruction worsens the patient will have _______(6) and have a prolonged expiratory phase
  • Breath sounds are decreased with expiratory _______(7)

Emphysema

Characterized by enlargement of the air spaces distal to the terminal bronchiole, with destruction of their walls
- Types
- Centriacinar
- Panacinar

Chronic Bronchitis

Characterized by excessive mucus production in the bronchial tree, sufficient to cause excessive expectoration of sputum
- *Hallmark is enlarged, mucus glands in the large bronchi and chronic inflammation in the _______(8)

Answer 9

Answers:
1. elastic recoil
2. bronchial
3. airway secretion
4. emphysema
5. alpha1-antitrypsin deficiency
6. tachypnea
7. wheezing
8. small airways

Question 10

Diagnosis

• A chronic productive cough, progressive exercise limitation, and expiratory airflow obstruction
• Symptoms may be non-specific but a diagnosis is likely in a smoker
  
  • Emphysema vs _______(1)
• Pulmonary function test
  
  • Decrease in _______(2)
  • Lung volumes are _______(3) (RV, FRC, and TLC)
  • _______(4)
• Chest X-ray
  
  • Abnormalities may be minimal
  • _______(5)
  • Bullae may be present

Study Lung volumes Diagram

Answer 10

Answers:
1. bronchitis
2. FEV1/FVC ratio
3. increased
4. Can’t fully exhale
5. Hyperlucency

Question 11

Study Comparative features of COPD

Treatment of COPD

• The treatment of COPD is aimed at relieving the symptoms and halting the progression of the disease
  
  • Smoking cessation
  • Oxygen supplementation is recommended if the PaO2 is less than _______(1), the hematocrit is greater than 55%, or there is evidence of cor pulmonale with the goal to maintain the PaO2 between _______(2)
  • _______(3) is 80-100 mmHg
  • TAKE Their inhalers the morning of, BRING their inhaler with them
• Drug therapy
  
  • Bronchodilators are the mainstay
  • Anticholinergic drugs
  • Inhaled corticosteroids
  • Broad-spectrum antibiotics
  • Annual flu and pneumococcal vaccination
  • Diuretic therapy
• Lung volume reduction therapy

Preoperative
- Pulmonary Function Test
- Clinical findings are more predictive of pulmonary complications than spirometric results
- Smoking history
- Nutritional status
- Poor nutritional status with serum albumin < _______(4) is powerful predictor of postoperative pulmonary complications

Answer 11

Answers:
1. 55 mmHg
2. 60-80 mmHg
3. Normal PaO2
4. 3.5g/dL

Question 12

Major risk factors associated with postoperative pulmonary complications

‘Patient Related
- Age >60 yr
- ASA > II
- CHF
- Preexisting pulmonary disease (_______(1))
- Smoker

Procedure Related
- Emergency surgery
- Type of surgery (Abdominal or thoracic surgery, head and neck surgery, neurosurgery, vascular/aortic aneurysm surgery)
- _______(2)

Test Predictors
- Albumin level of < _______(3)

Intraoperative
- Regional is suitable for surgeries that do not involve the peritoneum
- Great choice if large amounts of sedatives and anxiolytics are not needed
- Regional anesthesia that produces sensory anesthesia above T6 is not recommended

General anesthesia
- Inhaled agents are a good choice as they are eliminated rapidly and minimize residual ventilator depression post-op
- Volatile agents cause bronchodilation (Sevoflurane)
- Avoid Desflurane as it causes airway irritation and increased airway resistance
- Emergence may be prolonged with inhaled agents due to air trapping of the inhaled agents
- Limit the use of nitrous oxide
- Be careful with opioids as they can lead to prolonged ventilator depression
- Make sure you inform the inspired gas fractions to assess adequacy of the airway

Answer 12

Answers:
1. COPD
2. General anesthesia
3. 3.5 g/dL

Question 13

Mechanical ventilation

• Larger tidal volumes and slower rates
  
  • Tidal volumes of _______(1)
  • Respiratory rates of _______(2)
• Ventilator settings should allow sufficient expiratory time to avoid air trapping
• Air trapping can be detected by the following methods
  
  • The ETCO2 waveform does not plateau and its still upsloping at the time of the next breath
  • When the expiratory flow on the ventilator does not reach baseline or zero
  • Direct measure of PEEP (done by advanced ventilators)
  • When you disconnect the ventilator and notice that the BP increases from the release of PEEP
• Avoid barotrauma by preventing high positive airway pressures

Answer 13

Answers:
1. 6-8 mL/kg
2. 6-8

Question 14

Management of Anesthesia- Postoperative

• Prophylaxis against post-op pulmonary complications is important especially maintaining the _______(1)
  
  • Lung expansion maneuvers
    
    • Incentive spirometry
    • Deep breathing exercises
    • Chest physiotherapy
    • Positive pressure breathing techniques
    • Early ambulation
• In patients with severe COPD, postop mechanical ventilation may be necessary
  
  • Patients with a _______(2) of less than 0.5 with a preoperative PaCO2 greater than _______(3) may need postoperative mechanical ventilation
  • Remember if the patients “lives” with a high PaCO2, do not try to correct it back to normal

Asthma

• Disease characterized by increased responsiveness of the airways to various stimuli and manifested by inflammation and widespread narrowing of the airways that changes in severity, either spontaneously or as a result of treatment

Signs and Symptoms

• It’s an episodic disease
• Most attacks are short lived
• It can be life-threatening if not treated
• Clinical manifestations include wheezing, productive or nonproductive cough, dyspnea, chest discomfort or tightness that leads to air hunger

Answer 14

Answers:
1. FRC (Functional Residual Capacity)
2. FEV1/FVC ratio
3. 50 mmHg

Question 15

Pathology

• The smooth muscle of the airways contract during an attack, causing bronchoconstriction
• There is also hypertrophy of mucous glands, edema of the bronchial wall, and extensive infiltration by eosinophils and lymphocytes
• The mucous is increased in the airways and _______(1)

Pathogenesis

• It’s a heterogeneous disease, and genetic and environmental factors such as viruses, occupational exposure, and allergens contribute to its initiation and continuance
• Epidemiologic studies indicate that asthma begins in childhood in a majority of cases
• Environmental factors has led to an increase in asthma over the last _______(2)

Hypothesis

• Children not exposed to typical childhood infectious agents have a greater incidence of developing an allergic diathesis or asthma
• Obesity, poor physical fitness, and exposure to pollutants can predispose you to asthma
• The trigger to asthma cannot always be _______(3)

Diagnosis utilizing spirometry

• The typical asthmatic patient has an FEV1 that is less than _______(4)
• Flow-volume loops show characteristic ______(a) scooping of the expiratory limb of the loop
• Flow-volume loops in which the inhaled or exhaled portion of the loop is flat helps distinguish wheezing caused by airway obstruction from asthma or another cause

Diagnosis

• ABG
  
  • Mild asthma is accompanied by a normal PaCO2 and PaCO2
  • Tachypnea and hyperventilation during an asthma attack usually results in hypocabria and respiratory _______(5)
  • Hypercarbia can occur with muscle fatigue
• Chest X-ray
  
  • Hyperinflation of the lungs

Answer 15

Answers:
1. slow moving
2. 20 years
3. identified
4. 35%
a. downward
5. alkalosis

Question 16

Treatment

• Emphasis of treatment is preventing and controlling bronchial inflammation
• Asthma treatment has 2 components
  
  • Controller treatments modify the airway so that acute airway narrowing occurs less frequently
    
    • Inhaled and systemic corticosteroids, _______(1), and anti________(2)
• Reliever or rescue treatments treat acute bronchospasm
  
  • β-adrenergic agonists and anticholinergic drugs
    
    • _______(3) is the B2-agonist most commonly used
• Bronchoactive drugs
  
  • β-adrenergic agonist
    
    • B1- receptors in the heart (increase HR and force of contraction)
• B2 – receptors relax smooth muscle in the bronchi, blood vessels, and uterus
• B2 selective adrenergic agonist are used to treat asthma
  
  • Metaproterenol, albuterol, terbutaline, and pirbuterol (intermediate duration)
  • Formoterol and salmeterol (long-acting agents used in combination with a corticosteroid)
  • Drugs are delivered by _______(4)
• Inhaled corticosteroid
  
  • They inhibit the inflammatory/immune response, and they enhance B receptor expression or function
  • Patients who use B2 agonist more than twice a week are placed on corticosteroids
• Bronchoactive drugs
  
  • Other treatments
    
    • _______(5)
• Anticholinergics
  
  • Useful in reversible bronchoconstriction in patients with COPD
• Cromolyn and Nedocromil
  
  • Mast cell stabilizers
    
    • Block airway inflammation

Answer 16

Answers:
1. theophylline
2. leukotrienes
3. Albuterol
4. aerosol
5. Methylxanthines

Question 17

Status asthmaticus

• Bronchospasm that does not resolve despite treatment
• It is life-threatening
• Emergency treatment
  
  • B2-agonist by inhalation
  • _______(1)

Asthma – Preoperative

• Assess disease severity, the effectiveness of the current treatment, and the potential need for additional treatment before surgery
• Goal is to come with an anesthetic plan that prevents or blunts expiratory airflow obstruction
• Pre-op evaluation
  
  • Ask the patient about the severity and characteristics of the asthma
    
    • Age of onset
    • Triggering events
    • Hospitalizations for asthma
    • Allergies
    • Cough
    • Sputum characteristics
    • Current medications
    • Anesthetic history
• Listen to the patients breath sounds
• Assess labs, blood eosinophils count often parallels the degree of airway inflammation and airway hyperactivity
• PFT before and after bronchodilator treatment
  
  • A reduction of FEV1 or FVC of less than _______(2) as well as FEV1/FVC less than _______(3) of predictive values, is considered a risk factor for preoperative complications
• Assess if the patients needs any treatments prior to anesthesia
  
  • Antibiotics
  • Bronchodilator therapy
  • Supplementation with stress-dose corticosteroids, if the patient is on chronic steroids
• The patients should be free from _______(4) prior to surgery

Answer 17

Answers:
1. Corticosteroids
2. 70%
3. 65%
4. wheezing

Question 18

Asthma – Intraoperative

• During induction and maintenance, airway reflexes must be suppressed to avoid bronchoconstriction
• Regional anesthesia should be considered in brittle asthmatic
• General anesthesia should be accomplished with an intravenous induction
  
  • Propofol’s bronchodilating effects is unknown
  • Ketamine has bronchodilating effects but increases airway secretions
  • Lidocaine 1.5-1.5mg/kg 1-3 minutes prior to intubation suppresses airway reflexes
  • Narcotics prevent increased airway resistance
• The depth of anesthesia during maintenance should depress hyperactive airway reflexes
  
  • Sevoflurane is a bronchodilator
  • Consider an LMA as it is less irritating to the airway
• Ventilation
  
  • A low inspiratory flow rate produces optimal distribution of ventilation and perfusion
  • Allow sufficient time for exhalation to avoid air trapping
  • Humidify the airway in patients with exercise induced asthma
  • Liberal administration of fluids to keep the secretions in the airway less viscous
• Avoid muscle relaxants that cause ______(a) release
  
  • E.g. atracurium and mivacurium, am I missing others?
• Attempt to extubate the patient while airway reflexes are suppressed “______(b) extubation”
• If a deep extubation is not safe, make sure the airway reflexes are suppressed
  
  • Intravenous lidocaine
  • Pretreatment with inhaled bronchodilators - _______(1)
• Intraoperative Bronchospasm
  
  • Make sure you have ruled out other causes of bronchospasm
  • Mechanical obstruction of the breathing circuit, the airway, or the ETT
• If the bronchospasm is caused by asthma
  
  • ______(c) the anesthetic with a volatile agent, ketamine, propofol, lidocaine or a combination
  • Administer 100% O2
  • Consider B2-agonist treatment (Albuterol)
  • In severe cases, administer intravenous or subcutaneous epinephrine (10 mcg/kg)
  • Corticosteroid administration – Hydrocortisone ______(d) mg/kg
  • Consider aminophylline, if long term postoperative mechanical ventilation is needed
• Tracheal Obstruction
  
  • Can be caused by a foreign body, stenosis after a prolonged intubation, or compressing masses (I.e., an enlarged thyroid or a malignant mass)
  • Inspiratory and expiratory _______(2) is present
  • Abnormal inspiratory and expiratory flow volume curves
  • No response to ______(e)
• Tracheal stenosis
  
  • Develops after a prolonged intubation
  • The tracheal ischemia may progress to destruction of the cartilaginous rings and circumferential constricting scar formation
  • The use of high-volume, low pressure ETT cuffs is preferred
  • The patient becomes symptomatic when the lumen of the airway is less than _______(3) in diameter
  • The patient may have _______(4)
  • Flow-volume loops _______(5)
  • The stenosis is relieved with tracheal dilation or tracheal resection

Answer 18

Answers:

a. histamine
b. deep
1. albuterol
c. Deepen
d. 2-4
2. stridor
e. bronchodilators
3. 5 mm
4. audible stridor
5. are flattened

Question 19

Restrictive diseases

• Restrictive diseases are those in which expansion of the lung is restricted by alterations in the lung parenchyma, diseased pleura, the chest wall, or a _______(1)
• Restrictive diseases are characterized by a reduction in all lung volumes, decreased lung compliance, and _______(2)

Answer 19

Answers:
1. neuromuscular disease
2. preservation of expiratory flow rates

Question 20

Diffuse Interstitial Pulmonary Fibrosis

• Principle feature is thickening of the interstitium of the alveolar wall
• Infiltration with lymphocytes and plasma cells -> a cellular exudate consisting of macrophages and other mononuclear cells is seen within the alveoli -> the alveolar architecture is destroyed and scarring occurs which cause multiple air-filled cystic spaces formed by dilated terminal and respiratory bronchioles called “honeycomb lung”
• Cause of the disease is _______(1)

Pulmonary Function Test

• Spirometry reveals a ______(a) pattern
  
  • The FVC is reduced, but the gas is exhaled so quickly that even though the FEV1 is also low
  • the FEV1/FVC% may exceed normal value
• All lung volumes are ______(b), the TLC, FRC, and RV
• The fibrous tissue reduces the dispensability of the lung
• The lung volumes are small and large pressures are needed to distend the lungs
• The airway resistance is normal or _______(2)

Gas Exchange

• The arterial PaO2 and PCO2 are typically _______(3) and the pH is normal
• Hypoxia is mild at rest until the disease is advanced
• In the advanced stages of the disease physiologic dead space and shunt are _______(4)
• These patients typically have shallow rapid breathing pattern
• Other types of Restrictive diseases

Answer 20

Answers:
1. unknown
a. restrictive
b. reduced
2. decreased
3. reduced
4. increased

Question 21

Other types of Restrictive diseases

Sarcoidosis

• Characterized by the presence of granulomatous tissue and can occur in other organs such as the lymph nodes, heart, lungs, skin, eyes, spleen, and lungs
• Cause is unknown but one possibility is that an unknown antigen is recognized by alveolar macrophages and it results in the activation of _______(1) and the production of _______(2)
• There are 4 stages in sarcoidosis
  
  • The restrictive pattern is seen in stages _______(3)
• All lung volumes are small
• Lung compliance is reduced
• The resting PaO2 is reduced is low and often falls considerably with exercise

Hypersensitivity pneumonitis

• Also known as extrinsic allergic alveolitis
  
  • It’s a hypersensitivity reaction affecting the lung parenchyma that occurs in response to inhaled organic dust such as fungi, spores, and animal or plant material
    
    • Example “farmers lung”
  • The alveolar walls are thickened and infiltrated with lymphocytes, plasma cells, and occasional eosinophils that together with collections of histiocytes, which cause the formation of small granulomas
• Signs and symptoms
  
  • Dyspnea and cough ______(a) hours after inhalation of the antigens
  • Chest x-ray shows pulmonary infiltrates
  • Pulmonary fibrosis develops after multiple episodes

Answer 21

Answers:

1. T-lymphocytes
2. interleukin-2
3. 2 and 3
4. 4-6

Question 22

Restrictive diseases – Preoperative

• Patients usually present with dyspnea and nonproductive cough
• Cor pulmonale may be present
• Chest X-ray
  
  • Ground glass or nodular pattern
• ABG will show _______(1) with normocarbia
• PFT will show a _______(2) pattern
• A vital capacity less than _______(3) indicates severe pulmonary function

Restrictive disease– Intraoperative

• These patient do not tolerate apneic periods
  
  • Small FRC and low oxygen stores
• GA, supine position, and controlled ventilation all contribute to further decreases in FRC
• Uptake of inhaled agents is faster in these patients because of the decrease in FRC
  
  • Inhalation induction is _______(4)
• Keep peak airway pressures as ______(a) as possible to prevent barotrauma

Restrictive diseases

• Diseases of the Pleura
  
  • Pneumothorax
  • Tension pneumothorax
  • _______(5)
• Diseases of the Chest Wall
  
  • Pleural effusion
  • Scoliosis
  • _______(6)
• Neuromuscular Disorders
  
  • Guillain-Barre syndrome
  • Amyotrophic lateral Sclerosis
  • _______(7)

Answers:
1. hypoxemia
2. restrictive
3. 15mL/kg
4. quicker
5. Pleural effusion
6. Ankylosing Spondylitis
7. Myasthenia gravis

Answer 22

Answers:
1. hypoxemia
2. restrictive
3. 15mL/kg
4. quicker
a. low
5. Pleural effusion
6. Ankylosing Spondylitis
7. Myasthenia gravis

Question 23

Diseases of the pleura

Pneumothorax

• The pressure in the intrapleural space is subatmospheric as a result of the elastic recoil forces of the lung and chest wall
• When air enters the space, the lung collapses and the rib cage springs out
• Spontaneous pneumothorax usually occurs in young males due to high mechanical stress that occurs in the upper zone of the _______(1)
  
  • Symptoms are pain on ______(a) side accompanied by dyspnea
  • Breath sounds are reduced on the affected side and its diagnosed by _______(2)

Tension pneumothorax

• When air enters the intrapleural space during inspiration but cannot escape during expiration
• It causes a large pneumothorax in which pressure may exceed atmospheric pressure and it interferes with venous return in the thorax
• It’s a _______(3)
• It can cause respiratory distress, tachycardia and signs of mediastinal shift such _______(4)
• Treatment
  
  • _______(5)

Answer 23

Answers:
1. upright lung
a. one
2. chest x-ray
3. medical emergency
4. tracheal deviation
5. Chest tube

Question 24

Diseases of the Chest Wall

Scoliosis

1. Refers to lateral curvature of the spine and kyphosis to posterior curvature
   
   • Can be caused by bony tuberculosis or _______(1).
2. Signs and _______(2)
   
   • Depends on the severity of the curvature; _______(3) on exertion
   • Rapid and _______(4) breathing
   • Hypoxemia worsens with increased severity of curvature which leads to CO2 retention and cor pulmonale
3. PFTs will reveal a reduction in all _______(5) volumes
4. In advanced disease the patient has a reduced ventilator response to CO2, respiratory muscles are inefficient, the vascular bed is restricted causing a rise in pulmonary artery pressures

Ankylosing Spondylitis

5. The disease has an _______(6) etiology
6. There is a gradual onset of immobility of the vertebral joints and fixation of the _______(7)
7. The movement of the chest wall is _______(8)
8. There is a reduction in FVC and TLC, but the FEV1/FVC and the airway resistance are _______(9)
9. Chest compliance is _______(10)

Answer 24

Answers:
1. neuromuscular disease
2. symptoms
3. dyspnea
4. shallow
5. lung
6. unknown
7. ribs
8. reduced
9. normal
10. reduced

Question 25

Disorders of the Mediastinum

Mediastinal mass have various causes
- Lymphoma, thymoma, teratoma, and _______(1)
- Large mediastinal masses may be associated with airway obstruction, loss of lung volumes, pulmonary artery or cardiac compression, and superior vena cava obstruction

Superior vena syndrome
- Develops when the mass obstructs venous drainage in the upper thorax
- Leads to: dilation of collateral veins in the thorax and neck, edema of the face, neck, and upper chest, edema of the conjunctiva, increased intracranial pressure to include headaches and altered mental status
- Dyspnea is common
- Usually caused by a _______(2)

Management of Mediastinal Mass
- Preoperative evaluation should include a chest x-ray, measurement of a flow-volume loop, chest imaging studies, and clinical evaluation for evidence of tracheobronchial compression
- Must assess the size of the mass to predict whether airway difficulties will be expected
- A _______(3) is the best anesthetic choice for a diagnostic tissue biopsy
- The patient may be asymptomatic when awake but may develop airway obstruction under anesthesia in the supine position
- Symptomatic patients may need to be induced in the _______(4) position
- Topical anesthesia of the airway with/without sedation to facilitate fiberoptic laryngoscopy
- An inhalation induction with maintenance of _______(5)

Answer 25

Answers:
1. retrosternal goiter
2. cancerous mass
3. local anesthetic technique
4. sitting
5. spontaneous ventilation

Question 26

Neuromuscular disorders

• Neuromuscular disorders that interfere with the transfer of central nervous system input to the skeletal muscles necessary for inspiration and exhalation can result in _______(1) disease.
• All of the diseases below can lead to dyspnea and respiratory failure
  
  • _______(2)
  • Amyotrophic lateral sclerosis (ALS)
  • _______(3)
  • Muscular dystrophies
• The patient’s inability to take a deep breath leads to reduced FVC, TLC, inspiratory capacity, and FEV1
• These patients usually do not complain of dyspnea until the _______(4) is involved
• These diseases are usually monitored by FVC and _______(5)

Management of Anesthesia

• Avoid or limit drugs with _______(6) effects
• In patients with a pneumothorax, avoid ______(a)
• Regional anesthesia is a good choice for peripheral operations as long as the sensory block is below T10
• Mechanical ventilation should facilitate optimal ventilation and oxygenation
  
  • Since the lungs have poor compliance, higher inspiratory pressures may be needed
  • Postoperative mechanical ventilation should be considered in patients with advanced _______(7) disease

Answer 26

Answers:
1. restrictive
2. Guillain Barre syndrome
3. Myesthenia gravis
4. diaphragm
5. blood gasses
6. prolonged respiratory depressant
a. N2O
7. restrictive

Question 27

Vascular diseases

Pulmonary edema

• An abnormal accumulation of fluid in the extravascular spaces and tissues of the lung
• It’s a complication of a variety of heart and lung diseases and may be life-threatening
• It’s due to leakage of intravascular fluid into the interstitium of the lungs and into the alveoli
• It can be caused by increased capillary pressure (hydrostatic or _______(1) pulmonary edema) or by increased capillary permeability
• It typically manifests as bilateral symmetrical opacities on X-ray (see next slide).
  
  • A _______(2) distribution (______(a) pattern) of the lung opacity is common; seen with increased capillary pressure
  • The presence of air bronchograms on chest x-ray suggest increased _______(3) pulmonary edema

Various causes of pulmonary edema

• _______(4)
• Neurogenic problems
• _______(5)
• High-altitude pulmonary edema
• Re-expansion of collapsed lung
• Upper airway obstruction (negative-pressure)

Answer 27

Answers:
1. cardiogenic
2. perihilar
a. butterfly
3. permeability
4. Aspiration
5. Opioid overdose

Question 28

Pulmonary edema – Preoperative

• Elective surgery should be _______(1) in patients with acute pulmonary edema
• Large pleural effusions may need to be drained
• Persistent hypoxemia may require mechanical and _______(2)

Pulmonary edema – Intraoperative

• These patients are critically ill
• The ICU management should continue into the operating room
• Have an intraoperative plan for ventilation
  
  • To avoid barotrauma and hemodynamic compromise it is reasonable to ventilate with low tidal volumes (6 mL/kg) with a compensatory increase in ventilator rate (______(a) mL/kg)
  • Attempt to maintain the PIP less than _______(3) cm H2O
  • In patients with severe ARDS, a more sophisticated ventilator (i.e., _______(4) or HFJV) may be needed

Pulmonary embolism

• PE is a condition that is preventable and potentially life-threatening
• Most pulmonary emboli arise from detached portions of venous thrombi that have formed in the deep veins of the _______(5)
• Non-thrombotic emboli such as air, fat, and amniotic fluid can also occur
• Factors that lead to venous thrombi formation (Sounds like the coagulation triangle or something)
  
  • Stasis of blood
  • Alterations in the blood coagulation system
  • Abnormalities of the vessel wall
• Diagnosis is difficult; it can mimic other cardiopulmonary illnesses
• The most consistent symptom of acute PE is _______(6)
• ______(b) are the most common signs of PE but are _______(7)
• Other symptoms
  
  • Wheezing, hemoptysis, pleural rub, a loud pulmonic component of the second heart sound, a right ventricular shift, and bulging neck veins

Answer 28

Answers:

1. delayed
2. PEEP
   a. 14-16
3. 30
4. HFOV
5. lower extremity, right side of the heart, and pelvic area
6. acute dyspnea
   b. Tachypnea and tachycardia
7. nonspecific

Question 29

ABG

• Could be normal or demonstrate arterial hypoxemia and _______(1)
• In the presence of PFO or ASD
  
  • Severe hypoxemia
  • ECG findings are ST-T wave changes and ______(a) axis deviation
  • Peaked P waves, atrial fibrillation, and RBB may be present if the PE causes acute cor pulmonale

S/S

• Manifestations under general anesthesia may be nonspecific
  
  • Unexplained arterial hypoxemia
  • Hypotension
  • Tachycardia
  • _______(2)
  • Bronchospasm
  • The ECG and CVP may indicate onset of pulmonary HTN and RV dysfunction
• Capnography will demonstrate a _______(3) in ETCO2
• Lab test
  
  • A positive D-dimer strongly suggest a thromboembolism is present
  • Troponin levels may be elevated
• Pulmonary _______(4) is the gold standard for the diagnosis of PE

Answer 29

Answers:
1. hypocapnia
a. right
2. Tachypnea
3. decrease
4. arteriography

Question 30

Treatment

• Anticoagulation, thrombolytic therapy, inferior vena cava filter placement, and surgical embolectomy
• Heparin remains the cornerstone of treatment of acute PE
  
  • An intravenous bolus of _______(1) followed by an intravenous infusion should be administered if the patient is considered to have a high likelihood of PE
• In patients with significant bleeding after anticoagulation or recurrence of PE will have a vena cava filter placed
• Hypotension caused by the PE will require treatment
  
  • Inotropes such as dopamine or _______(2)
  • Vasoconstrictor such as norepinephrine
  • Pulmonary vasodilator to control pulmonary HTN
• Pulmonary artery embolectomy is reserved for patients who are unresponsive to medical therapy or who cannot receive thrombolytic therapy
• When life-threatening PE occurs the goal is to support vital function
  
  • The patient who comes to the operating room for the treatment of life-threatening PE
    
    • Patients is usually intubated and mechanically ventilated
    • Monitor cardiac filling pressures
    • Use ______(a) pressures to guide fluid administration
    • Cardiac output may need to be supported with inotropic drugs
      
      • _______(3), dobutamine, amrinone, milrinone

Induction and maintenance

• Avoid arterial hypoxemia, hypotension, or pulmonary HTN
• Maintain anesthesia with any drug that does not cause ______(b) depression
• Avoid ______(c) as it may increase PVR
• Use a muscle relaxant that does not release ______(d)
  
  • _______(4)

Answer 30

Answers:
1. 5,000 to 10,000 IU
2. dobutamine
a. right atrial
3. Dopamine
b. myocardial
c. N2O
d. histamine
4. Cisatracurium

Question 31

Respiratory failure

• Acute respiratory failure is the inability to provide adequate arterial oxygenation and/or elimination of CO2
• Diagnosis
  
  • PaO2 is less than _______(1) despite oxygen supplementation in the absence of a right to left shunt
  • A PaCO2 higher than _______(2) in the absence of respiratory compensation for respiratory alkalosis
  • pH is _______(3)
• It is often accompanied by a _______(4) in FRC and lung compliance

Answer 31

Answers:
1. 60 mmHg
2. 50 mmHg
3. decreased
4. decrease

Question 32

Adult Respiratory Distress Syndrome (ARDS)

• It is caused by an ______(a) injury to the lung and is manifested clinically by acute hypoxemic respiratory failure
• Pathogenesis
  
  • Manifest as rapid onset of respiratory failure accompanied by arterial hypoxemia refractory to treatment
  • There is an influx of protein-rich edema fluid into the alveoli as a result of increased alveolar capillary membrane permeability
  • Proinflammatory _______(1) may be produced locally in the lungs
  • In some patients, it progresses to fibrosing ______(b) with persistent arterial hypoxemia and decreased lung compliance

Signs and Symptoms
- Arterial hypoxemia resistant to treatment with ______(c) is the first sign
- Pulmonary HTN can lead to _______(2)
- Death from ARDS is usually caused by multiple organ failure or sepsis

Diagnosis
- Acute refractory hypoxemia
- Diffuse infiltrates of _______(3)
- PCWP of less than _______(4)

Treatment
- Treatment is directed at supporting oxygenation and ventilation

Goals
- Correcting hypoxemia
- Removing excess carbon dioxide
- Find and treat the cause of ARDS for example an infection
- Secure a patient airway
- Prevent GI bleeding and thromboembolism
- Inhaled _______(5)

Answer 32

Answers:

a. inflammatory
1. cytokines
b. alveolitis
c. O2
2. right-sided heart failure
3. chest x-ray
4. 18 mmHg
5. blood gas

Question 33

Treatment – Tracheal intubation and PEEP

• Initial steps in treatment is to secure the airway
• Keep inspired oxygen concentration to maintain the PaO2 between 60-80 mmHg
• Avoid barotrauma by maintaining peak airway pressures below _______(1) cm H2O

Application of PEEP

• Helps prevent alveolar collapse at end expiration and increases lung volumes, especially FRC
• Improves ventilation/perfusion matching
• ______(a) the magnitude of right to left intrapulmonary shunting
• PEEP is indicated when high concentrations of inspired oxygen (FIO2 > 0.5) are needed to maintain PaO2
• High levels of PEEP _______(2) and cause barotrauma
• PEEP is added in increments of 2.5-5 cm H2O until the PaO2 is at least _______(3) with an FIO2 of less than _______(4)

Treatment – Fluid and hemodynamic management

• The rationale for restricting fluids in patients with ARDS is to decrease the risk of pulmonary edema
• Maintain urine output at _______(5)
• Diuresis with furosemide may help with excessive fluid administration
• The goal of fluid therapy is to maintain the intravascular fluid volume at the lowest level consistent with adequate organ perfusion as assessed by metabolic acid-base balance and renal function

Treatment - Misc

• Removal of airway secretions
• Adequate hydration and humidification of inspired gases
• Infection
  
  • Antibiotic therapy based on sputum culture and sensitivity testing
• Nutritional support
• It’s important to _______(6)
• Hyperinflation

Answer 33

Answers:
1. 35-40
a. Decreases
2. decrease cardiac output
3. 60 mmHg
4. 0.5
5. 0.5-1 mL/kg/hr
6. prevent muscle weakness