Obstructive Lung Diseases

Question 1

Obstructive Lung Disease

Answer 1

Obstructive sleep apnea
Asthma
COPD
Miscellaneous

Question 2

Obstructive Sleep Apnea

Answer 2

Not technically an obstructive lung disease
Mechanical breathing obstruction occurs during sleep when pharyngeal muscles relax → chronic hypoxemia ↑CO2 ↓FRC
Obesity = most significant precipitating factor
Risk factor ↑morbidity

Question 3

STOPBANG

Answer 3

○ Snoring
○ Tired
○ Observed apnea
○ Pressure HTN
○ BMI >35kg/m2
○ Age >50yo
○  Neck circumference >40cm
○ Gender M

Question 4

OSA S/S

Answer 4

Habitual snoring, fragmented sleep, daytime somnolence
Comorbidities r/t obesity & hypoxemia
- Systemic & pulmonary HTN
- Ischemic heart disease
- Congestive heart failure

Question 5

OSA Diagnosis

Answer 5

Polysomnography - records # abnormal respiratory events
STOPBANG
Apnea-hypopnea index AHI
Normal <5
Mild 5-15
Moderate 15-30
Severe >30

Question 6

FEV1

Answer 6

Forced expiratory volume in 1 second
TLC 5L
Normal FEV1 = 4L
80-120%

Question 7

FVC

Answer 7

Forced vital capacity
Volume air forcefully exhaled after deep inhalation
Females 3.7L
Males 4.8L

Question 8

FEV1:FVC Ratio

Answer 8

Normal 75-80%

Question 9

FEV 25-75%

Answer 9

Air flow measurement at midpoint forced exhalation

Question 10

Maximum Voluntary Ventilation

Answer 10

MVV
Maximum amount air inhaled & exhaled in 1 minute
Females 80-120L/min
Males 140-180L/min

Question 11

DLCO

Answer 11

Diffusion capacity
Patient inhales helium & carbon monoxide
Measures volume CO transferred across the alveoli into the blood per minute per unit alveolar partial pressure
Single breath 0.3% CO + 10% helium held for 20 seconds
Normal value 17-25mL/min/mmHg

Question 12

Acute Upper Respiratory Infection

Answer 12

Common cold
Infectious (viral or bacterial) nasopharyngitis 95%
S/S:
- Non-productive cough
- Sneezing
- Rhinorrhea
- Bacterial include fever, purulent nasal discharge, productive cough, & malaise

Question 13

Acute Upper Respiratory Infection

Anesthetic Management

Answer 13

Hydration
↓secretions
Limit airway manipulation
LMA vs. ETT

Question 14

Asthma

Answer 14

REVERSIBLE airway obstruction
- Bronchial hyperreactivity
- Bronchoconstriction
- Lower airways chronic inflammation
Genetic & environmental

Question 15

Asthma Pathophysiology

Answer 15

Inflammatory pathway activation → airway mucosa infiltration w/ eosinophils, neutrophils, mast cells, T/B cells, & inflammatory mediators
→ EDEMA

Question 16

Asthma S/S

Answer 16

Wheezing, productive/non-productive cough, dyspnea, chest tightness, SOB, airflow obstruction
FEV1 <35% ↑FRC
TLC = WNL
DLCO unchanged
CXR hyperinflation d/t air trapping
R ventricle strain T wave inversion V1-4 & II, III, aVF

Question 17

Asthma Treatment

Answer 17

Corticosteroids
Long-acting bronchodilators
Leukotriene modifiers
Anti-IgE
Methylxanthines
Mast cell stabilizer

Question 18

Status Asthmaticus

Answer 18

Life-threatening emergency
Bronchospasm does not respond to treatment
β2 agonists
IV corticosteroids
Supplemental O2
IV magnesium sulfate

Question 19

Asthma Anesthetic Considerations

Answer 19

Regional vs. general anesthesia
↓airway manipulation
Propofol & Ketamine - bronchodilation
IV or transtracheal Lidocaine
Sevoflurane less pungent
Light anesthetic potential bronchospasm
Avoid histamine releasing drugs

Question 20

COPD

Answer 20

Chronic obstructive pulmonary disease
NONREVERSIBLE loss alveolar tissues & progressive airway obstruction
Type A - Emphysema (pink puffers)
Type B - Chronic bronchitis (blue bloaters)

Question 21

COPD Risk Factors

Answer 21

Cigarette smoking
Occupational exposures
Pollution
Recurrent respiratory infections
Low birth weight
Antitrypsin deficiency

Question 22

Chronic Bronchitis

Answer 22

Type B
Characterized by excessive sputum production
- Mucus gland hypertrophy
- Small airway inflammatory changes
- Tissue granulation
- Peri bronchial fibrosis
Clinical S/S indicate pulmonary complications

Question 23

COPD Spirometry

Answer 23

Normal lung volumes
↓FEV1/FVC ratio
↓FEV 25-75
↑FRC & TLC 
Severity determined by GOLD criteria

Question 24

COPD Treatment

Answer 24

Designed to relieve symptoms & slow disease progression

• Smoking cessation
• Oxygen
• Long-acting β2 agonists
• Inhaled corticosteroids
• Long-acting anticholinergic
• Lung volume reduction surgery

Question 25

Lung Volume Reduction Surgery

Answer 25

``` Remove worse lung portion to optimize remaining Severe COPD ↓V/Q mismatch Double-lumen ETT Avoid N2O One lung ventilation VT 3-4mL/kg IBW ```

Question 26

COPD Anesthetic Considerations

Answer 26

``` Preop pulmonary function test Hypoxemia ↑PaCO2 Baseline HCO3¯ (renal compensation) Determine response to bronchodilators CV involvement R ventricle function Desflurane → irritation Avoid N2O attenuates HPV ↑V/Q mismatch Limited opioid & benzodiazepine use (prolonged ventilatory depression) ```

Question 27

Smoking Cessation

Answer 27

At least 6 weeks prior to surgery Benefits seen w/in 4-6hr Immediate cessation NOT recommended

Question 28

Auto PEEP

Answer 28

Air trapping Capnography - expiratory flow does not reach baseline before next breath + pressure ventilation PPV applied w/o adequate expiration ↑intrathoracic pressure ↓VR ↑pulmonary artery pressure → R heart strain

Question 29

Bronchospasm Treatment

Answer 29

``` Deepen anesthetic Short-acting bronchodilator Suction secretions IV steroids Epinephrine ```

Question 30

Expiratory Outflow Obstructions

Answer 30

``` Bronchiectasis Cystic Fibrosis Primary ciliary dyskinesia Bronchiolitis obliterans Tracheal stenosis ```

Question 31

Bronchiectasis

Answer 31

Irreversible airway dilation & collapse resulting from inflammation d/t chronic infections Significant hemoptysis 200mL over 24hr Resultant airway collapse ↑recurrent infection risk

Question 32

Bronchiectasis S/S

Answer 32

``` Chronic cough w/ purulent sputum CT imaging to confirm Hemoptysis Pleuritic chest pain Dyspnea Wheezing Finger clubbing ```

Question 33

Bronchiectasis Anesthetic Considerations

Answer 33

Delay elective procedures until patient optimized General anesthesia w/ ETT - Frequent suctioning - Avoid nasal intubation - Double lumen tube prevent cross-contamination

Question 34

Cystic Fibrosis

Answer 34

Autosomal recessive disorder Chromosome 7 Prevents chloride transport & Na+/H2O movement in & out cells → abnormally thick sputum production outside epithelial cells 1° cause morbidity & mortality chronic pulmonary infection

Question 35

Cystic Fibrosis Diagnosis

Answer 35

``` Sweat chloride >70mEq/L Chronic purulent sputum production Malabsorption (pancreatic enzyme therapy) Bronchoalveolar lavage ↑neutrophils COPD common in adult patients ```

Question 36

Cystic Fibrosis Treatment

Answer 36

``` Directed toward symptom alleviation - Clear airway secretions - Correct organ dysfunction - Nutrition (impaired ability to absorb nutrients) - Prevent intestinal obstruction Gene therapy (?) ```

Question 37

Cystic Fibrosis Anesthetic Considerations

Answer 37

Delay elective procedures until patient optimized - Control infection & remove secretions Vitamin K treatment (fat-soluble vitamins absorption) General anesthesia w/ volatile agents AVOID anticholinergic medications Awake extubation Adequate pain control

Question 38

Primary Ciliary Dyskinesia

Answer 38

Congenital ciliary activity impairment in the respiratory tract & sperm cells Pulmonary infections Organ inversion

Question 39

Kartagener's Syndrome

Answer 39

Chronic sinusitis Bronchiectasis Situs inversus

Question 40

Primary Ciliary Dyskinesia Anesthetic Considerations

Answer 40

``` Regional anesthesia preferred Dextrocardia - reverse EKG placement L IJ central line R uterine displacement (term mothers to prevent vena cava compression) Avoid NP airways d/t sinusitis risk ```

Question 41

Bronchiolitis Obliterans

Answer 41

Small airways & alveoli disease in children d/t RSV Lower bronchioles destruction Adults d/t viral pneumonia, collagen vascular disease (RA), silo filler's disease (NO2 inhalation), or graft vs. host disease

Question 42

Bronchiolitis Obliterans Organizing Pneumonia

Answer 42

BOOP Similar features as interstitial lung disease Treatment typically ineffective S/S management Corticosteroid ↓swelling Bronchodilators to optimize the airway diameter

Question 43

Tracheal Stenosis

Answer 43

Tracheal mucosa ischemia → scarring | Prolonged intubation or cuff over-inflation

Question 44

Tracheal Stenosis S/S

Answer 44

Adult symptomatic when tracheal diameter <5mm Dyspnea even at rest Accessory muscle use during inspiration & expiration Flow loops flattened inspiratory & expiratory curves

Question 45

Tracheal Stenosis Treatment

Answer 45

``` Dilation = temporary measure - Balloon or surgical dilators - Laser scarred tissue Tracheobronchial stent Best treatment = tracheal resection w/ anastomosis ```

Question 46

Tracheal Stenosis Anesthetic Considerations

Answer 46

Translaryngeal intubation Volatile agents to ensure maximum inspired oxygen concentration Helium ↓gas mixture density & improves flow