Obstructive Lung Diseases Flashcards Preview

AS - N932 Advanced Pathology > Obstructive Lung Diseases > Flashcards

Flashcards in Obstructive Lung Diseases Deck (46)
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1

Obstructive Lung Disease

Obstructive sleep apnea
Asthma
COPD
Miscellaneous

2

Obstructive Sleep Apnea

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

3

STOPBANG

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

4

OSA S/S

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

5

OSA Diagnosis

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

6

FEV1

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

7

FVC

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

8

FEV1:FVC Ratio

Normal 75-80%

9

FEV 25-75%

Air flow measurement at midpoint forced exhalation

10

Maximum Voluntary Ventilation

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

11

DLCO

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

12

Acute Upper Respiratory Infection

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

13

Acute Upper Respiratory Infection
Anesthetic Management

Hydration
↓secretions
Limit airway manipulation
LMA vs. ETT

14

Asthma

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

15

Asthma Pathophysiology

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

16

Asthma S/S

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

17

Asthma Treatment

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

18

Status Asthmaticus

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

19

Asthma Anesthetic Considerations

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

20

COPD

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

21

COPD Risk Factors

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

22

Chronic Bronchitis

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

23

COPD Spirometry

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

24

COPD Treatment

Designed to relieve symptoms & slow disease progression
- Smoking cessation
- Oxygen
- Long-acting β2 agonists
- Inhaled corticosteroids
- Long-acting anticholinergic
- Lung volume reduction surgery

25

Lung Volume Reduction Surgery

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

26

COPD Anesthetic Considerations

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)

27

Smoking Cessation

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

28

Auto PEEP

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

29

Bronchospasm Treatment

Deepen anesthetic
Short-acting bronchodilator
Suction secretions
IV steroids
Epinephrine

30

Expiratory Outflow Obstructions

Bronchiectasis
Cystic Fibrosis
Primary ciliary dyskinesia
Bronchiolitis obliterans
Tracheal stenosis