Introduction to obstructive airway disease

1. Obstructive Airway Diseases

2. Obstructive Airway Diseases
● COPD
○ Chronic bronchitis
○ Emphysema
● Asthma
● Bronchiectasis

4. COPD
Chronic Bronchitis
● Persistent or recurrent excess of secretion in the
bronchial tree on most days for at least 3 months
in the year, over 2 years
○ Mucous gland hyperplasia
● Risk factors
○ Cigarette smoke
○ Air pollution
○ Dust exposure - cadmium
○ Infection
Emphysema
● Characterised by abnormal, permanent
enlargement of the airspaces distal to the
terminal bronchioles, and destruction of their
walls without fibrosis
○ Loss of elastic recoil
○ Airway narrowing
● 3 morphological patterns
○ Centriacinar
○ Panacinar
○ Paraseptal

6. COPD Exacerbation - COPD X
● Usually multifactorial
○ Infection - viral, bacterial
○ Medicine non-compliance
○ Iatrogenic
● History
● Exam
● Bloods +/- ABG
● ECG
● PFTs
● CXR
Management
● O2
○ Controlled via Venturi if CO2 retainer
○ Otherwise high dose via face mask
● Nebulizers
● Steroids
● Antibiotics
● Diuretics
● BiPAP

8. Asthma
● Hyperreactive airways leading to episodic,reversible bronchoconstriction, owing to increased
responsiveness of the tracheobronchial tree to various stimuli
○ Atopic
○ Non-atopic
● Non-specific triggers
○ Exercise
○ Cold air
○ Emotional distress
○ Aspirin/NSAIDs

11. Asthma Presentation
1. History
a. Precipitating factors
b. Previous attacks
c. RF - ICU, Comorbidities, Compliance
2. Exam
a. Inspection
b. Vitals
c. Auscultation
d. PEF/FEV
3. Investigations
a. Bloods/ABG
b. CXR?
Initial Management
● Position
● O2
● Salbutamol nebs
● Ipratropium nebs
● Steroid
● IVH - insensible losses

12. Status Asthmaticus
ABG - Hypoxia, Hypercapnia, Acidosis, Hypokalaemia

13. Advanced Management
● IV Magnesium
○ 2g over 20 minutes (up to 6g)
● IM Adrenaline/IV Adrenaline
● IV Salbutamol
○ 3-6ug/kg over 5 minutes
○ Infusion 10ug/min (titrate up to 40-60ug)
○ ECG - arrhythmias
○ Bloods - hypokalaemia, lactic acidosis
● IV Ketamine
○ Pre-induction/Induction

14. Mechanical Ventilation
● Increases both morbidity & mortality
● Pre-oxygenation - BiPAP
● Avoid hyperinflation
○ Pneumothorax
○ Reduced venous return
● Permissive hypercapnia
○ Respiratory acidosis
Ventilator settings
● Low RR
● Small Vt
● High peak inspiratory flow (70-100l/min)
● Prolonged expiratory time (I:E, 1:3
● PEEP to compensate for PEEPi