Post on 22-Mar-2018
PATHOPHYSIOLOGY OF AIRWAY OBSTRUCTION
Faisal Yunus
Department of Pulmonology and Respiratory Medicine, Faculty of Medicine, University of Indonesia – Persahabatan Hospital,
Jakarta
Airway obstruction has several mechanisms,depend on its abnormality: - Stridor - Bronchial asthma - Chronic bronchitis - Emphysema - Bronchiectasis - Endobronchial tumour - Tumour that suppress the airway
INTRODUCTION
Key action
STRIDOR
Vocal cord inflammation Trauma Infection ~ Croup ~ Foreign body Paralyse
Tracheal edema Tracheal tumour
BRONCHIAL ASTHMA
Bronchial hyperreactivity Diffuse bronchoconstriction Mediator release Mucosal edema Reversible airway obstruction
Eosinophil
Mast cell
Allergen
Th2 cell
MODERN VIEW OF ASTHMAMODERN VIEW OF ASTHMA
VasodilatationNew vessels
Plasma leakOedema
Neutrophil
Mucushypersecretionhyperplasia
Mucus plug
Macrophage
BronchoconstrictionHypertrophy/hyperplasia
Cholinergic reflex
Epithelial shedding
Subepithelialfibrosis
Sensory nerve activation
Nerve activation
GINA2005
Inflammatory cell infiltration/activation
Mucosal oedemaCellular proliferationEpithelial damageBasement membrane
thickening
BronchoconstrictionBronchial hyper-
reactivityHyperplasia Inflammatory
mediator release
Symptoms\exacerbations
Smooth muscle dysfunction
Airway inflammation
ASTHMA PATHOGENESISASTHMA PATHOGENESIS
CHRONIC OBSTRUCTIVE PULMONARY DISEASE ( COPD)
Chronic airway irritation Airway limitation partly reversible Two types : - chronic bronchitis - emphysema
Cigarette smoke
Alveolar macrophage
Neutrophil
PROTEASES
Alveolar wall destruction(Emphysema)
Mucus hypersecretion(Chronic bronchitis)
PROTEASEINHIBITORS
Neutrophil chemotactic factors
CELLULAR MECHANISMS OF COPDCELLULAR MECHANISMS OF COPD
Neutrophil elastaseCathepsins
Matrix metalloproteinases
Cytokines (IL-8)Mediators (LTB4)4 ))
?CD8+
lymphocyte
-
MCP-1
ASTHMASensitizing Agent
COPDNoxious Agent
Asthmatic airway inflammationCD4+ T-lymphocytes
Eosinophils
COPD airway inflammationCD8+ T-lymphocytes
MacrophagesNeutrophils
Completely Airflow limitation Completely reversible irreversible
GOLD 2005
Alveolar Emptying in COPD
In COPD, airflow is limited because alveoli lose their elasticity, supportive structures are lost, and small airways are narrowed
Chronic Bronchitis
Chronic irritation: - Tobacco smoke - Indoor air polution - Outdoor air polution Mucosal membrane hypertrophy Mucosal membrane hyperplasia Mucosal gland hypersecretion - Reid index
Emphysema
Chronic irritation: - Tobacco smoke - Indoor air polution - Outdoor air polution Abnormal dilatation of the airway distal from terminal bronchiolus Loss elasticity of the lung ( elastic recoil)
Bronchiectasis
Abnormal dilatation of medium bronchus: - chronic infection - airway obstruction - congenital abnormality - Kartagener syndrome Abnormal airflow - turbulence
CONCLUSION
Airway obstruction has several mechanisms, its pathophysiology depends on its abnormality