Asthma and COPD - Spirometry PDF

Asthma, COPD, and Basic Lung Function Tests Oli and Jo Session Overview 1. Asthma - Aetiology - Pathophysiology - including stages - Investigation/Diagnosis & Treatment 1. COPD - Aetiology - Pathophysiology - Investigation/Diagnosis & Treatment 1. Basic Lung Function Testing...

Asthma, COPD, and Basic Lung Function Tests Oli and Jo Session Overview 1. Asthma - Aetiology - Pathophysiology - including stages - Investigation/Diagnosis & Treatment 1. COPD - Aetiology - Pathophysiology - Investigation/Diagnosis & Treatment 1. Basic Lung Function Testing - Obstructive vs Restrictive Disorders - Spirometry - Flow-Volume Loops 1. Practice Questions 2. Summary Tables  Learning Outcomes Asthma COPD Define chronic obstructive pulmonary disease (COPD), chronic List the main aetiology factors in the development of extrinsic bronchitis, and emphysema asthma. List the main aetiology factors in the development of COPD. Describe the structural, functional and immunological changes Describe the structural, functional and immunological changes associated with extrinsic asthma. associated with COPD. Delineate the immediate/early, late, and chronic phases of Explain the reversible and irreversible causes of airflow asthma pathogenesis. obstruction in COPD in the context of the underlying List common investigations that can be used in the diagnosis of pathophysiology. List common signs and symptoms of COPD. asthma. List common investigations used in the diagnosis of COPD. List Function Lung the classes ofTesting drugs commonly used in the management of Explain the importance of smoking cessation in COPD. asthma and correlate their mechanism of action with basic Explain the principles and utility of spirometry. List the classes of drugs commonly used in the management of pathophysiology. COPD Define FEV1 and explain how a combination of FVC and FEV1 can be used to in theand correlateoftheir assessment mechanism of action with basic lung function. Outline the main differences between obstructive and restrictive disease patterns shown on lung function testing. pathophysiology. Asthma - Aetiology “Asthma is a chronic lung disease affecting people of all ages. It is caused by inflammation and muscle tightening What is asthma? around the airways, which makes it harder to breathe” Really High Iguanas -Reversible Airway Obstruction -Hyperresponsiveness Atopy = asthma, -Inflammation allergies, & eczema Types + Causes - Extrinsic = exact - Intrinsic  Asthma - Pathophysiology + Stages Late Immedia te Chronic Immediate/Early (0-60 min) - IgE binds to allergen, attaches to Mast Cell, Mast Cell degranulates chemical mediators, & we get bronchoconstriction Late (1-8 hours) - Vascular leakage + oedema, inflammatory cell infiltration (Eosinophils + Neutrophils), & mucus secretion Chronic (long-term) - Goblet cell hyperplasia (increase), basement membrane thickening, & smooth muscle hypertrophy (growth) and hyperplasia  Asthma - Investigation/Diagnosis & Treatment Investigations/Diagnosis - Strong History and Clinical Signs (> 5y/o) - Diurnal PEFR Variability - Bronchodilator Reversibility (12% FEV1) - FeNO - Bronchial Challenge - Histamine Treatment - Salbutamol, add ICS, if necessary LTRA - Severe =O SHIT ME! - Oxygen, Salbutamol, Hydrocortisone IV, Ipratropium, Theophylline, Magnesium Sulphate, & Escalation Question s? COPD - Aetiology Smoking! Pollutants alpha -1 anti-trypsin deficiency (A1ATD)  Chronic Bronchitis vs Emphysema  Inflammation in the  Smaller airways (smaller larger airways (bronchus, bronchioles, alveoli) larger bronchioles) Alveolar wall Mucus gland destruction hypertrophy and hyperplasia  Air space enlargement →  Hypersecretion of mucus reduced gas exchange surface area.  Shortness of breath  Chronic productive cough (dyspnoea) COPD - Chronic Bronchitis (EMIIS) Epithelium changes Thickening and scarring of airway tissue Chronic bronchitis Mucus (EMIIS) production increases Immune cell buildup Inflammation in airway cells COPD - Emphysema Alveolar wall Inflammatory Loss of destruction cell elasticity accumulation - Cannot stretch and recoil - Leads to air space - Predominantly properly, impairs lung enlargement. macrophages and CD8+ function - Reduces number of alveoli T-lymphocytes. and pulmonary capillaries, - Contribute to ongoing reduces surface area for inflammation and further gas exchange. damage in the lungs. Types of emphysema: - Centriacinar emphysema - most commonly caused by smoking and affects the central parts of the alveoli. - Panacinar emphysema - more often linked to alpha-1 antitrypsin deficiency, affects entire alveolus. Mechanisms of Oxidative Inflammatory Protease- alveolar stress cells and mediators antiprotease imbalance destruction: COPD - Investigations/Diagnosis & Treatment Symptoms: Investigations: Productive cough (sputum) Spirometry → reduced Wheeze FEV1:FVC ratio. Breathlessness (dyspnoea) (CXR; ABG; Hb) Frequent infective exacerbations with Treatment - mostly purulent sputum. symptomatic: Smoking cessation Bronchodilators etc. Other aspects of care. Question s?  Lung Function Testing - Obstructive vs. Restrictive Obstructive - can’t get air Out - Asthma, COPD, & Cystic Fibrosis - FEV1 impacted RestrIctIve - can‘t get air In - Pulmonary Fibrosis, Scoliosis, Obesity, & - MND FVC (& FEV1) impacted When you have a patient in front of you try to determine if symptoms are worse on exhalation or inhalation to help narrow differential diagnoses even before you go to lung function testing  Lung Function Testing - Spirometry & Flow-Volume Loops Norm Obstructi Restricti al ve ve Spirometry - FEV1 = forced FEV FVC expiratory volume in 1 FEV 1 1 second - FVC = forced vital capacity Flow-Volume Loops - Obstructive = Steeple pattern - Restrictive = Reduction in overall volume Practice Questions  Summary Tables Asthma COPD Pathophysiology Reversible, Hyper-responsive, and Inflammatory IgE + Mast Cells + Eosinophils Bronchoconstriction + Goblet + BM Investigations Hx, PEFR (Diurnal), Spirometry Reversibility, FeNO, & Bronchial Challenge Treatments SABA > + ICS > + LTRA OSHIT ME Obstructive Restrictive Pathology Can’t get air Out Can’t get air In Spirometry Reduced FEV1/FVC ratio Reduced FVC Flow-Volume Loops Steeple Pattern Reduction in Volume