Asthma, Cystic Fibrosis, & Restrictive Lung Disease Presentation 2024 PDF

Chronic Pulmonary Dysfunction – II Troy Seely BScPT, MScPT, DPT, FCAPMT Health Conditions and Disease in Rehabilitation RS 3060A © Troy Seely, 2024  Group Assignment Due on Monday Nov. 25th : – Please hav...

Chronic Pulmonary Dysfunction – II Troy Seely BScPT, MScPT, DPT, FCAPMT Health Conditions and Disease in Rehabilitation RS 3060A © Troy Seely, 2024  Group Assignment Due on Monday Nov. 25th : – Please have a hard copy of the group assignment handed in to me at the beginning of lecture next week. – Also, you will post your group assignment on UWO Brightspace ( look for announcement later this week ) Besides your group assignment, every group member must complete the peer evaluation of their teammates and post to UWO Brightspace ( look for announcement later this week ) © Troy Seely, 2024  Outline Introduction/Review – COPD review – Ventilation-perfusion (V/Q) reviewed Discuss Asthma – Epidemiology – Etiology: categories of provocative factors – Pathology: hyper-reactivity; 2-stage response Discuss Cystic Fibrosis – Epidemiology: impact on life span – Etiology: hereditary – Pathology: mucus; some elements overlap COPD Discuss Restrictive Lung Disease – Group of diseases – Etiology (many diseases = many different causes) - broad summary only – Pathology: lung stiffness © Troy Seely, 2024 COPD Review Average Patients with patient with Patients with primarily COPD primarily chronic emphysema bronchitis Degree of inflammation or alveolar destruction © Troy Seely, 2024  Abnormal Ventilation-Perfusion Reviewed In asthma, no pathology in alveoli. Bronchospasm restricts ventilation. In chronic bronchitis, mucus plug could block ventilation. If you take away the alveolar wall, you take away the capillary bed on the other side (emphysema). Adapted from: K.L. McCance and S.E. Huether. Pathophysiology: The Biologic Basis for Disease in Adults and Children 4th edition, St. Louis, 2002 © Troy Seely, 2024  Asthma Asthma is defined as a reversible, obstructive lung disease that is characterized by airway inflammation and associated with airway hyper-responsiveness (reactivity of smooth muscle causing bronchospasm) to various stimuli ( _______ Triggers ). © Troy Seely, 2024  Asthma: Epidemiology Asthma is the most common chronic disease of childhood, affecting ____of 9.4% all children. Asthma can occur at any age, although it is more likely to occur for the first time before the age of 5 years old. – In childhood, it is 3 times more common and more severe in boys than in girls. Young boys have “dysanapsis” = smaller airway diameters relative to lung volumes compared to girls. © Troy Seely, 2024  Asthma: Etiology There are two main types of asthma: – Allergic asthma – Nonallergic asthma The most common phenotype of asthma is allergic (or extrinsic asthma). – Allergic asthma has a immunologic response driven by mast cells present in the bronchus to the respiratory bronchiole pathways. – This response is affiliated with environmental triggers (pollen, mold, dust, animal dander). © Troy Seely, 2024  Asthma: Etiology Non allergic (or intrinsic) asthma is less common and triggering factors can be unknown. – Tends to be adult onset – Often secondary to chronic or recurrent infections of the bronchi, sinuses, or tonsils. – This type of asthma can develop from a hypersensitivity to bacteria or viruses causing an infection. © Troy Seely, 2024  Asthma: Etiology Other recognized categories include: – Exercise – induced asthma – Aspirin – sensitive asthma – Occupational asthma Smoke induced Firefighters Latex induced Nurses Flour Bakers Animal Proteins Farmers/Butchers 30 – 50% Exposure to biologic dusts, gases, and fumes can cause a _____% increase risk of asthma. © Troy Seely, 2024  Asthma: Pathology The presentation of asthma is due to inflammation of the bronchial mucosa, leading to narrowing of the airways, bronchospasm and increased bronchial secretions, all in response to a trigger. – The narrowed airways increase the resistance to airflow and cause air trapping on exhalation, leading to hyperinflation. – Similar to what presentation? ______ COPD (chronic bronchitis) © Troy Seely, 2024  Asthma: Pathology The narrowed airways also provides an abnormal distribution of ventilation to the alveoli, affecting the ventilation to perfusion ratio. – Asthma exacerbations can improve spontaneously – Or with medical interventions and are interspersed with symptom-free intervals © Troy Seely, 2024  Asthma Pathology: Early Response Antibodies bind to the foreign substance (i.e. the antigen = the allergen) on surface of mucosa in airway This triggers an inflammatory response Inflammatory mediators (e.g. histamine) cause: Smooth muscle constriction of the airways Mucosal edema Mucus secretion © Troy Seely, 2024 Asthma Pathology: Late Response - I 4-8 _____ hours hrs after early response (up to 24 hrs), and can occur in 50% of patients. Inflammatory cell recruitment causes 2nd wave of inflammatory mediator release causing: – More bronchospasm, edema and mucus secretion Epithelial damage & impaired mucociliary function from toxic inflammatory effects, which may aggravate bronchoconstriction & mucus production. © Troy Seely, 2024 Asthma Pathology: Late Response - II Chronically increased numbers of inflammatory cells may lead to ‘long-term’ changes in airway such as: – Goblet cell hyperplasia – Airway wall remodeling Subepithelial fibrosis Smooth muscle hypertrophy © Troy Seely, 2024  Early asthmatic response Late asthmatic response (4-8 hours later) in 50% of patients Early Effects Characteristic of asthma: - reversibility of abnormal Late Effects pulmonary function tests Hallmark feature: Increased hyperreactivity - direct relationship between # of inflammatory cells & bronchial hyperreactivity Thickening of airway walls: as airway walls thicken, narrowing due to © Troy Seely, 2024 smooth muscle contraction is much greater than in normal airways  Normal Lung (a) Compared to Acute Asthmatic Episode (b) 1. ‘Shortness of breath’ - Increased resistance from mucus plugs and thickened edematous airway walls - This leads to hyperinflation - Greater muscular effort to breath required - All this contributes to increasing symptoms of ‘shortness of breath’ 2. ‘Wheezing’ - Smooth muscle constriction & mucus hypersecretion/retention causes turbulent airflow resulting in ‘wheezing’ © Troy Seely, 2024  Asthma – Clinical Presentation Clinical symptoms during an exacerbation can include dyspnea on exertion or at rest, cough, chest pain and wheezing. Posture – the chest is held in an expanded position, indicating that hyperinflation of the lungs has occurred. Accessory muscles of ventilation may be required for breathing. © Troy Seely, 2024  Asthma – Clinical Presentation Auscultation – wheezing is the main characteristic of asthma, but crackle may also be present. – In severe airway obstruction, breath sounds may be markedly decreased due to poor air movement, with wheezing being present in both inspiration and expiration. © Troy Seely, 2024  Asthma – Clinical Presentation Pulmonary function tests show decreased FEV1 (less than 70-80% of the predicted value), increased residual volume and FRC due to air trapping. – The reversibility of these pulmonary function test abnormalities is characteristic of asthma. – During remission, the patient with asthma will have normal or near-normal pulmonary test findings. © Troy Seely, 2024  Asthma and Lung Volumes Relationship of Asthma lung volumes in someone with healthy lungs Consistent with hyperinflation: FRC increased Consistent with hyperinflation: © Troy Seely, 2024 RV increased  Asthma Classification 2 concepts Frequency Severity Step 4: severe persistent – Continual symptoms; frequent exacerbations; limited physical activity Step 3: moderate persistent – Daily symptoms; ‘does’ affect activity Step 2: mild persistent – Exacerbations < daily; but > 2x/week; ‘may’ affect activity Step 1: mild intermittent – Exacerbations 2x/week at most; asymptomatic otherwise © Troy Seely, 2024 Asthma case  Asthma – Clinical Course By the time adulthood is reached, many children with asthma no longer have symptoms of the disease. When the onset of asthma symptoms begins later in life, the clinical course is usually progressive. – Showing changes in pulmonary function test even during periods of remissions (? airway remodeling in response to chronic airway inflammation) © Troy Seely, 2024  Cystic Fibrosis Cystic fibrosis (CF) is an inherited, chronic disease that affects the excretory glands of the body. – Secretions made by these glands are thicker, more viscous than usual, and can affect a number of systems in the body including: Pulmonary Pancreatic Hepatic Reproductive © Troy Seely, 2024  Cystic Fibrosis: Epidemiology In Canada: ~ ________ 4200 persons live with CF in Canada 1 child born with CF in every ~3600 live births. © Troy Seely, 2024  Cystic Fibrosis and Lifespan What is this telling you? © Troy Seely, 2024  Cystic Fibrosis and Lifespan Year of Birth Median Predicted Survival Age 1993-1997 31 2003-2007 37 2013-2017 44 2018-Present Day 61 © Troy Seely, 2024  CF Impacts on Lifespan Canadian Cystic Fibrosis Foundation – In 1960 Most with CF didn't survive to go to school – Today Canadians with CF are living longer – 61% are adults 50% live until their early 50’s – 53.3 yrs in 2016 But CF still limits a person’s life span © Troy Seely, 2024  Cystic Fibrosis: Etiology CF is an autosomal recessive genetically transmitted disorder….what does that mean? : Requires that both parents be carriers of the disease or have the disease in order for their child to have the disease ( 1 in 4 chance) © Troy Seely, 2024 https://www.researchgate.net/figure/ © Troy Seely, 2024  Cystic Fibrosis: Etiology The CF gene has been identified on the long arm of chromosome 7. This gene functions to transport electrolytes and water in and out of the epithelial cells of many organs in the body. – Defective transport of chloride, sodium and water leaves the mucus made by excretory glands thickened and difficult to move. © Troy Seely, 2024  Normal Epithelia CF Epithelia Choride ion (Cl-) moves through CF gene mutation: abnormal specialized Cl- channels in expression of transmembrane transmembrane proteins proteins Along with other regulatory Epithelia impermeable to Cl- mechanisms, a balanced Increased absorption of Na+ movement of Cl-, Na+, H2O and H2O from airspace leading leading to well-hydrated mucus to dehydrated mucus © Troy Seely, 2024 From: Kumar V., Cotran R.S., Robbins S.L. (Eds.). (2003). Robbins Basic Pathology. Philadelphia: Saunders.  Cystic Fibrosis Pathology Normal epithelial mucus production Cystic Fibrosis ‘Chloride pump’ pumps Cl – No ‘Chloride pump’ into extracellular fluid Epithelial cells produce watery mucus Sodium ions follow Epithelial cells by electrical attraction produce dehydrated thick sticky mucus Water follows by osmosis Mucus traps foreign Mucus still traps particles & bacteria foreign particles & bacteria Cilia moves mucus Thickened mucus impairs to oropharynx clearance by cilia Retention of bacteria-laden mucus promotes chronic bacterial Infections © Troy Seely, 2024  Cystic Fibrosis: Pathology The chronic pulmonary component of CF is related to the abnormally viscous mucous secreted in the trachea and bronchial regions. – The altered secretions result in airway obstruction and hyperinflation. – Partial or complete obstruction of the airways reduce ventilation to the alveolar units where ventilation and perfusion are not matched. © Troy Seely, 2024  Cystic Fibrosis: Pathology Bronchial obstruction by the abnormal mucus predisposes the lung to infections (pneumonia), fibrosis, and large cystic dilations that involve all bronchi. – Recent research is investigating high salt concentration as inhibitor to immune response. Dysfunction of the pulmonary system is the most common cause of morbidity and mortality in patients with CF. © Troy Seely, 2024  Pathogenesis & Progression of Pulmonary Disease in Cystic Fibrosis Cystic fibrosis abnormal mucous chronic infection Usually pulmonary exacerbation by FEV1 inflammatory response increased airflow obstruction atelectasis bronchiectasis abnormal ventilation/perfusion acute & chronic hypoxia acute & chronic hypercapnia cor pulmonale acute & chronic respiratory failure © Troy Seely, 2024  Atelectasis Atelectasis is collapse of lung tissue, and can range from asymptomatic to respiratory failure. Two main types: – Compression atelectasis Due to external pressure on lung by tumour, fluid, or air in pleural space or abdominal distension. – Absorption atelectasis Due to the removal of air from obstructed or hypoventilated alveoli © Troy Seely, 2024  Bronchiectasis Bronchiectasis is a chronic condition where the walls of the bronchi are thickened from frequent inflammation and infection. – In all people with CF older than 0.5 years This destroys elastic & muscle in bronchi – Causing abnormal dilatation Leads to: – Bronchospasm – Copious mucus production © Troy Seely, 2024 – Subsequent ventilation-perfusion abnormalities  Cystic Fibrosis: Clinical Presentation Initial presentation of CF can be due to any number of involved systems: – Diabetes due to pancreatic dysfunction – Failure to thrive due to gastrointestinal dysfunction – Frequent pulmonary infections and chronic cough © Troy Seely, 2024  Cystic Fibrosis: Clinical Presentation Specific to lung function: – Thick secretions are present that are difficult to clear – Chest wall becomes barrel-shaped from hyperinflation – Auscultation: breath sounds decreased with wheezing and crackles – Pursed-lip breathing, cyanosis, digital clubbing © Troy Seely, 2024  Restrictive Lung Disease This is a group of diseases, with differing etiologies, that result in difficulty expanding the lungs and a reduction in lung volume. All conditions would have: – Difficulty expanding the lungs Therefore, all – Reduced lung volume increase the ‘work’ of breathing – Reduced lung capacities © Troy Seely, 2024  RLD: Epidemiology Prevalence of RLD: – Adults aged 35-44 years is 2.7 cases per 100,000 persons. – Patients older than 75 years is >175 cases per 100,000 persons among © Troy Seely, 2024  Restrictive Lung Disease: Etiology Could be due to harmful effects of: – Radiation therapy – Inorganic dust (i.e. from metals or minerals) – Noxious gases – Asbestos exposure – Tuberculosis The most common restrictive lung disease is idiopathic pulmonary fibrosis (IPF). © Troy Seely, 2024 Restrictive Lung Disease: Pathophysiology Often begins with inflammation, progressing to thickening of alveolar walls and the interstitium. Alveoli – Distal air spaces become fibrosed making them more resistant to expansion (i.e. increased stiffness). – Contrast this with the increased compliance of COPD. © Troy Seely, 2024  What is the Interstitium? Complex structural space between ‘air space’ epithelium, & the ‘vascular’ endothelium © Troy Seely, 2024  Role of the Interstitium? Separates yet binds together vascular and pleural ‘cell layers’. Components include – Connective tissue matrix – Immune cells Communicates with lymphatic system in lungs. Provides structural integrity yet permits structural deformation. © Troy Seely, 2024  RLD Symptoms Shortness of breath (dyspnea) is the major symptom Cough is nonproductive Weakness and easily fatigued Limited chest expansion Related to elastic and air flow resistive components Rapid, shallow breathing of breathing © Troy Seely, 2024 Elastic & Air Flow Resistive Components of Breathing e.g. chronic bronchitis Total work minimized by e.g. RLD: idiopathic pulmonary fibrosis slow deep breathing Total work minimized ~15 breaths/min Total work minimized by rapid shallow breathing © Troy Seely, 2024  Lung Capacity: RLD vs Normal Difficulty expanding the lungs RLD Normal VC reduced TLC reduced FRC reduced © Troy Seely, 2024  Summary of CPD Epide- Etiology Pathology Primary miology Symptoms COPD > 55 -tobacco -bronchi: inflammatory -chronic cough -air -alveoli: tissue breakdown -expectoration pollution -exertional -genetics dyspnea Asthma -