Bronchial Asthma Definition Patho-physiology Diagnosis Management

Asthma prevalence in Saudi Arabia Children and Adolescents: 20 % Adults : 10 %

Airway Hyper-responsiveness Pathology of Asthma Inflammation Airway Hyper-responsiveness Airway Obstruction Symptoms of Asthma

Source: Peter J. Barnes, MD Mechanisms: Asthma Inflammation Source: Peter J. Barnes, MD

During an asthma attack… When exposed to an asthma trigger… Bronchioles constrict to limit exposure to the trigger. Mucous membrane becomes irritated and swells. Mucous is produced to trap the irritant. Coughing initiated to pop open bronchioles and expel the mucous build-up. Air retention volume in alveolar sacs increases – can’t get air out or in. CO2 build-up in alveolar sacs and in system tissues which can lead to acidosis. The body attempts to blow off the excess CO2 – rapid shallow breathing. (hyperventilation) Hungry for O2 and trying to get rid of CO2 at the same time. Fatigued muscles in this effort. If this continues, the person with asthma can die. A person with asthma undergoes what is called “airway remodeling” – where there is permanent damage to the airways and decreased overall capacity….airway hyperactivity. A hyperactive airway is more susceptible to triggers. Taking medication: Rescue inhaler – dilates bronchioles, doesn’t alleviate mucous or congestion in any appreciable way Daily corticosteroid –works to reduce airway hyperactivity

Asthma Microscopic Pathology Obstructed Inflammed Bronchi Nov-17

10 Minutes After Allergen Challenge Bronchoconstriction Before 10 Minutes After Allergen Challenge

Thick bronchi with Mucous plugs Nov-17

Pathophysiology

Source: Peter J. Barnes, MD Asthma Inflammation: Cells and Mediators Source: Peter J. Barnes, MD

ALLERGIC TRIGGERS

Triggers of Asthma (Irritants) Infections Chemicals Diet/Medications Strong Emotions Exercise Cold temperature Exposure to smoke Examples: Allergens: cat dander, cockroach allergens, house dust mite allergens, dog dander, fungi/molds Infections: Rhinitis, sinusitis, and Viral infections Diet/Medications:Aspirin sensitivity, Sulfite sensitivity, Beta Blockers Irritants: Animal dander, Exposure to indoor chemicals, Dust, Outdoor pollutants (like ozone & PM), Mold,fungi, Pollen

“Real Life” Variability in Asthma Acute inflammation symptoms subclinical Chronic inflammation Asthma is a chronic inflammatory disease with a variable course characterized by episodic attacks of acute inflammation.1 Acute inflammation in asthma is associated with bronchoconstriction, plasma exudation/edema, vasodilatation, and mucus hypersecretion. Chronic inflammation in asthma is associated with subepithelial fibrosis, smooth-muscle hyperplasia/hypertrophy, mucus gland hyperplasia, and new-vessel formation. If asthma remains uncontrolled or poorly controlled, the underlying chronic inflammation may lead to structural changes (remodelling) that reduce the extent of airway response to therapy. 1. Barnes PJ. New drugs for asthma. Clin Exp Allergy 1996;26:738-745. Structural changes TIME Barnes PJ. Clin Exp Allergy 1996.

diagnosis is obvious

DIAGNOSIS OF ASTHMA History and patterns of symptoms Physical examination Measurements of lung function

Bronchial Asthma Asthma is diagnosed clinically by history and P/E In case of doubt : - Spirometry - Methacholine challenge test

History Tightness of the chest, cough & expectoration, wheeze Comes in episodes, (recurrent ) With exposure to allergens and irritants History of asthma attacks Relieve using salbutamol Allergy in skin, eyes, nose Family history of asthma or allergy

Physical Examination Wheeze /Rhonchi (no crackles) Tachypnea (signs of allergy of skin , nose , eyes) Remember Absence of symptoms at the time of examination does not exclude the diagnosis of asthma

Peak Flow Meter

Managing Asthma: Peak Expiratory Flow (PEF) Meters Allows the patient to assess the status of his or her asthma These are peak expiratory flow meters. PEF meters come in different styles, but they all measure the amount of air a person can blow out in liters per minute. You set the indicator to zero, take a deep breath, put your lips around the mouthpiece and exhale as hard and fast as you can. Then you read the number on the scale. The proper use of PEF meters can help predict asthma episodes and monitor response to therapy. The goal is to monitor the airflow consistently to recognize any changes from normal. People with asthma need to know how and when to use the PEF meter and how to record the results. 21

What Types of Spirometers Are Available?                   Spirotel Sensaire Satellite  Review types of spirometers: stand alone (base station) types, handheld, PC or PDA based types. See handout for a listing of features. Note that some use disposable flow sensors, some use permanent. All require calibrations but many of the disposable types include factory calibration using code numbers or bar codes to identify the flow table to be used.    Spirometer Systems Simplicity Spirotel MicroPlus Renaissance KoKo* Vitalograph 2120 Sensaire SpiroCard* Satellite Renaissance KoKo Vitalograph 2120

Spirometry: Obstructive Disease 5 4 Normal 3 Volume, liters FVC = 3.2L 94 % FEV1 = 1.8L 66 % FEV1/FVC = 56% 2 Obstructive 1 1 2 3 4 5 6 Time, seconds

What is Asthma ? A chronic inflammatory disorder of the airway with Infiltration of mast cells, eosinophils and lymphocytes in response to allergens Airway hyper-responsiveness ( twitchy airways) Recurrent episodes of wheezing, coughing and shortness of breath Variable and often reversible airflow limitation (airway obstruction )

ICS = inhaled cortico-steroids budesonide, fluticasone, beclomethasone, ciclosenide, mometasone B2 Agonists : ( stimulants) Short acting : SABA salbutamol Long Acing : LABA: Rapid acting formeterol Non- Rapid acting salmeterol

budesonide = Pulmicort fluticasone = Flixotide Ciclosenide = Alvesco

Combinations: Symbicort : budesonide + formoterol Seretide: fluticasone + salmeterol Foster: beclomethasone + formeterol

Anti-cholinergic drugs: Ipratropium (Atrovent) inhaler, solution for nebulizer Tiotropium (Spiriva) inhaler

Reliever/ Rescue Bronchodilator (beta2 agonist) Salbutamol Bronchodilator (beta2 agonist) Quickly relieves symptoms (within 2-3 minutes) Not for regular use

Preventer/ Controller Anti-inflammatory Takes time to act (1-3 hours) Long-term effect (12-24 hours) Only for regular use (whether well or not well)

Leukotriene modifiers (montelukast) Anti-IgE (omalizumab =Xolair ) Controller Drugs Inhaled steroids Leukotriene modifiers (montelukast) Anti-IgE (omalizumab =Xolair ) Systemic steroids

Adults Patients with Asthma

Need controller medication Rules of Two Use of a quick-relief inhaler more than: 2 times per week Awaken at night due to asthma symptoms more than: 2 times per month Consumes a quick-relief inhaler more than: 2 times per year Need controller medication

Poor Asthma Control why ? Before increasing medications, check: Inhaler technique Adherence to prescribed regimen Environmental changes Also consider alternative diagnoses

Why inhalation therapy? Oral Slow onset of action Large dosage used Greater side effects Not useful in acute symptoms Inhaled Rapid onset of action Less amount of drug used Better tolerated Very effective

summary Asthma can be controlled but not cured It can present in at any age. It produces recurrent attacks of symptoms of SOB , cough with or without wheeze Between attacks patients with asthma lead normal lives In most cases there is some history of allergy in the family. Understanding the disease, learning the technique and compliance with medications is the key for good control of asthma