ASTHMA Victor Politi, M.D., FACP Medical Director, SVCMC School of Allied Health

What is Asthma? Asthma is a chronic condition that occurs when the main air passages of the lungs, the bronchial tubes, become inflamed. The muscles of the bronchial walls tighten and extra mucus is produced, causing the airways to narrow. can lead to minor wheezing to severe difficulty in breathing. In some cases, breathing may be so labored that an asthma attack becomes life-threatening

Definitions Asthma Status Asthmaticus Reversible airway obstruction Airway inflammation Increased bronchial hyperresponsiveness Status Asthmaticus Severe airway obstruction developing over days-weeks

The Respiratory System

Pathophysiology Hallmark of Asthma -Bronchial wall Hyperresponsiveness Early Phase Asthma Reaction Bronchoconstriction Antigenic Stimulation of bronchial wall Mast Cell Degranulation releases Histamine Chemotactics Proteolytics Heparin Smooth Muscle Bronchoconstriction

Pathophysiology Late Phase Asthma Reaction: Bronchial Inflammation Inflammatory Cells Recruited Neutrophils Monocytes Eosinophils Release Cytokines, Vasoactives, Arachidonic acid Epithelial and Endothelial Cell inflammation Release of Interleukin 3-6, TNF, Interferon-gamma

Risk Factors Family History Parental tobacco use One parent with asthma: up to 25% risk for child Two parents with asthma: up to 50% risk for child Parental tobacco use Associated aspirin or NSAID allergy Classic Triad: Asthma, Nasal polyps, Aspirin allergy RSV Bronchiolitis history Strongly associated with later development of asthma Strenuous exercise in areas of high ozone (pollution)

Types of Asthma Extrinsic Asthma (Allergic) Intrinsic Asthma (Non-allergic) Mixed Asthma (Extrinsic and Intrinsic) Occupational Asthma Drug Induced Asthma Aspirin-induced Asthma NSAID-induced Asthma Exercise Induced Asthma Cough Variant Asthma Very common! (Especially in children)

Asthma Statistics For reasons no one quite understands, the number of asthma cases has risen dramatically during the past decade, especially among children living in the inner city. Approximately 14 million Americans have asthma, including more than 6 million children. Asthma is the most common chronic illness of childhood. Among young children, asthma is more common in boys than in girls. After puberty asthma becomes more common in girls

Intrinsic Asthma Non-allergic asthma Pathophysiology Non-IgE, Non-allergic asthma Precipitating Factors Irritant exposure (Air Pollution, Fumes, Perfumes, Household cleaning agents, Insecticides, paint, tobacco, cold air Infection URI, purulent rhinitis, acute sinusitis GERD Epidemiology Much more common in adults than children Onset age over 40 years old

Extrinsic Asthma Allergic Asthma Pathophysiology IgE mediated response to allergens Immediate allergic reaction Late-phase allergic reaction Causes Indoor allergens House –Dust mites (most common extrinsic allergen) Animal proteins (animal dander) Mold spores Cockroaches Outdoor allergens Pollens , mold spores Epidemiology Much more common in children than adults Age Onset under 40 years old

Asthma Triggers

Asthma Triggers

Asthma Triggers

All Asthma attacks give a warning Warning signs and symptoms for adults can include: Increased shortness of breath or wheezing Disturbed sleep caused by shortness of breath, coughing or wheezing Chest tightness or pain Increased need to use bronchodilators — medications that open up airways by relaxing the surrounding muscles A fall in peak flow rates as measured by a peak flow meter

All Asthma attacks give a warning Warning signs and symptoms for children may include An audible whistling or wheezing when the child exhales Coughing, especially if the cough is frequent and occurs in spasms Waking at night with coughing or wheezing Shortness of breath, which may or may not occur when the child exercises A tight feeling in the child's chest

Asthma and Other Conditions Differentiating between asthma and chronic obstructive pulmonary disease (COPD) such as emphysema and chronic bronchitis can be especially challenging. Asthma and COPD each cause similar symptoms. Not uncommon for older adults — especially longtime smokers — to have both conditions. Various tests — including skin or blood tests for allergies, and spirometry — can help determine whether asthma is present.

What is cardiac asthma? Cardiac asthma isn't actually asthma. It refers to the wheezing that's caused by CHF Excess fluid in the lungs (pulmonary edema) associated with heart failure causes signs and symptoms such as shortness of breath, coughing and wheezing, which mimic asthma

Exercise Induced Asthma Exercise-induced asthma — or exercise-induced constriction of the bronchial tubes (bronchospasm) a condition in which the airways narrow significantly during vigorous exercise. Typical Symptoms Cough, Wheezing, Shortness of breath, Chest tightness Typically symptoms present about 10 minutes after stopping exercise

Exercise Induced Asthma Exercise-induced wheezing or shortness of breath is typical for people who have chronic asthma. But exercise-induced wheezing or shortness of breath can occur when sensitive airways constrict when exercising, especially when combined with cold air, low humidity or pollution.

Chronic Asthma or Exercise Induced Asthma Basic difference between chronic asthma and exercise-induced asthma People with exercise-induced asthma have symptoms only with physical activity. People with chronic asthma often have exercise-induced wheezing or shortness of breath, but they may have asthma symptoms at other times as well.

Exercise Induced Asthma - Medications The most common medications for exercise-induced asthma are bronchodilators, which are taken about 15 to 30 minutes before exercising Medications Include: Albuterol (Proventil, Ventolin) Pirbuterol (Maxair) Ipratropium and albuterol combination (Combivent)

What's the difference between asthma and COPD? similar symptoms but very different Asthma causes reversible lung inflammation, COPD causes irreversible lung damage It's important to distinguish between the two conditions because they're treated differently

What's the difference between asthma and COPD? Smoking history. Asthma may occur in nonsmokers as well as in smokers. But COPD is usually associated with a long history of smoking

What's the difference between asthma and COPD? Symptoms Periodic wheezing and chest tightness, especially at night, is typical of asthma. COPD is more likely to cause a daily morning cough that produces mucus. In COPD, patients may develop a permanently expanded barrel chest because too much air is trapped in the lungs.

Cough Variant Asthma Chronic cough – Occur any age group PFTs –normal Cough > 3 weeks Nonproductive Usually nocturnal – but can occur anytime Occur any age group PFTs –normal Rule out other causes of chronic cough TX Similar to common forms of asthma

Asthma Evaluation Differential Diagnosis General All that wheezes is not asthma!! However most recurrent cough and wheeze is asthma Upper airway disease Allergic rhinitis sinusitis Large airway obstruction Foreign body Vocal cord dysfunction Vascular rings of laryngeal webs Laryngotracheomalacia Tracheobronchial-stenosis Enlarged lymph node or tumor

Asthma Evaluation Differential Diagnosis Small Airway obstruction Viral Bronchiolitis Bronchiolitis obliterans Cystic Fibrosis Bronchopulmonary dysplasia Heart disease Other Causes Psychogenic cough GERD ACE inhibitors

Asthma Evaluation History General: History is not always accurate Confirm with PFTs every 3-6 month Patient may underplay symptoms 10% of patients do not recognize severe Symptoms of their asthma Age of onset and asthma diagnosis Past history of respiratory failure or intubation Recognize cohorts at additional risk Elderly Pregnancy

Asthma Evaluation History History of early life injury to airways Bronchopulmonary Dysplasia Parental smoking Disease progression Present management and response Frequency of systemic corticosteroid use History steroid-induced complications Comorbid conditions Chronic sinusitis Assess in all asthma patients Consider empiric treatment if refractory asthma

Asthma Evaluation History Family History (any asthma, allergic rhinitis, etc.) Social History Home characteristics Heating and cooling system Wood burning stove Humidifier Carpeting over concrete Smokers in home Daycare and school situation impacting compliance

Asthma Evaluation Signs: Respiratory distress Tachypnea Dyspnea Anxiety Accessory Muscle Use Intercostal muscle use Sternocleidomastoid use Scalenes Muscle use Cyanosis in severe cases (lips) Tachycardia

Asthma Evaluation Radiology: chest x-ray Indications Initial asthma diagnosis Low yield in acute asthma exacerbations Abnormal findings at presentation: 5% Abnormal findings if no improvement in 12 hours: 34% Status Asthmaticus or no acute asthma improvement Excludes other diagnoses CHF Pneumonia Excludes complications Pneumothorax Pneumomediastinum

Asthma Evaluation Labs ABGs Hypoxemia Hypercarbia (or normal CO2) with decompensation CBC Eosinophilia may be present Increased Levels of IgE may be present Sputum Sample May show casts of small airways Thick mucoid sputum Curschmann's spirals Charcot-Leyden crystals

Asthma Evaluation Other Diagnostic Tests PFT’s – Pulmonary Function Testing Spirometry Methacholine Challenge

What are PFT's? Pulmonary function testing is one of the basic tools for evaluating a patient's respiratory status. In patients with suspected pulmonary disease, it is often the first diagnostic test employed in the work up. Pulmonary function tests (PFT's) are also used for pre-operative evaluation, managing patients with known pulmonary disease, and quantifying pulmonary disability

PFT- Spirometry A versatile test of pulmonary physiology. Reversibility of airways obstruction can be assessed with the use of bronchodilators. After spirometry is completed, the patient is given an inhaled bronchodilator and the test is repeated. The purpose of this is to assess whether a patient's pulmonary process is bronchodilator responsive by looking for improvement in the expired volumes and flow rates

PFT- Spirometry spirometry can be used to detect the bronchial hyperreactivity that characterizes asthma. By inhaling increasing concentrations of histamine or methacholine, patients with asthma will demonstrate symptoms and produce spirometric results consistent with airways obstruction at much lower threshold concentration than normal

PFT- Spirometry Normal values vary depending on gender, race, age, and height. It is therefore not possible to interpret PFT's without such information. There is no single set of standard reference values, however, and "normal" varies with the reference value used in each laboratory

PFT- Spirometry Definitions FEV1 - forced expiratory volume 1 - the volume of air that is forcefully exhaled in one second. FVC - forced vital capacity - the volume of air that can be maximally forcefully exhaled FEV1/FVC - ratio of FEV1 to FVC, expressed as a percentage FEF25 - 75 - forced expiratory flow - the average forced expiratory flow during the mid (25 - 75%) portion of the FVC PEF - peak expiratory flow rate - the peak flow rate during expiration

PFT- Spirometry In general, a > 12% increase in the FEV1 (an absolute improvement in FEV1 of at least 200 ml) or the FVC after inhaling a beta agonist is considered a significant response. However, the lack of an acute bronchodilator effect during spirometry does not exclude a response to long term therapy

Mild Obstruction Flow Volume                          Normal Flow Volume Loop                                                                                                                             

Asthma Medications Two general types of asthma medications Anti-inflammatory Corticosteroids reduce swelling & mucous in airways Bronchodilators Relax muscle bands around airways allowing more air to flow, also increases mucous movement

Quick Relief Medications Short acting beta-agonists (bronchodilators that are the drug of choice to relieve asthma attack and prevent exercise-induced asthma symptoms) Anticholinergics (bronchodilators used in addition to short-acting beta agonists when needed or as an alternative to these drugs when needed) Systemic corticosteroids (anti-inflammatory drug used in an emergency to get rapid control of the disease while initiating other treatments and to speed recovery)

Status Asthmaticus Emergency Management of Asthma Exacerbation

Indications of severe attack Breathless at rest Hunched forward Talking in words rather than sentences Agitated Peak flow rate < than 60% of normal

Status Asthmaticus A medical emergency in which symptoms are refractory to initial bronchodilator therapy Symptoms: chest tightness, rapidly progressive shortness of breath, dry cough, and wheezing. Typically, patients present a few days after the onset of a viral respiratory illness, following exposure to a potent allergen or irritant, or after exercise in a cold environment.

Asthma Exacerbation Management Step 1: Initial Assessment Routine asthma evaluation as previously mentioned Vital Signs (heart rate, respiratory rate, Peak Expiratory Flow Rate (PEF) or FEV1 O2 saturation Respiratory Status Lung auscultation Assess accessory muscle use Chest x-ray has low yield in acute exacerbations ABGs

Asthma Exacerbation Management Inhaled short acting Beta Agonist (nebulized) One dose up to every 20 minutes for one hour Anticholinergic (Ipratropium bromide or Atrovent) Add to nebulized albuterol Indication: FEV1 or PEF <50% of predicted (Severe) Systemic Corticosteroid (PO or IV Indications) Severe episode (FEV1 or PEF <50% predicted) No immediate response Oral corticosteroid recently taken by patient Oxygen indications Adults: O2 saturation <91% Children: 02 saturation <96%

Additional measures for severe exacerbation Nebulized Albuterol w/Atrovent hourly or continuous Systemic corticosteroid Epinephrine 0.01 mg/kg up to 0.3 mg SC May be repeated every 5 minutes Oxygen 100% (warm, humidified) by non-rebreather mask Two Intravenous Lines Consider : Aminophylline or Theophylline Magnesium 40 mg/kg up to 2 grams IV for 1 dose Rapidly effective in pediatric asthma exacerbations Also shown effective in severe adult acute asthma Some studies question benefit

Additional measures for severe exacerbation – Intubation/mechanical ventilation Intubation is best done semi-electively before crisis Intubation criteria are based on clinical judgment Oral intubation is preferred Lower resistance and easier suctioning Lower incidence of sinusitis Indications Impending or actual respiratory arrest Extreme fatigue Altered mental status Significant respiratory distress Severe respiratory acidosis & metabolic acidosis

Medications To Be Wary Of with Asthma Patients Many adults take multiple prescription and over-the-counter medications to treat a variety of conditions. Some medications may trigger or worsen asthma symptoms. Angiotensin-converting enzyme (ACE) inhibitors Won’t directly trigger asthma, can produce persistent cough causing increased wheezing Beta blockers NSAIDs can trigger severe and even fatal asthma attacks

Asthma Management Goals

Asthma Management Goals Medical professionals need to be alert to the signs/symptoms of asthma They must be able to treat asthma cases in a timely manner to avoid worsening of the condition and/or the development of status asthmaticus

Questions?