Asthma Lecture

Introduction: Asthma is a chronic inflammatory disease of the airways affecting 14 million people in the United States. It is the most common chronic illness in children with 3-5% having been diagnosed. 5000 people die from asthma yearly. Asthma is a reversible, treatable and preventable disease. Risk factors for asthma include poverty, atopy, genetics, allergen/irritant exposure and gender. Asthma is defined as a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role, in particular mast cells, eosinophils, T lymphocytes, neutrophils and epithelial cells. In susceptible individuals inflammation causes chest tightness, breathlessness, recurring wheezing, and cough that is particularly worse at night since less norephinephrin is produced by the adrenal cortex. Norepinephrine is the body’s natural bronchodilator. This causes airflow obstruction that is reversible with adequate treatment. Asthma attacks may be avoided with the avoidance of triggers.

Types: Asthma is characterized by airway obstruction (least partially reversible), Hyperreactivity (increased bronchial responsiveness to a variety of stimuli) and inflammation (mast cells, eosinophils, lympocytes and neutrophils).  Known allergic Asthma (Intrinsic): Caused by a identified allergen (treatment includes avoidance of this allergen)  Unknown allergic Asthma (Extrinsic): Treatment involves identifying allergen with skin testing  Exercise induced Asthma: Symptoms only present during strenuous exercise

The Airway in Asthma:

 Increased mucus production from goblet cells and inflammatory cells leading to mucus plugs and atlectasis  Disruption of bronchial epithelium (lining of lung)  Edema  Increased Vascular Permeability (meaning prone to cells migrating into lung lining)  Increased thickness of basement membrane (can cause airway re-modeling, a change in the shape of your lungs after numerous Asthma exacerbations from scarring)  Smooth Muscle constriction

Diagnosing Asthma: When a patient presents with symptoms of asthma but has never been diagnosed, ask these questions and assess the following...

 Does the patient have wheezing, cough, and chest tightness that worsens with certain triggers or is worse at night?  Is their bronchospasm and is it reversible with bronchodilators?  Is there a history of smoking or second hand smoke?  History of beta blockers, aspirin sensitivity, ACE inhibitors?  Food allergies: sulfates, peanuts  Sensitive to weather changes: hot to cold or cold to hot  Other allergies: Molds, dust mites, pet dander, cockroach droppings, pollens (recent skin rash tests?) * see handout on environmental and other factors contributing to asthma.  Is there an exposure to irritants at work, school, home (irritants include chemicals, fumes, smoke)?  Does the patient present to the hospital with yearly bronchitis?  Do respiratory symptoms linger with respiratory infections  Does the patient have GERD (gastroesophogeal reflux disease)  Does the patient have allergies? If so what are they allergic to?  Does the patient have frequent sinusitis or rhinitis?  Family history of Asthma of Allergies? Review of Symptoms:

 HEENT: history of frequent sinusitis or allergic symptoms  Heart: obtain an EKG, Ecocardiogram to rule out other diseases, check for palpitations  GI: Heartburn, reflux symptoms  Skin/extremities: Rashes, ectopic dermatitis

Physical Exam:

 HEENT: Nasal Polyps (use oliscope, looks bluish, common with aspirin sensitivity)  Signs of Sinusitis: Nasal turbinate erthema (soreness), Purulent drainage, Lymphadenopathy (adenoids swollen, ear tenderness), teeth hurt, post nasal drip, cold lasting 3 weeks  Allergies: Watery eyes, dark circles under eyes, pale nasal mucosa  Lungs: Wheezes or increased expiratory time from air trapping, hyperinflation in exacerbation, cough without sputum  Cardiac: Murmurs  Skin/extremities: rahes (ecxema)

Testing to Diagnose Asthma:

 Spirometry: Pre and Post bronchodilator testing; 12-15% change or >200 ml in FEV1 indicates a reversible component and therefore Asthma (COPD is not reversible) * Note: not for children under the age of 5, diagnosis made by symptoms. Spirometry is very dependent on a patients age, race and height.  Immunoglobulin’s IgA and IgA for inherited deficiencies  Allergy testing: Skin or in vitro (blood) * see handout on the differences between the two  Complete Blood Count: detect infection, rule out anemia  Sputum cultures: detect high levels of eosinophils  Chest x-ray: rule out other diseases/causes  Sweat Chloride Test: rule out Cystic Fibrosis

Diseases that Mimic Asthma:

 Cystic Fibrosis  Foreign Body Aspiration (Unilateral Wheeze, asthma bilateral)  Vocal Cord Dysfunction (sometimes referred to “made up” asthma, patient may have no conscious awareness of it but wheezes during exhalation due to malfunctioning vocal cord, not bronchospasm.  Medialstinal Mass  RSV or Bronchiolitis  Parasitic Disease  Heart Failure (need lassix not bronchodilators) Peak Flow Meters- Used as an assessment tool, important for the use in moderate to severe persistent asthma. Patients are to perform a peak flow twice a day; morning and mid afternoon, with an expected lower outcome in the morning. A predicated value will be based on the patient’s best effort while asymptomatic as determined by a log of results. This value will then supersede any predicted found in any reference manual. Important to note: Do not switch brands of peak flows since each is different and will interpret results differently. *See handout on using a peak flow correctly.

*Once asthma has been diagnosed a asthma classification is given based on severity and frequency of symptoms. (see handout on Asthma Classifications)

Treatment of Asthma:

Pharmacology: * see handouts for list of long term and short term medications with dosages.

 Short Term- fast acting bronchodilators: Given for quick relief of bronchospasm. May require multiple dosages to achieve proper relief. Given as a Metered Dose Inhaler or Aerosolized in a small volume nebulizer.  Long Term- slow acting bronchodilators: Given prophalactically to prevent asthma. Given as a Metered dose inhaler, liquid syrup, tablet, or Dry powder inhaler.  Inhaled Corticoid Steroids: Given Prophalatically to prevent inflammation. Given as a DPI, MDI or aerosol.

Proper education of use and technique of medication devices is vital in patient efficiency and compliance. Correlating school and work schedules with drug maintenance is also important. Incorporating folk remedies and counseling family concerns regarding their hesitance to comply with treatment regimes is the duty of all healthcare workers whom deal with asthmatic patients. Patient education is vital in order for them to understand and treat their illness properly. Help children and adults formulate Asthma Action Plans that instruct patients what to do when an asthma attack occurs * see handout.