Module 2: Asthma and Allergies PDF

ASTHMA/ALLERGIES Patho Cause Disease Course & Expected Findings Risk Factors Labs Asthma • Intermittent and reversible airflow obstruction. • Affects airways only, not alveoli. Inflammation & bronchoconstriction Determine factors that trigger symptoms. Keep a diary to identify triggers. Allerg...

ASTHMA/ALLERGIES Patho Cause Disease Course & Expected Findings Risk Factors Labs Asthma • Intermittent and reversible airflow obstruction. • Affects airways only, not alveoli. Inflammation & bronchoconstriction Determine factors that trigger symptoms. Keep a diary to identify triggers. Allergens, cold air, dry air, airborne particles, ASA/NSAIDs (prod of leukotrienes with inflammatory suppression, not a true allergy), exercise, food with MSG • Audible Wheeze, increased RR, SOB • Increased Cough • Use of Accessory Muscles • Barrel Chest • Long Breathing Cycle • Cyanosis • Hypoxemia Important to know risk factors for Asthma • Genetic • Environmental ABG’s - PaO2, PaCO2 initially, PaCO2 later in attack NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 1 Diagnostics Asthma Pulmonary function tests (PFTs) • Forced vital capacity (FVC) – Total vol of air expired with max force • Forced expiratory volume in first second (FEV1) – vol of air forcefully expired during the 1st second after taking a full breath • Peak expiratory flow rate (PEFR) – Green 80% ok – Yellow 50-80% use rescue inhaler – Red 50% is a serious resp obstruction Meds NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 2 Asthma **Always administer bronchodilator 1st before ICS--> Opens airway and allows ICS to reach target better** **If you have exercise-induced asthma, use your bronchodilator inhaler 30 minutes before exercise to prevent or reduce bronchospasm** Complications & Nursing Care Step wise method used for prescribing. Depends on what works. Xanthine drugs (Theophylline, Aminophylline) may also be used, but this is rare now because they have side effects and needs levels drawn frequently b/c of possible toxicity. 1. Improve air flow and GAS EXCHANGE 2. Self-management education a. Personal asthma action plan i. Peak flow numbers should be monitored daily, usually in the morning (before taking meds). ii. Stress at home and work should be avoided. 3. Exercise and activity to promote gas exchange as tolerated 4. Oxygen therapy 5. Status Asthmaticus a. Severe, life-threatening, acute episode of airway obstruction (Listen for no wheeze or air – emergency!) b. Intensifies once it begins, often does not respond to common therapy c. Patient can develop pneumothorax and cardiac/respiratory arrest d. Treatment—IV fluids, potent systemic bronchodilator, steroids, epinephrine (adrenaline), oxygen, Magnesium sulfate may be given rapidly to relax the muscles. **Important to Know how to Teach a patient to use an inhaler correctly** NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 3 Asthma Patho Cause Disease Course & Expected Findings Allergies Also called atopic allergy, hay fever, most common type 1st exposure→T lymphocytes tell B lymphocytes to create IgE specific to allergen→ Mast cells (tissue) basophils (blood stream) have IgE receptors with lots of IgE attached→allergen binds to IgE →and causes degranulation (allergic cascade) Optional Video Link • • Caused by excessive production of immunoglobulin E (IgE) antibody class Allergens contracted by o Inhalation (environmental pollens, spores, animal dander, dust, grass, ragweed) o Ingestion (foods, food additives, drugs) o Injection (bee venom, drugs, biologic substances) o Contraction (latex, pollens, foods, environmental proteins) Symptoms include sneezing, runny nose, and red, watery, and itchy eyes. Can be seasonal. NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 4 Allergies Risk Factors Labs Diagnostics • Genetic ABG’s Allergic asthma - serum eosinophil counts & immunoglobulin E (IgE) levels Diagnosis involves history-taking, examination of the nasal passages, and sometimes skin testing. • Skin Prick Test (SPT) – allergen prick, symptoms w/in 15 min. + reaction doesn’t diagnose allergy or predict severity precisely. – means not allergic. • Intradermal Skin Test – may use if skin prick is neg. Used for drug/venom/food allergies. • Blood Tests (Specific IgE, RAST) – Used if other tests contraindicated, like taking anticoags. Add allergen to blood sample & measure antibodies to attack allergen. High rate of false positives. • Physician Supervised Challenge Tests • Patch Test – to test for contact dermatitis. Checked after 48-96 hours of allergen patch with bandage cover. NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 5 Allergies Meds Procedures Complications & Nursing Care • • • Supportive therapy – no nasal washing! Complementary and alternative therapy—vitamin C, zinc Steroids - Used for anti-inflammatory effect and act to decrease edema in the bronchial airways and decrease mucus secretion. • leukotriene inhibitors – Montelukast (Singulair) • Antihistamines – Diphenhydramine (Benadryl) • Eye decongestants • Decongestants – Avoid use of nasal decongestant sprays regularly because they can cause a rebound effect. • Bronchodilators • Anti-inflammatories • Antipyretics • Mast cell stabilizers Immunotherapy- Allergy Shots: Subcutaneous injection of low amount of allergens, then gradual increased amount. Decreased allergic response d/t competition. Allergen in small amounts cannot bind to IgE--> Leads to IgG Production against allergen--> Allergen attaches to IgG instead of mast cell--> IgG clears the allergen from the body. Angioedema & Anaphylaxis – Can be fatal - Potential for airway obstruction as a result of mucosal swelling & Anxiety as a result of cerebral hypoxia and threat of death NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 6 Allergies Urticaria (Hives) • Determine factors that trigger symptoms. Keep a diary to identify triggers. NUR3225 Module 2: Asthma and Allergies Updated 8/30/20 MR 7