190 likes | 362 Views
Asthma in the United states. Approximately 20 million Americans have asthma Nine million of these cases occurred in children under the age of 18 From 1980 to 1994, prevalence has increased by a 75% Asthma prevalence in children under five has increased by over 160% during this same time period
E N D
Asthma in the United states • Approximately 20 million Americans have asthma • Nine million of these cases occurred in children under the age of 18 • From 1980 to 1994, prevalence has increased by a 75% • Asthma prevalence in children under five has increased by over 160% during this same time period • Annually, asthma contributes to about 5,000 deaths1
What is Asthma??? • “A common disorder in which chronic inflammation of the bronchial tubes (bronchi) makes them swell, narrowing the airways. Asthma involves only the bronchial tubes and does not affect the air sacs (alveoli) or the lung tissue (the parenchyma of the lung) itself.”2 • Three hallmark signs of asthma: • Coughing • Wheezing • Dyspnea • The recurrent episodes that occur are due to airflow obstruction and are often reversible (spontaneously or with medication
Nocturnal Asthma • Includes 70-80% of asthmatics • Asthma symptoms occur exclusively at night • Common Causes: • Supine posture • GE reflux • Late phase reaction to antigens • Exposure to allergens in bedding (mites) • Fluctuations in airway caliber • Impaired mucociliary clearance
Pathophysiology • A variety of changes in the airway are responsible for limiting the airway, all of which are influenced by airway inflammation: • Bronchoconstriction • Airway Hyperresponsivness • Airway Edema • Causes of airway reactivity: • Pharmacologic and Immunologic Stimuli • Physical Agents • Thermal Stimuli
Pathogenisis • Allergic • 35-55% of asthmatic patients • Antigen antibody reaction • Animal dander, mites, cockroaches, mice • Physical Exercise • Especially in cold weather • Usually short in duration • Respiratory infection • Occupational Stimuli • Animal handlers • Bakers • Platinum refiners • Wood and vegetable sources
Pathogenisis • Environment and air pollution • Cold weather • Ozone • NO2 • Pharmacologic • Aspirin • Tartrazine dye • Beta-Blockers • Sulfites • Contrast Media • Psychological • Anxiety • Fear • Stress • Laughter
Signs of an attack! • Dyspnea, cough, wheezing • Chest tightness • Anxiety • Lungs hyperinflated • One word responses • Rapid pulse
Goal of Therapy:Control of asthma • Prevent bothersome and chronic asthma symptoms • Reduce the use of the inhaled SABA to ≤2 days per week • Maintain normal pulmonary function • Maintain normal activity levels (work, school, exercise) • Meet both the patient’s and family members’ satisfaction with asthma care
Non-PCOL • Eliminate any precipitating factors • Smoking, pets, clean sheets more often • Keep hydrated • Water, coffee • Avoid sedatives • Respiratory Function
Stepwise approach • Classify patient based on severity:
Stepwise Approach • Use lowest level of treatment required to maintain asthma control:
Medications MDI Products SABA: short-acting beta agonist
Medications MDI Products LABA: long-acting beta agonist
Medications Theophylline • Very narrow therapeutic window (5 to 15 mcg/ml) • Available IV and PO • Many drug interactions due to metabolism via CYP450’s • Side Effects: • GI- nausea, vomiting, abdominal pain • CNS- nervousness, insomnia, headache • Cardiac-increased heart rate, ventricular tachycardia, and seizures • Bottom line: not used anymore in asthma
Medications Corticosteroids • Known as the “backbone” of asthma therapy • Downfall: side effects affect every organ • By-mouth therapy • May be required at any step of therapy • QOD therapy is usually ineffective • Initial prednisone dose is 40-60mg/day then taper
medications • MDI Products
References: • 1. see notes • 2. asthma def. www.emedicinehealth.com