Asthma PDF

Asthma Affects all ages but more common in children. In childhood M>F, puberty 1:1, adult onset asthma F>M. 3 components of asthma: airway inflammation, airway hyperresponsiveness and airway limitation (obstruction) (which is usually variable and reversible) Infl...

Asthma Affects all ages but more common in children. In childhood M>F, puberty 1:1, adult onset asthma F>M. 3 components of asthma: airway inflammation, airway hyperresponsiveness and airway limitation (obstruction) (which is usually variable and reversible) Inflammation Cells involved (mast cells, basophils, eosinophils, macrophages) and (epithelial cells, endothelial cells, smooth muscles, goblet cells, myofibroblasts) Mediators involved (histamine, PAF, PGs -D2,D4,E4,C4-, IL-5,13-, leukotrienes, IgE) Airflow limitation (reversible) FEV1/FVC remodeling occurs> , fixed narrowing by: 1- Bronchoconstriction (smooth muscle contraction) 1- Fibrosis {increased 2- Edema (increased permeability of blood vessels) thickening of epithelial 3- Increased secretions (goblet cells) BM) Hyperresponsiveness 2- Hypertrophy and hyperplasia of smooth === Severe asthma =— Mild asthma muscle === Moderate asthma == Normal i) 3- Hyperplasia of goblet cells YA} with loss of cilia = 40 = Triggers: w. 207) 1- Dust mites 2- cockroaches and other insect g debris 3- pollutens 4-respiratory infections B ao © 5- tobacco 6- NSAIDs, aspirin, beta blockers 40- : eas. 7- exercise 8-GERD, aspiration, post nasal drip. TS 9- cat dander Increasina concentration of histamine Risk factors: Peak flow (L/min) Early reaction 1- genetic: atopy and high IgE levels $00- (type) _ J Fess mediator 2- environmental: indoor and outdoor pollutions, release. 400 7 Late(type reaction Il) allergens 1 Inflammatory cell.... ,. 300- recruitment and 3- infections: viral and atypical bacterial infections | activation 2004 4- obesity | Challenge, 5- race and gender 100-) e.g. allergen 04 | Af T T T T T no T 0 1 23 4 5 6 7 24 Time (hours)  e Clinical features (more in night and early morning): recurrent episodes of cough, wheezes, chest tightness and breathlessness e Signs on P/E: tachycardia, tachypnea, pulsus paraduxus, prolonged expiratory phase with or without wheezes, use of accessory muscles Note: the pt is normal on P/E in between attacks but some conditions increase the probability of asthma: eczema and nasal polyps e DDx: 1- laryngospasm (vocal cord dysfunction) 2- cardiac asthma 3- COPD 4- upper airway obstruction 5- others: anemia, obesity, LV dysfunction, bronchiectasis e Lab investigations: 1- lung function tests a) Peak expiratory flow b) Spirometry with bronchodilator reversibility: FEV1, FVC, ratio c) Bronchial challenge test 2- blood tests: a) CBC for eosinophils count b) IgE level c) RAST (radioallergosorbent testing) to detect if there is specific serum IgE allergens d) ABG in acute excerbations 3- chest imaging: a) Chest radiograph: normal in mild to moderate, hyperinflation in severe, useful in acute exacerbations to exclude pneumothorax and pneumonia b) Chest CT: to exclude bronchiectasis in allergic bronchopulmonary aspergilosis (ABPA) 4- exhaled NO (FeNO): high exhaled NO indicates eosinophilic inflammation, useful in pediatrics and to assess the adherence to medications 5- skin prick test Goals of management: management: 1- control of symptoms 1- patient education 2- maintain normal 2- reduce exposure and activity including vaccinations exercise (pneumococcal — pneumovax23- and 3- maintain pulmonary.. annual influenza vaccine) function 3- pharmacological 4- prevent excerbations. therapy as a stepwise 5- avoid adverse effects approach of medications 6- prevent asthma mortality  Components of Severity Persistent Intermittent Mild Moderate Severe Symptoms < 2 daysiwook gig yal Daily Trio bed Macnee 12% (and 200 mL) increase following administration of a | bronchodilator/trial of glucocorticoids. Greater confidence is gained if the increase is >15% and >400 mL ¢ >20% diurnal variation on => 3days in a week for 2 weeks on PEF diary e FEV, >15% decrease after 6 mins of exercise (FEV, = forced expiratory volume in 1 sec; PEF = peak expiratory flow) | 17.20 Levels of asthma control Partly controlled (any present Characteristic Controlled in any week) Uncontrolled Daytime symptoms None (< twice/week) > twice/week Limitations of activities None Any Nocturnal symptoms/awakening None Any 2 3 features of partly controlled Need for rescue/‘reliever’ treatment None (< twice/week) > twice/week asthma present in any week Lung function (PEF or FEV,) Normal < 80% predicted or personal best (if known) on any day Exacerbation None = 1/year 1 in any week (FEV = forced expiratory volume in 1 sec; PEF = peak expiratory flow)  Asthma=suspected Asthma = diagnosed Diagnosis and Evaluation: * assess symptoms, measure lung function, check inhaler technique and adherence assessment * adjust dose « update self-management plan « move up and down as appropriate I I I I I I I I I I I I I Regular preventer I I I (Consider monitored I initiation of treatment I with low-dose ICS I I I Short-acting f, agonists as required —- consider moving up if using three doses a week or more Patient satisfaction eos ll Ti gmt of modifiable risk factors é tidities Neti-pharmacoiogical strategies ~ Education & skilts training Asthma medication options: CX Asthma medications Adjust treatment up and down for individual patient needs PREFERRED “STEP 4 CONTROLLER to prevent exacerbations 90% 2- high dose SABA/SAMA 3- systemic steroids (oral or IV) 4- magnesium sulfate 5- ICU for close observation 6- antibiotics not indicated unless there are symptoms of pneumonia (high fever, purulent sputum) Impending respiratory failure: due to increased obstruction and muscle fatigue. Intubation and mechanical ventilation Respiratory Arrest ees Le Mild Moderate = Severe == Iiminent Breathlessness While walking At rest, limits activity At rest, interferes with While at rest, mute conversation Talks in Sentences Phrases Words Silent Alertness May be agitated Usually agitated Usually agitated Drowsy or confused Signs Respiratory rate Increased Increased Often > 30/minute > 30/minute Body position Can lie down Prefers sitting Sits upright Unable to recline Use of accessory muscles; Usually not Commonly Usually Paradoxical thoracoabdominal suprasternal retractions movement Wheeze Moderate, often only Loud; throughout Usually loud; throughout Absent end expiratory exhalation inhalation and exhalation Pulse/minute < 100 100-120 > 120 Bradycardia Pulsus paradoxus Absent < 10 mmHg — May be present Often present > 25 mmHg Absence suggests respiratory 10-25 mm Hg muscle fatigue PEF or FEV, % predicted or% 270% 40-69% < 40% < 25% personal best Pao, (on air, mm Hg) Normal! > 60! < 60: possible cyanosis < 60: possible cyanosis Pco, (mm Hg) < 42mm Hg! < 42mm Hg! 242! 2 42' 5a, (on air, %) > 95%! 90-95%! < 90%! < 90%!