Acute bronchitis/flu/asthma Flashcards

Question

Extrinsic (Immune) Initial exposure to antigen:

Answer 1

Prompts naive T-cell differentiation to T helper (Th) 2 cells Followed by production of IgE antibodies, which bind to mast cells and basophils (ready to respond to subsequent antigen exposure)

Answer 2

Initial exposure to antigen: T cells and production of igE that bind to MAST cells and basophils. Early Phase: Inhaled antigen → **IgE-bound mast cells and basophils degranulate** (early-phase reaction) → release of **mediators** (**prostaglandin D₂, histamine, leukotrienes**) → **airway smooth muscle contraction** → airway tightening and/or obstruction Late phase: Recruitment of inflammatory cells: **Th2 cells** → production of mediators and cytokines **Eosinophils** (the most prominent cells) increase the release of inflammatory mediators IL-3, IL-4, IL-5, IL-13 Differentiation of eosinophils (IL-5) Prolonged survival of eosinophils (IL-3 and IL-4) Production of IgE (IL-4) ↑ mucus glands, airway fibrosis (IL-13) | prostaglandin D₂, histamine, leukotrienes/eosinophils/ ## Footnote IL-3, IL-4, IL-5, IL-13

Answer 3

The airways of most asthmatic patients are normal at baseline During flares – often triggered by allergens: Increased smooth muscle tone Increased inflammation/edema Increased mucus production leading to mucus “plugs” Results in narrowed airways and restricted exhalation

Answer 4

Non-eosinophilic No associated family history of asthma Does not involve Th2 cells Environmental factors (pollution, smoking, infections, allergens) → involve **Th1 and Th17 cell** responses → **neutrophilic inflammation** and **airway hyperresponsiveness** **Neutrophilic inflammation:** High sputum neutrophil counts Associated with severe asthma exacerbations Often difficult to treat (less responsive to corticosteroids) | typically more severe and more difficult to treat

Answer 5

Symptoms Occur with characteristic triggers (allergens, cold air, exercise) Recurrent wheezing Dyspnea: chest tightness/heavy weight on the chest Cough: Dry or productive of sputum Worse at night and in the early morning hours Signs Asymptomatic when under control When symptomatic: Tachypnea Tachycardia Hypoxemia Expiratory ± inspiratory wheezing and rhonchi Prolonged expiratory phase of respiration Nasal flaring Retractions Use of accessory muscles to breathe

Answer 6

Pulmonary function testing – most useful diagnostic study **Recommended that bronchodilators be stopped before the test** **Spirometry:** Maximal inhalation followed by rapid forceful exhalation (at least 6 seconds) Measures: FEV1 (forced expiratory volume in 1 second) FVC (forced vital capacity or the maximal volume exhaled with maximally forced effort) **↓ FEV1 and FEV1/FVC ratio < 0.70 (suggests airway obstruction**) **Bronchodilator response:** Nebulized or 2–4 puffs of bronchodilator given, then spirometry rechecked after 15 minutes Increase in FEV1 by > 12% and 200 mL (bronchodilator responsiveness) 80% of the FVC at 1 second FEV1/FVC ratio 0.70 or greater | Normal spiro:

Answer 7

A stimulus (methacholine, exercise, histamine, inhaled mannitol) is tried, to trigger bronchoconstriction **≥ 20% reduction in FEV1 with challenge/testing (airway hyperresponsiveness**)

Answer 8

**Used more for monitoring than for diagnosis** Maximal inhalation, then fast forceful exhalation (< 2 seconds) into peak flowmeter A single peak flow is obtained during symptoms Results compared with average normal values (based on height and age) Post-bronchodilator administration (15 minutes after 2 puffs of a bronchodilator), improvement of > 20% suggests reversible airway obstruction

Answer 9

* Exclude other diagnosis (pneumothorax or pneumonia in exacerbations) * Indicated for atypical presentation of asthma (fever, crackles, hypoxemia) * Normal in mild asthma * May show hyperinflation in severe asthma (flattened diaphragm, wide intercostal spaces)

Answer 10

Alpha-1 antitrypsin level: detects alpha-1 antitrypsin deficiency (for patients with persistent airway obstruction)

Answer 11

Arterial blood gas (in severe asthma exacerbation): Obtain when oxygen saturation of < 94%, no bronchodilator response, mental status change(s) What would you expect the ABG to be for a severe asthma exacerbation? ↓ pH – respiratory acidosis ↓↓ PaO2 ↑ PaCO2 ↓ HCO3

Answer 12

Complete blood count: may show eosinophilia (suggests atopic asthma) Elevated IgE levels Moderate-to-severe asthma

Answer 13

Early on in an acute episode, we will see hypocarbia (due to hyperventilation) → ↑ pH (respiratory alkalosis) Severe asthma attack can lead to respiratory failure

Answer 14

Goals: Control of symptoms and triggers Reduce future risks and complications Non-pharmacologic management Patient education: Asthma symptoms Indications for and proper technique of bronchodilator and corticosteroid inhaler use Discuss “written” asthma action plan (PEF monitoring and corresponding action) Smoking cessation Influenza, COVID-19, and pneumococcal vaccinations

Answer 15

Used when symptoms occur Begin working within minutes and can last several hours Provide quick, short-term relief of asthma symptoms Example: Short-acting bronchodilators: Albuterol Levalbuterol Long-acting bronchodilators: Salmeterol Formoterol

Answer 16

Also known as maintenance medications Used on a daily basis Prevent the need to use rescue medications Example: Inhaled corticosteroids (ICS): Budesonide Fluticasone Mometasone Leukotriene receptor antagonists (LTRAs): Zafirlukast Montelukast (oral)

Answer 17

Bronchodilators: Beta-2 Agonists Short-acting beta-2 agonists: Albuterol (inhalation, oral) Levalbuterol (inhalation) Long-acting beta-2 agonists: Salmeterol (inhalation) Formoterol (inhalation) Mechanism of action and effects Drug binds the β-2 receptor Bronchial smooth muscle Smooth muscle of the blood vessels Effect Smooth muscle relaxation → dilation of bronchioles Decrease mast cell degranulation and histamine release Inhibit microvascular leakage into the airways Increase mucociliary clearance SABA: onset within 5 minutes and duration of 4–6 hours LABA: duration of up to 12 hours

Answer 18

Clinical uses SABA: Rapidly acting bronchodilator, used in acute asthma exacerbation Prevention of exercise-induced asthma LABA: Used as acute symptom reliever for moderate to severe asthma Prevention of nocturnal symptoms Used only with inhaled corticosteroids, not as a monotherapy **Black Box Warning: monotherapy has an increased risk of asthma-related death** Side effects β2-mediated skeletal muscle tremors (most common side effect) Other effects: Tachycardia (cardiac β receptor stimulation) Hyperglycemia Hypokalemia…administer albuterol Tx for hyperkalemia!

Answer 19

Bronchodilators: Muscarinic Antagonists SAMA: ipratropium bromide (inhalation) LAMA: tiotropium bromide (inhalation) Mechanism of action and effects Relaxes bronchial smooth muscle through competitive inhibition of muscarinic (M3) cholinergic receptors, thereby preventing bronchoconstriction Clinical uses **Less effective than β2-agonists for acute exacerbation, but provides additive benefit** Long-term maintenance treatment in children **> 6 years of age** and adults with severe symptomatic asthma uncontrolled with ICS Side effects Rare due to poor absorption into circulation Blurry vision, dry mouth, dizziness, urinary retention | best result from saba with sama

Answer 20

Antileukotriene Agents Leukotriene receptor antagonists (LTRAs): zafirlukast, montelukast (oral) (Singulair) Mechanism of action and effects Inhibit leukotriene receptors Effects (by targeting leukotriene): ↓ smooth muscle contraction ↓ vascular permeability and mucus secretion Reduced activation of inflammatory cells Clinical uses **Exercise-induced bronchospasm Mild persistent asthma + allergic rhinitis** Aspirin-exacerbated respiratory disease Additive benefit for moderate-to-severe persistent asthma Considered in patients with difficulty with compliance or inhaler technique (children) Side effects Headaches, fatigue, dyspepsia, hepatotoxicity Drug interaction: increased warfarin effect | not the biggest player.. might not be on exam

Answer 21

Corticosteroids Inhaled corticosteroids (ICS): budesonide, fluticasone, mometasone Systemic corticosteroids: Oral: prednisone, prednisolone IV: hydrocortisone, methylprednisolone Mechanism of action and effects Blocks the release of arachidonic acid, consequently halting the release of inflammatory mediators Effects: ↓ airway hyperresponsiveness ↓ airway mucosal edema ↓ capillary permeability ↓ leukotriene release Clinical uses **Drug of choice for long-term control of persistent types of asthma** Early systemic corticosteroids in acute exacerbations often abort the exacerbation, decrease the need for hospitalization, prevent relapse, and speed recovery Short-term oral corticosteroid treatment (< 7 days) of acute severe exacerbations Tapering required if oral corticosteroid > 2 weeks

Answer 22

Side effects ICS have less severe and fewer side effects than systemic steroids Include: Thrush, skin bruising, weight gain, hyperglycemia → diabetes, hypertension, immune suppression, ophthalmic changes, osteopenia/osteoporosis, respiratory infections, deceleration of growth velocity in children

Answer 23

way more symptoms with systemic steroids versus inhaled

Answer 24

Anti-IgE or IgE antibody (omalizumab) IL-5 antagonist: mepolizumab, reslizumab IL-5 Receptor antagonist: benralizumab Anti-IL-4 receptor antagonist (dupilumab) Clinical use Management of moderate-to-severe asthma | script usually given by pulminologist or allergist

Answer 25

National Asthma Education and Prevention Program (NAEPP) Global Initiative for Asthma (GINA) (preffered)

Answer 26

For severe asthma exacerbation Oxygen therapy goal: 93%–95% oxygen saturation (adults) Inhaled therapy: High dose of SABA via nebulizer or spacer Nebulized ipratropium (anticholinergic) if no response to beta-2 agonists Intravenous medication(s): **IV corticosteroids:** If asthma does not improve consistently after **SABA treatment** If exacerbation occurs despite ongoing daily oral steroid therapy If exacerbation is recurrent after recent discontinuation of systemic steroids Consider IV **magnesium sulfate** (bronchodilator activity) 2 g infused over 20 min; contraindicated in renal insufficiency

Answer 27

Status asthmaticus Severe, intense, prolonged bronchospasm that is resistant to treatment Endotracheal intubation and mechanical ventilation in case of impending respiratory failure: * Mental status changes (confused, agitated, or drowsy) * Silent chest on auscultation * Respiratory fatigue (respiratory rate > 30/min, heart rate > 120/min, use of accessory muscles) * Respiratory acidosis with increasing hypercapnia * Low oxygen saturation (< 92%) despite high-flow oxygen

Acute bronchitis/flu/asthma Flashcards

(52 cards)