Lab 4 - COPD, Asthma Flashcards
Asthma - Diagnosis
History: previous measurements; compare values with values expected for the pt (age, gender, ethnicity, height)
Lung function tests:
- Spirometry (reduced FEV1, FEV1/FVC ratio, PEF)
- Bronchodilator reversibility test (increase in FEV1 by more or equal 200 ml/12% 15 min after inhalation of albuterol/salbutamol 400mcg)
- PEF: twice daily
- Flow volume loops (reduced peak flow and max expiration flow)
- Whole body plethysymography (increased airway resistance and total lung capacity and residual V)
Airway hyperresponsiveness:
- exposure to bronchoconstrictors (histamine), calculate provocative conc that reduces FEV1 by 20%
- exercise testing (post-exercise bronchoconstriction)
Hematalogic: total serum IgE, CBC (peripheral eosinophilia)
Imaging:
- CXR usually normal, but may show hyperinflated lungs in severe pts, pnemothorax in acute exacerbations, pneumonia in bronchopulmonary aspergillosis
- CT: bronchiectasis in severe asthma
- Skin prick test: positive in allergic asthma
- Fractional exhaled NO: eosinophilic airway inflammation
- Sputum eosinophilia –> airway inflammation
Asthma - Differential diagnosis
Upper airway obstruction by a tumor or laryngeal edema (confirmed with flow volume loops (reduced inspiratory and expiratory flow and bronchoscopy which shows upper airway narrowing)
Endobronchial obstruction with a foreign body (persistent wheezing in a specific area of chest)
LV failure: wheezing of asthma, but presence of basilar crackles
Vocal cord dysfunction
Eosinophilic pneumonia and systemic vasculitis (Churg-Strauss syndrome), polyarteritis nodosa –> wheezing
Salbutamol - dose and route
0,1 mg/dose (1-2) doses in aerosol (nebulizer, metered-dose inhaler with a spacer)
Salbutamol - MoA
SABA, b2 adrenergic agonist, inhibits mast cell mediator release
Salbutamol - Adverse effects
Tremor, peripheral vasodilation, tachycardia, palpitations. hypokalemia (increased uptake by skeletal muscle cells)
Salbutamol - Contraindication
Thyrotoxicosis, HTN, CHD
Salbutamol - Interactions
Increased risk of hypokalemia with glucocorticoids, diuretics and hypoxia
Salmeterol - dose and route
50 mcg/dose (2 doses) in aerosol
Ipratropium - dose and route
30 mcg/dose (1-2 doses) 3-4 ganger daglig, in aerosol
Ipratropium - MoA
SAMA, muscarine receptor antagonists, prevent cholinergic nerve-induced bronchoconstriction and mucus secretion. Used in acute severe asthma following B2 agonists
Ipratropium - Adverse effects
Dry eyes, dry mouth, cycloplegia, constipation, urinary retention
Ipratropium - Contraindication
closed angle glaucoma, BPH
Theophylline - Dose and route
5-6 mg/kg IV
Theophylline - When used, MoA and adverse effects
Severe asthma if other drugs doesn't work Both bronchodilator (inh PDE, increase cAMP) and anti-inflammatory effects Adverse effects: nausea, vomiting, headache, anxiety, dizziness
Fluticasone - dose and route
125 mcg, twice daily in aerosol
Fluticasone - MoA
ICS, reduces eosinophils in the airway and sputum, and nr of activated T lymphocytes and surface mast cells in airway mucosa.
Fluticasone - Adverse effects
Oropharyngeal candidiasis, dysphonia, sore/irritated throat, toothache
Fluticasone - Contraindications
In high doses: Adverse effects of systemic corticosteroids may occur
Fluticasone - Interactions
CYP3A4 inh (cimetidine, fluconazole, verapamil) –> systemic effects in therapeutic doses
Prednisolone - dose and route
30 mg/day PO for 5-10 days
Prednisolone - Adverse effects
Cushing syndrome, osteoporosis, growth retardation, DM, PUD, HTN
Prednisolone - Contraindications
Psychosis, PUD, heart disease, HTN, DM, osteoporosis
Montelukast - dose and route
10 mg/d PO
Montelukast - MoA
Leukotriene inhibitor. Inhibits bronchoconstriction.
Montelukast - Adverse effects
Hypersensitivity, Churg Strauss syndrome, liver injury
Montelukast - Interactions
Inh CYP enzymes –> increases levels of phenytoin, warfarin, lovastatin
Asthma - Treatment
SABA –> ICS –> LABA –> high dose ICS + Leukotriene inh –> OCS
Asthma exacerbation - Treatment
O2 (achieve saturation >90%) –> SABA and OCS or IV (Methylprenisolone 40 mg IV) –> new b2 agonist + Ipratropium –> Theophylline –> intubation, mechanical ventilation (noninvasive positive pressure ventilation)
COPD - Diagnosis
Physical exam: cough sputum, exertional dyspnea, Hoovers sign, Hyperinflation (barrel chest), tripod position (to facilitate actions of sternocleidomastoid, scalene, and intercostal muscles), pink puffers vs blue bloaters
Lung function test:
- Post- bronchodilator spirometry: 0,4 mg salbutamol. Reduced FEV1 and FEV1/FVC –> reduced below 0,7. Increased total lung capacity, FRC and RV
- Reduced diffusing capacity for carbon monoxide (lung parenchymal destruction)
ABG and oximetry: hypoxemia, PCO2 and pH
Increased hematocrit: chronic hypoxemia
Imaging:
- CXR: hyperinflation (increased lung V, flattened diaphragm), emphysema (bullae), pulmonary HTN
- CT: emphysema, coexisting interstitial lung diseases, bronchiectasis, lung cancer
alpha1AT def testing
CBC: asses for erythrocytosis (can occurs secondary to hypoxemia), anemia (worsen dyspnea)
ECG/Echo: exclude CHF, identify cor pulmonale in pst with chronic hypoxia
COPD- Treatment
Nicotine replacement therapy
A: SABA or SAMA
B: LABA or LAMA –> persistent symptoms: Both
C: LAMA –> Further exacerbations: LABA + LAMA or LABA + ICS
D: LAMA + LABA or LABA + ICS –> further exacerbations: LABA + LABA + ICS –> further exacerbations: Roflumilast
If continued symptoms, try theophylline or oral corticosteroids
COPD- nonpharm therapy
Influenza vaccine (pneumococcal, Bodetella pertussis)
Pulmonary rehabilitation
Lung volume reduction surgery
Lung transplantation
COPD- Differential diagnosis
CHF, PE, chronic asthma, pulmonary fibrosis
Tiotropium - Dose and route
18 mcg 1 dose/day capsule for inhalation (inhalationpowder)
