Asthma And COPD Flashcards
Pathophysiology of asthma7
Characterised by airflow limitation and hyperresponsiveness as well as bronchial inflammation Caused by a combination of atopy and allergy
The chronicity of asthma depends on
Airway inflammation and remodelling
Pathophysiology of COPD
There is an increase in mucous secreting goblet cells especially in larger bronchi.may have inflammation and pus in lumen Chronic inflammatory cells, predominantly CD8 cells. Ulcered epithelial layer and squamous epithelium may replace columnar Scarring and thickening causes airway narrowing
Diagnosis of COPD
Usually clinical and based on breathlessness and sputum production in chronic smoker
Test and criteria for airflow limitation reversibility in COPD
Lung function tests FEV1:FVC ratio is reduced and PEFR low And airflow limitation usually reversible if FEV change is less than 15%
Differences between asthma and COPD
COPD affects the airway and parenchyma while asthma just affects airway Inflammation primarily eosinophils and CD4 while COPD is neutrophils and CD8
Classification of COPD severity
Stage 0: At risk, cough or sputum present but lung function normal. Stage 1: Mild COPD, FEV1/forced vital capacity (FVC) <70%, with an FEV1 ≥80% predicted, with or without chronic symptoms. Stage 2: Moderate COPD, FEV1/FVC <70% and FEV1 % pred>30% and <80%. Stage 2 is split at an FEV1 of 50% pred since the existing data support the value of inhaled corticosteroids below an FEV1 of 50% pred but not above. Stage 3: Severe COPD, FEV1 <30% pred and FEV1/FVC <70%.
Classification of asthma severity
Intermittent Mild persistent Moderate persistent Severe persistent
Intermittent asthma
Symptoms (difficulty breathing, wheezing, chest tightness, and coughing): Occur on fewer than 2 days a week. Do not interfere with normal activities. Nighttime symptoms occur on fewer than 2 days a month. Lung function tests (spirometry and peak expiratory flow[PEF]) are normal when the person is not having an asthma attack. The results of these tests are 80% or more of the expected value and vary little (PEF varies less than 20%) from morning to afternoon.
Mild persistent asthma
Symptoms occur on more than 2 days a week but do not occur every day. Attacks interfere with daily activities. Nighttime symptoms occur 3 to 4 times a month. Lung function tests are normal when the person is not having an asthma attack. The results of these tests are 80% or more of the expected value and may vary a small amount (PEF varies 20% to 30%) from morning to afternoon.
Moderate persistent asthma
Symptoms occur daily. Inhaled short-acting asthma medication is used every day. Symptoms interfere with daily activities. Nighttime symptoms occur more than 1 time a week, but do not happen every day. Lung function tests are abnormal (more than 60% to less than 80% of the expected value), and PEF varies more than 30% from morning to afternoon.
Severe persistent asthma
Symptoms: Occur throughout each day. Severely limit daily physical activities. Nighttime symptoms occur often, sometimes every night. Lung function tests are abnormal (60% or less of expected value), and PEF varies more than 30% from morning to afternoon.
COPD goals of therapy
The GOAL of treatment in COPD is to: reduce symptoms, prevent exacerbations and decrease mortality
Asthma goals of therapy
The GOAL of treatment in ASTHMA is to: reduce inflammation and to achieve¸total control
Role of PEFR monitoring
Objective measure of airflow limitation as correlates with FEV1 Monitoring of PEF may be useful include the acute care of asthma exacerbations in adults, home monitoring of asthma, and assessment of occupational asthma
Role of PEFR monitoring in COPD
greater variability in daily PEFR measurements in patients with severe to very severe COPD (with similar comorbidities, age, medication use, and symptoms) could help to objectively identify patients with more unstable disease with a propensity for greater exacerbation and a higher mortality.
Symptoms when assessing severity
severe airflow obstruction in asthma include tachypnea, tachycardia, prolonged expiratory phase of respiration (decreased I:E ratio), and a seated position with use of extended arms to support the upper chest (“tripod position”) [1,2]. Use of the accessory muscles of breathing (eg, sternocleidomastoid) during inspiration and a pulsus paradoxus (greater than 12 mmHg fall in systolic blood pressure during inspiration) are usually found only during severe asthmatic attacks
Triggers of acute exacerbation of asthma
●Respiratory infections (viruses, bacteria) ●Allergen exposure (inhalant, food, and occupational) ●Inhaled respiratory irritants (including tobacco and cannabis smoke and cold, dry air) ●Temperature and weather ●Physical activity ●Hormonal fluctuations ●Medications ●Emotional factors (eg, anxiety, stress) Comorbidities, such as rhinitis, rhinoviral infection, gastroesophageal reflux, obesity, obstructive sleep apnea, depression, and anxiety can trigger asthma symptoms as well
Triggers of acute exacerbation of COPD
Respiratory infections, most commonly viral (eg, rhinovirus) or bacterial, are estimated to trigger approximately 70 percent of COPD exacerbations Atypical bacteria are a relatively uncommon cause The remaining 30 percent are due to environmental pollution, pulmonary embolism, or have an unknown etiology
Association between COPD and smoking
Most important risk factor Smoking cessation reduces the accelerated decline in lung function that is associated with smoking, which decreases the likelihood that COPD will develop
Asthma and association with smoking
studies appear to show a relationship between smoking and airway hyperresponsiveness Studies have also provided evidence for an association between smoke exposure and asthma development. Active smoking increases the risk for developing asthma Passive exposure to tobacco smoke was associated with increases in the risks of doctor-diagnosed asthma (OR 1.39), wheezing, bronchitis, and dyspnea.
Self management plan in asthma
The three topics of primary importance for patient education are the function and appropriate use of medication, the pathophysiology of asthma, and the prevention and treatment of symptoms
The three characteristics of asthma for patients and families to understand are
that airways inflammation, sensitivity to triggers, and the temporary occurrence of airflow obstruction leading to shortness of breath are all components of asthma
Stepwise approach to asthma management
COPD stepwise treatment
Types of controllers
those with anti-inflammatory action (corticosteroids and leukotriene blockers) and those with a sustained bronchodilator action (longacting ß2 agonists and slow-release theophyllines
Inhaled corticosteroids
- Beclomethasone 2. Budesonide 3. Fluticasone 4. Ciclesonide
Leukotriene modifiers
- Montelukast
- Zafirlukast
Oral corticosteroids
- Prednisone
- Prednisolone
- Methylprednisone
- Methylprednisolone
Long-acting ß2 agonists
- Salmeterol
- Formoterol
Relievers
These include short-acting inhaled ß2 agonists (SABAs) and the anti-cholinergic ipratropium bromide. T
Short-acting ß2 agonists
- Salbutamol
- Fenoterol
- Terbutaline
Anti-cholinergics
Ipratropium bromide
SABA
MOA, indications, benefits, risks
beta-2 agonists act as ligands to adrenergic receptors with increased selectivity towards beta-2 adrenergic receptors the change in Ca2+ results in the inhibition of myosin light chain phosphorylation, subsequently preventing airway smooth muscle contraction.
provide relief from acute symptoms of asthma and are usually used as 2 puffs as needed
They may only be used as the sole therapy in mild intermittent asthma where the symptoms are mild and infrequent ( 80% predicted)
Side effects of ß2 agonists include tachycardia, tremor, headache and irritability.
LABA
MOA
indictions
benefits
risks
Adrenoreceptor agonist
Binds to exosite of beta 2 adrenoreceptor in lungs and bronchiolar smooth muscle. Leads to relaxation of bronchial smooth muscle and bronchodilation
They are useful for control of nocturnal symptoms and exercise-induced asthma. They are recommended as an addition to low dose inhaled corticosteroids in preference to increasing the dose of inhaled corticosteroids
LABAs should never be used without inhaled corticosteroids in asthma because current evidence suggests an increased risk of deaths if LABAs are used as monotherapy. Some patients may not respond to LABAs. Side effects of these drugs include palpitations and tremor.
Inhaled coricosteroids
MOA
Indications
benefits
risks
Control of protein synthesis. depression of migration of polymorphonucleur leukocytes and fibroblasts, reverse of capillary permeability and lysosomal stabilization
mainstay of treatment for are the mainstay of treatment for patients with chronic persistent asthma
inhaled corticosteroids reduce airway inflammation, decrease bronchial hyperresponsiveness and improve asthma control. In addition, they may modify airway remodelling and prevent an accelerated decline in lung function. Their long-term use in adequate doses has been shown to decrease exacerbations and mortality.
local side effects such as dysphonia and oropharyngeal candidiasis.
Theophyline
MOA
Indications
benefits
risks
Phosphodiesterase inhibitor to bronchodilate and vasodilate
complementary mode of action to other bronchodilators.
Their disadvantages include a narrow therapeutic range, drug interactions and frequent side effects (nausea, vomiting, abdominal pain, gastrooesophageal reflux, palpitations, insomnia, irritability and seizures)
Ipratropium bromide
MOA
Indications
Benefits
Risks
Antocholinergic effects on bronchial smooth muscle
Used in patients, particularly the elderly, who cannot tolerate ß2 agonist side effects. It may also be of value as add-on treatment in patients who do not obtain adequate symptom relief with the short-acting ß2 agonists alone (
Leukotriene receptor antagonists
MOA
Indications
Benefits
Risk
Inhibits the cyst 1 leukotriene receptor linked to asthma released after allergen exposure
may be of value in patients with aspirin-sensitive asthma
In mild persistent asthma as add-on treatment to inhaled corticosteroids
MgSO4
MOA
Indications
Benefits
Risks
CNS depressant and ihibition of myometrial contraction
reduces admissions and improves pulmonary functions
Indication of oral corticosteroids and how they are prescribed
may be considered in patients with poorly controlled asthma on high doses of inhaled corticosteroids and other controller medications.
Long term oral corticosteroids (>7.5mg prednisone/day), whilst relatively inexpensive, are associated with serious systemic side-effects
Long term effects of coticosteroids
Hyptension and water retention
Osteoporosis and DM
Diagnosis of acute exacerbation of athma
Unable to complete sentences in one breath
RR >25/MIN
HR>110PE 33-50%
If severe PEF<300%, silent chest, feeble resp, exhaustion, confusion, coma, low sats<92, cyanosis
Managament of acute severe asthma
Salbutamol 5mg Prednisolone 30mg
If PEF still <75% repeat salbutamol and ipratropium
Monitor vitals
Management of acute exacerbation of COPD
Salbutamol 5mg Ipratrpium 500mcg
If sats <88% 02 at 24-28%
IV hydrocortisone 200mg and oral prednisolone 30mg
Ab if signs of infection
indications for antibiotics in the treatment of an acute exacerbation of COPD
Signs of infection in CXR
Pyrexia
Blood cultures
Sputum should be sent for culture if purulent
Asthma/COPD adjustment in management in DM
Particular caution is required when prescribing oral corticosteroids. Inhaled corticosteroids are safe and have no significant effect on glycaemic control.
Asthma COPD management adjustment in hypetension
Pulmonary congestion may manifest with wheezing and may be misdiagnosed as asthma particularly in patients with mitral stenosis and in the elderly. ß blockers are contraindicated in asthma.
Asthma COPD management adjustment in angina
Fluid retention and hypokalaemia induced by corticosteroids and high doses of ß2 agonists may occasionally be a problem in asthma with associated cardiac disease.
