Respiratory Diseases Flashcards
Define Asthma?
Asthma is a chronic lung disease that inflames and narrows the airways.
Asthma causes recurring periods of wheezing, chest tightness, shortness of breath and coughing
Airway narrowing is reversible
Describe the differences between a normal airway and an asthmatic airway
Normal airway: Fully patent
During Asthma symptoms: Narrowed airway (limited air flow)
Tightened muscles constrict airwat
Inflamed/thickened airway wall
Mucus
What is the global burden of asthma?
300 million people suffer from asthma worldwide
- 255 000 asthma deaths in 2005
approx 3500 in US
approx 1100 in UK
-over 80% of all asthma deaths occur in LMICs
What are asthma triggers?
- Exercise
- Pollen
- Bugs in the home
- Chemical fumes
- Cold air
- Fungus spores
- Dust
- Smoke
- Strong odors
- Pollutions
- Anger
- Stress
- Pets
What are different species of house dust mites?
Dermatophagoides pteronyssinus
Blomia tropicalis
Mite faeces contain allergens (Der p 1, Blo t 5, etc)
What are risk factors for asthma?
- Parents with asthma (genetics)
- Atopy
- Atopy refers to the genetic tendency to develop allergic diseases such as allergic rhinitis, asthma and atopic dermatitis (eczema).
- Atopy is typically associated with heightened immune responses to common allergens, especially inhaled allergens and food allergens.
- Childhood respiratory infections
- Exposure to allergens or infections while the immune system is developing
How do we measure atopy in epidemiological studies?
Either allergen Skin Prock Tesr reactivity (SPT)
Or allergen-specific IgE (asIgE)
What is a Bronchiodilator response (BDR)?
Bronchiodilator testing is utilised as a diagnostic method in obstructuve airway diseases.
In terms of the ISAAX phase II investigation: the aims of the investigation was to compare different methods for measuring BDR in participants with asthma and COPD & to study to the extent to which BDR was related to symptom burden and phenotypic characteristics
What is spirometry and how is it used as an asthma diagnosis?
Spirometry is one of the most commonly used approaches to test pulmonary function
It measures the vol of exhaled air vs time
Increased bronchial flow rate in a patient with asthma. (reversibility)
- Spirometry can help to assess if inhaled medication or inhalers can open up your airways by bronchodilator responsiveness testing (sometimes known as reversibility testing).
- Usually, medication causes a bigger change in scores if you have asthma than COPD. People with COPD have an FEV1/FVC ratio lower than 70%.
Define FEV1 and FVC
- Forced expiratory volume (FEV1) is a measurement taken from a pulmonary function test. It calculates the amount of air that a person can force out of their lungs in 1 second.
- Working out a person’s FEV1 value can help diagnose chronic lung diseases, such as chronic obstructive pulmonary disease (COPD).
Vital capacity is the maximum amount of air a person can inhale after a maximum exhalation. It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume.
What is the FEV1/FVC ratio?
An obstructive defect is a disproportional decrease in maximal airflow from the lung (FEV) in relation to the maximal volume (FVC) that can be displaced from the lung. In practical terms, an FEV/FVC ratio of less than 0.70 defines an obstructive ventilatory defect.
What does fractional inhaled nitric oxide mean?
NICE has recommended FeNO testing to help diagnose asthma in adults and children when diagnosis is unclear.
It has also recommended FeNO testing to help manage asthma in peopel who have symptoms despite using inhaled corticosteroids.
What is the management of asthma?
- Quick relief (rescue) medications
- Short-acting beta agonists
- Ipratropium
- Oral and IV corticosteroids
- Long-term control
- Inhaled corticosteroid
- Leukotriene modifiers
- Long-acting beta agonists
- Combination inhalers
- Avoid triggers
What is the treatment for different levels of asthma?
Step 1 is intermittent Asthma!
- STEP 1: Preferred SABA PRN
After step 1, we move onto persistent Asthma requiring daily medication. You must consult with a specialist after stage 4
- STEP 2: Preferred Low dose ICS. Alternative: Corimolyn LTRA, Nedocromil or theophylline
Goes all the way up to step 6
What are the issues with Asthma in LMICs?
- Increasing burden of disease
- Urbanisation and urban risk factors
- Access to healthcare and drugs
- Underdiagnosis/poor training
- Use of ER for control
- Affordable inhaled drugs
- Low dose ICS/inhaled beta-2 agonists
- Economic costs to family
- Different risk factors and predominance of non-atopic disease
- Ascaris
- Ascaris infections, with a worldwide prevalence above 10%, can cause respiratory pathology. However, long-term effects on lung function in humans are largely unknown.
- Ascaris
Give an example of an LMIC with poor access to asthma medications
Equador
The majority of drugs were for the acute phase
Mainly bronchiodilators
- Hardly any patients in Ecuador are taking inhaled corticosteroids. This is a problem because ICS are important for long-term asthma control
- In LMICs there are highly unequal societies
The world is becoming more urban-> pollution increases-> increase likelihood of aquiting asthma
Define COPD
- Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients
- Its pulmonary component is characterised by airflow limitation that is not fully reversible.
- The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases
- Severe COPD leads to respiratory failure, hospitalisation and eventually death from suffocation
What are thee two different conditions associated with COPD?
Emphysema: The walls between alveoli are damaged leading to fewer and larger air sacs instead of many tiny ones.
Leads to a large reduction of gas exchange in the lungs
Chronic bronchitis: The lining og the airways is constantly irritated and inflamed causing the lining to thicken. Lots of thick mucus forms in the airways, making it hard to breathe.
Most people who have COPD have elements of both emphysema and chronic bronchitis
What are the differences between the symptoms of someone with emphysema and chronic bronchitis?
Chronic bronchitis:
- Overweight and cyanotic
- Elevated Hb
- Peripheral edema
- Rhonchi and wheezing
Emphysema
- Older and thin
- Severe dyspnea
- Quiet chest
- X-ray, hyperinflation with flattened diaphragms
What are risk factors for COPD?
- Cigarette smoke
- Occupational dust and chemicals
- Environmental tobacco smoke (ETS)
- Indoor and outdoor air pollution
- Nutrition
- Infections
- Socio-economic status
- Aging populations
What is the diagnosis of COPD?
Symptoms: Cough, sputum, shortness of breath
Exposure to risk factors
If a patient presents with both, then you must perform spirometry
What does spirometry for COPD diagnosis tell you?
- Can tell you the classification of severity
*
Describe the decline in FEV1
- Declines with age
- The smoking and smoking cessation has on FEV1
*
What is the classification of COPD severity by spirometry?
Talk about the global trends in COPD
Of the six leading causes of death in the US, only COPD has been increasing steadily since 1970
COPD mOrtality by Gender (US from 1980-2000)
Men had greater deaths up untill the year 2000
Describe COPD mortality worldwide
What are other co-morbidities that are associated with COPD patients?
- Myocardial infarction, angina
- Osteoporosis
- Respiratory Infection
- Depression
- Diabetes
- COPD & Lung cancer
What are the four components of care with regards to a COPD patient?
Assess and monitor disease
Reduce risk factors
Manage Stable COPD
Manage exacerbations
Describe therapy at each stage of COPD
What are the issues of Asthma and COPD in LMICs
- Social and economic burden of COPD is increasing
- COPD is under siagnosed and under-treated
- In middle and high income countries, smoking is the major cause of COPD but in low income countries exposure to inddor air pollution, such as the use of biomass fuels for cooking and heating, causes the COPD burden
- 3 billion at risk
What is the burden of COPD in LMICs?
- 3 million deaths from COPD worldwide-90% in LMICs
- COPD is increasing in prevalence worldide-
- Total deaths from COPD are projected to increase by more than 30% in the next 10 years
- Estimated that COPD will be third leading cause of death worldwide in 2030
What are the changing and circumstances demographics of COPD in LMICs?
Increasing exposure to risk factors especially smoking among women in LMIC
Changing demographics with popualtions in LMIC with greater LE and more people reaching the COPD age range
What are current COPD initiatives?
Global Alliance against Chronic Respiratory Diseases (GARD)
The Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) or PLATINO in Latin America
