Respiratory Patient/disease Flashcards
Define the 2 different types of respiratory disease
OBSTRUCTIVE- characterised by increased resisntance of pulmonary airways
RESTRICTIVE- impediment to lung expansion not due to airway resistance
- Diffuse pulmonary fibrosis (lung tissue becomes fibrous) e.g. sarcoidosis
- Immobility of thoracic cage
- Weakness of the respiratory muscle
State some obstructive lung disorders
Bronchial asthma
COPD
Deffinition of asthma
- A chronic inflammatory disorder of the airways … in susceptable individuals, inflammatory symptoms are usually associated with widespread but variable airflow obstruction and an increase in airway response to a variety of stimuli.
- Obstruction is often reversible, either spontaneously or with treatment
What is the prevalence and mortality of asthma
-UK 2012- 8 million have asthma with 6 million taking medication
-Incidences for developing asthma dropping 237/10,000 2012 from 518/10,000 2004
-New cases highest in children
-In UK, 1,246 people die from asthma in 2012, up from 1,205 in 2008
0.2 of all deaths, 1.1% of lung deaths
Most over 65
NHS cost of asthma
- 60,000 emergency hospital admissions per year
- £667 million of prescription items
- Total cost to NHS £1 billion per year
What types of asthma are there
- Chronic and acute
- Chronic = prophylactic Therapy
- Acute = can be life threatening- immediate emergency treatment required
- Adult and children
- Occupational- late onset
- Exercise
- All forms are precipitating factors
Children: risk factors for asthma
- Family history of Atopy (genetic tendency to develop allergic disease)
- Co-existence of atopy
- Male sex
- Wheeze in children (parental smoking, premature birth, viral infection in early life)
- Wheeze not always a predictor of asthma in adult life. Earlier onset better prognosis
Environmental factors for asthma
ALLERGENS- grass, mould spores, animal fur, house dust mites
FOOD- milk, egg, tartrazine, alcohol, nuts
NON-SPECIFIC IRRITANTS- dust, cigarette smoke, atmospheric pollution
MEDICAL CONDITIONS- pregnancy, respiratory infections (viral worst)
Other precipitating factors
-OCCUPATIONAL CAUSES- metal salts, lab animals/microbes,
dyes, plastics
-DRUGS- antimicrobials, penicillins, tetracyclines
Beta blockers, NSAID, sulphasalazine
Diagnosis of asthmas 1/3
- A clinical diagnosis- there is no absolute confirmatory clinical test
- E.g. blood test
- Not always simple
- Symptoms are not unique (share with other disease)
- Hallmark is variability, intermittent nature, provoked triggers, worse at night
Diagnosis of asthma 2/3
-Compare results of test for patient when asymptomatic and symptomatic
-Carry out quality spirometry using the lower limit of normal to demonstrate obstruction
-Obstructive spirometry which is reversed by bronchodilators increase likelyhood of asthma
Normal spirometry in asymptomatic patient doesn’t rule out asthma
Diagnosis of asthma 3/3
-Record the patient as likely to have asthma and start carefully monitored treatment (6 week steroid)
Assess patient status and do an FEV1 clinical test
With good symptomatic and objective response to treatment confirm diagnosis of asthma
If response is poor check inhaler technique and adherence, then consider other prognosis
Investigations- lung function test
Forced expiratory volume (FEV)- patient inhales as deeply as possible- then exhale into spirometer
Forced Vital Capacity- max volume of air exhaled with max effort after max inspiration
FEV1- FEV in the first second of exhalation
FEV1/FEV ratio- measure capability of lungs
Normal range= 70% of total capacity exhaled in 1 sec this is lower in COPD
-In obstruction lung disorders- the ratio is reduced
-FEV1, FVC- there are normal values for comparison but these vary with age, race, gender, height and weight
Lung functional tests (Peak flow)
Peak flow- good for patients to self assess, less reproducible results than spirometer, advantage- portable, patient can do at home
Measure- peak expiratory flow rate- PEF
Max flow rate that can be forced out in expiration
Can be used to assess the improvement or deterioration in the disease as well as effectiveness of treatement
Clinical signs of chronic asthma
Moderate hypoxaemia- PO2 50-70 mmHg (80-90mmHg) but blood pH is normal and no hypercapnia (too much CO2)
Ventilation perfusion ratio- severe impairment
Eosinophilia (>400 mm3)- very characteristic of bronchial asthma, Charcot Leyden crystals in sputum, measure sputum samples
Tests for asthma control
Asthma control questionnaire (ACQ)
Asthma quality of life questionnaire (AQLA)
Asthma Control Test (ACT)
COPD
-This is the name of lung diseases including chronic bronchitis, emphysema and chronic obstructive airways disease
-People with COPD have difficulties breathing
Typical symptoms include:
-increasing breathlessness when active,
-a persistent cough with phlegm, -frequent chest infection
Chronic obstructive pulmonary disease
Characterised by airflow restriction which is not always fully reversible
2 main elements:
Chronic bronchitis: permanently increased airway resistance
Emphysema: increase beyond normal in the size of the air spaces distal to the terminal bronchiole
Chronic bronchitis
- Hypertrophy of sub-mucous glands and increased in size and number of goblet cells
- Continuous increase in secreation-thick
- Poor muck-ciliary clearance- developing secondary inflammation with the lung and increased risk of infection
- Plugging of airways- blocks of respiratory units and so reduced exchange areas
Emphysema
- Centrilobar- dilation and destructive changes in respiratory bronchioles- cigarette smoking
- Panlobular- whole pulmonary lobe affected, all alveoli walls disrupted. Hereditary form. -Disruption of pulmonary blood vessels.
- Lack of alpha-antitrypsin (AT) implicated in aetiology of some forms of emphysema. Also free radical activation of proteolytic enzymes
COPD morbidity
-25,000 deaths a year 15% are workplace related -Around 1.2 million people have COPD -Most common cause is smoking -Smoking cessation is important -if it fails NHS will not fund repeat within 6 months
Characteristics of COPD
- No single test- clinical judgement
- Symptoms affect lifestyle and ultimately seriously affect life. –Treatment is to achieve best control of symptoms
- Appears usually, >age incidence age related
- Other airborne pollutants are linked to this
- Incidence= 8-15% in males and 3-5% in females
Symptoms of COPD
Exertional breathlessness Chronic cough Regular sputum production Winter bronchitis Wheeze
Dyspnoea scale
1- not troubled by breathlessness except strenuous exercise
2-Short of breath when hurrying or walking up a slight hill
3-Walks slower than contemporaries on level ground because of breathlessness or has to stop for breath when walking at own pace
4-Stops for death after walking about 100m or after a few minutes on level ground
5- to breathless to leave the house
Chronic bronchitis- blue bloater
Chronic cough- heavy sputum
Obesity is common
Smoking history
Blood gases- low PaO2 (<90 mmHg), elevated PaCO2 (>45mmHg), respiratory acidosis
Cor-pulmonale- early development
Respiratory failure
Reduced FEV1 and FVC and increased residual volume
Emphysema- pink puffer
Dyspnoea
Weight loss
Blood gases- normal PaO2, slightly high PaCO2
Cor-pulmoale- late development
Respiratory failure
Reduced FEV1
FVC and residual volume greatly increased
Value of FEV 1
Absolute FEV1 the best measure of airway function. 70% predicted and consistent
Serial measures indicate poor progression
PEFR is poor indicator in COPD- doesn’t link well to FEV1 and understates disease
Spirometer is recommended- need at least 3 good readings, need 2 readings within 5% or 100 ml of eachother
Pulmonary hypertension and cor-pulmonale
Co-existing chronic bronchitis and emphysema cause destruction of large parts of the pulmonary circulation and elevated pulmonary resistance
Developing right ventricular hypertrophy then right heart failure
Hypoxaemia and perhaps hypercapnia
Peripheral vasodilation- raises CO2 and exacerbates pulmonary hypertension
Peripheral odema
Guidelines of diagnosis- clinical assessment
-Undertake a structured clinical assessment to assess the initial probability. This should be based
+A history of recurrent episodes (attacks) of symptoms ideally corroborated by variable peak flow when symptomatic and asymptomatic
+Symptoms of wheeze, cough, breathlessness and chest tightness that vary over time
+Recorded observation of wheeze heard by a healthcare professional
+Personal/family history of other atopic conditions (In particular atopic eczema/dermatitis, allergic rhinitis)
+No symptoms/signs to suggest alternative diagnosis
Investigation of COPD
-Spirometry should be performed at the time of diagnosis and done by trained personnel
-Post-bronchodilator spirometry to confirm diagosis of COPD
-Consider alternative diagnosis or investigations in
+Older people without typical symptoms of COPD where FEV1/FVC is <0.7
+Younger people with symptoms of COPD where FEV1/FVC ratio is >0.7
-Further investigations- chest radiograph (to exclude other conditions), FBC- to identify anaemia or polycthaemia, BMI calc
Progression and complications of COPD
-Late progressive COPD can lead to
+Elevated pulmonary resistance- destruction of large parts of pulmonary circulation
+Peripheral vasodilation- raises CO2 and exacerbates pulmonary HTN
+Develop into right ventricular hypertrophy- then right HF
+You also get peripheral oedema
