PATHOLOGY- Respiratory disorders Flashcards
How can non infectious chronic lung diseases be classified?
Obstructive or restrictive
How do we distinguish between different types of chronic lung diseases?
- FEV1 (Forced expiratory volume in 1 sec)
- FVC (Forced vital capacity)
What does FEV1 stand for
Forced expiratory volume in 1 sec
amount of air expelled in 1s afer deepest breath
What does FVC stand for?
Forced vital capacity
total amount of air expelled
State the normal FEV1: FVC ratio
0.75 - 0.8
What would a FEV1: FVC < 0.7 mean
Obstructive (resistance to expiration)
What would a FEV1: FVC > 0.85 mean
Restrictive
Give examples of obstructive lung diseases
- Emphysema
- Chronic bronchitis
- Asthma
- Small airway disease
- Bronchiectasis
Which 2 lung diseases fall under chronic obstructive pulmonary diseases (COPD)
- Emphysema
- Chronic bronchitis
What is chronic obstructive pulmonary disease (COPD)
What is it characterised by
A clinical syndrome- chronic bronchitis and emphysema
Characterised by obstructive lung FTs and reduced expiratory flow
what is the difference between COPD and asthma
asthma is reversible, damage from COPD is not
How many people in the UK suffer from COPD
1.2 million
Name the most common lung disease in the uK
Asthma (followed by COPD)
What would the FEV1:FVC ratio of a person with COPD be
<0.7
obstruction to expiration
Why are Emphysema and Chronic bronchitis grouped together?
Both diseases are characterised by airflow restriction and therefore most patients have a mixture of both
They share similar aetiology (smoking)
Define chronic bronchitis
- Persistent cough with sputum production
- Cough present for at least 3 month over at least 2 consecutive years
- Absence of any other identifiable cause
What is the pathogenesis of chronic bronchitis
- Chronic airway irritation leading to epithelial/ cililary dysfunction
- Mucous hyper secretion/ mucous gland hypertrophy/ goblet cell metaplasia
- Mucous and cilliary dysfunction lead to airway obstruction
- Chronic inflammation leading to fibrosis and small airway obstruction
- Airway obstruction and mucous hyper secretion leading to decreased alverolar ventilation and so alveolar hypoxia
- Alveolar hypoxia leading to V:Q mismatch and pulmonary vasoconstriction
v:q mismatch= ventilation:perfusion mismatch
What are the overall effects of chronic bronchitis
- Hypoxaemia
- Hypercapnia
- Pulmonary hypertension
Define emphysema
What does it lead to
Irreversible abnormal enlargement of airspaces distal to the terminal bronchioles
This leads to alveolar wall and capillary destruction
How does emphysema lead to airway obstruction?
Abnormal enlargement occurs that leads to loss of recoil and bronchiole collapse
This leads to airway obstruction
Describe the pathogenesis of emphysema
- Inflammatory stimulus such as cytokines and proteases
- Alveolar connective tissue is broken down
- This affects the central acinus bronchioles and spare distal alveoli
- This affects the entire acinus bronchioles and alveoli
What is another term for chronic bronchitis
Blue bloaters
Describe patients with blue bloaters
They have a large, oedematous cyanotic with mild dyspnoea
Give some symptoms of chronic bronchitis
- Cough/ wheeze (due to mucous hypersecretion and airway obstruction)
- Cyanotic blue colour (due to impaired alveolar oxygenation)
- Often obese
Why do some patients with chronic bronchitis turn cyanotic
They have an impaired oxygenation leading ro decreased levels of oxygen and increased CO2 in the alveolus
This leads to hypoxaemia, hypercapnia and polycythaemia giving patients a blue hue
What is polycythaemia?
Increased production of red blood cells in response to hypoxia
What can some patients with COPD become resistant or tolerant to?
CO2
Which side of the heart can fail in a patient with chronic bronchitis? Why?
Right heart failure
Pulmonary vascular vasoconstriction leading to pulmonary hypertension
Why can oedemas form in patients with chronic bronchitis
Due to fluid retention
What is another term for emphysema
Pink puffers
Describe patients with Pink puffers
Thin, cachectic with severe dysnopea
Why are patients with emphysema sometimes described as pink puffers?
As they have pursed lip breathing
What causes patients with emphysema to have pursed lips
Loss of parenchyma/ loss of elastic recoil
This causes alveolar aid to trap and small airways to collapse
Leading to pursed lips
Do patients with emphysema have increased or decreased expiratory volume?
Increased
Give some symptoms of emphysema
- Pursed lips
- Barrel chested
- Dyspnoea/ cachexia
Give some of the clinical features of COPD
- Productive cough
- Breathlessness
- Respiratory failure
- Cor pulmonate (rh failure)
How do we manage COPD
- Beta- agonists
- Muscarinic antagonist
- Inhaled steroids
- Oxygen
- Smoking cessation
When giving a patient with COPD oxygen what do you need to be careful of?
Hypoxic drive
What do Emphysema and Chronic bronchitis have in common
They are both examples of chronic obstructive pulmonary diseases (COPD)
If someone is describes as a pink puffer what might they have?
Emphysema
If you have a patient with COPD what should you monitor and take into consideration being a dentist?
- Monitor oxygen
- Keep them upright
- Avoid rubber dam and sedation
- Avoid sedation if severe cases
State the target saturation in COPD patients
88-92%
What is asthma
Reversible small airway obstruction characterised by bronchospasm, airway inflammation and oedema
Is asthma a chronic or acute disorder?
Chronic disorder of conducting airways
What are the episodic bronchoconstrictions in asthma due to?
- increased airway sensitivity to stimuli
- Inflammation of the bronchial walls
- Increased mucus secretion
Name the 2 different types of asthma
- Atopic
- Non atopic
What is atopic asthma
Allergen sensitisation
what is non-atopic asthma
no evidence of antigen sensitivity
Give some triggers for asthma
- Allergens
- Chemical irritants
- Strong smells
- Temperature change
- Exertion
- Stress
- Drugs
What causes asthma
It is a type 1 hypersensitivity disorder mediated by IgE
- When you initially exposed to your trigger IgE is produced
- On second re exposure IgE cross linking occurs
- This leads to mast cell degeneration
- This causes bronchospasm and vascular permeability
- This all causes oedema/airway narrowing
List some symptoms of asthma
- Cough
- Wheezing
- Difficulty creating
- Often need to use accessory muscles in upper body
- Tight chest feeling
How should you manage an acute asthma attack
- Help the casualty take their reliever (blue inhaler)
- Sit the casualty upright and get them breathing normally
- Continue to give 2 puffs of reliever inhaler ever 2 minutes if symptoms don’t improve
- If symptoms don’t resolve after 10 puffs of inhaler call 999
- If casualty feels better after taking their inhaler they can go back to their previous activity
what are 4 medications for asthma
Short acting relievers
- Inhaled $2 agonists (e.g. salutamol, terbutaline)
Long-acting relievers/disease controllers
- Inhaled long-acting 2 agonists (e.g. salmeterol, formoterol)
- Inhaled corticosteroids (e.g. beclometasone, budesonide, fluticasone)
Other bronchodilators / bronchodilator activity
- Inhaled antimuscarinic agents (e.g. ipratropium)
- Oral corticosteroids (e.g. prednisolone 40 mg daily)
Steroid sparing agents
What is the relationship between asthma and dentistry
Possible increased caries risk in asthmatic patients
What considerations should you take as a dentist if your patient is asthmatic
- Keep their reliever inhaler on hand during the appointment
- Keep appointment times later in the day
- Avoid aspirins and NSAIDs
What is tuberculosis
An infectious disease characterised by caseating granulomatous inflammation
who must be notified if somone has tuberculosis
PHE
How many death annually are caused by tb
1.4 million deaths
caseating granulomatous
A lesion that has a lot of macrophages leading to the formation of a granuloma
Why can it be hard to diagnose primary tb?
95% of patients are asymptomatic
Name the 2 different types of tb?
Primary (non immune host)
Secondary (immune host)
primary=unexposed
secondary=previous exposure
Give some symptoms of tb
- Cough
- Malaise
- Weight loss
- Fever
- Haemoptysis
- Night sweats
- Pain on breathing
- Back pain
- heart failure
- Neurological symptoms
How do you diagnose tb
- Mantoux test
- Look at histology for caseating granulomata
- Look at microbiology
- Interferon gamma release assay
How is tb treated
Treated with a cocktail of antimicrobial therapy for 6 months
What is the Mantoux test
Tuberculin skin prick test
