Transcript Respiratory tract infection

Dr A.J.France
RESPIRATORY TRACT INFECTION
© A.J.France 2010
Objectives
 Define the range of conditions
 Recognise the common clinical presentations
 Understand the significance of pre-existing
respiratory disease
 Look at the different features seen in
immuno-compromised patients
© A.J.France 2010
Range of conditions – Upper tract
 Common cold - coryza
 Sore throat - Pharyngitis
 Sinusitis
 Epiglottitis
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Range of conditions – Lower
 Acute bronchitis
 Acute exacerbation of chronic bronchitis
 Pneumonia
 Influenza
© A.J.France 2010
Vocal cords – the dividing line
 Upper Resp Tract
 Lower Resp Tract
 Air conditioning
 Gas exchange
 Filtration
 Usually sterile
 Commensal organisms
 Temperature regulation
 Shared with Gastro –
Intestinal tract
© A.J.France 2010
Common cold - coryza
 Acute viral infection of the nasal passages
 Often accompanied by sore throat
 Sometimes a mild fever
 Spread by droplets and fomites
 Complications can include
 Sinusitis
 Acute bronchitis – see later
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Treatment for coryza
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Acute sinusitis
 Preceded by a common cold
 Purulent nasal discharge
 Treatment….
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Special conditions
 Acute tonsillitis and quinsy – go to ENT lecture
 Diphtheria
 Life threatening due to toxin production
 Characteristic pseudo-membrane
 Not seen in UK due to vaccination
 Acute epiglottitis in children
 Life threatening due to obstruction
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Acute bronchitis
 The cold which goes to the chest
 Preceded by common cold
 Clinical features
 Productive cough
 Fever – minority of cases
 Normal chest examination
 Normal chest X-ray
 May have a transient wheeze
© A.J.France 2010
Acute bronchitis -Treatment
 Antibiotics are NOT indicated
 Unless they have underlying chronic lung
disease.
© A.J.France 2010
Acute exacerbation of chronic bronchitis
 Remember – pre-existing lung disease with
excess sputum and broncho-constriction.
 Clinical features
 Usually preceded by upper resp tract infection
 Worsening of sputum production which is now
purulent
 More wheezy
 Breathless
© A.J.France 2010
Acute exacerbation of chronic bronchitis
 On examination
 Breathless
 Wheeze
 Coarse crackles
 May be cyanosed
 In advanced disease – ankle oedema
© A.J.France 2010
Acute exacerbation of chronic bronchitis
 Management in primary care
 Antibiotic. e.g. doxycycline or amoxicillin
 Bronchodilator inhalers
 Short course of steroids in some cases
 Refer to hospital if
 Evidence of respiratory failure
 Not coping at home
© A.J.France 2010
Acute exacerbation of chronic bronchitis
 Management in hospital – same as before
AND
 Measure arterial blood gases
 CXR to look for other diseases
 Give oxygen if has respiratory failure
© A.J.France 2010
Right upper lobe
Lobar pneumonia
Pneumonia: Introduction
 Significant risk of fatal outcome
 5-10% mortality from pneumococcal pneumonia
 30% if bacteraemic
 2600 deaths from pneumococcal pneumonia
in UK every year
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Middle lobe. Lobar
pneumonia
Lobar pneumonia
Normal
Red hepatisation
Lobar pneumonia
Lung biopsy - autopsy
Symptoms of pneumonia
 Malaise
 Cough
 Anorexia
 Pleurisy
 Sweats
 Haemoptysis
 Rigors
 Dyspnoea
 Myalgia
 Preceding URTI
 Arthralgia
 Abdominal pain
 Headache
 Diarrhoea
 Confusion
© A.J.France 2010
Right lower lobe pneumonia - abdominal pain ?
Pneumonia
 Signs
 Investigations
 Fever
 Blood culture
 Rigors
 Serology
 Herpes labialis
 Tachypnoea
 Arterial gases
 Crackles
 Full blood count
 Rub
 Urea
 Cyanosis
 Liver function
 Hypotension
 Chest X-ray
© A.J.France 2010
Herpes simplex stomatitis
Cyanosis
CURB 65 severity score for pneumonia
 C New onset of confusion
 U Urea >7
 R Respiratory rate >30/min
 B Blood pressure
 Systolic <90 OR Diastolic <61
 65 age 65 years or older
 Score 1 point for each of above
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Pneumonia. Other severity markers
 Temperature < 35 or > 40
 Cyanosis PaO2 < 8 kPa
 WBC < 4 or > 30
 Multi-lobar involvement
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Pathogens in pneumonia
 Strep pneumoniae (pneumococcus)
 H. influenzae
 Mycoplasma pneumoniae
 Influenza
 Chicken pox – in adult smokers
 Legionella
 Coxiella burnetti
 Chlamydia psittaci
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Community acquired pneumonia:
Management
 Antibiotics
 Amoxicillin + Doxycycline
 (see “antibiotic man” for details)
 Oxygen
 Maintain SaO2 94-98 %
 Fluids
 Bed rest
 No smoking
© A.J.France 2010
Complications of pneumonia
 Respiratory failure
 Pleural effusion
 Empyema
 Death
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Empyema
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Empyema
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Special cases of pneumonia
 Hospital acquired
 Need extended gram negative cover
 Aspiration pneumonia
 Need anaerobic cover
 Legionella
 Chest symptoms may be absent
 GI disturbance is common
© A.J.France 2010
History taking in pneumonia
 Cough
 Foreign travel
 Breathless
 Pets, including birds
 Chest pain
 Contact history
 Fever
 Other medical
conditions
 Pre-existing chest
disease
 Smoking history
 Lifestyle
 Prescribed drugs
© A.J.France 2010
Prevention of pneumonia
 Influenza and pneumococcal vaccines
 Over 65
 Chronic chest or cardiac disease
 Diabetes
 Immunocompromised
 e.g. splenectomy
 Influenza vaccine
 Health care workers
© A.J.France 2010
Coffee break
© A.J.France 2010