Respiratory Tract Infection Flashcards
What conditions affect the upper respiratory tract?
* Common cold – coryza * Sore throat – Pharyngitis * Sinusitis * Epiglottitis
What is the upper RT?
Above the vocal cords
What conditions affect the lower respiratory tract?
* Acute bronchitis * Acute exacerbation of chronic bronchitis * Pneumonia * Influenza
What is coryza?
Common cold - acute viral infection of the nasal passages
What are symptoms of coryza?
* Sore throat * Sometimes a mild fever
How is coryza spread?
Spread by droplets and fomites
What are complications of coryza?
* Sinusitis * Acute bronchitis
How can you avoid over-treating a patient for common cold (mistaking for influenza A, B etc), etc?
Identifying pathogens via viral throat swab (red-topped tube), followed by PCR
What is a red-topped tube used for?
Contains viral material
What are the symptoms/signs of strep throat?
* Exudate * Pus * Sore throat * Dysphagia * Dysphonia
What are symptoms of tonsillitis?
* Swollen tonsils * Erythematous * Dysphagia * Dysphonia
Do you only suffer from tonsillitis once?
No, reccurent
What is a possible treatment for tonsillitis?
Tonsilectomy
What is Quinsy?
A complication of tonsillitis - tonsilar abscess
What is the treatment for Quinsy?
Can be drained (risk of cutting internal carotid artery)
Is tonsillitis as dangerous as Quinsy?
No, Quinsy much more dangerous
What is epiglottitis?
Swelling of epiglottis - can block airway
What is the treatment for epiglottitis?
* Intubation by anaesthetist * Antibiotics
What viruses are responsible for coryza?
* Adenovirus * Rhinovirus * Respiratory Syncytial Virus (RSV)
Is there treatment for coryza (common cold)?
No, self-limiting
What causes acute sinusitis?
Preceded by a common cold
What are symptoms of sinusitis?
* Frontal headache * Retro-oribital pain * Maxilliary sinus pain * Tooth ache * Nasal discharge
What is the treatment for sinusitis?
* Usually self limited * Resolves in 10 days * Some need antibiotics
Why can sinusitis be dangerous?
Lymphatic drainage of face goes to brain, can spread to brain
What is diphtheria?
Life threatening condition due to toxin production
Why is diphtheria not common today?
Eradicated by vaccination
What are characteristics that make diphtheria so dangerous?
* Toxin production * Pseudo membrane can block airways
What causes acute bronchitis?
Preceded by common cold
What are clinical features of acute bronchitis?
* Productive cough * Fever – minority of cases * Normal chest examination * Normal chest X-ray * May have a transient wheeze
What is the treatment for acute bronchitis?
* Usually self limiting in normal people * Antibiotics are NOT indicated for normal people * Can lead to significant morbidity in patients with chronic lung disease
Why is acute bronchitis dangerous for people with chronic lung disease?
Can lead to significant morbidity
What is the incubation time (time for virus to manifest) of rhinoviruses?
1-5 days
What is the incubation time (time for virus to manifest) of Group A streptococci?
1-5 days
What is the incubation time (time for virus to manifest) of influenza and parainfluenza viruses, RSV, Pertussis, Diptheria and Epstein-Barr virus?
* Influenza and parainfluenza viruses: 1-4 days * RSV: 7 days * Pertussis: 7-21 days * Diphtheria: 1-10 days * Epstein-Barr virus: 4-6 weeks
What are clinical signs of COPD?
* Respiratory Distress * Wheeze * Coarse crackles * May be cyanosed * In advanced disease – ankle oedema
What can cause acute exacerbation of COPD?
May be preceded by upper respiratory tract infection
What are symptoms of acute COPD exacerbation?
* Increased sputum production * Increased sputum purulence * More wheezy * Breathless
How is acute exacerbation of COPD managed in primary care?
* Antibiotic. e.g. doxycycline or amoxicillin * Bronchodilator inhalers * Short course of steroids in some cases
When is a patient with acute exacerbation of COPD referred to hospital?
* Evidence of respiratory failure * Not coping at home (acopia)
How is COPD managed in hospital?
* Same treatment received in primary care And * Measure arterial blood gases * CXR to look for other diseases * Give oxygen if has respiratory failure
How is COPD managed in hospital?
* Same treatment received in primary care And * Measure arterial blood gases * CXR to look for other diseases * Give oxygen if has respiratory failure
What is the mortality risk of pneumonia?
* 5-10% mortality from pneumococcal pneumonia * 30% if bacteraemic
What condition can be identified from this CXR? (pic)
Right upper lobe pneumonia
Why is pneumonia so significant?
Commonest cause of death in people under 50
What condition can be identified from this CXR? (pic)
Middle lobe pneumonia
Why is consolidation of the lung due to pneumonia called red hepatisation?
Resemblance to the liver rather than lung tissue
What is the histology of a lung infected with pneumonia?
Complete filling of alveolar spaces with inflammatory cells
What are symptoms of pneumonia?
* Malaise
* Anorexia
* Sweats
* Rigors
* Myalgia
* Arthralgia
* Headache
* Confusion
* Cough (sputum)
* Pleurisy
* Haemoptysis
* Dyspnoea
* Preceding URTI
* Abdominal pain
* Diarrhoea
What are clinical signs of pneumonia?
* Fever
* Rigors
* Herpes labialis
* Tachypnoea
* Crackles
* Rub
* Cyanosis
* Hypotension
Why is reactivation of herpes simplex virus common in pneumonia?
Due to alteration in the immune system
What techniques are used to investigate pneumonia?
* Blood culture
* Serology
* Arterial gases
* Full blood count
* Urea
* Liver function
* Chest X-ray
What is used to stage the severity of community acquired pneumonia?
CURB65 severity score
What is the CURB65 severity score?
Used to grade severity of community acquired 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 the above)
Describe the relationship between mortality and CURB65 score
Mortality increases as CURB65 Increases
What percentage mortality is suggested by 1, 2, 3, 4 and 5 CURB65 score?
* 0 - 0.6%
* 1 - 2.7%
* 2 - 6.8%
* 3 - 14.0%
* 4 - 27.8%
* 5 - 27.8%
What percentage mortality is suggested by 1, 2, 3, 4 and 5 CURB65 score for a COPD patient?
0 - 10.6%
1 - 12.7%
2 - 16.8%
3 - 24.0%
4 - 37.8%
5 - 37.8% (10% increase mortality for COPD patients)
What are the CURB65 mortality rates based on?
Development of sepsis (what ultimately kills people)
What are other severity markers for pneumonia (other than CURB65)?
Temperature < 35 or > 40
Cyanosis
PaO2 < 8 kPa
WBC < 4 or > 30
Multi-lobar involvement
What is used to treat community acquired pneumonia?
* Antibiotics (amoxicillin, doxycycline) * Oxygen * Fluids * Bed rest * Smoking cessation
What is the main pathogen involved in hospital contraction of pneumonia?
Steptococcus pneumoniae
What increases the risk of psittacosis?
Keeping birds
What diseases can mycoplasma bacteria cause?
* Arthritis
* Autoimmune haemolytic anaemia
* Immune thrombocytopenic purpura
* Hepatitis
* Pneumonia
What are the characteristics of mycoplasma bacterium?
* No cell wall – resistant to beta-lactam antibiotics
* Causes protracted paroxysmal cough
* Cillial dysfunction
* H2O2 producuction damages repsiraotry membranes
What antibiotics are used to treat community acquired pneumonia?
* Amoxicillin
* Doxycycline
How is the organism responsible for pneumonia predicted?
* Young vs old - young people tend to get mycoplasma, old people tend to get simpler things
* Severity
* Immuno-competent vs immuno-compromised
Why do young people tend to recover better from pneumonia than older people?
* C - Good cerebral vasculature
* U - Good kidneys
* R - Can increase VT (tital volume)
* B - Inotropic, chronotropic and vascular responses
* 65 – cant be
What is the problem with CURB65 score for young people?
CURB65 score massively underestimates severity of pneumonia in young peeople
What is the problem with CURB65 score for old people?
CURB65 score can overestimate severity of pneumonia in old people
When are IV antibiotics used to treat pneumonia?
IV antibiotics when:-
* Oral route not availible
* Drug resistant organisms
* Deep seated infections – abscesses, endocarditis
What are complications of pneumonia?
* Respiratory failure * Pleural effusion * Empyema * Death
What is empyema?
Collection of pus in the pleural cavity caused by microorganisms, usually bacteria
What are lifestyle risks associated with respiratory disease?
* PWID (injecting drugs) – staph aureus
* Alcohol/homelessness – TB, klebsiella
*Frequently hospitalised - pseudomonas
* Returning traveller – legionalla, TB
* Indian sub-continent – TB
* Eastern Europe – MDR TB (XDR TB)
What are special cases of pneumonia?
* Hospital acquired- need extended gram negative cover
* Aspiration pneumonia - need anaerobic cover
* Legionella
What is legionella?
A severe form of pneumonia
What are the symptoms of legionella?
* Chest symptoms may be minimal
* GI disturbance is common
* Confusion common
How is pneumonia prevented?
Influenza and pneumococcal vaccines
Who are given influenza and pneumococcal vaccines in order to prevent pneumonia?
* Over 65
* Chronic chest or cardiac disease
* Diabetes
* Immunocompromised
