Respiratory Tract Infections (DISEASE MECHANISMS) Flashcards
What is included under upper respiratory infections?
Coryza (common cold)
Pharyngitis (sore throat)Sinusitis
Epiglottitis
What is included under lower respiratory infections?
Acute bronchitis
Acute exacerbations of chronic bronchitis
Pneumonia
Influenza
What is coryza?
Acute inflammation of the nasal passages
What are the symptoms of coryza?
Sore throat (often) Mild fever (37.5 (sometimes)
What are the possible complications of coryza?
Sinusitis
Acute bronchitis
What is the recommended treatment for coryza?
Rest and paracetamol
How does coryza spread?
Droplets
Fomites
What causes coryza?
Adenovirus
Rhinovirus
Respiratory syncytial virus
Which virus causes respiratory disease in children?
Respiratory syncytial virus
What precedes acute sinusitis?
Common cold
What symptom indicates acute sinusitis?
Purulent nasal discharge
Where can acute sinusitis in the ethmoid sinuses spread?
Eyes and brain
What is the danger in acute sinusitis of the cavernous sinuses?
Cain fact/block the carotid artery and CN III - can be fatal
What are the symptoms of acute tonsillitis and quinsy?
Painful to eat & hard to breathe
Why should you NEVER blindly cut open the quinsy to drawn pus?
Because the carotid artery runs down the quinsy
Why is diphtheria life-threatening?
Toxin production
What is characteristic of diphtheria?
Pseudomembrane
Why is acute epiglottis life-threatening in children?
Obstruction - swelling of the epiglottis blocks the larynx
What symptom indicates acute epiglottis in children?
Hot runny nose (because can’t swallow own saliva)
How do you treat acute epiglottis in children?
One attempt at intubation; if fails - emergency tracheostomy
What should you NOT do if suspect acute epiglottis in a child? Why?
Ask them to open their mouth - will cough & obstruct the airway and die
What priced acute bronchitis?
Common cold
How does chronic bronchitis present clinically?
Productive cough (possibly sputum)
Minority have fever
Normal chest exam & X-ray
May have transient wheeze
How is acute bronchitis treated?
Usually self-limiting
No antibiotics (usually)
Significant morbidity in patients with chronic lung disease
What is the incubation time of the rhinovirus?
1-5 days
What is the incubation time of group A streptococci?
1-5 days
What is the incubation time of influenza & para-influenza virus?
1-4 days
What is the incubation time of RSV?
7 days
What is the incubation time of pertussis?
7-21 days
What is the incubation time of diphtheria?
1-10 days
What is the incubation time of the Epstein-Barr virus?
4-6 weeks
What are the clinical features of acute exacerbations of COPD?
Usually preceded by URTI
Increase sputum production and purulence
More wheezy
Breathless
What would be expected upon examination of a patient with acute exacerbations of COPD?
Respiratory distress Wheeze Coarse crackles May be cyanosed Ankle oedema in advanced disease
How are acute exacerbations of COPD treated in primary care?
Antibiotic (doxycycline/amoxicillin)
Bronchodilator inhaler
Sometimes short steroid course
When should a patient with acute exacerbation of COPD referred to hospital?
Evidence of respiratory failure
ot coping at home
How would acute exacerbation of COPD be managed in hospital?
Same as in primary care AND …
Measure ABGs
CXR to look for other disease
Give O2 if in respiratory failure
The presence of what (3) in the alveoli would indicate pneumonia?
Neutrophils
Lymphocytes
Macrophages
What are the symptoms of pneumonia? (15)
Malaise Anorexia Sweats Rigors (Shaking/shivering) Myalgia Arthralgia Headache Confusion Cough (due to pus in chest) Pleurisy Haemoptysis (RBCs enter alveolar spaces) Dyspnoea Preceding URTI Abdominal pain (if infect in base of lung) Diarrhoea (if swallow sputum)
What are the signs of pneumonia?
Fever Riggers Herpes labialise Tachypnoea Crackles Pleural rub Cyanosis Hypotension
How do you investigate pneumonia?
Blood culture Serology ABGs Full blood count Urea Liver function Chest x-ray
How is the CURB65 severity score calculated
1 point for each of C - new onset of Confusion U - Urea >7 R - Respiratory rate > 30 B - Blood pressure systolic <90 or diastolic >61 65 - age 65 or older
What severity markers are there for pneumonia?
CURB65 score
Temperature <35 or >40
Cyanosis - PaO2 < 8 kPA
WBC <4 or >30Multi-lobar involvement
Which pathogens cause pneumonia?
S. pneumonia (most) H. influenza Legionella sp. Staph. Aureus M. pneumonia C. pneumonia Gram neg enterobacteria Viruses Influenza A & B (Possible that none is found)
Pneumonia and other infectious disease is particularly linked to which animal?
Birds
Mycoplasma pneumonia shows prevalence peaks every _ years
4
Chicken pox pneumonia can be ____ in adult smokers
fatal
Younger people tend to get which pathogen for pneumonia?
M. pneumonia
Older people tend to get which pathogen for pneumonia?
Strep. pneumonia
How is community-acquired pneumonia treated?
Antibiotics (amoxicillin / doxycycline) Oxygen - maintain SaO2 at 94-98% or 88-92% Fluids Bed Rest No smoking
What are the possible complications of pneumonia?
Respiratory failure
Pleural effusion
Empyema
Death
How is empyema treated?
Drained using ultrasound to guide the needle
What does hospital acquired pneumonia require?
Extended gram neg cover
What does aspiration pneumonia require?
Anaerobic cover
How does Legionella present?
Chest symptoms may be minimal
GI disturbances are common as well as confusion
How can pneumonia be prevented?
Influenza & parainfluenza vaccine (>65 yrs / chronic cardiac disease / immunocompromised) Influenza vaccine (Health care workers)
