Clinical consequences of respiratory infections Flashcards
What are the 4 respiratory infections?
- URTI
- Acute Bronchitis
- Exacerbation of chronic airway disease
- COPD
- Bronchiectasis
•Pneumonia (CXR diagnosis in hospital, clinical in community setting)
What are the different classifications of pneumonia?
Anatomical
- lobar
- broncho-pneumonia
- diffuse
Setting
- community acquired
- hospital acquired
- ventilator related
What ages are patients more likely to get pneumonia?
More common in very young and very old
How many people per million die of pneumonia?
What percentage of people with pneumonia need hospital admission?
214 for every million dies of pneumonia
About 25% require hospital admission
What are the clinical signs of pneumonia?
- Reduced Air Entry /PN
- Bronchial Breathing
- Increased Vocal resonance
- Crackles
Are they confused?
Which diagnostics are used for pneumonia?
•Bloods tests
- Assess for evidence of infection/Inflammation
- Assess renal function
- Assess liver function
- Blood cultures
- HIV test
- Sputum
- Viral throat swab/ Mycoplasma
- Urine –legionella Ag
- Arterial blood gas
What does this show?
Lobar Pneumonia - CT
What does this show?
Broncho-pneumonia
How is pneumonia severity tested?
The CURB 65 score
- Confusion
- raised blood Urea (>7 mmol/L)
- raised Respiratory rate (>30/min)
- low Blood pressure (S<95; D≤60)
- age > 65 years
If no Urea – CRB-65 score
What would be appropriate action for different CURB-65 scores?
How is pneumonia managed in the community with no risk factors?
- Rest
- Push fluids
- Analgesics
- Antibiotic
Safety net
Refer if no improvement in 48 hrs
How is pneumonia managed in the hospital?
- Oxygen if required
- Fluid replacement if required
- Antibiotics
- Critical care management
Which pathogens are responsible for community acquired pneumonia?
Streptococcus pneumoniae 39%
Chlamydia pneumoniae 13%
Mycoplasma pneumoniae 11%
Haemophilus influenzae 5%
Staphylococcus aureus 2%
Viruses 12%
What does antibiotic choice depend on?
– Setting
– Severity
– Co-morbidities (esp resp disease)
– Epidemiology
– Patient allergies
Which antibiotics will be used to treat pneumonia in -
Community
Hospital - not severe
Hospital - severe
What are the clearence rates for community acqured pneumonia (CAP)?
- In adults aged 18-60, 95% of CAP will clear within 6 weeks (hence CXR at 6/52)
- In older people clearance is slower
–35.1% within 3 weeks
–60.2% within 6 weeks
–84.2% within 12 weeks
Which factors make community acquired pneumonia clearence slower?
Clearance is slower with comorbidity, bacteremia, multilobar involvement, or enteric gram-negative bacilli pneumonia
What does this chest x-ray show?
Consolidation obscuring L heart border (i.e. in lingula) with air bronchograms
What do these ABG results show?
•Type 1 respiratory failure
Metabolic acidosis
Which patients can you kill with oxygen?
worsening Type 2 Respiratory failure patients
What are the different patient interfaces for oxygen?
- Nasal cannulae
- Controlled (fixed percentage - venturi) masks
- Uncontrolled masks
- Hudson
- Reservoir mask
What units does oxygen reach the patient as?
•Oxygen reaches the patient either as
litres per minute
percentage inspired oxygen
What can you only give to patients in critical care?
Can give higher oxygen concentration, positive pressure and reduce work of breathing
–Nasal HiFlow
–CPAP (continuous positive airway pressure)
–NIV (Non-invasive ventilation)
–Intubation and invasive Ventilation
–If everything fails consider ECMO (Extracorporeal membrane oxygenation)
What are the general complications of pneumonia?
General –
- respiratory failure
- sepsis – multi-system failure
What are the local complications of pneumonia?
Local –
- pleural effusion
- empyema
- lung abscess
- “organising pneumonia”
What are the possible reasons for pneumonia failing to respond?
- Wrong or incomplete diagnosis
- Antibiotic problem
- Complication developing
- Underlying bronchial obstruction
- Approach: Re review
Patient has pneumonia which is failing to respond.
On examination -
- Left side reduced expansion
- Left sided Reduced AE
- Stony dull percussion note
Whats the diagnosis?
Pleural parapneumonic Effusion
Whats the diagnosis?
Pleural parapneumonic Effusion
When should a Pleural parapneumonic Effusion be considered?
To be considered when the patient is not responding to treatment for pneumonia
What are the 3 types of Pleural parapneumonic Effusion?
–Simple parapneumonic
–Complicated parapneumonic
–empyema
What are the dominant pathogens which cause Pleural parapneumonic Effusion?
Dominant microbiology is Pneumococcus, but also Staph. aureus and Strep. milleri
Which differential diagnosis should be considered with
Pleural parapneumonic Effusion?
•Consider differential diagnosis of pleural tuberculosis
What are the indications for drainage of empyema?
- visibly purulent effusion
- radiologically loculated effusions
- positive microbial culture from effusion
- pleural pH less than 7.2
What does this chest x-ray show?
Lung absesses
Circular with straight line through it.
Why do lung absesses form?
- Formation of abscess can be another cause of failure to respond
- Need to think of cause
- Consider endocarditis
How are lung absesses treated?
- Need lavage
- Prolonged antibiotic course
What does this show?
Lung
Abscess
What are the common differential diagnoses of pneumonia?
CAP and lung cancer
CAP and heart failure
pulmonary emboli / infarction
What are the unusal and rare differential diagnoses of pneumonia?
Unusual
- specific infections, eg Tuberculosis
- complicating chronic bronchial suppuration,
eg bronchiectasis, Cystic Fibrosis
Rare
- vasculitis
- pulmonary eosinophilia
Crytogenic organising pneumonia
- Treated for bilateral CAP
- Failure to improve
What does this imply?
‘Atypical pneumonia’
–Antibiotics ineffective
- Treated for bilateral CAP
- Failure to improve
What are the alternate diagnoses for this patient?
–Hypersensitivity pneumonitis
–COP
–Heart faluire
–Vasculitis
This is an atypical pneumonia which didn’t respond to antibiotics.
Patient is HIV positive.
What is the diagnosis?
Pneumocystis jiroveci (PJP)
