clinical consequences of respiratory infection

Question 1

what are types of respiratory infection

Answer 1

URTI
Acute bronchitis
Exacerbation of chronic airway disease (COPD, bronchiectasis)
Pneumonia (CXR diagnosis in hospital, clinical in community setting)

Question 2

what are classifications of pneumonia

Answer 2

Anatomical
Lobar
Broncho-pneumonia
Diffuse

Setting
Community acquired
Hospital acquired
Ventilator related

Question 3

what is the prevalence of pneumonia

Answer 3

Common in very young and old
345 per 100,000 year
25% hospital admission and10% to ITU
10% all LRTIs

Question 4

how is pneumonia assessed clinically

Answer 4

Fully history – jobs, hobbies, pets, travel, risk of immunocompromised, home situation, smoking
Full examination
BP/HR/Sats

Question 5

what are signs of pneumonia

Answer 5

reduced air entry/PN, bronchial breathing, increased vocal resonance and crackles

Question 6

how is pneumonia diagnosed

Answer 6

Blood 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

Question 7

what does a chest x ray of pneumonia look like

Answer 7

consolidation in a lung lobe

can also be seen on CT

Question 8

how can the severity of pneumonia be assessed

Answer 8

The CURB 65 score
Confusion 
Raised blood Urea (>7mmol/L)
Raised Respiratory rate (>30/min)
Low BP (S<95, D <60)
Age >65 years 
If no urea CRB 65 score 
score 1-4 increasing in severity

Question 9

how is community pneumonia managed

Answer 9

(no risk factors)
Rest
Push fluids
Analgesics
Antibiotic 
Safety net 
Refer if no improvement in 48 hours

Question 10

how is hospital pneumonia managed

Answer 10

Oxygen if required
Fluid replacement if required
Antibiotics
Critical care management

Question 11

what is the bacteriology of community acquired pneumonia

Answer 11

strep pneumoniae most likely, then
chlamydia pneumoniae
mycoplasma pneumoniae
haemophilus influenzae
staph aureus
viruses

Question 12

what does antibiotic treatment of pneumonia depend on

Answer 12

Choice depends on
Setting
Severity
Co-morbidities (esp resp disease)
Epidemiology
Patient allergies

Question 13

what antibiotics treat pneumonia

Answer 13

Community – amoxicillin or doxycycline
Hospital – not severe – amoxicillin +/- doxycycline or doxycycline
Hospital – severe amoxicillin and doxycycline or ceftriaxone/levofloxacin

Question 14

what happens after pneumonia treatment

Answer 14

CAP follow up: 6 week xray

Question 15

why is the CAP followup 6 weeks

Answer 15

Clearance rates after CAP
Adults (18-50) 95% of CAP clear in 6 weeks
Older people, clearance is slower (or with comorbidities like bacteremia, multi-lobar involvement or enteric gram-negative bacilli pneumonia)

Question 16

what happens if pneumonia patients deteriorate

Answer 16

Deteriorate – high flow oxygen

MET call – repeat clinical assessment

Question 17

how is respiratory failure treated

Answer 17

You can save lives but kill with oxygen (worsening type 2 respiratory failure)
How it is given depends on the clinical circumstances and the patients background condition

Question 18

what are patent interfaces for oxygen

Answer 18

Nasal cannulae
Controlled (fixed percentage – venturi masks)
Uncontrolled masks (Hudson and reservoir masks)
Oxygen reaches the patient as litres per minute (or percentage
inspired oxygen – venturi)

Question 19

how is oxygen given in critical care

Answer 19

can give higher oxygen concentration, positive pressure and reduce work of breathing
nasal hiflow
CPAP (continuous positive airway pressure)
NV (non-invasive ventilation)
Intubation and invasive ventilation
If everything fails consider ECMO (extracorporeal membrane oxygenation)

Question 20

what are the complications of pneumonia

Answer 20

General 
Respiratory failure 
Sepsis – multi-system failure 
Local 
Pleural effusion
Emphysema
Lung abscess
“Organising pneumonia” – infection persists and needs treating with steroids

Question 21

why may pneumonia fail to respond

Answer 21

Wrong or incomplete diagnosis
Antibiotic problem 
Complication developing 
Underlying bronchial obstruction
Approach: re-review

Question 22

what is Pleural parapneumonic effusion

Answer 22

To be considered if patient is not responding to treatment
Can be
Simple parapneumonic
Complicated parapneumonic
Empyema
Dominant microbiology is pneumococcus but also staph, aureus and strep milleri
Consider differential diagnosis of pleural tuberculosis

Question 23

what should be considered with empyema

Answer 23

Indications for drainage 
Visibly purulent effusion 
Radiologically loculated effusions 
Positive microbial culture from effusion 
Pleural pH less than 7.2

Question 24

what should be considered with lung abscesses

Answer 24

Formation of abscess can be another causes of failure to respond
Need to think of cause 
Need lavage 
Consider endocarditis
Prolonged antibiotic course

Question 25

what is the differential diagnosis for pneumonia - why they’re not recovering

Answer 25

LRTI and lung cancer
LRTI and heart failure 
Pulmonary emboli/infarction
Unusual 
Specific infections eg TB
Complicating chronic bronchial suppuration eg bronchiectasis, CF

Rare
Vasculitis
Pulmonary eosinophilia
Crytogenic organising pneumonia