Pneumonia (clinical consequences of resp infections)

Question 1

Classification of Pneumonia

Answer 1

Anatomical - lobar, bronchopneumonia, diffuse

Setting - community acquired, hospital acquired, ventilator related

Question 2

Prevalence

Answer 2

More common in very young and very old
345/100 000 per year
25% require hospital admission - and of these 10% need ITU care

Question 3

Pneumonia Diagnostics

Answer 3

RR/HR/BP/Sats, signs of pneumonia - reduced air entry/vocal resonance/crackles
Blood tests - assess for evidence of infection/inflammation, assess renal and liver function, blood cultures, HIV test
Sputum
Viral throat swab
Urine - legionella Ag
Arterial Blood Gas

Question 4

Assessing severity

Answer 4

CURB 65 score: Confusion, Raised blood urea (>7mmol/L), raised respiratory rate (>30/min), Low BP (S<95;D<60), 65 years

Question 5

Management and Treatment

Answer 5

Community: rest, fluids antibiotics - amoxicillin or doxycycline
Hospital (not severe): oxygen, fluids, antibiotics - amoxicillin +/- doxycycline or just doxycycline
Hospital (severe): oxygen, fluids, critical care, antibiotics - amoxicillin + doxycycline or ceftriaxone/levofloxacin

Question 6

Clearance Rates after CAP

Answer 6

In adults, 18-60, 95% of community acquired pneumonia will clear within 6 weeks - hence 6 week CXR
Clearance slower in: older people, people with increased comorbidity bacteremia, multi-lobar involvement, or enteric Gram-negative bacilli pneumonia

Question 7

In Critical Care

Answer 7

Can give higher O2 concentration, positive pressure and reduce work of breathing
Nasal Hiflow, CPAP (continuous positive airway pressure), NIV (non-invasive ventilation), Intubation & invasive ventilation, consider ECMO (extracorporeal membrane oxygenation)
Complications: general (resp failure and sepsis) and local (pleural effusion, empyema, lung abscess organising pneumonia)

Question 8

Failure to respond

Answer 8

Wrong/incomplete diagnosis, antibiotic problem, complication developing, underlying bronchial obstruction - review
Left side reduced expansion
Left sided reduced AE
Stony dull percussion note

Question 9

Pleural Parapneumonic Effusion

Answer 9

When patient isn’t repsonding to treatment: simple, complicated or empyema
Dominant microbiology: pneumococcus, S. Aureus, Strep milleri
Consider differential diagnosis of pleural TB
Empyema: indications for drainage include visible purulent effusion, radiologically loculated effusions, positive microbial culture from effusion, pleural pH below 7.2

Question 10

Lung Abscess

Answer 10

Another cause of failure to respond
Consider endocarditits
Lavage and prolonged antibiotic course

Question 11

Differential Diagnosis

Answer 11

Common: LRTI and lung cancer; LRTI and heart failure; PE/MI
Unusual: specific infection (TB); complicating chronic bronchial suppuration (bronchiectasis/CF)
Rare: vasculitis; pulmonary eosinophilia; cytogenic organising pneumonia
Atypical pneumonia - antibiotics ineffective
Alternative diagnosis - COPD/hypersensitivity pneumonitis/HF/vasculitis