Pneumonia

Classifications;

• Community acquired – may be primary or secondary due to underlying disease
  • Strep pneumoniae
  • H. influenzae
  • Mycoplasma pneumoniae
  • Staph aureus
  • Legionalla
  • Moraxella catarrhalis
  • Chlamydia
  • Coxiella burnetii
• Hospital acquired;
  • E.Coli
  • Staph aureus
  • Pseudomonas
  • Klebsiella
  • Bacteriodes
  • Clostridia
• Aspiration
• Immunocompromised
  • Strep pneumoniae
  • H. influenzae
  • Staph aureus
  • PCP
  • Mycobacteria

Tests

• CXR
• Assess oxygenation – pulse ox, ABG
• Bloods – FBC, U&E, LFTs, CRP, blood cultures
• Sputum -  cytology and culture
• pleural fluid
• Consider bronchoscopy and BAL if immunocompromised or on ITU

Severity

• CURB-65 score;
  • Confusion (MMT less or equal to
  • Urea >7mmol/L
  • RR > or equal to 30
  • BP less than 90 systolic and/or 60 diastolic
  • Age >65
• Score greater or equal to 3 is severe pneumonia
• Score 0-1 home treatment is possible
• Score of 2 requires hospital therapy
• Other features that increase risk of death;
  • Bilateral or multilobar involvement
  • PaO2 <8kPa or SaO2 <92%

Management

• Antibiotics (orally if not severe and not vomiting)
• Oxygen (keep PaO2 above 8kPa and Sats >92%
• IV fluids
• Analgesia (paracetamol 1g/8hr)
• If severe admit to ITU (shock, hypercapnia, uncorrected hypoxia)
• All patients require a 6wk check up with CXR

Complications;

• Pleural effusion
• Empyema (Turbid fluid, pH <7.2, ? glucose, ­LDH)
• Lung abscess
• Respiratory failure – most commonly Type I
  • Treat with high flow O2, aim to keep sats at 90-94%
• Hypotension – dehydration and vasodilation due to sepsis
  • If systolic <90 give a 250ml challenge over 15mins, if BP doesn’t rise insert a central line and give fluids until BP rises
• AF
  • Digoxin may be required short term
• Septicaemia
• Brain abscess
• Pericarditis/myocarditis
• Cholestatic jaundice – may be due to sepsis or antibiotic treatment (particularly flucloxacillin or co-amoxiclav)

Lung Abscess

• Causes;
  • Inadequately treated pneumonia
  • Aspiration
  • Bronchial obstruction
  • Pulmonary infarction
  • Septic emboli
  • Subphrenic or hepatic embolus
• Clinical features;
  • Swinging fever, cough with purulent sputum, pleuritic chest pain, haemoptysis, malaise, weight loss
  • Signs – clubbing, anaemia, crepitations
  • Empyema may develop
• Tests;
  • Bloods – FBC, ESR, CRP, blood cultures
  • Sputum – microscopy, culture, cytology
  • CXR – walled cavity often with a fluid level
  • Consider CT to rule out obstruction and bronchoscopy to obtain diagnostic specimens
• Treatment – antibiotics, continue until it has healed (4-6wk)

Preventing pneumococcal infections

• Give pneumovax vaccine to those with;
  • Age >65
  • Chronic heart, kidney or lung conditions
  • Diabetes
  • Nephrosis
  • Immunosuppression
• (CI – fever, pregnancy, lactation)

Empirical treatment of pneumonia

Specific pneumonias