Pneumonia

• Pneumonia is a lower respiratory tract infection of the lung tissue that causes inflammation in the alveolar space
• Types of pneumonia:

  • CAP - can be primary or secondary to underlying cause
  • HAP - in hospital for more than 48 hours
  • Ventilator acquired
  • Aspiration pneumonia
• Presentation of pneumonia:

  • cough productive of sputum
  • Dyspnoea
  • Fever
  • Haemoptysis
  • Pleuritic chest pain
  • Delirium - can be only sign in elderly
• Chest signs characteristic of pneumonia:

  • Reduced expansion
  • Bronchial breath sounds
  • Course crackles
  • Dullness to percussion
  • Wheeze - particularly in those with associated respiratory conditions
• Streptococcus Pneumoniae is the most common causative pathogen of pneumonia
• Urinary antigen tests are needed for causes of atypical pneumonia:

  • Legionella
  • Chlamydia
  • Mycoplasm
  • Not treatable with penicillin
• CURB-65 score for CAP:

  · Confusion present (abbreviated mental test score <8/10)

  · Urea level >7mmol/L

  · Respiratory rate >30/min

  · Blood pressure systolic <90 mmHg or diastolic <60 mmhg

  · Age > 65
• Patients with a CURB-65 score of 0 or 1 can usually be treated in primary care with no investigation
• Investigations for pneumonia:

  • CXR - lobular consolidation and pleural effusion
  • FBC and CRP - raised WCC and inflammation
  • U&Es - urea for CURB-65 and AKI
  • Sputum culture
  • Blood culture if pyrexical
  • Urine antigen tests
• Treatment of CAP:

  • Oral first line - amoxicillin, clarithromycin or doxycycline
  • High severity/ IV first line - co-amoxiclav and clarithromycin
• Treatment of HAP:

  • Oral first line - co-amoxiclav
  • Severe - IV Taz
• Patients diagnosed with pneumonia will need a follow up in 6 weeks +/- a chest x-ray
• Complications of pneumonia:

  • Respiratory failure - common
  • AF
  • Pleural effusion that can lead to empyema
  • Pericarditis
  • Septic shock
  • Lung abscesses
  • Post infective bronchiectasis
• Pneumonia = inflammation of the lung parenchyma with the normal air-filled lungs becoming filled with infective liquid
• Risk factors:

  • Age - infants and those over 65
  • Smoking
  • Alcohol
  • Pre-existing respiratory conditions
  • Hospitalisation
  • Proton pump inhibitors
  • Poor oral hygiene
• Legionella and pneumococcal urinary antigen: this should be requested in those with moderate or high-severity CAP or where other risk factors exist.
• Vaccinations available:

  • Pneumococcal
  • haemophilus influenza type b
• Viral respiratory tract infections can lead to primary viral pneumonia and predispose to secondary bacterial pneumonia. The most common viruses detected in cases of CAP are influenza A and B.
• Fungal pneumonia is rare and primarily seen in immunocompromised patients and endemic areas. These include Cryptococcus neoformans, candida species, Aspergillus species, Histoplasma capsulatum and Pneumocystis jirovecii (AIDS defining illness)