Pneumonia definition

• Pneumonia:

  • This term refers to the inflammation of lung parenchyma associated with alveoli filling with exudate
  • Pneumonia can result from a variety of causes including infection
  • Also can occur secondary to chemical or physical injury to the lungs
  • Pneumonia may also be described as idiopathic (unknown) when infectious causes have been excluded
• Epidemiology

  • Pneumonia is very common in UK affecting 1 in every 100 people each year
  • Although more than 100 strains of microorganism cause pneumonia only a few are responsible for most cases
  • The most common causes of pneumonia are viruses and bacteria
  • Less common causes of infectious pneumonia are fungi and parasites
• Pathophysiology

  • Symptoms of infectious pneumonia are caused by invasion of lungs by microorganisms and by immune system's response to that infection
  • Organisms invade spaces between cells and between alveoli via connecting pores
  • This invasion triggers the immune system
  • Neutrophils engulf and kill organisms
  • White blood cells (mainly lymphocytes) activate chemical cytokines which allow fluid to leak into the alveoli
• Lung with pneumonia

  A) pneumonia

  B) inflammation

  
• Main problems:

  • The combination of cell destruction and fluid filled alveoli interrupts the normal transportation of oxygen into the blood
  • Affected alveoli can no longer be used for ventilation causing hypoxaemia
  • Affected alveoli remain patent with no loss of volume (atelectasis)
  • This airless state is called consolidation
• Symptoms - Typical symptoms associated with pneumonia:

  • Cough
  • Chest pain
  • Fever and rigors
  • Rapid shallow breathing / Shortness of breath
  • Haemoptysis
  • Weight loss
  • (sometimes) Sputum production
• Pneumonia Chest Xray:

  A) pneumonia

  
• Auscultation:

  • Reduced breath sounds over pneumonic area
  • Bronchial breath sounds transmitted from trachea and main airways – Indication of consolidation
  • Inspiratory crackles before pneumonia organises or during resolution of consolidation
• Complications:

  • Respiratory and circulatory failure
  • Pleural effusion
  • Empyema
  • Abscess
• Management:

  • High flow O2 therapy
  • Antibiotics if bacterial in origin
  • Fluid resuscitation
  • Positioning to maximise V/Q
  • Analgesia for chest pain
  • Airway clearance techniques if productive of sputum
  • Ventilatory support (non-invasive / invasive)