Sepsis: A life threatening organ dysfunction caused by a dysregulated host response to an infection

Sepsis is increasingly recognised as an important cause of mortality in the UK and there has been increasing efforts recently to improve the care of patients who present with sepsis.

septic shock: a more severe form sepsis, technically defined as 'in which circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone

Aetiology

Most common sites of infection leading to sepsis are:

• respiratory
• GI
• renal
• GU
• blood
• skin and soft tissue
• bone and joints

Usually bacterial causes. rarely fungal, viral or parasitic

About 80% of hospital-treated sepsis cases originate from community-acquired infection

Pathophysiology

• The mechanism of cell injury is not fully understood, but it is theorized that immune and coagulation systems are switched on by infection and cause dysfunction of one or more organs with variable severity
• Involves early activation of pro-inflammatory responses leading to tissue damage and anti-inflammatory responses leading to immunosuppression. This causes organ dysfunction via =
  • tissue hypoxia
  • mitochondrial dysfunction
  • microvascular and macrovascular damage
  • apoptosis