Systemic inflammatory response syndrome
Two or more of the following clinical signs of systemic response to endothelial inflammation:
• Temperature > 38°C or < 36°C x Heart rate > 90 beats/min
• Tachypnoea (respiratory rate > 20 breaths/min or hyperventilation (Paco2 < 4.25 kPa))
• White blood cell count > 12 ⋅ 109/l or < 4 ⋅ 109/l or the presence of more than 10% immature neutrophils In the setting (or strong suspicion) of a known cause of endothelial inflammation such as:
• Infection (bacteria, viruses, fungi, parasites, yeasts, or other organisms)
• Pancreatitis x Ischaemia x Multiple trauma and tissue injury x Haemorrhagic shock x Immune mediated organ injury x Absence of any other known cause for such clinical abnormalities
Sepsis
Systemic response to infection manifested by two or more of the following:
• Temperature > 38°C or < 36°C x Raised heart rate > 90/min
• Tachypnoea (respiratory rate > 20 breaths/min or hyperventilation (Paco2 < 4.25 kPa))
• White blood cell count > 12 × 109/l or < 4 × 109/l or the presence of more than 10% immature neutrophils
Septic shock
Sepsis induced hypotension (systolic blood pressure < 90 mm Hg or a reduction of >40 mm Hg from baseline) despite adequate fluid resuscitation
Multiple organ dysfunction syndrome
Presence of altered organ function in an acutely ill patient such that homoeostasis cannot be maintained without intervention
Pathogenesis
Systemic sepsis may complicate an obvious primary infection such as community acquired pneumonia or a ruptured abdominal viscus. Frequently, however, an infective source cannot be identified and the type of organism cultured may provide no clue to its anatomical origin.
Infections that complicate critical illness may arise from the gastrointestinal tract. This region is