septicaemia

Last edited 09/2019 and last reviewed 05/2023

Septicaemia is probably misnamed as blood poisoning; it is a systemic disease associated with the presence and persistence of pathogenic organisms or their toxins in the blood.

Sepsis should be defined as life-threatening organ dysfunction caused by a dysregulated host response to infection:

  • for clinical operationalization, organ dysfunction can be represented by an increase in the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score of 2 points or more, which is associated with an in-hospital mortality greater than 10% (1)

  • septic shock should be defined as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone
    • The international definitions require that hypotension requiring the use of vasoactive infusions and a high arterial lactate content be used to describe septic shock: in General Practice and Urgent Care hypotension in the presence of presumed infection is an appropriate surrogate to describe presumed septic shock (3)

  • patients with septic shock can be clinically identified by a vasopressor requirement to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate level greater than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia
    • combination is associated with hospital mortality rates greater than 40%

    • in out-of-hospital, emergency department, or general hospital ward settings, adult patients with suspected infection can be rapidly identified as being more likely to have poor outcomes typical of sepsis if they have at least 2 of the following clinical criteria that together constitute a new bedside clinical score termed quickSOFA (qSOFA):
      • respiratory rate of 22/min or greater,
      • altered mentation, or
      • systolic blood pressure of 100 mm Hg or less (1)

NICE state "..Sepsis is a clinical syndrome caused by the body's immune and coagulation systems being switched on by an infection. Sepsis with shock is a life-threatening condition that is characterised by low blood pressure despite adequate fluid replacement, and organ dysfunction or failure. Sepsis is an important cause of death in people of all ages.....

Previous terminology included terms SIRS (systematic inflammatory response syndrome), severe sepsis and septic shock but new terminology suggests using terms sepsis and septic shock only . Sepsis is defined as a life-threatening organ dysfunction due to a dysregulated host response to infection and septic shock as persisting hypotension requiring vasopressors to maintain a mean arterial pressure (MAP) of 65 mmHg or more and having a serum lactate level of greater than 2 mmol/l despite adequate volume resuscitation..."

  • The Systemic Inflammatory Response Syndrome (SIRS) criteria is no longer form part of the diagnostic criteria for sepsis (3)

Septic shock is defined as a subset of sepsis where particularly profound circulatory, cellular and metabolic abnormalities substantially increase mortality.