Pyrexia - PACT - ESICM

For opportunistic infections in surgical patients:
Task 1. Assessing and measuring fever in ICU
Dunn DL. Diagnosis and treatment of opportunistic infections in
immunocompromised surgical patients. Am Surg 2000; 66(2): 117–125.
PMID 10695740
Systemic inflammatory response syndrome (SIRS)
In any patient with fever, one has to consider the likelihood of microbial
infection and sepsis as opposed to SIRS which has been defined as:
Fever (>38 °C) or hypothermia (90 b/min)
Tachypnoea (>20/min), or fall in arterial PCO2 (12.0 x 10 9 /L) or leukopenia (10%
immature (band) forms.
See PACT module on Sepsis and MODS.
Sepsis is defined as SIRS in the presence of a clinical or microbiologically
proven infection. Infection is indicated by a host response to micro-organisms
or the invasion of otherwise sterile host tissues by (replicating) microorganisms.
However, the predictive value of SIRS for severe microbial infection may be
poor; specificity is low and sensitivity high. For example, the criteria are often
met in trauma patients even in the absence of microbial infection. Hence, the
clinical value of SIRS is in doubt. Nevertheless, meeting severe sepsis (organ
dysfunction associated with sepsis) and septic shock criteria (hypotension below
90 mmHg in sepsis despite volume resuscitation) carries a higher mortality rate
than meeting SIRS criteria alone, so that the latter classifications may have
prognostic (rather than diagnostic) significance.
THINK: The usefulness of SIRS and sepsis criteria in patients with fever remains
unclear. The sensitivity of the syndrome may be too high and specificity too low for
microbial infection, even when supplemented by other ‘sepsis signs’.
You may wish to consider the following references.
Pittet D, Rangel-Frausto S, Li N, Tarara D, Costigan M, Rempe L, et al. Systemic
inflammatory response syndrome, sepsis, severe sepsis and septic shock:
incidence, morbidities and outcomes in surgical ICU patients. Intensive
Care Med 1995; 21(4): 302–309. PMID 7650252
Bossink AW, Groeneveld AB, Koffeman GI, Becker A. Prediction of shock in
febrile medical patients with a clinical infection. Crit Care Med 2001;
29(1): 25–31. PMID 11176153
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