Systemic inflammatory response syndrome without systemic inflammation in acutely ill patients admitted to hospital in a medical emergency

Criteria of the systemic inflammatory response syndrome (SIRS) are known to include patients without systemic inflammation. Our aim was to explore add itional markers of inflammation that would distinguish SIRS patients with s ystemic inflammation from patients without inflammation. The study included 100 acutely ill patients with SIPS. Peripheral blood neutrophil and monocy te CD11b expression, serum interleukin-6, interleukin-1 beta, tumour necros is factor-alpha and C-reactive protein were determined, and severity of inf lammation was evaluated by systemic inflammation composite score based on C D11b expression, C-reactive protein and cytokine levels. Levels of CD11b ex pression, C-reactive protein and interleukin-6 were higher in sepsis patien ts than in SIPS patients who met two criteria (SIRS2 group) or three criter ia of SIRS (SIRS3 group). The systemic inflammation composite score of SIRS 2 patients (median 1.5; range 0-8, n = 56) was lower than that of SIRS3 pat ients (3.5; range 0-9, n = 14, P = 0.013) and that of sepsis patients (5.0; range 3-10, n = 19, P < 0.001). The systemic inflammation composite score was 0 in 13/94 patients. In 81 patients in whom systemic inflammation compo site scores exceeded I, interleukin-6 was increased in 64 (79.0%), C-reacti ve protein in 59 (72.8%) and CD11b in 50 (61.7%). None of these markers, wh en used alone, identified all patients but at least one marker was positive in each patient. Quantifying phagocyte CD11b expression and serum interleu kin-6 and C-reactive protein concurrently provides a means to discriminate SIRS patients with systemic inflammation from patients without systemic inf lammation.