CRP and systemic inflammatory response syndrome: Patients with severe sepsis had markedly higher levels of C-reactive protein (CRP: 161.8 ng/ml; IQR 109.5–215.7 ng/ml) and procalcitonin (PCT: 8.8 ng/ml; IQR 2.15–39.2 ng/ml) than patients with severe SIRS (CRP: 5.50 ng/ml; IQR 1.90–18.2 ng/ml, p < 0.0001 and PCT: 0.20 ng/ml; IQR 0.10–1.10 ng/ml, p = 0.0002).