Drotrecogin alfa (activated) may attenuate severe sepsis-associated encephalopathy in clinical septic shock

INTRODUCTION: Sepsis-associated encephalopathy (SAE) is a diffuse cerebral dysfunction induced by the immuno-inflammatory response to infection. Elevated levels of the brain-specific S100B protein are present in many septic patients and reflect the severity of SAE. Adjunctive treatment with drotrecogin alfa (activated) (DrotAA), the human recombinant form of activated protein C, has been shown to improve mortality in patients with severe sepsis-induced organ failure. We studied the effect of DrotAA on S100B levels in patients with acute septic shock who presented with increased baseline values of this biomarker. METHODS: All patients received standard goal-directed resuscitation treatment. Patients with pre-existing or acute neurological disorders were excluded. Based on the Glasgow coma scale (GCS), patients were classified into two groups: GCS ≥ 13 and GCS <13. DrotAA was given as a continuous infusion of 24 μg/kg/h for 96 h. S100B was measured before sedation and the start of DrotAA (0 h) and at 32 h, 64 h and 96 h and at corresponding time points in patients not treated with DrotAA. The lower limit of normal was < 0.5 μg/L. RESULTS: Fifty-four patients completed the study. S100B was increased in 29 (54%) patients. Twenty-four patients (9 with GCS ≥ 13 and 15 with GCS <13) received DrotAA. S100B levels in DrotAA-treated patients with a GCS <13, though higher at baseline than in untreated subjects (1.21 ± 0.22 μg/L vs. 0.95 ± 0.12 μg/L; P = 0.07), progressively and significantly decreased during infusion (0.96 ± 0.22 μg/L at 32 h, P = 0.3; 0.73 ± 0.12 μg/L at 64 h, P < 0.05; and 0.70 ± 0.13 μg/L at 96 h, P < 0.05 vs. baseline). This patient group had also significantly lower S100B values at 64 h and at 96 h than their untreated counterparts. In the patients with a GCS ≥ 13, S100B levels were not influenced by DrotAA treatment. CONCLUSIONS: S100B-positivity is present in more than half of the patients with septic shock. When increased S100B levels are used as a surrogate for SAE, adjunctive DrotAA treatment seems to beneficially affect the evolution of severe SAE as discriminated by an admission GCS <13.