Hemofiltration does not influence early S-100B serum levels in septic shock patients receiving stress doses of hydrocortisone or placebo

Background: The prognosis in patients with hyperdynamic septic shock correlates with the presence and the severity of septic encephalopathy. However, the neurological evaluation is considerably influenced by the use of analgesia sedation during mechanical ventilation. An early concentration peak of the neuroprotein S-100B in serum reflects both cellular damage at an increased permeability of the blood-brain-barrier and a delayed renal elimination. Thus, the objective of this study was to analyze the effect of continuous veno-venous hemofiltration (CVVH) on early S-100B serum levels in septic shock patients, who were treated with either stress doses of hydrocortisone or placebo. Methods: Twenty-four consecutive patients, who met the ACCP / SCCM criteria for septic shock, were enrolled in this prospective, randomised, double-blind, single-center trial. The severity of illness at recruitment was graded using the APACHE 11 and SAPS II scoring systems; the MODS was described by the SOFA score. All patients were prospectively randomised to receive either stress doses of hydrocortisone or placebo. Hydrocortisone was started in 12 patients with a loading dose of 100 mg and followed by a continuous infusion of 0.18 mg/kg/h for 6 days. Results: Median S-100B serum levels of the hydrocortisone group decreased from 0.32 ng/ml (0.19-3.60) at study entry to 0.07 ng/ml (0.04-0.32) 6 days later without significant differences compared to the placebo group. Patients undergoing CVVH showed significantly higher S-100B serum values compared to patients without CVVH (p<0.001). However, initial median S-100B serum levels of the CVVH group even increased from 0.92 ng/ml (0.16 - 4.63) to 2.33 ng/ml (0359 - 2.44) 30 hours after study entry, reaching data ranges already known in patients with out-of-hospital cardiac arrest or severe traumatic brain injury. Conclusion: Early S-100B serum levels in septic shock patients receiving either stress doses of hydrocortisone or placebo were not influenced by CVVH. For the first time, we observed a similar extent of S-100B serum increase in CVVH patients, who had significantly higher S-100B serum values compared to those without CVVH, as reported for out-of-hospital cardiac arrest or severe traumatic brain injury. Hypercortisolemia induced by the infusion of stress doses of hydrocortisone did not significantly reduce early S-100B serum concentrations with time.