The influence of N-acetyl-L-cystein infusion on cytokine levels and gastric intramucosal pH during severe sepsis

INTRODUCTION: The purpose of the present study was to evaluate the effects of continuously infused N-acetyl-L-cystein (NAC) on serum cytokine levels and gastric intramucosal pH in humans suffering from severe sepsis. METHODS: Fifty-three patients were included in the study. In the NAC group (n = 27), after an initial intravenous bolus of NAC (150 mg/kg over 5 min), a continuous intravenous infusion of 12.5 mg/kg per hour was given for 6 hours. Patients in the control group (n = 26) were administered dextrose (5% solution) at the same dosage. We recorded the following: haemodynamic parameters, nasopharyngeal temperature, arterial blood gas changes, plasma cytokine levels, biochemical parameters, intramucosal pH, length of stay in the intensive care unit, duration of of mechanical ventilation and mortality. All measurements were taken at baseline (15 min before the start of the study) and were repeated immediately after the bolus infusion, and at 24 and 48 hours after initiation of the continuous NAC infusion. RESULTS: No differences were found between groups in levels of the major cytokines, duration of ventilation and intensive care unit stay, gastric intramucosal pH and arterial oxygen tension/inspired fractional oxygen ratio (P > 0.05). CONCLUSION: We found that NAC infusion at the doses given did not affect cytokine levels, outcomes, or gastric intramucosal pH in patients with severe sepsis. Because of the limited number of patients included in the study and the short period of observation, our findings need confirmation in larger clinical trials of NAC infused in a dose-titrated manner. However, our results do not support the use of NAC in patients with severe sepsis.