Effect of continuous infusion of midazolam on immune function in pediatric patients after surgery

The current study was performed to investigate the effects of midazolam on immune function in pediatric patients after surgery and possible mechanism involved. Patients who needed sedation for more than 2 consecutive days after undergoing surgery in the Pediatric Surgery Department of our hospital were enrolled for the study. Fifty-six patients (5-14 years old) were randomly divided into midazolam and propofol treatment groups (N = 28 each in each group). Pediatric patients received midazolam or profolol via continuous intravenous administration, and their plasma cytokine levels were compared after 48 h. Cultured rat C6 brain glioma cells were pretreated with a range of concentrations of midazolam or propofol for 60 minutes prior to incubation with 10 ng/mL IL-1β in serum-free medium or vehicle for 36 h. IL-6 concentration was subsequently measured using ELISA. In comparison with levels measured before the infusion of midazolam for 48 h, concentrations of all cytokines decreased, with the differences in IL-1β, IL-8, and TNF-α concentrations reaching significance (all P < 0.05). Midazolam significantly suppressed the IL-1β-induced release of IL-6 in rat C6 glioma cells. This inhibition was concentration-dependent between 0.3 and 3 μM, with 3 μM concentration of midazolam decreasing the IL-1β-induced release of IL-6 by 43.58%. Midazolam can significantly inhibit the release of cytokines in pediatric patients after surgery. One of the mechanisms may be the inhibition of IL-1β- induced release of IL-6 in the central nervous system.