Effects of propofol and dexmedetomidine with and without remifentanil on serum cytokine concentrations in healthy volunteers: a post hoc analysis

Background: Anaesthetic agents are likely to alter circulating cytokine concentrations. Because preceding studies have not been able to exclude the contribution of surgical trauma, perioperative stress, or both to circulating cytokine concentrations, the effects of anaesthesia remain unclear. The aim of this study was to quantify serum cytokines in healthy volunteers administered i.v. anaesthetic agents in the absence of surgical trauma and perioperative stress. Methods: Serum samples obtained during previous standardised studies from healthy volunteers were compared before and 6-8 h after induction of anaesthesia with propofol (n=31), propofol/remifentanil (n=30), dexmedetomidine (n=17) or dexmedetomidine/remifentanil (n=15). Anaesthetic regimens were standardised and volunteers did not undergo any surgical intervention. Serum concentrations of interleukin (IL)2, IL4, IL6, IL10, IL17, IL18, IL21, IL22, IL23, C-X-C motif ligand 8, interferon gamma, E-selectin, L-selectin, major histocompatibility complex class I chain-polypeptide-related sequence (MIC)A, MICB, Granzyme A, and Granzyme B were quantified using a multiplexed antibody-based assay (Luminex). Results: Samples were obtained from volunteers of either sex aged 18-70 yr. After anaesthesia with propofol alone, concentrations of IL4 (P= 0.012), IL6 (P= 0.027), IL21 (P= 0.035), IL22 (P= 0.002), C-X-C motif ligand 8 (P= 0.004), MICB (P= 0.046), and Granzyme A (P= 0.045) increased. After anaesthesia with propofol and remifentanil, IL17 (P= 0.013), interferon gamma (P= 0.003), and MICA (P= 0.001) decreased, but IL6 (P= 0.006) and L-selectin (P= 0.001) increased. After dexmedetomidine alone, IL18 (P= 0.002), L-selectin (P= 0.017), E-selectin (P= 0.002), and Granzyme B (P= 0.023) decreased. After dexmedetomidine with remifentanil no changes were observed. Conclusions: In healthy volunteers not undergoing surgery, different i.v. anaesthesia regimens were associated with differential effects on circulating cytokines.