Effects of dexmedetomidine on monocyte pyroptosis in peripheral blood of patients with cardiac valve replacement / 中华麻醉学杂志

ABSTRACT

Objective:To investigate the effects of dexmedetomidine on monocyte pyroptosis in peripheral blood of patients with cardiac valve replacement.Methods:Forty-four American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients of both sexes, aged 45-64 yr, with body mass index of 18-25 kg/m 2, of New York Heart Association Ⅱ or Ⅲ, scheduled for elective cardiac valve replacement, were divided into 2 groups ( n=22 each) using a random number table method: dexmedetomidine group (group Dex) and normal saline group (group NS). In group Dex, dexmedetomidine was intravenously infused in a dose of 0.5 μg/kg over 10 min starting from the end of anesthesia induction, followed by a continuous infusion at 0.5 μg·kg -1·h -1 until the end of operation, while the equal volume of normal saline was given instead of dexmedetomidine in group NS.Before skin incision (T 1), at 30 min after the beginning of cardiopulmonary bypass (CPB) (T 2), immediately after the end of CPB (T 3) and at 24 h after CPB (T 4), the blood samples of internal jugular vein were collected for determination of the concentrations of plasma interleukin-18 (IL-18) and IL-1β (by enzyme-linked immunosorbent assay), and the expression of NOD-like receptor family, pyrin domain containing 3 (NLRP3), caspase-1 and gasdermin-D (GSDMD) in monocytes (by Western blot). The intraoperative consumption of propofol, sufentanil and norepinephrine, time of postoperative mechanical ventilation and time of intensive care unit stay were recorded. Results:The levels of plasma IL-18 and IL-1β and expression of NLRP3, caspase-1 and GSDMD in monocytes were significantly higher at T 2-4 than at T 1 in two groups ( P<0.05). Compared with group NS, the levels of plasma IL-18 and IL-1β were significantly decreased and the expression of NLRP3, caspase-1 and GSDMD was down-regulated at T 2-4, postoperative mechanical ventilation time was shortened ( P<0.05), and no significant change was found in the consumption of propofol, sufentanil and norepinephrine and time of intensive care unit stay in group Dex ( P>0.05). Conclusion:The mechanism by which dexmedetomidine reduces inflammatory responses may be related to inhibiting the NLRP3/caspase-1 pathway and reducing monocyte pyroptosis in the patients undergoing cardiac valve replacement.