Effects of dexmedetomidine used to supplement analgesia with sufentanil on stress response and inflammatory response after cardiac valve replacement with CPB

Objective To evaluate the effects of dexmedetomidine used to supplement analgesia with sufentanil on the stress response and inflammatory response after cardiac valve replacement with cardiopulmonary bypass (CPB). Methods Forty-four patients of both sexes, aged 18-64 yr, with body mass index of 18-30 kg/m2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ (New York Heart Association Ⅱ or Ⅲ), scheduled for elective cardiac valve replacement with CPB, were randomly divided into sufentanil analgesia group (group S, n=20) and dexmedetomidine supplementing sufentanil analgesia group (group DS, n=24) using a random number table.After induction of general anesthesia, the patients were endotracheally intubated and mechanically ventilated.Combined intravenous-inhalational anesthesia was used to maintain anesthesia.Dexmedetomidine was infused at 0.3 μg·kg-1·h-1 from closure of the chest to the end of surgery in group DS, while the equal volume of normal saline was given instead in group S. The patient-controlled intravenous analgesia (PCIA) was used for postoperative analgesia.PCIA solution contained sufentanil 2 μg/kg in 100 ml of normal saline in group S, or sufentanil 2 μg/kg plus dexmedetomidine 3 μg/kg in 100 ml of normal saline in group DS.The PCIA pump was set up with a 0.5 ml bolus dose, a 5 min lockout interval and background infusion at a rate of 1.5 ml/h.Visual analogue scale score was maintained≤3.When visual analogue scale score≥4, morphine 0.1 mg/kg was injected intravenously.The occurrence of analgesics-related respiratory depression, bradycardia and hypotension was recorded.At the end of surgery (T0), and 12, 24, 48 and 72 h after surgery (T1-4), blood samples were collected from the central vein for determination of serum cortisol, β-endorphin, C-reactive protein, interleukin-2 (IL-2), and IL-6 concentrations by enzyme-linked immunosorbent assay. Results No analgesics-related adverse events were detected in the two groups.Compared with group S, the requirement for morphine was significantly decreased, the serum cortisol concentration was decreased at T2-4 and the serum β-endorphin, C-reactive protein concentrations were decreased at T1-4, the serum IL-2 concentrations were increased at T1-4, and the serum IL-6 concentrations were increased at T3 in group DS (P<0.05). Conclusion Dexmedetomidine used to supplement analgesia with sufentanil can alleviate the stress response and inflammatory response after cardiac valve replacement with CPB. Key words: Dexmedetomidine; Sufentanil; Pain, postoperative; Oxidative stress; Inflammation; Cardiopulmonary bypass; Heart valve prosthesis implantation