Clinical Trial Summary
Cardiac surgery with cardiopulmonary bypass (CPB) provokes a systemic inflammatory response
that can often lead to dysfunction of major organs. Activation of the contact system,
endotoxemia, surgical trauma, and ischemic reperfusion injury are all possible triggers of
inflammation. Previous studies demonstrated that pro-inflammatory cytokines play an important
role during this process. However, very little is known about the susceptibility of the
splanchnic organs to ischemic reperfusion injury. Although the incidence of intestinal
complications reported to be low, the in-hospital mortality in these patients was high at 15%
to 63%.
Dexmedetomidine, a highly selective α2-adrenergic agonist, can reduce the consumption of
other sedative and antinociceptive drugs and provide sufficient sedative effects with minimal
respiratory side effects. In addition, dexmedetomidine gradually has gained popularity in the
field of critical care. Preemptive administration of dexmedetomidine has shown to be
protective against inflammation, intestinal, renal, and myocardial injuries in animal and
human studies. Dexmedetomidine is also used as an anesthetic adjuvant during surgery to offer
good perioperative hemodynamic stability and an intraoperative anesthetic-sparing effect.
Perioperative use of dexmedetomidine can reduce intestinal and hepatic injury after
hepatectomy with inflow occlusion under general anesthesia. However, whether or not it can
exert protective effects on the above-mentioned organs, especially intestine, after cardiac
surgery remains unclear. The aim of this study is to evaluate the effects of dexmedetomidine
on intestinal, hepatic, and other organ injury in patients receiving cardiac surgery with
CPB.
In this double-blinded randomized controlled study, serum diamine oxidase activity, which is
a sensitive and specific marker for the detection of intestinal injury, is taken as the
primary endpoint. Other parameters reflecting the functions of liver (AST/ALT), lung (lung
injury score and CC-16), kidney (BUN/Cre), and heart (CK-MB/Troponin T), the biomarker of
endothelial injury (endocan) will also be determined. Besides, microcirculation parameters
measured with Cytocam® and near-infrared spectroscopy (NIRS) will be used to estimate the
protective effect of dexmedetomidine on microcirculation. The variables will be collected
perioperatively and will be followed up for 3 days after the surgery. Clinical outcome
parameters will be followed up for 3 months after the surgery.
