Effect of Remote Ischemic Preconditioning on Intestinal Ischemia-Reperfusion Injury in Adults Undergoing On-Pump CABG Surgery: A Randomized Controlled Pilot Trial.

OBJECTIVE:Cardiopulmonary bypass (CPB) surgery commonly threatens the heart and remote organs with ischemia-reperfusion injury. Transient episodes of ischemia to nonvital tissue, known as remote ischemic preconditioning (RIPC), is thought to help local and remote vital organs to withstand subsequent ischemic insults. DESIGN:Prospective, randomized, double-blinded control trial. SETTING:Tertiary referral academic teaching hospital. PARTICIPANTS:Thirty patients undergoing elective CPB surgery INTERVENTION: RIPC was achieved via three 5-minute cycles of upper limb ischemia using a blood pressure cuff or control (sham cuff). MEASUREMENTS AND MAIN RESULTS:Primary outcome was the occurrence of intestinal injury, as measured by an increase in intestinal fatty acid binding protein (I-FABP). Secondary outcomes included incidence of gastrointestinal complications and duration of intensive care unit (ICU) stay. RIPC did not affect serum IFABP levels at the end of surgery and on the first postoperative day (p = 0.697 and p = 0.461, respectively). For all patients, mean I-FABP levels significantly increased at the end of surgery and decreased to under baseline levels on the first postoperative day (from a mean [± standard deviation] baseline value of 764 ± 492 pg/mL to 2,002 ± 974 pg/mL and decreased to 568 ± 319 pg/mL, p < 0.001). All patients remained clinically absent of gastrointestinal complications until hospital discharge. Duration of ICU stay was not correlated with I-FABP levels at the end of surgery. Neither duration of CPB nor duration of aortic clamping significantly correlated with postoperative I-FABP levels. CONCLUSIONS:These findings suggest that RIPC does not affect intestinal injury in patients undergoing CPB surgery. In patients undergoing cardiac surgery, intestinal injury appears to be moderate and transient without any clinical relevant complication.