Effects of Remote Ischemic Preconditioning on Delirium and Neurological Function in Patients Undergoing Cardiac Surgery: A Multicenter Randomized Controlled Trial

Background: Postoperative delirium (POD) and neurological dysfunction are very common following cardiac surgery and deteriorate the patient's prognosis and the outcome of surgical procedures. A clinically effective management strategy or drug is not yet available for POD. Additionally, it is unknown whether remote ischemic preconditioning (RIPC) has neuroprotective and anti-delirium benefits in patients who undergo cardiac surgery. Methods: This study examined whether RIPC can improve POD and neurological function in cardiac surgery patients. We screened 510 consecutive adult patients aged 18 and older who underwent cardiac surgery between January 2018 and December 2022. Then, 448 of these patients were recruited in the trial as the intention to treat (ITT) group, who were then randomly assigned to receive either a control (n = 223) or RIPC treatment (n = 225). The primary outcome measures were hospitalization postoperative delirium, sixmonth modified Rankins scale (mRS), hospital cerebral infarction, 30-day overall mortality, neuron-specific enolase (NSE) and S-100b levels, related adverse effects, hospital costs, and hospital stay. Results: A statistically significant variation was not observed between the two groups in terms of the baseline clinical data. In contrast to the control group, the POD in the RIPC group was considerably alleviated. RIPC treatment also decreased the levels of NSE and S-100b, which alleviated nerve injury. The adverse impacts of RIPC-induced objective indicators of tissue or neurovascular damage were similar in both groups, showing no significant variations between the two. The hospital stays and hospitalization costs also decreased significantly in the RIPC-treated patients. Conclusion: The study findings suggested that RIPC may benefit cardiac surgery patients by reducing POD, alleviating injury, and lowering hospital expenditures and length of stay. Cardiac surgery patients can be treated with RIPC, which is an effective and safe technique.