Effect of Shenmai injection on cognitive function after cardiopulmonary bypass in cardiac surgical patients: a randomized controlled trial

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common complication after cardiac surgery that influences the clinical outcomes and quality of life of patients. This study aimed to evaluate the effects of Shenmai injection (SMI) on POCD of patients who underwent cardiac valve replacement under cardiopulmonary bypass (CPB). METHODS: This prospective, randomized, controlled trial was conducted from September 2014 to January 2017. Eighty-eight patients receiving cardiac valve replacement under CPB were randomized into the control (C) or the SMI (S) group. SMI (0.6 mL/kg) was administered intravenously from the time of anesthesia induction to the beginning of CPB. Cognitive function was assessed at 3 days before surgery and 3 days, 7 days, and 1 month after surgery using the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ) score. The serum levels of neuroglobin (Ngb), hypoxia-inducible factor-1α (HIF-1α), and neuron-specific enolase (NSE) were measured at 30 min after induction (T(0)), immediately after the endonasal temperature rewarmed to 36 °C (T(1)), and 1 h (T(2)), 6 h (T(3)), 24 h (T(4)), 48 h (T(5)), and 72 h (T(6)) after CPB. RESULTS: Compared with the baseline values at T(0), the serum Ngb levels in group C were significantly decreased at T(1–2) and then increased at T(3–6), while the levels in group S were decreased at T(1–2) and increased at T(4–6), compared to group C (p < 0.05). The serum HIF-1α levels at T(1–4) and the serum NSE levels at T(1–6) were significantly increased in both groups (p < 0.05). The serum levels of Ngb at T(3), HIF-1α at T(1–3), and NSE at T(3–4,6) were lower in group S, compared to group C (p < 0.01). The MoCA-BJ scores were decreased at 3 and 7 days after surgery in both groups, and the MoCA-BJ scores in group S were higher than those in group C at 3 and 7 days after surgery (p < 0.01). CONCLUSION: Cognitive function is impaired postoperatively in patients who have undergone cardiac valve replacement under CPB. In addition, treatment with the traditional Chinese medicine SMI decreases the serum levels of Ngb, HIF-1α, and NSE as well as attenuates cognitive dysfunction. TRIAL REGISTRATION: This trial was registered with Clinicaltrials.gov as ChiCTR-TRC-14004373 on March 11, 2014.