ObjectiveTo investigate the brain protective effect of dexmedetomidine combined with ulinastatin on patients undergoing valve replacement under cardiopulmonary bypass.

MethodsEighty patients undergoing elective cardiac valve replacement were randomly divided into control group (group N), dexmedetomidine group (group D), ulinastatin group (group U), and dexmedetomidine combined with ulinastatin group (group U+D).Group D was pumped 1.0 μg/kg for 15 minutes before induction, and then 0.4 μg·kg^-1·h^-1 until the end of the operation.Group U was given 20 000 U/kg intravenously immediately after induction.The usage of dexmetomidine and ulinastatin in group U+D was the same as above, and group N had the same amount of 0.9% sodium chloride solution.Before cardiopulmonary bypass (T₁), ascending aorta opening (T₂), shutdown (T₃), and 6 hours after surgery (T₄), blood gas analysis was performed to detect internal jugular vein oxygen saturation (SjvO₂), arterial internal jugular vein oxygen content difference (Da-jvO₂), and cerebral oxygen uptake rate (CERO₂) in four groups of patients, and local cerebral oxygen saturation (rSO₂) was recorded.Serum interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), S-100 β, and neuron specific enolase (NSE) were measured by ELISA at the time point T₁ to T₄ and 24 hours after surgery (T₅).Finally, postoperative neurocognition was assessed on the first day before surgery (T₀) and the seventh day after surgery (T₆), and the incidence of delirium within one week after surgery was statistically analyzed.

ResultsAt T₂-T₃, compared with group N, the levels of SjvO₂ were remarkably raised in other three groups, while the leves of Da-jvO₂ and CERO₂ were remarkably descend; compared with group D and group U, the levels of SjvO₂ were remarkably raised in group D+U, while the levels of Da-jvO₂ and CERO₂ was remarkably descend (P < 0.05 to P < 0.01).At T₂, compared with group N, the levels of rSO₂ was remarkably raised in other three groups; compared with group D and group U, the levels of rSO₂ were remarkably raised in group D+U (P < 0.05 to P < 0.01).At T₂-T₄, compared with group N, the concentration of NSE, S100β, IL-6 and TNF-α was lower in group D, group U and group D+U; compared with group D and group U, the concentration of NSE, S100β, IL-6 and TNF-α was lower in Group D+U (P < 0.05 to P < 0.01).At T₆, compared with group N, the MMSE score of others three groups raised; compared with group D, the MMSE score of group D+U increased (P < 0.01), compared with group U, the MMSE score of group D+U increased, there was significant difference (P < 0.01).At T₆, compared with group N, there was no significant difference in the incidence of delirium in group D and group U, but the incidence of delirium in group D+U was decreased within one week after operation (P < 0.01), and the incidence of delirium in group D+U was lower than that in group D (P < 0.05).

ConclusionsDexmetomidine combined with ulinastatin can further inhibit the sympathetic activity and inflammatory reaction of patients with rheumatic valvular disease during CPB, significantly improve perioperative cerebral oxygen metabolism, reduce brain injury, and have a certain brain protective effect.