| Objective: To observe the plasma cortisol levels and mini-mental state examination(MMSE) scores at different time points postoperatively, and preliminarily investigate the effect and mechanisms of etomidate on postoperative cognitive function in patients undergoing cardiac valve replacement surgery.Methods: 60 ASA Ⅱ-Ⅲ patients aged 40-60 years old who were scheduled for heart valve prosthesis implantation with cardiopulmonary bypass(CPB), were randomly divided into etomidate group(Group E, n=30) and control group(Group P, n=30). Anesthesia were induced with midazolam, vecuronium, sufentanil intravenously in both groups, and combined with etomidate in group E whereas propofol in group P. Anesthesia were maintained with target controlled infusion(TCI) of etomidate or propofol either. Central venous blood samples were collected in times of 10 min before anesthesia inducement, ending of operation, and 12 h, 24 h, 48 h together with 72 h postoperatively, respectively. Enzyme linked immunosorbent assay(ELISA) was adopted to measure the total plasma cortisol concentrations. MMSE was applied to analysis the incidence of postoperative cognitive dysfunction(POCD). MMSE scores were determined by the same experimenter to evaluate the cognitive function of patients at the following time points: 1 day before surgery(d0), 1 day after surgery(d1), 4 days after surgery(d2), 7 days after surgery(d3) and the same day discharging from hospital(d4). All statistical analysis were performed using SPSS 17.0. Data are expressed as mean( x) ± SD(s). Statistical significance of data was assessed with paired t-test, independent-samples t-test, or chi-square test as appropriate. P<0.05 was considered statistically different, while P<0.01 was statistically significant.Results:(1) There was no striking difference between the two groups in age, sex, years of schooling, running time of CPB, duration of anesthesia and ASA grading.(2) The change of hemodynamics:After anesthesia induction, the systolic pressure(SBP), diastolic pressure(DBP) and mean arterial pressure(MAP) decreased significantly in both groups(P<0.01), and the decline level in group P was much more significant than group E(P<0.01). The heart rate increased in group P with statistical difference(P<0.01) while had no obvious change in group E. The central venous pressure(CVP) showed no significant change before and after anesthesia inducement, and it was also not significantly different between the two groups.(3) The change of blood glucose:There was no statistical difference in blood glucose before anesthesia between the groups(P>0.05). Compared with the preoperative blood glucose level, it raised at the ending of surgery, and 12 h, 24 h, 48 h, 72 h postoperatively; and the level in group P was significantly higher than that in group E 12 h after operation(P<0.01).(4) The change of plasma cortisol concentration:There was no statistical difference in preoperative plasma cortisol concentration between the two groups(P>0.05). Compared with the level before operation, the concentration of total plasma cortisol reduced at the ending of surgery, and 12 h, 24 h, 48 h, 72 h after operation in group E(P<0.05); in contrast, the concentration in group P were higher than that before operation at the time points postoperatively(P<0.01). When comparing between the groups, concentration in group P were higher at the ending of operation and 12 h, 24 h postoperatively than group E(P<0.01), while there were no significant differences at other time points between groups.(5) The change of MMSE scores:There was no significant statistical difference between the two groups in MMSE scores before operation(P>0.05). Although MMSE scores at d1, d2, d3, d4 in both groups showed an upward trend, the scores were significantly lower than that at d0(P<0.01). And the scores of MMSE had no significant difference between two groups at different time points.(6) The incidence of POCD:There was no significant difference in the incidence of POCD between the two groups.Conclusion:Etomidate as well as propofol TCI are both safe anesthesia choice for cardiac valve prosthesis implantation with CPB. Etomidate has less influence on hemodynamics and doesn’t increase the incidence of POCD. |
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