异丙酚对低温体外循环期间脑氧代谢的影响

EFFECT OF PROPOFOL ON CEREBRAL OXYGEN METABOLISM DURING HYPOTHERMIA CARDIOPULMONARY BYPASS

①目的 观察不同剂量异丙酚对低温体外循环 (CPB)期间颈内静脉球血氧饱和度 (SjO2 )、脑氧摄取率 (CEO2 )、脑动脉颈内静脉血氧含量差 (Ca jO2 )的影响。②方法 33例心脏瓣膜置换术病人 ,随机分成 3组 ,Ⅰ组静注异丙酚 5mg·kg- 1 ·h- 1 ;Ⅱ组静注异丙酚 2mg·kg- 1 ·h- 1 ;Ⅲ组 (对照组 )不静注异丙酚。在CPB前 (T1 )、降温至 33℃ (T2 )、低温稳定期 (T3)、复温至 33℃ (T4 )以及CPB结束后 2 0min(T5)测定SjO2 、CEO2 、Ca jO2 。③结果 Ⅰ、Ⅱ组T2 ～T5时 ,Ⅲ组T2 、T3时SjO2 明显高于T1 时 (F =6 .2 4～ 1 0 .50 ,q =3 .59～ 7.59,P <0 .0 5) ;Ⅲ组T4 、T5时SjO2 明显低于T3时 (q =4.1 4、4 .69,P <0 .0 5) ;Ⅱ组T4 时SjO2 明显高于Ⅲ组 (F =4.1 8,q =4.0 8,P <0 .0 5)。Ⅰ、Ⅱ组T2 ～T5时 ,Ⅲ组T2 、T3时CEO2 均比T1 时下降 (F =4.1 5～ 8.70 ,q =4.98～8.2 0 ,P <0 .0 5) ;Ⅲ组T4 、T5时CEO2 明显高于T3时 (q=4.30、6 .35 ,P <0 .0 5) ;Ⅱ组T4 时CEO2 明显低于Ⅲ组 (F =4.41 ,q =4.48,P <0 .0 5)。Ⅱ组T2 ～T5时 ,Ⅲ组T2 ～T4 时Ca jO2 均较T1 时明显下降 (F =6 .30～ 1 0 .50 ,q =5 .0 5～ 8.60 ,P <0 .0 5) ;Ⅲ组T4 、T5时Ca jO2 明显高于T3时 (q =4.30、1 3 .70 ,P <0 .0 5) ;Ⅲ组T4

Objective\ To observe the effect of propofol on internal jugular venous oxyhemoglobin saturation (S jO 2), cerebral oxygen extraction rate (CEO 2) and arterial jugular venous oxygen content differences (Ca jO 2) during hypothermia cardiopulmonary bypass (CPB). \ Methods\ Thirty three patients undergoing heart valve replacement were randomly divided into three groups. Propofol 5 mg·kg -1 ·h -1 intravenously for group Ⅰ and 2 mg·kg -1 ·h -1 for group Ⅱ, no propofol was used for group Ⅲ (control group). The change of S jO 2, CEO 2,Ca jO 2 were observed at the following time points:before CPB (T 1), 33 ℃ cooling (T 2), stable hypothermic duration (T 3), 33℃ rewarming (T 4) and 20 minutes after CPB (T 5). \ Results\ S jO 2 at points T 2 to T 5 in groups Ⅰ and Ⅱ, S jO 2 at points T 2 and T 3 in group Ⅲ was markedly higher than that at T 1 ( F=6.24-10.50, q= 3.59- 7.59, P <0.05 ). At points T 4 and T 5, S jO 2 significantly lower than that at point T 3 for group Ⅲ ( q=4.14,4.69; P < 0.05 ). For group Ⅱ, S jO 2 at point T 4 was markedly higher than that of group Ⅲ ( F=4.18, q=4.08, P <0.05). CEO 2 in groups Ⅰ and Ⅱ at points T 2 to T 5 and in group Ⅲ at points T 2 and T 3 declined compared with at point T 1 (F=4.15-8.70, q=4.98-8.20, P <0.05); CEO 2 in group Ⅲ at points T 4 and T 5 was higher than that at T 3 ( q= 4.30 , 6.35, P <0.05). For group Ⅱ, CEO 2 at T 4 markedly lower than that of group Ⅲ ( F=4.41, q=4.48, P <0.05). Ca jO 2 of group Ⅱ at T 2 to T 5 and of group Ⅲ at T 2 toT 4 declined compared with at T 1 ( F=6.30-10.50, q=5.05-8.60, P <0.05). Ca jO 2 of group Ⅲ at T 4 and T 5 higher than that at T 3 ( q=4.30, 13.70, P <0.05). Ca jO 2 of group Ⅲ at T 4 was markedly higher than that of group Ⅱ ( F=3.72, q=3.84, P <0.05)\ Conclusion\ Propofol may decrease the imbalance of cerebral oxygen demand and supply during the rewarming period of CPB, but it does not always mean that the deeper the anesthesia the more helpful to maintaining the balance.