Abstract：
Post-induction hypotension (MAP < 65 mmHg) occurs frequently and is usually caused by the cardiovascular adverse effects of the anaesthetic induction drugs used. We hypothesize that a clinically significant difference in the incidence and severity of hypotension will be found when different doses of propofol and remifentanil are used for induction of anaesthesia.
METHODS: This is a secondary analysis of a randomised controlled trial wherein four groups (A-D) of patients received one out of four different combinations of propofol and remifentanil, titrated to a predicted equipotency in probability of tolerance to laryngoscopy (PTOL) according to the Bouillon interaction model. In group A, a high dose of propofol and a low dose of remifentanil was administered, and across the groups this ratio was gradually changed until it was reversed in group D. Mean and systolic arterial blood pressure (MAP, SAP) were compared at four time points (Tbaseline, Tpost-bolus, T3min, Tnadir) within and between groups Heart rate, bispectral index (BIS) and the incidence of hypotension were compared.
RESULTS: Data from 76 patients was used. At Tpost-bolus a statistically significant lower MAP and SAP was found in group A versus D (p = 0.011 and p = 0.002). A significant higher heart rate was found at T3min and Tnadir between groups A and B when compared to groups C and D (p = < 0.001 and p = 0.002). A significant difference in BIS value was found over all groups at T3min and Tnadir (both p < 0.001). All other outcomes did not differ significantly between groups.
CONCLUSIONS: Induction of anaesthesia with different predicted equipotent combinations of propofol and remifentanil did result in statistically different but clinically irrelevant differences in haemodynamic endpoints during induction of anaesthesia. Our study could not identify preferable drug combinations that decrease the risk for hypotension after induction, although they all yield a similar predicted PTOL.
METHODS: This is a secondary analysis of a randomised controlled trial wherein four groups (A-D) of patients received one out of four different combinations of propofol and remifentanil, titrated to a predicted equipotency in probability of tolerance to laryngoscopy (PTOL) according to the Bouillon interaction model. In group A, a high dose of propofol and a low dose of remifentanil was administered, and across the groups this ratio was gradually changed until it was reversed in group D. Mean and systolic arterial blood pressure (MAP, SAP) were compared at four time points (Tbaseline, Tpost-bolus, T3min, Tnadir) within and between groups Heart rate, bispectral index (BIS) and the incidence of hypotension were compared.
RESULTS: Data from 76 patients was used. At Tpost-bolus a statistically significant lower MAP and SAP was found in group A versus D (p = 0.011 and p = 0.002). A significant higher heart rate was found at T3min and Tnadir between groups A and B when compared to groups C and D (p = < 0.001 and p = 0.002). A significant difference in BIS value was found over all groups at T3min and Tnadir (both p < 0.001). All other outcomes did not differ significantly between groups.
CONCLUSIONS: Induction of anaesthesia with different predicted equipotent combinations of propofol and remifentanil did result in statistically different but clinically irrelevant differences in haemodynamic endpoints during induction of anaesthesia. Our study could not identify preferable drug combinations that decrease the risk for hypotension after induction, although they all yield a similar predicted PTOL.
摘要：
诱导后低血压（MAP<65mmHg）经常发生，通常由所用麻醉诱导药物的心血管不良反应引起。我们假设，当不同剂量的异丙酚和瑞芬太尼用于麻醉诱导时，低血压的发生率和严重程度会有临床上的显着差异。
方法：这是一项随机对照试验的二次分析，其中四组（A-D）患者接受了四种不同的异丙酚和瑞芬太尼组合中的一种，根据Bouillon相互作用模型，滴定到对喉镜检查（PTOL）的耐受性概率的预测等效度。在A组中,给予高剂量异丙酚和低剂量瑞芬太尼，在各组中，该比率逐渐改变，直到D组逆转为止。平均动脉压和收缩压（MAP，SAP)在四个时间点进行比较(Tbaseline，Tpost-bolus,T3min,Tnadir）组内和组间心率，比较脑电双频指数（BIS）和低血压的发生率。
结果：使用来自76例患者的数据。在Tpost推注时,在A组与D组中发现统计学上显著较低的MAP和SAP(p=0.011和p=0.002)。与C组和D组相比，A组和B组的T3min和Tnadir心率明显更高（p=<0.001和p=0.002）。在T3min和Tnadir时，所有组的BIS值均存在显着差异（均p<0.001）。所有其他结果在组间没有显著差异。
结论：在麻醉诱导过程中，丙泊酚和瑞芬太尼不同的预测等效组合诱导麻醉确实导致了统计学上不同但临床上不相关的血流动力学终点差异。我们的研究无法确定降低诱导后低血压风险的优选药物组合，尽管它们都产生了相似的预测PTOL。
方法：这是一项随机对照试验的二次分析，其中四组（A-D）患者接受了四种不同的异丙酚和瑞芬太尼组合中的一种，根据Bouillon相互作用模型，滴定到对喉镜检查（PTOL）的耐受性概率的预测等效度。在A组中,给予高剂量异丙酚和低剂量瑞芬太尼，在各组中，该比率逐渐改变，直到D组逆转为止。平均动脉压和收缩压（MAP，SAP)在四个时间点进行比较(Tbaseline，Tpost-bolus,T3min,Tnadir）组内和组间心率，比较脑电双频指数（BIS）和低血压的发生率。
结果：使用来自76例患者的数据。在Tpost推注时,在A组与D组中发现统计学上显著较低的MAP和SAP(p=0.011和p=0.002)。与C组和D组相比，A组和B组的T3min和Tnadir心率明显更高（p=<0.001和p=0.002）。在T3min和Tnadir时，所有组的BIS值均存在显着差异（均p<0.001）。所有其他结果在组间没有显著差异。
结论：在麻醉诱导过程中，丙泊酚和瑞芬太尼不同的预测等效组合诱导麻醉确实导致了统计学上不同但临床上不相关的血流动力学终点差异。我们的研究无法确定降低诱导后低血压风险的优选药物组合，尽管它们都产生了相似的预测PTOL。
