Sedative clearance during extracorporeal membrane oxygenation
Sedative clearance during extracorporeal membrane oxygenation
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DOI：
10.1191/0267659105pf827oa
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发表时间：
2005-01-01
期刊：
影响因子：
1.2
通讯作者：
Annich, G
中科院分区：
文献类型：
--
作者：
Bhatt-Mehta, V;Annich, G
使用体外模型评估聚氯乙烯 (PC) 管和膜式氧合器 (MO) 对新生儿体外膜氧合 (ECMO) 回路中劳拉西泮和吗啡浓度的影响，该模型包括带有 MO、热交换器、膀胱和 PVC 管的闭合 ECMO 回路。该回路充满了血液、电解质、白蛋白和肝素，并通过频繁测量血气 pH 值和温度探针始终保持生理 pH 值和温度。劳拉西泮和吗啡分别在三个独立但相同的循环中分别进行研究，在循环初试当天（新循环）研究 6 小时，然后在 24 小时（旧循环）再次研究 6 小时。每个回路（新的和旧的）在回路中添加一次劳拉西泮至终浓度 250 ng/mL，或添加吗啡至终浓度 70 ng/mL。在每个回路的注射部位以及 MO 前后，在基线处、每 30-60 分钟一次、持续 6 小时抽取系列样品。分别使用电子捕获气相色谱法和质谱气相色谱法分析劳拉西泮和吗啡浓度。不同采样点和时间点的吗啡和劳拉西泮浓度以原始浓度的百分比表示。这项单剂量研究表明，根据回路的使用年限，在旁路过程中，高达 50% 剂量的劳拉西泮和 40% 吗啡可能被 PVC 和 MO 提取。随着电路老化，这个数量可能会增加。这些数据可以部分解释 ECMO 期间需要较高剂量的劳拉西泮和吗啡来镇静患者。
The effects of polyvinyl chloride (PC) tubing and membrane oxygenator (MO) on the concentrations of lorazepam and morphine in the neonatal extracorporeal membrane oxygenation (ECMO) circuit were evaluated using an in vitro model that included a closed ECMO circuit with a MO, heat exchanger, bladder and PVC tubing. The circuit was primed with blood, electrolytes, albumin and heparin and maintained at physiologic pH and temperature throughout by frequent measurement of blood gas pH and a temperature probe. Lorazepam and morphine were each studied separately in three separate, but identical circuits for 6 h on the day of circuit prime (new circuit) and then again for 6 h at 24 h (old circuit). Each circuit (new and old) was spiked once with lorazepam to a final concentration of 250 ng/mL or with morphine to a final concentration of 70 ng/mL in the circuit. Serial samples were drawn at baseline and every 30-60 min for 6 h at the site of injection and pre- and post-MO for each circuit. Lorazepam and morphine concentrations were analysed using gas chromatography with electron capture and gas chromatography with mass spectrometry, respectively. The concentrations of morphine and lorazepam at various sample sites and time points were expressed as a percentage of the original concentration.This single-dose study shows that up to 50% of a dose of lorazepam and 40% of a dose of morphine may be extracted by PVC and MO during bypass, depending on the age of the circuit. As the circuits become older, this amount could increase. These data may explain, in part, the higher doses of lorazepam and morphine required to sedate patients during ECMO.