Oualha Mehdi, Capelo Mikaël, Spreux-Varoquaux Odile, Drouet-Chaillou Isabelle, Tréluyer Jean-Marc, Hubert Philippe, Lesage Fabrice
Service de Réanimation Pédiatrique. Hôpital Necker Enfants-Malades, Assistance Publique- Hôpitaux de Paris, Université Paris Descartes, 149, Rue de Sèvres, 75743, Paris Cedex 15, France,
Eur J Pediatr. 2014 Jan;173(1):69-73. doi: 10.1007/s00431-013-2121-5. Epub 2013 Aug 11.
In children, because of the dead volume of the central venous catheter (CVC) and the low flow rate of norepinephrine (NE) infusion, the delay between start-up and effective administration can be adversely long. A theoretical calculation enables to estimate the delay and variations of effective administration. However, numerous factors can hinder this theoretical approach. Herein, we measured via bench testing the actual delay and stability of NE administration kinetics. Using an assembly reproducing our currently-implemented catecholamine administration protocol, diluted NE (200 μg ml(-1)) was infused at an initial rate of 2 ml h(-1) (theoretically 6.67 μg min(-1)) for a period of 24 h. An assay measuring the amount of NE (μg) exiting the CVC was conducted by high-pressure liquid chromatography with colorimetric detection. The theoretical calculation of the delay in administered NE, taking into account a CVC dead volume of 0.3 ml, was 9 min. The measured percentage of the administered dose as a function of time in minutes (M) was M0-M3 (0 %), M3-M6 (0 %), M6-M9 (13 %), M9-M12 (28 %), M12-M15 (70 %), and M15-M18 (100 %) The amount of NE (μg) at fixed rate (2 ml h(-1)) was established at 6.9 ± 0.4 μg min(-1) during the 24 h.
Continuous NE infusion via a CVC at low rate is stable. In children, because of CVC dead volume and low flow rate infusion, the delay in achieving intended dose delivery is significantly longer than that estimated by theoretical calculation. New modalities of initiation of catecholamine infusion adapted to the child are warranted.
在儿童中，由于中心静脉导管（CVC）的死腔以及去甲肾上腺素（NE）输注流速较低，启动与有效给药之间的延迟可能会长到产生不利影响。理论计算能够估算有效给药的延迟和变化情况。然而，众多因素可能会妨碍这种理论方法的应用。在此，我们通过实验台测试测量了NE给药动力学的实际延迟和稳定性。使用一套重现我们当前实施的儿茶酚胺给药方案的装置，以2 ml/h（理论上为6.67 μg/min）的初始速率输注稀释的NE（200 μg/ml），持续24小时。通过高压液相色谱比色检测法对流出CVC的NE量（μg）进行测定。考虑到CVC死腔为0.3 ml，给药NE延迟的理论计算结果为9分钟。以分钟为时间函数测得的给药剂量百分比为：M0 - M3（0%）、M3 - M6（0%）、M6 - M9（13%）、M9 - M12（28%）、M12 - M15（70%）以及M15 - M18（100%）。在24小时内，以固定速率（2 ml/h）给药的NE量（μg）确定为6.9 ± 0.4 μg/min。
通过CVC以低速率持续输注NE是稳定的。在儿童中，由于CVC死腔和低流速输注，达到预期给药剂量的延迟明显长于理论计算所估计的时间。有必要采用适合儿童的儿茶酚胺输注起始新方式。
