Department of Anaesthesia, General Intensive Care and Pain Therapy, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Br J Anaesth. 2012 Apr;108(4):670-4. doi: 10.1093/bja/aer502. Epub 2012 Feb 6.
Despite caudal blockade being the most widely used regional anaesthetic procedure for infants and children undergoing subumbilical surgery, the question whether the injection velocity of the local anaesthetic itself affects its spread in the epidural space has not yet been investigated. Thus, the aim of the present study was to measure the cranial spread of caudally administered local anaesthetics in infants and children by means of real-time ultrasonography, with a special focus on comparing the effect of using two different speeds of injection.
Fifty ASA I-II infants and children, aged up to 6 yr, weighing up to 25 kg, undergoing subumbilical surgery, were enrolled in this prospective, randomized, observer-blinded study. Caudal blockade was performed under ultrasound observation using ropivacaine 1 ml kg(-1) 0.2% or 0.35% and an injection given at either 0.25 ml s(-1) or 0.5 ml s(-1), respectively.
Ultrasound observation of the local anaesthetic flow and the extent of cranial spread was possible in all patients. All caudal blocks were considered successful, and all surgical procedures could be completed without any indications of insufficient analgesia. No statistically significant difference could be observed between the two injection speeds regarding the cranial spread of the local anaesthetic in the epidural space.
The main finding of the present study is that the speed of injection of the local anaesthetic does not affect its cranial spread during caudal blockade in infants and children. Therefore, the prediction of the cranial spread of the local anaesthetic, depending on the injection speed, is not possible.
尽管骶管阻滞是小儿下腹部手术最常用的区域麻醉方法，但局部麻醉剂本身的注射速度是否会影响其在硬膜外腔中的扩散尚未得到研究。因此，本研究旨在通过实时超声测量下腹部手术小儿骶管给药时局部麻醉剂的颅侧扩散，特别关注比较使用两种不同注射速度的效果。
本前瞻性随机观察者盲法研究纳入了 50 名 ASA I-II 级、年龄在 6 岁以下、体重在 25kg 以下的小儿，均行下腹部手术。在超声观察下进行骶管阻滞，使用罗哌卡因 1ml/kg0.2%或 0.35%，注射速度分别为 0.25ml/s 和 0.5ml/s。
所有患者均能观察到局部麻醉剂流动和颅侧扩散的程度。所有骶管阻滞均被认为是成功的，所有手术过程均可在无镇痛不足迹象的情况下完成。在硬膜外腔中局部麻醉剂的颅侧扩散方面，两种注射速度之间没有观察到统计学上的显著差异。
本研究的主要发现是，在小儿骶管阻滞中，局部麻醉剂的注射速度不会影响其在硬膜外腔中的颅侧扩散。因此，不能根据注射速度预测局部麻醉剂的颅侧扩散。
