Caudal epidural blocks in paediatric patients: a review and practical considerations

Abstract

Caudal epidural blockade in children is one of the most widely administered techniques of regional anaesthesia. Recent clinical studies have answered major pharmacodynamic and pharmacokinetic questions, thus providing the scientific background for safe and effective blocks in daily clinical practice and demonstrating that patient selection can be expanded to range from extreme preterm births up to 50 kg of body weight. This narrative review discusses the main findings in the current literature with regard to patient selection (sub-umbilical vs mid-abdominal indications, contraindications, low-risk patients with spinal anomalies); anatomical considerations (access problems, age and body positioning, palpation for needle insertion); technical considerations (verification of needle position by ultrasound vs landmarks vs 'whoosh' or 'swoosh' testing); training and equipment requirements (learning curve, needle types, risk of tissue spreading); complications and safety (paediatric regional anaesthesia, caudal blocks); local anaesthetics (bupivacaine vs ropivacaine, risk of toxicity in children, management of toxic events); adjuvant drugs (clonidine, dexmedetomidine, opioids, ketamine); volume dosing (dermatomal reach, cranial rebound); caudally accessed lumbar or thoracic anaesthesia (contamination risk, verifying catheter placement); and postoperative pain. Caudal blocks are an efficient way to offer perioperative analgesia for painful sub-umbilical interventions. Performed on sedated children, they enable not only early ambulation, but also periprocedural haemodynamic stability and spontaneous breathing in patient groups at maximum risk of a difficult airway. These are important advantages over general anaesthesia, notably in preterm babies and in children with cardiopulmonary co-morbidities. Compared with other techniques of regional anaesthesia, a case for caudal blocks can still be made.

Keywords: caudal block; paediatric; perioperative care; postoperative pain; regional anaesthesia; ultrasound-guided.

Copyright © 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Figures

Fig 1

A transverse ultrasound view illustrating the sacrococcygeal ligament (upward arrow) and the two sacral cornua (two downward arrows).

Fig 2

The longitudinal paramedian position of the linear high-frequent ultrasound probe for observation of the administration of local anaesthetic for caudal blockade.

Fig 3

Ultrasound image of the epidural space in a baby weighing 3 kg. The upward arrow indicates the dura mater, the double-ended arrow the epidural space, and the downward arrow the L5 spinous process. (Left to right=cranial to caudal.)

Fig 4

Ultrasound visualisation of how the local anaesthetic is spreading inside the epidural space. The double-ended arrow indicates the dimensional increase of the epidural space in the anteroposterior plane. (Left to right=cranial to caudal.)