Continuous extradural anaesthesia in children. Clinical and haemodynamic implications.

This study reports the experience of a department of paediatric anaesthesia with 234 continuous extradural anaesthetics performed in 229 children over a 15-month period. Fifty-nine of the children were aged 0-2 yr, 71 were aged 2-8 yr and 104 were older than 8 yr. The surgical procedures lasted more than 60 min (mean 150 +/- 10.6 min); all were carried out under light general anaesthesia. Technical procedure and difficulties are reported. The only local anaesthetic agent used was bupivacaine with or without adrenaline. Mean initial dosage was 0.75 ml kg-1 for children weighing less than 20 kg and 1 ml/10 cm of height for children taller than 100 cm. Using 0.25% bupivacaine mean times until a further injection were 92.0 +/- 2.0 min for bupivacaine with adrenaline and 71.0 +/- 2.5 min for bupivacaine without adrenaline (P less than 0.001). A much longer duration of analgesia was found for younger children using the solution with adrenaline. A haemodynamic study was performed in 74 unpremedicated children (ASA I; aged 0-2 yr (n = 15), 2-8 yr (n = 26) and older than 8 yr (n = 35). Before induction of anaesthesia, heart rate (HR) was significantly increased in the youngest children, but no significant change was found for systolic arterial pressure (SAP). After extradural anaesthesia with 0.25% bupivacaine with adrenaline 1:200000, minimal changes in HR or SAP occurred in children younger than 8 yr; in those older than 8 yr a significant decrease in both HR and SAP was observed. Changes in SAP were at their maximum 25 min after the extradural block and changes in HR were not statistically significant before the 25th min following injection of local anaesthetic. The catheter remained in place in 155 children for postoperative analgesia, mainly for the first 48 h.