[Application of combined epidural-spinal anesthesia in pediatric surgery and postoperative analgesia]

To compare the anesthetic and analgesic efficacy of ropivacaine and bupivacaine and their side reactions in combined spinal-epidural anesthesia (CSEA) and postoperative analgesia in pediatric surgery.

Fifty children for lower abdominal surgery, aged 6-14 years, were randomly assigned to receive either ropivacaine (Group R, n=25) or bupivacaine (Group B, n=25) for CSEA. Spinal injection for Group R was a mixture of 1.5 ml of 10 g x L(-1) ropivacaine, 0.5 ml distilled water and 1ml of 100 g x L(-1) dextrose. The injection for Group B was the same as that for Group R except 0.5 ml of 7.5 g x L(-1) bupivacaine. The terminal concentrations of anesthetics were 5 g x L(-1) for the two groups. The injection volume was calculated as: ml=(age x 0.2 + weight x 0.5) divided by 2. When operations prolonged to 1.5 h, epidural infusion at the rate of 1 mg x (kg(-1) x h(-1)) started with 2.5 g x L(-1) ropivacaine for Group R and 2.5 g x L(-1) bupivacaine for Group B. The observed variables were the changes in blood pressure, heart rate, SpO(2), block level, visual analogue scores, and motor block. Epidural postoperative analgesia was performed for Group R with 100 ml of 0.75 g x L(-1) ropivacaine to which 100 mg tramadol and 5 mg were added, and for Group B with 100 ml of 0.75 g/L(-1) bupivacaine instead. Backgroup infusion was 3 ml x h(-1) for the children aged 6-9 years or 4 ml x h(-1) for the children aged 10-14 years, bolus was 2 ml controlled by children or their parents when necessary, and locktime was 15 min. The observed variables were the efficacy of postoperative analgesia, recession of motor block of legs, and the incidence of headache, nausea and vomiting, leg numbness, and urinary retention within 24 h after operation.

There was no significant difference between the two groups in block level. Motor block was much milder in Group R than that in Group B during operation, and recessed faster after operation. Only one case of nausea occurred in each group, and one case of urinary retention in Group B without statistical significance.

Either ropivacaine or bupivacaine can be satisfactorily used in CSEA for analgesia during and after operation. However, ropivacaine has a weaker motor block than bupivacaine, which benefits early walking after operation and recovery of bowl movement.