The efficacy of pre- versus postsurgical axillary block on postoperative pain in paediatric patients

We compared the effects of pre- and postsurgical axillary block on pain after hand and forearm surgery in 55 children in a double-blind randomized study. The successful blocks are reported here (n=49). Children aged 1-11 years and ASA I or II were allocated randomly to receive axillary block with 2 mg.kg-1 of 0.25% bupivacaine, either after induction but before the surgery (presurgical group, n=25) or immediately after surgery, before the end of anaesthesia (postsurgical, n=24). In all patients, a standard general anaesthesia technique was used. The Faces Pain Scale (FPS) and analgesic requirements were recorded for 24 h at various times after operation. Eight patients (32%) in the presurgical group and 20 patients (83.33%) in the postsurgical group did not require additional analgesic within the first 24 h after operation (P< 0.05). In patients who had pain during the observation period, the pain started 13.66+/-2.61 h in the presurgical group and 13.14+/-2.34 h in the postsurgical group after performing block (P> 0.05). The FPS scores were similar in both groups during the first 8 h in the postoperative period (P> 0.05). There was a significant difference at 10 h after surgery (P< 0.05). Cumulative FPS score was higher in the presurgical group (10.50+/-1.06) than in the postsurgical group (9.45+/-1.28) (P< 0.05), but both groups had effective analgesia overall, the mean FPS score being less than 2. Additional analgesic consumption was similar in these patients in both groups. A lower isoflurane concentration was used in the presurgical group (0.68% vs 1.72%, P< 0.001). We did not demonstrate the superiority of preemptive analgesia, but our results indicate that presurgical axillary block with 0.25% bupivacaine allows the use of inhalational anaesthetics at lower concentrations while providing a reasonably painless postoperative period.