Summary The present study tested the hypothesis that patients receiving epidural bupivacaine before surgery would require less morphine postoperatively and/ or report less intense pain than patients receiving epidural bupivacaine after incision but before the end of surgery. Forty-nro patients (ASA class I-III) scheduled for lower abdominal surgery were randomly assigned to I of 2 groups of equal size and prospectively studied using a double-blind, placebo-controlled crossover design. Epidural catheters were placed in the Tlz-Ll or L1-L2 interspaces pre-operatively, the position of the catheter was confirmed with 3Vo chloroprocaine with epinephrine L :200,000, and sensory testing was carried out until levels had receded to below T12. Group I received 15 ml of 0.5Vo epidural bupivacaine injected 35 min before incision followed by 15 ml of epidural normal saline 30 min after incision. Group 2 received 15 ml of epidural normal saline injected 37 min before incision followed by 15 The results suggest that single-shot pre-emptive epidural local anaesthesia is associated with a short-term morphine-sparing effect which is most pronounced between 12 and 24 h after surgery. Extending the pre-operative blockade into the postoperative period may prolong the initial advantage conferred by pre-emptive epidural local anaesthesia.

Summary This study tested the hypothesis that high dose systemic alfentanil administered before and during aMominal hysterectomy would pre-empt post'operative pain to a greater extent than administration of either low dose alfentanil or no alfentanil perioperatively. Patients (ASA I or 2) were randomly assigned to group 1 (r = 15), no opioid; group 2 (n = 15), low dose alfentanil; or group 3 (n = l5). high dose alfentanil. Anaesthesia was induced in group I with midazolam and thiopentone and was maintained with isoflurane andTO% N2O in 02, Anaesthesia was induced in group 2 with midazolam, thiopentone and i.v. alfentanil (30pg kg-l), and was maintained with isoflurane. 70VoN2O in 02, and bolus doses of i.v. alfentanil (10-20pg kg-l) every hour. Anaesthesia was induced in group 3 withmidazolamandi.v. alfentanl (l0opgkg-t),and wasmaintained wtlt70% N2Oin Oz,andanintusionof i.v. alfentanil(l-2pgkg-l min-l). Blood samples were drawn at 30 and 120 min after surgery and assayed for plasma alfentanil. Morphine consumption and VAS pain scores were consistently lowest in group 3 over the 48 h study period, A composite measure of pain and morphine consumption was significantly lower in group 3 than group 2 up to 6 h after surgery and significantly lower than group I up to 12 h. No adverse effects were observed. A 6-month follow-up did not reveal any significant differences among the three groups. It is concluded that intra-operative high dose alfentanil anaesthetic pre-empts post-oporative pain after abdominal hysterectomy, but the effects are small and of short duration.Surgical procedures carried out under general anaesthesia using standard (and even high) doses of opioids intraoperatively provide suboptimal protection from the injury banage brought about by incision and subsequent noxious surgical events.

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