Influence Of Pre-emptive Epidural Sufentanil Combined With Ropivacaine On Stess Response Following Surgery

BackgroundSystemic endocrine-metabolic reponse is proportional to the severity of surgical stress;it can be influenced by the mode of anaessthesia and may be partially inhibited by efficient postoperative pain relief. In animals, continued pain after injury is accompanied by functional changs in the nervous system,including reduced thresholds of tissue nociceptors and increased excitability of the central nervous system(CNS)(central sensitization).Pre-emptive analgesia describes the concept of being able to reduce pain perception and overall analgesic needs by using agents to inhibit CNS sensitization before the application of painful stimuli. Opioids can reduce central neurone activation by presynaptically inhibiting neurotransmitter release from primary afferent terminals or by postsynaptically reducing the firing of dorsal horn nociresponsive neurones, thereby inhibiting central sensitization Some clinical trials on pre-emptive analgesia using the i.v. and epidural administration of opiods indicate that the pre-emptive administration of analgesics can lead to clinically appreciable analgesic effects. However, the use of local anesthetic or opiods alone for postoperative epidural analgesia is unsatisfactory. Epidural opioids combined with local anesthetic solution improve the quality of postoperativeanalgesia reducing the related adverse effects of either class of drug alone. Ropivacaine is a new, long-acting local anesthetics. As a new lipid soluble opioid,sufentanil has been used to relieve acute and chronic pain. We considered that pre-emptive epidural sufentanil combined with ropivacaine could attenuate central sensitization,reduce postoperative hormonal reponses. To test this hypothesis, we compared the effects of pre-emptive epidural sufentanil combined with ropivacaine and postoperative epidural analgesia following upper abdominal surgery.ObjectiveTo study the Influence of pre-emptive epidural sufentanil combined with ropivacaine on stess response and postoperative analgesic effect compared with postoperative epidural analgesia following upper abdominal surgery.MethodsWe studied 22 patients undergoing upper abdominal surgery, ASA physical status I and II. Exclusion criteria were a previous history of a chronic pain condtion or regular ingestion of analgestic drugs, a psychiatric history and any contraindication to epidural anaesthesia. None of the patients were narcotic addicts. A prospective, randomized, double-blind design was used. The patients were divided into two groups(control group and pre-emptive group).All patients were premedicated with 0.5mg atropine 0.5h before operation. An epidural cather was inserted at the Tio~Tn interspace before induction of general anaesthesia. Anaesthesia, was induced in both groups using propofol l~2mg kg"1, midazolam 0.05~0.08mg kg'1, sufentannil 0.5 ug kg"1, vecuroniurn 0.15 mg kg"1 to facilitate orofracheal intubation with a cuffed tube. Anaesthesia was maintained with a continuous infusion of propofol 5~7mg kg^h1 and isoflurane 0.8—1.5% end-tidal concentration. Injected vecuronium and sufentanil intermittently.The patients in the pre-emptive group received a fixed dose of O.Sugml"1sufentanil and 0.15% ropivacaine 15 ml as an epidural infusion zomin before surgical incision. This was followed the fixed dose of O.Sugml'1 sufentanil and 0.15% ropivacaine 250 ml as patient control epidural analgesia for 50 hours,5ml every hour. The patients in the contral group did not received epidural analgesia until they awaked after the end of surgery. They received a fixed dose of O.Sugml'1 sufentanil and 0.15% ropivacaine 15 ml, this was also followed by the same fixed dose 250ml as PCEA for 5ml every hour. After spontaneous respiration had been re-established, all the patient was transferred to postanaesthesia care unit and remained there for more than two hours.Neuoendocrine stress responses were assessed by measuring plasma concentrations of adrenocorticotropin (ACTH), cortisol and C reaction protein(CRP) before insertion of the epidural Catheter(baseline concentration), 2 hours after surgery and on the first post operative morning (first postoperative day concen tration).Pain scores on a visual analog scales (VAS) at rest and coughing were obtained at the following times:2> 4> 6^ 8^ 12> 24 hour after the operation.Results1. There were no significant differences between two groups with regard to sex, age, weight, duration of OP. and blood loss.2. Epidural blockade segment were Tj~Li.3. There were significant differences between two groups of VAS 2h after surgery at rest and counghing (P<0.01).4. The baseline concentrations of cortisol ,ACTH and CRP were similar in the two groups.Both groups had statistically Signficant increases in plasma cortisol, ACTH and CRP 2h after surgery and on the first postoperative morning from the baseline (P<0.01);The medians increases in plasma cortisol, ACTH and CRP 2h after surgery and on the first postoperative morning relative to baseline were greater in the control group than in pre-emptive group(P<0.05).ConclusionsPre-emptive epidural O.Sug.mT1 sufentanil combined with 0.15% ropivacaine reduce neuroendocrine responses more and can supply a better postoperative analgesic effect compared with PCEA after surgery. Therefore, it is a deirable analgesic method.