Study On Preemptive Analgesia Effect Of Lornoxicam On The Concentrations Of Substance P In Plasma And Interleukin 6 In Serum

The traditional approach to postoperative analgesia is to start therapybefore surgery is completed and before the patient complains of pain. Theintense noxious stimulus of surgical incision can sensitise the central nervoussystem and this sensitization can lead to functional changes in the centralnervous system that can decrease pain threshold of central and cause the painexperienced after operation to be perceived as more severe than it woule havebeen otherwise. Preemptive analgesia may be defined that techniques andagents of antinociception should be applied before central function changes toattenuating and preventing central and peripheral sensitization. It might behoped that preemptive analgesia, in addition to reducing actue postoperativepain, might also provide prophylaxis against the stress response produced bypain and its associated hormonal and biochemical parameters.Few earlier studies approve the theory of preemptive analgesia ofnon-steroid anti-inflammatory drugs. With the improvement of the design andmethod of experiments, more and more findings manifest the effect ofpreemptive analgesia of NSAIDs. Compared with very few studies about thepreemptive analgesia effect of lornoxicam, a great deal of researches onpostoperative analgesia with lornoxicam which is a new non-steroidanti-inflammatory drug have been done. Previous clinical studies haveevaluated the postoperative analgesia effect of lornoxicam, as the substitution ofopioid drugs, but very few studies have addressed thestress-related biologicalparameters of pain. Therefore the present study was undertaken to assess theintensity of pain after operation and the changes in the concentrations ofsubstance P in plasma and interleukin 6 in serum.Objective: To investigate the effect of preemptive analgesia withlornoxicam in patients undergoing gynecological surgery and its preemptiveanalgesia effect on the production of substance P in plasma and interleukin 6 inserum .Methods : Sixty ASAⅠ ～ Ⅱ patients undergoing selectivetransabdominal hysterectomy with epidural anesthesia were randomly dividedinto three guoups (n=20). Group A was allocated to receive 16 mglornoxicam intravenously before epidural puncture (about 20 minutes before thesurgerical incision). Group B received 16 mg of lornoxicam i.v. bolus at thetime of suturing peritonaeum and Group C as a contral group with no treatment.Pain was assessed by patients using visual analog scales (VAS) at 4h,6h,8h,12h,24h after surgery.Venous blood samples were collected before epiduralpucture and at suturing peritonaeum,12h,24h after surgery. Concentrations ofsubstance P in plasma and interleukin 6 in serum were measured withradioimmunity method .The administration of analgesic after operation and thecondition of nausea/vomiting were observed. Results: The groups were similarin body weight, age, duration of surgery, consumption of local analgesic andintraoperative transfution of fluid(P﹥0.05) (1)There was significant differenceof VAS at 4h,6h,8h,12h after surgery between GroupA and Group B, alsobetween group A and group C(P<0.05). Moreover, patients in group B and Cfelt more severe pain than those in group A, however, the difference in theintensity of pain between group B and C was no statistical meaning(P﹥0.05).VAS in three groups had insignificant difference at 24h after surgery(P﹥0.05).(2) The concentrations of substance P in three groups were similar andstatistically insignificant before surgery(P ﹥ 0.05). Plasma substance Pconcentrations in there groups during and after operation were significantlyhigher than those before surgery(P﹤0.01) and got a peak at 12h after surgery.No difference was observed in blood substance P during and after surgerybetween group B and group C(P﹥0.05), however, there was significantdifference of plasma substance P between group A and group B as well asbetween group A and group C during operation and 12h, 24h after surgery(P﹤0.05). (3)Serum IL-6 concentrations in three groups before surgery weresignificantly higher than those during and after surgery (P﹤0.05), though theywere similar and statistically insignificant before surgery in three groups(P﹥0.05). No significant differences were observed about serum IL-6concentrations between group B and group C during operation and 12h,24hafter surgery, but patients in group A had higher serum IL-6 concentrations thanthose in group B and group C during and 12h, 24h after surgery(P﹤0.05). (4)The cases of demanding analgesic after surgery had statisticallyinsignificance.Compared with group B and Group C , the time of requiringanalgesic after surgery had been delayed in group A. A case of nausea wasobserved in group A and group C respectively and there was no significantdifference about nausea. No vomiting case was found in threegroups.Conclusions: The administration of lornoxicam before epiduralpuncture has the effect of preemptive analgesia in the hysterectomy and thesingle intravenous dose of lornoxicam before surgery have not increased theincidence of side-effects such as nausea and vomiting. The preemptiveanalgesia effect of lornoxicam also contributes to indirectly inhibiting theproduction of substance P in plasma and IL-6 in serum.