Safety And Efficacy Of Morphine And Oxycodone On Visceral Pain After Laparoscopic Surgery

Objective:To compare the safety and efficacy of low background dose morphine and oxycodone injection combined with patient-controlled analgesia to treat visceral pain after laparoscopic hysterectomy.Methods:This prospective,randomized designed study was conducted during June 2014 and February 2015 at the Jinxin obstetrics and gynecology Hospital in accordance with the principles of the Helsinki Declaration and after obtaining approval of the study from the institutional.Ninety female patients,40-65 years old,the American Society of Anesthesiologists(ASA)physical status 1-2,undergoing laparoscopic hysterectomy or subtotal hysterectomy,were randomly divided into oxycodone group(Group O,N=45)and morphine group(Group M,N=45).Group O: background dose of oxycodone was 0.01 mg/kg/h,bolus dose was 0.01 mg/kg,lock time 15 min;Group M: background dose of morphine hydrochloride was 0.01 mg/kg/h,bolus dose was 0.01 mg/kg,lock time 15 min;Before surgery,the pressure pain threshold(PPT)and pressure tolerance threshold(PTT)were tested by hand-held pressure algometer in all patients in order to testify if there was statistical difference between two groups or not;the patients were induced by propofol,remifentanil and atracurium and had oral endotracheal intubation.Propofol and remifentanil were infused by target controlled infusion device during operation;cisatracurium were infused to maintain muscle relaxation.Before the suture of incision,ropivacaine and epinephrine mixed solution were injected around the surgical incision.In the post-anesthesia care unit(PACU),endotracheal tube was removed when patients were awake.The patients were received 1mg oxycodone or morphine when VAS score between 30mm-50mm;2mg oxycodone or morphine when VAS score over 50 mm.The VAS score were calculated every 15 min until it was less than 30 mm and then the PCA pump was connected.Other outcomes were observed: VAS score after pulling out the endotracheal tube;morphine or oxycodone consumption before connecting PCA pump;the total oxycodone or morphine consumption and the VAS score(when resting and cough)in 30 minutes,1,2,3,6 and 24 hours after operation;the incidence of postoperative nausea or vomiting,itching and RASS sedation score.Results:The VAS score after the patient awake was oxycodone group56 mm,morphine group 58mm;the average consumption of opioids was2.5 ± 0.8mg in group O and 4±1.3mg in group M(P=0.038)before connecting PCA pump.The dose of opioids consumption in group O was lower than that in group M;The dose of 24 h oxycodone consumption(26.8 ± 10.2mg)was significantly lower than that of morphine consumption(26.8± 6.1mg,P=0.001);the resting VAS score on 6 and 24 hour in group O was significantly lower than that in group M: M group(6h,24h):35±12mm,36±10mm;O group(6h,24h):27±9mm,24±8mm;The cough VAS score on 3,6 and 24 hour was significantly lower in O group than that in M group,O group(3h,6h,24h):27±9mm,27±9mm,24±8mm;M group(3h,6h,24h):35±12mm,35±12mm,36±10mm,(P=0.031).The level of sedation in oxycodone group was significantly lower than that in morphine group,P=0.006;the incidence of nauseaing and vomiting was 5.71%(two patients)in group O and 13.89%(five patients)in group M.One patient occurred itching in M group.There was no respiratory depression both in the O group and M group.Conclusion:Compared to morphine,oxycodone showed better visceral pain control with less adverse reactions after laparoscopic hysterectomy.