Clinical Observation Of Dexmedetomidine In Postoperative Analgesia For Open Gynecological Surgery

Objective: To observe the efficacy of hydrochloride dexmedetomidine（Dex） at different dosages about analgesic and sedative after opengynecological surgery under general anesthesia, investigate appropriatedosage satisfied the perfect analgesis and proper sedation in order to reducethe amount of opioid analgesic, then reduce the incidence of pain-and drug-related side effect contributing to providing experience to clinical practice.Methods: Sixty patients （ASA Ⅰ-Ⅱ）, aged38-61yr, weighing49-70kgundergoing open gynecological surgery （including hysterectomy andaccessory excision）under general anesthesia，mid-line incision on the lowerabdominal, were randomly divided into3groups （n=20）, Group S: sufentanil1.5μg/kg; Group D1: sufentanil1μg/kg+Dex0.06μg·kg^-1·h^-1; GroupD2:sufentanil1μg/kg+Dex0.1μg·kg^-1·h^-1, filled with normal saline （NS） to100ml （background infusion at2ml/h with a bolus dose of0.5ml and a15min lockout interval）. The exclusive criteria included: psychiatrical orneurological disease, kinesia, digestive disease, coagulation disorder, diabetesmellitus, narcotic drug allergy, opioid or diazepam history, pathologicalatrionector, atrioventricular block. Cases with normal liver function andNYHK Ⅰ were chosen. The opioid was not prescribed before the operation.Vital signs, such as blood pressure （BP）, heart rate （HR）, respiration （R）,saturation of pulse oximetry （SpO₂）, were monitored. After well preparationthe anesthesia was induced with iv midazolam injection0.5¹mg/kg,sufentanil citrate0.3⁰.4μg/kg and propofol injection1²mg/kg. Trachealintubation was facilitated with cisatracurium0.15⁰.2mg/kg. The patientswere mechanically ventilated. Adjust tidal volume6⁸ml/kg, respiratory rate10¹2times per minute to stablice P_ETCO₂35⁴5mm Hg（1mm Hg=0.133kPa）. During the operation propofol3⁵mg kg^-1·h^-1and remifentanil hydrochloride0.1⁰.3μg·kg^-1·min^-1were pumped to maintain cyclostationarydepending on the stimulation intensity of surgical.10min before the end ofsurgery sufentanil0.1μg/kg and tropisetron4mg were slowly intravenouslyinjected.3-5min before the end of surgery the pump was stopped. Theelectronic analgesia pump was connected at the end of surgery and the timewas started to count. After autonomous respiration well patients were send topost anesthesia care unit （PACU）. The patients ’ age, weight, duration ofanesthesia, total amount of liquid infusion, the number of patients attempted,attempts and effected attempts of PCIA, number of patients needed additionalanalgesic, sleep quality, exhaust time, hospital days, satisfaction wererecorded respectively. Visual analogue scale （VAS score）, the level ofsedation （Ramsay score）, postoperative nausea and vomiting score （PONYscore） at2,6,24,48,51h after surgery were recorded. Other complication notreported was recorded.Results: Compared with group S, the VAS score was significantlyincreased in group D1at2,6,24,48h, decreased at51h in group D1andgroup D2. Ramsay score was significantly increased in group D2at2h and6h after operation. PONY score was significantly decreased in group D1andgroup D2at6,24,48h. The patients attempted PCIA were significantlyincreased in group D1and group D2but the attempts were only significantlydecreased in group D1. Patients needed additional analgesic （intramusculartramadol0.1g） were significantly increased in group D1, exhaust time afteroperation was significantly decreased both in group D1and group D2. Thesleep quality and satisfaction were significantly better in group D2.（P<0.05）Compared with group D1, the VAS score was significantly decreased ingroup D2at2,6,24,48h. The PCIA attempts were significantly decreasedand satisfaction was significantly increased in group D2.（P<0.05）. Nosignificance existed in the rest comparisions.（P>0.05） There was notbradycardia, hypotension, respiratory depression or urinary retention appearedamong the three groups. The complication had not been reported before wasnot found. Conclusions: Dex0.1μg·kg^-1·h^-1composite sufentanil1μg/kg given forpatients under gynecological laparotomy could get perfect analgesic andproper sedation, could not only reduce the consumption of sufentanil forpostoperative PCIA, but also improve sleep quality, reduce side effects painand sufentanyl-related without increasing new side effects. Patients were morecomfortable and satisfied.