Effects Of Calot’s Triangle Block With Ropivacaine On Postoperative Pain Management In Patients Undergoing Laparoscopic Cholecystectomy

Objectives To evaluate the effect of calot’s triangle block (CTB) with ropivacaine on postoperative pain management in patients undergoing laparoscopic cholecystectomy (LC).Methods After this clinical study approved by the ethics committee of the First Affiliated Hospital of Chongqing Medical University, the consecutive patients who had undergone LC between February,2014 and July,2014 at our hospital were connected. All potentially eligible participants will be asked to give written informed consent before they were enrolled in this study. One hundred and forty ASA I or II patients aged 18-64 years, BMI ranged from 18 kg/m2 to 31 kg/m2, scheduled for elective LC under general anesthesia, were randomly divided into two groups (n= 70):experimental group and control group. All patients were asked to fasting 6-8 h and ban clean drinking 2 h in the preoperative; atropine 0.5 mg and promethazine 25 mg was injected musculosa 30 min before induction of anesthesia. After patients entered the operating room, vital signs monitoring and establish peripheral venous access. In experimental group,1% ropivacaine 10 ml was injected by a bile duct needle into calot’s triangle of the patients before surgical dissection, while the equal volume of 0.9% normal saline was injected into calot’s triangle in patients of control group. The patients in both groups received PCIA for up to 48 h postoperatively. The PCIA pump was connected 10 min before the end of surgery. And, all patients received the preventive use of antiemetic as intravenous injection of 2 mg tropisetron. The formula of the PCIA included tramadol 800 mg and flurbiprofen axetil 100 mg with 0.9% normal saline added up to a volume of 80 mL in total, the PCIA pump was set up with a 5 ml loading dose, a 2 ml bolus dose, a 15 min lock time and background infusion at a rate of 1 ml/h. Pain was assessed by VAS scores at 2,4,6,12,24, 48 h postoperatively at rest and in motion. The number of attempts, number of successful deliverers, the doses of PCIA and rescue tramadol doses were recorded. The first postoperative off-bed time, the first flatus time and length of stay were recorded. The adverse effects such as incomplete analgesia (VAS score≥4), Postoperative nausea and vomiting, shoulder pain within 48 h after surgery were recorded. Calot’s triangle damage related to puncture and local anesthetic toxicity in both groups were also recorded. The incidences of chronic pain, the NRS of pain at rest and in motion, the characteristic of pain and usage of analgesics were investigated with telephone interview at 3 months and 6 months postoperatively.Results There was no significant differences of between the two groups of ratio of gender, age, BMI, ratio of ASA, the duration of anesthesia and operation, the consumption of sufentanil and remifentanil (P>0.05). When compared with control group, the VAS scores of the patients at 2 h,4 h,6 h, 12 h,24 h after surgery during static and dynamic were significantly decreased, and at 48 h after surgery during dynamic were significantly decreased in experimental group (P< 0.05). There was no significant differences of between the two groups of the VAS scores the patients at 48 h after surgery at rest (P>0.05). The number of attempts, number of successful deliverers, the doses of PCIA, remedial analgesia rate, rescue tramadol doses and the incidence of incomplete analgesia were significantly lower in experimental group than control group (P<0.05). There was no significant difference in the incidence of postoperative nausea and vomiting, shoulder pain, the first postoperative off-bed time, the first flatus time and length of stay between the two groups (P> 0.05). There were no occurrence of calot’s triangle damage related to puncture in both groups. And there were no occurrence of local anesthetic toxicity in experimental group. At the end of the telephone follow-up a total of 139 patients entered into the final statistical analysis, at the third month after surgery, the overall incidence of CPSP in control group was 46.38%, the visceral pain was 33.33%, the incision pain was 13.04%; the overall incidence of CPSP in experimental group was 24.29%, the visceral pain and incision pain was 14.29% and 15.71%, respectively. The overall incidence of CPSP and the incidence of visceral pain were significantly lower in experimental group than control group in the third month (P< 0.05). At the sixth month after surgery, the incidence of chronic pain in each group was lower than 3 months after operation, the overall incidence of CPSP in control group was 26.09%, the visceral pain and incision pain was 15.94% and 10.14%, respectively; the overall incidence of CPSP in experimental group was 12.86%, the visceral pain and incision pain was 7.14% and 8.57%, respectively. The overall incidence of CPSP was obviously lower in experimental group than control group in the sixth month (P< 0.05).Conclusions (1) Calot’s triangle block with 1% ropivacaine 10 ml can optimize postoperative analgesia in patients undergoing laparoscopic cholecystectomy. (2) Calot’s triangle block with 1% ropivacaine 10 ml can reduce the incidence of CPSP in patients undergoing laparoscopic cholecystectomy.