Effect of bupivacaine on postoperative pain and analgesics use after single-incision laparoscopic appendectomy: double-blind randomized study

PURPOSE: Local anesthetics can decrease postoperative pain after appendectomy. This study sought to verify the efficacy of bupivacaine on postoperative pain and analgesics use after single-incision laparoscopic appendectomy (SILA). METHODS: Between March 2014 and October 2015, 68 patients with appendicitis agreed to participate in this study. After general anesthesia, patients were randomized to bupivacaine or control (normal saline) groups. The assigned drugs were infiltrated into subcutaneous tissue and deep into anterior rectus fascia. Postoperative analgesics use and pain scores were recorded using visual analogue scale (VAS) by investigators at 1, 8, and 24 hours and on day 7. All surgeons, investigators and patients were blinded to group allocation. RESULTS: Thirty patients were allocated into the control group and 37 patients into bupivacaine group (one patient withdrew consent before starting anesthesia). Seven from the control group and 4 from the bupivacaine group were excluded. Thus, 23 patients in the control group and 33 in the bupivacaine group completed the study. Preoperative demographics and operative findings were similar. Postoperative pain and analgesics use were not different between the 2 groups. Subgroup analysis determined that VAS pain score at 24 hours was significantly lower in the bupivacaine group (2.1) than in the control group (3.8, P = 0.007) when surgery exceeded 40 minutes. During immediate postoperative period, bupivacaine group needed less opioids (9.1 mg) than control (10.4 mg). CONCLUSION: Bupivacaine did not decrease pain and analgesics use. When surgery exceeded 40 minutes, bupivacaine use might be associated with less pain and less analgesics use.