Radiol Oncol 2025; 59(1): 132-138. doi: 10.2478/raon-2025-0003 132 research article Effectiveness of tramadol or topic lidocaine compared to epidural or opioid analgesia on postoperative analgesia in laparoscopic colorectal tumor resection Alenka Spindler-Vesel1,2, Matej Jenko1,2, Ajsa Repar3, Iztok Potocnik2,3, Jasmina Markovic-Bozic1,2 1 Clinical Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia 2 Medical Faculty, University of Ljubljana, Slovenia 3 Department of Anaesthesiology and Intensive Care, Institute of Oncology Ljubljana, Slovenia Radiol Oncol 2025; 59(1): 132-138. Received 18 June 2024 Accepted 24 October 2024 Correspondence to: Assist. Prof. Jasmina Markovič Božič, M.D., Ph.D., Clinical Department of Anaesthesiology and Surgical Intensive Therapy. University Medical Centre Ljubljana, Zaloška c. 7, 1525 Ljubljana, Slovenia. E-mail: jasmina.markovic1@kclj.si Disclosure: No potential conflicts of interest were disclosed. This is an open access article distributed under the terms of the CC-BY license (https://creativecommons.org/licenses/by/4.0/). Background. Chronic postoperative pain is the most common postoperative complication that impairs quality of life. Postoperative pain gradually develops into neuropathic pain. Multimodal analgesia targets multiple points in the pain pathway and influences the mechanisms of pain chronification. Patients and methods. We investigated whether a lidocaine patch at the wound site or an infusion of metamizole and tramadol can reduce opioid consumption during laparoscopic colorectal surgery and whether the results are comparable to those of epidural analgesia. Patients were randomly divided into four groups according to the type of postoperative analgesia. Group 1 consisted of 20 patients who received an infusion of piritramide. Group 2 consisted of 21 patients who received an infusion of metamizole and tramadol. Group 3 consisted of 20 patients who received patient-controlled epidural analgesia. Group 4 consisted of 22 patients who received piritramide together with a 5% lidocaine patch on the wound site. The occurrence of neuropathic pain was also investigated. Results. Piritramide consumption was significantly lowest in group 3 on the day of surgery and on the first and second day after surgery. Group 4 required significantly less piritramide than group 1 on the day of surgery and on the first and second day after surgery. The group with metamizole and tramadol required significantly less piritramide than groups 1 and 4 on the first and second day after surgery. On the day of surgery, this group required the highest amount of piritramide. Conclusions. Weak opioids such as tramadol in combination with non-opioids such as metamizole were as effective as epidural analgesia in terms of postoperative analgesia and opioid consumption. A lidocaine patch in combination with an infusion of piritramide have been able to reduce opioid consumption. Key words. laparoscopic surgery; colorectal tumor; postoperative analgesia; topical analgesia; epidural analgesia; opioid analgesia Introduction Chronic postoperative pain is one of the most common postoperative complications that se- verely impair patients’ quality of life. It occurs in about 10% of patients after major surgery and is a major health and economic problem. It typically starts as acute postoperative pain that is difficult Radiol Oncol 2025; 59(1): 132-138. Spindler-Vesel A et al. / Effectiveness of postoperative analgesia in laparoscopic colorectal tumor resection 133 to control and gradually turns into persistent neu- ropathic pain. Multimodal analgesics have the po- tential to reduce acute postoperative pain and tar- get multiple points in the pain pathway. For this reason, postoperative pain management should be multimodal and opioid sparing.1 Thoracic epi- dural analgesia could alleviate pain after laparo- scopic surgery.2-4 Although ERAS guidelines rec- ommend the use of less invasive techniques for pain relief5-8, opioids are frequently used periop- eratively despite their side effects.9-11 Non-opioids and 5% lidocaine patches applied topically could effectively reduce the use of opioids and their side effects.12,13 Indeed, efficient perioperative pain manage- ment is important to prevent late neuropathic pain, even after laparoscopic lower abdominal surgery. The incidence is generally low compared to open surgery.14 In comparison to epidural or opioid analge- sia, we wanted to investigate whether a lidocaine patch at the wound site or an infusion of metami- zole and tramadol can reduce opioid consumption in laparoscopic colorectal surgery and whether the results are comparable to those of epidural analge- sia. We also compared the incidence of postopera- tive neuropathic pain between the groups. The primary outcome of this study was opioid consumption (piritramide) during the postopera- tive period, measured at three time points (imme- diately after surgery, the first postoperative day, and the second postoperative day). Secondary out- comes included pain assessment (VAS scores) and the incidence of postoperative neuropathic pain. Patients and methods A prospective, randomised study with four paral- lel groups was conducted at the University Medical Centre (UMC) Ljubljana. The study included pa- tients from the Clinical Department of Abdominal Surgery who were categorised as high-risk ASA (American Society of Anaesthesiologists) class 2–3 surgical patients. Adult patients who had under- gone laparoscopic colorectal tumor resection were included in the study. Exclusion criteria included minors, pregnant women, patients undergoing laparotomy and patients undergoing palliative procedures. The study was approved by the Slovenian National Medical Ethics Committee (151/03/09, 220/03/09, 148/06/11) and registered with Clinical Trials under the ID number NCT04719884. Each patient was visited by a member of the re- search team one day prior to surgery to obtain in- formed consent and clarify any questions. Patients were randomised into four groups based on the type of postoperative analgesia. They were ran- domly assigned to one of four treatment groups using computer-generated random numbers. Randomization was performed prior to surgery by an independent statistician (simple randomisation was used), and allocation was concealed until the intervention was applied. Group 1 consisted of 20 patients who received an infusion of piritramide (patient-controlled anal- gesia, PCA). Group 2 consisted of 21 patients who received an infusion of metamizole and tramadol. FIGURE 1. Consort chart of the study. Thet diagram shows the flow of participants through each stage of a randomized trial. PCA = patient-controlled analgesia; PCEA = patient-controlled epidural analgesia Radiol Oncol 2025; 59(1): 132-138. Spindler-Vesel A et al. / Effectiveness of postoperative analgesia in laparoscopic colorectal tumor resection134 Group 3 consisted of 20 patients who received pa- tient-controlled epidural analgesia (PCEA). Group 4 consisted of 22 patients who received PCA to- gether with a 5% lidocaine patch on the wound site (Figure 1). Anaesthesia was performed by two anaes- thetists, with the technique being uniform in all groups. Standard monitoring was performed. On admission, intravenous access was established, and patients were premedicated with midazolam. In group 3, a thoracic epidural catheter was inserted at the level of Th 7–8 in the left lateral position before the procedure and tested with 3 ml of 2% lidocaine. Standard induction protocols were followed, in- cluding propofol (1–2 mg/kg) or etomidate (0.2 mg/ kg), fentanyl (3–5 μg/kg) and vecuronium (0.1 mg/ kg) or rocuronium (0.6 mg/kg). Anaesthesia was maintained with sevoflurane to keep the BIS value between 40 and 55. Analgesia was supplemented with fentanyl in groups 1, 2 and 4, while levobupiv- acaine 0.5% epidural was administered in group 2. Muscle relaxation was monitored and vecuro- nium (2–4 mg) or rocuronium (10–20 mg) was ad- ministered depending on the TOF values. At the end of the procedure, the volatile agents were dis- continued, and the muscle blockade was reversed with neostigmine (2.5 mg) and atropine (1 mg) or sugammadex (2 mg/kg). Postoperative analgesia began during wound closure: in group 1 with PCA (piritramide 0.5 mg/ ml; infusion 1.5 mg/h, bolus 1.5 mg, lockout 30 minutes), in group 2 with an infusion of tramadol 300 mg and metamizole 2.5 g (in 500 ml 0.9% NaCl, infusion rate 40 ml/h), in group 3 with PCEA (200 ml 0.125% levobupivacaine, 4 mg morphine, 0.075 mg clonidine; infusion 5 ml/h, bolus 5 ml, cut-off time 30 minutes) and in group 4 with PCA (piri- tramide 0.5 mg/ml; infusion 0.5 mg/h, bolus 1.5 mg, cut-off time 20 minutes) in combination with a 5% lidocaine patch on both sides of the wound. The plaster was removed after 12 hours and reap- plied after a 12-hour break. In all groups, paracet- TABLE 1. General patients’ and procedure characteristics Group 1 (PCA) Group 2 (tramadol- metamizole) Group 3 (PCEA) Group 4 (PCA and lidocaine) p Age (years) 59 65 60 59 0,394 Weight (kg) 76 75 79 76 0,833 Wound length (cm) 6,55 7,17 7,45 7,90 0,286 Duration of surgery (min) 139 133 117 112 0,024 Duration of hospitalization (days) 8 9 8 10 0,380 Day of first defecation 4 4 5 4 0,571 ANOVA test was used for comparison. p value of < 0.05 is statistically significant. PCA = patient-controlled analgesia; PCEA = patient-controlled epidural analgesia TABLE 2. Comparison of piritramide consumption between the group pairs Comparison P value (day 0) P value (day 1) P value (day 2) PCA PCEA 0.938 < 0.001 < 0.001 PCA tramadol-metamizole 0.083 < 0.001 < 0.001 PCA PCA + lidocaine 0.995 0.003 0.026 PCEA tramadol-metamizole 0.008 0.352 0.038 PCEA PCA + lidocaine 0.862 < 0 .001 < 0 .001 PCA + lidocaine tramadol-metamizole 0.030 < 0.001 < 0.001 Dwass-Steel-Critchlow-Fligner pairwise comparisons. p value of < 0.05 is statistically significant. PCA = patient-controlled analgesia; PCEA = patient-controlled epidural analgesia Radiol Oncol 2025; 59(1): 132-138. Spindler-Vesel A et al. / Effectiveness of postoperative analgesia in laparoscopic colorectal tumor resection 135 amol 1g/6–8hrs iv was administered regularly. In groups 1, 3 and 4, metamizole 2,5g/12hrs iv was also prescribed. The prescribed analgesia in all four groups was not changed during the study, as it would have made it more difficult to evaluate the difference in additional bolus consumption of piritramide. We monitored the side effects of the analgesics. Appropriate antiemetic therapy was planned, but our patients did not require it. No significant sedative effects were observed. After the operation, the patients were trans- ferred to the post-operative care unit (PACU) and later to the intensive care unit of the abdominal surgery department. They received additional bo- luses of piritramide (3 mg) if required. The dura- tion of the operation and the length of the wound were recorded intraoperatively. In the following two postoperative days, data such as visual ana- logue scale (VAS) scores, piritramide consump- tion, length of hospital stay and readmission to hospital were recorded. VAS was evaluated every six hours and when the additional piritramide bo- lus was needed. The DN4 (Douleur Neuropathique 4) and Pain Detect questionnaires were used to assess the oc- currence of neuropathic pain 30 days after surgery. Statistical analysis The results were analysed with R: A language and environment for statistical computing. (R Foundation for Statistical Computing, Vienna, Austria). The ANOVA test was used to determine differences between the study groups. Pairwise comparisons were performed using the Dwass- Steel-Critchlow-Fligner test. A p-value of < 0.05 was considered statistically significant. Power analysis A power analysis was performed to determine the appropriate sample size. Based on previous data from patients treated at our department and clinical relevance, we assumed a minimum effect size of 0.5 (Cohen’s d) for the reduction in opioid consumption between groups (based on previ- ous data, this corresponds to 3mg of piritramide). This effect size was considered clinically signifi- cant. To detect this effect with 80% power and a significance level of 0.05, a total of 80 patients (ap- proximately 20 per group) were required. The cal- culation was performed using standard formulas FIGURE 2. Piritramide consumption on day of surgery (day 0). FIGURE 3. Piritramide consumption on first postoperative day (day 1). PCA = patient-controlled analgesia; PCEA = patient-controlled epidural analgesia FIGURE 4. Piritramide consumption on second postoperative day (day 2). PCA = patient-controlled analgesia; PCEA = patient-controlled epidural analgesia Radiol Oncol 2025; 59(1): 132-138. Spindler-Vesel A et al. / Effectiveness of postoperative analgesia in laparoscopic colorectal tumor resection136 for comparing means in four independent groups (ANOVA). Results We analysed the data of 20 patients in group 1, 21 patients in group 2, 20 patients in group 3 and 22 patients in group 4 (Figure 1). The general patient characteristics, length of wound and duration of surgery are shown in Table 1. The duration of surgery was significantly shorter in the lidocaine group (p = 0.024). There was no statistically significant difference between the characteristics listed in Table 1 with regard to the gender or ASA status of the patients. In each group, patients were equally distributed in terms of gender. In group 1, there were 19 colon resections and 1 rectal resection. In group 2, there were 8 rectal re- sections and 12 colon resections. In group 3, there were 2 rectal resections and 18 colon resections, while in group 4, there were 3 rectal resections and 19 colon resections. All surgeries were lapa- roscopic. Patients in our study did not undergo ad- ditional anorectal excision during rectal surgeries. The duration of rectal surgeries and the length of postoperative wounds were comparable to bowel resections; therefore, we treated all surgeries as a group of laparoscopic colorectal resections. There was no statistically significant difference in VAS scores between the groups. The VAS scores were low (below 3). Figures 2–4 and Table 2 show the comparison of piritramide consumption on three consecutive postoperative days. After surgery, patients in group 3 (PCEA) re- quired less piritramide than patients in group 2 (tramadol-metamizole) (p < 0.08). There were no differences in piritramide consumption between patients in groups 2 and 3 on the first day after surgery, but on the second day after surgery, pa- tients in group 3 required less piritramide than those in group 2 (p < 0.038). Similarly, patients in group 4 (PCA + lidocaine) required less pirit- ramide than patients in group 2 (p < 0.03) on the day of the surgery. But on the first and second day after surgery, patients in groups 2 and 3 received statistically significantly less piritramide than patients in groups 1 and 4 (p < 0.001). Patients in group 4 required statistically significantly less pi- ritramide than patients in group 1 both on the first day (p < 0.003) and on the second day after surgery (p < 0.026). There were no significant differences between groups in Pain Detect or DN4 questionnaires scores using the Anova test (Table 3). Discussion Postoperative pain is managed in different ways in patients undergoing elective colorectal tumor resection, affecting patient outcomes and pain scores. The epidural catheter provides superior analge- sia for colorectal surgery, whether performed lapa- roscopically or with laparotomy.15 However, due to the frequent prolongation of the bowel recov- ery period and potential complications associated with catheter insertion, epidural analgesia is often replaced by other methods in minimally invasive procedures.2,4,5,16 Intravenous opioid-based patient- controlled analgesia (PCA) is a common method of postoperative analgesia, but peripheral analge- sics could also be used to attenuate the side effects of opioids.7,9,11 Therefore, group 2 in our study re- ceived an infusion of the weak opioid tramadol and metamizole. We found that the consumption of pi- ritramide was significantly reduced in this group on two consecutive days after surgery compared to group 1 (PCA) and group 4 (PCA + lidocaine). However, there was a significant requirement for additional opioids immediately after surgery. As expected, no additional analgesia was required in the epidural analgesia group. Pain scores measured using the VAS scale were low (below 3), indicating adequate postoperative analgesia in all groups. Several studies have shown that intravenous administration of lidocaine (for both laparoscopic and laparotomy procedures) improves postopera- tive analgesia in colorectal surgery, improves bow- el function and shortens hospital stay.6,17-22 Studies TABLE 3. The scores from Pain Detect and DN4 (Douleur Neuropathique 4) questionnaires in the study groups Group (No. of answers) Pain score (mean ± SD) DN4 (mean ± SD) PCA (12) 0 0 Tramadol and metamizole (12) 1.2 ±2.1 0.2 ± 0.4 PCEA (15) 0.1 ± 0.5 0.1 ± 0.4 Lidocaine (17) 0.06 ± 0.2 0 ANOVA test was used for comparison. p value of < 0.05 is statistically significant. DN4 = Douleur Neuropathique 4; PCA = patient-controlled analgesia; PCEA = patient- controlled epidural analgesia Radiol Oncol 2025; 59(1): 132-138. Spindler-Vesel A et al. / Effectiveness of postoperative analgesia in laparoscopic colorectal tumor resection 137 have also shown potential benefits in terms of long-term cancer outcomes.23 Patients receiving lidocaine reported low pain scores, but piritramide consumption was relatively high due to the additional PCA infusion. It is like- ly that total opioid consumption would have been significantly lower if only PCA bolus infusions had been programmed.22,24 The use of lidocaine patches did not result in lower opioid consumption after thoracotomy and sternotomy.25 In a study of 103 patients undergoing elective laparoscopic colorectal surgery, thoracic epidural anaesthesia, spinal diamorphine and PCA were compared. It was found that the use of patient-controlled analgesia was associated with significantly higher postoperative pain scores and higher pain intensity.26 Recovery of bowel function after laparoscopic colorectal surgery was similar in the epidural anal- gesia and intravenous lidocaine groups, although epidural analgesia provided better pain relief.27 In our study, topical lidocaine was applied to the wound site in group 4. Compared to the PCA group, topical lidocaine also reduced piritramide consumption but had no favourable effects on bow- el function, probably due to the local effect of lido- caine rather than systemic effects. No differences were observed in the postoperative recovery of bowel function in any of our groups. This finding is consistent with observations in another study of open colon resection, in which no differences were found between the epidural, intravenous opioid or intravenous lidocaine groups in terms of recovery of bowel function, length of hospital stay and post- operative pain control.28 67% of participants (56/83) completed pain ques- tionnaires and no neuropathic pain was noted 30 days after surgery, which is consistent with obser- vations from another study of laparoscopic colo- rectal surgery.29 The incidence of neuropathic pain is generally not expected in laparoscopic abdomi- nal surgery and does not exceed 5%.14 However, the reported incidence of chronic postoperative pain after laparoscopic colorectal surgery is 17%, similar to laparotomy.30 Conclusions In laparoscopic colorectal tumor surgery, weak opioid tramadol in combination with non-opioid metamizole could be as effective as patient-con- trolled epidural analgesia (PCEA) in terms of post- operative analgesia and opioid consumption. A lidocaine patch in combination with an infusion of piritramide (PCA) could reduce opioid consump- tion. References 1. Leslie JB, Viscusi ER, Pergolizzi JV Jr, Panchal SJ. Anesthetic routines: the anesthesiologist’s role in GI recovery and postoperative ileus. Adv Prev Med 2010; 2011: 976904. doi: 10.4061/2011/976904 2. Pirie K, Traer E, Finniss D, Myles PS, Riedel B. Current approaches to acute postoperative pain management after major abdominal surgery: a narrative review and future directions. Br J Anaesth 2022; 129: 378-93. doi: 10.1016/j. bja.2022.05.029 3. Liu SS, Carpenter RL, Mackey DC. Effects of perioperative analgesic tech- nique on rate of recovery after colon surgery. Anesthesiology 1995; 84: 757-65. doi: 10.1097/00000542-199510000-00015 4. Novak-Jankovič V, Markovič-Božič J. Regional anaesthesia in thoracic and ab- dominal surgery. Acta Clin Croat 2019; 58(Suppl 1): 96-100. doi: 10.20471/ acc.2019.58.s1.14 5. Reidel MA, Knaebel HP, Seiler CM, Knauer C, Motsch J, Victor N, et al. Postsurgical pain outcome of vertical and transverse abdominal incision: design of a randomized controlled equivalence trial [ISRCTN60734227]. BMC Surg 2003; 3: 9. doi: 10.1186/1471-2482-3-9 6. Herroeder S, Pecher S, Schonherr ME, Kaulitz G, Hahnenkamp K, Friess H, et al. Systemic lidocaine shortens length of hospital stay after colorectal sur- gery. Ann Surg 2007; 246: 192-200. doi: 10.1097/SLA.0b013e31805dac11 7. Kietzmann D, Bouillon T, Hamm C, Schwabe K, Schenk H, Gundert-Remy U, et al. Pharmacodynamic modelling of the analgesic effects of piritramide in postoperative patients. Acta Anaesthesiol Scand 1997; 41: 888-94. doi: 10.1111/j.1399-6576.1997.tb04805.x 8. Gustafsson UO, Scott MJ, Hubner M, Nygren J, Demartines N, Francis N, et al. Guidelines for perioperative care in elective colorectal surgery: Enhanced Recovery After Surgery (ERAS®) Society Recommendations: 2018. World J Surg 2019; 43: 659-95. doi: 10.1007/s00268-018-4844-y 9. Salicath JH, Yeoh EC, Bennett MH. Epidural analgesia versus patient- controlled intravenous analgesia for pain following intra-abdominal sur- gery in adults. Cochrane Database Syst Rev 2018; 8: CD010434. doi: 10.1002/14651858.CD010434.pub2 10. Lindberg M, Franklin O, Svensson J, Franklin KA. Postoperative pain after colorectal surgery. Int J Colorectal Dis 2020; 35: 1265-72. doi: 10.1007/ s00384-020-03580-4 11. Angst MS and Clark JD. Opioid-induced hyperalgesia: a qualitative system- atic review. Anesthesiology 2006; 104: 570-87. doi: 10.1007/s00384-020- 03580-4 12. Smoker J, Cohen A, Rasouli MR, Schwenk ES. Transdermal lidocaine for peri- operative pain: a systematic review of the literature. Curr Pain Headache Rep 2019; 23: 89. doi: 10.1007/s11916-019-0830-9 13. de Queiroz VKP, da Nóbrega Marinho AM, de Barros GAM. Analgesic effects of a 5% lidocaine patch after cesarean section: a randomized placebo- controlled double-blind clinical trial. J Clin Anesth 2021; 73: 110328. doi: 10.1016/j.jclinane.2021.110328 14. Shin JH and Howard FM. Abdominal wall nerve injury during laparoscopic gynecologic surgery: incidence, risk factors, and treatment outcomes. J Minim Invasive Gynecol 2012; 19: 448-53. doi: 10.1016/j.jmig.2012.03.009 15. Perivoliotis K, Sarakatsianou C, Georgopoulou S, Tzovaras G, Baloyiannis I. Thoracic epidural analgesia (TEA) versus patient-controlled analgesia (PCA) in laparoscopic colectomy: a systematic review and meta-analysis. Int J Colorectal Dis 2019; 34: 27-38. doi: 10.1007/s00384-018-3207-3 16. Guay J, Nishimori M, Kopp S. Epidural local anaesthetics versus opioid-based analgesic regimens for postoperative gastrointestinal paralysis, vomiting and pain after abdominal surgery. Cochrane Database Syst Rev 2016; 7: CD001893. doi: 10.1002/14651858.CD001893.pub2 17. McCarthy GC, Megalla SA, Habib AS. Impact of intravenous lidocaine infusion on postoperative analgesia and recovery from surgery: a system- atic review of randomized controlled trials. Drugs 2010; 70: 1149-63. doi: 10.2165/10898560-000000000-00000 Radiol Oncol 2025; 59(1): 132-138. Spindler-Vesel A et al. / Effectiveness of postoperative analgesia in laparoscopic colorectal tumor resection138 18. Sun Y, Li T, Wang N, Yun Y, Gan TJ. Perioperative systemic lidocaine for post- operative analgesia and recovery after abdominal surgery: a meta-analysis of randomized controlled trials. Dis Colon Rectum 2012; 55: 1183-94. doi: 10.1097/DCR.0b013e318259bcd8 19. Harvey KP, Adair JD, Isho M, Robinson R. Can intravenous lidocaine decrease postsurgical ileus and shorten hospital stay in elective bowel surgery? A pilot study and literature review. Am J Surg 2009; 198: 231-6. doi: 10.1016/j. amjsurg.2008.10.015 20. Kuo CP, Jao SW, Chen KM, Wong CS, Yeh CC, Sheen MJ, et al. Comparison of the effects of thoracic epidural analgesia and i.v. infusion with lidocaine on cytokine response, postoperative pain and bowel function in patients undergoing colonic surgery. Br J Anaesth 2006; 97: 640-6. doi: 10.1093/ bja/ael217 21. Paterson HM, Cotton S, Norrie J, Nimmo S, Foo I, Balfour A, et al. The ALLEGRO trial: a placebo controlled randomised trial of intravenous lido- caine in accelerating gastrointestinal recovery after colorectal surgery. Trials 2022; 23: 84. doi: 10.1186/s13063-022-06021-5 22. Tikuišis R, Miliauskas P, Samalavičius NE, Žurauskas A, Samalavičius R, Zabulis V. Intravenous lidocaine for post-operative pain relief after hand-as- sisted laparoscopic colon surgery: a randomized, placebo-controlled clinical trial. Tech Coloproctol 2014; 18: 373-80. doi: 10.1007/s10151-013-1065-0 23. Wall TP, Buggy DJ. Perioperative intravenous lidocaine and metastatic cancer recurrence - a narrative review. Front Oncol 2021; 11: 688896. doi: 10.3389/fonc.2021.688896 24. Weibel S, Jelting Y, Pace NL, Helf A, Eberhart LH, Hahnenkamp K, et al Continuous intravenous perioperative lidocaine infusion for postop- erative pain and recovery in adults. Cochrane Database Syst Rev 2018; 6: CD009642. doi: 10.10 02/14651858.CD009642.pub3 25. Liu M, Wai M, Nunez J. Topical lidocaine patch for postthoracotomy and poststernotomy pain in cardiothoracic intensive care unit adult patients. Crit Care Nurse 2019; 39: 51-7. doi: 10.4037/ccn2019849 26. Brown L, Gray M, Griffiths B, Jones M, Madhavan A, Naru K, et al; NoSTRA (Northern Surgical Trainees Reseach Association). A multicentre, prospective, observational cohort study of variation in practice in periop- erative analgesia strategies in elective laparoscopic colorectal surgery (the LapCoGesic study). Ann R Coll Surg Engl 2020; 102: 28-35. doi: 10.1308/ rcsann.2019.0091 27. Wongyingsinn M, Baldini G, Charlebois P, Liberman S, Stein B, Carli F. Intravenous lidocaine versus thoracic epidural analgesia: a randomized controlled trial in patients undergoing laparoscopic colorectal surgery using an enhanced recovery program. Reg Anesth Pain Med 2011; 36: 241-8. doi: 10.1097/AAP.0b013e31820d4362 28. Swenson BR, Gottschalk A, Wells LT, Rowlingson JC, Thompson PW, Barclay M, et al. Intravenous lidocaine is as effective as epidural bupivacaine in reducing ileus duration, hospital stay, and pain after open colon resection: a randomized clinical trial. Reg Anesth Pain Med 2010; 35: 370-6. doi: 10.1097/AAP.0b013e3181e8d5da 29. Andjelkovic L, Novak-Jankovic V, Pozar-Lukanovic N, Bosnic Z, Spindler-Vesel A. Influence of dexmedetomidine and lidocaine on perioperative opioid con- sumption in laparoscopic intestine resection: a randomized controlled clini- cal trial. J Int Med Res 2018; 46: 5143-54. doi: 10.1177/0300060518792456 30. Joris JL, Georges MJ, Medjahed K, Ledoux D, lle Damilot G, Ramquet CC, et al. Prevalence, characteristics and risk factors of chronic postsurgical pain after laparoscopic colorectal surgery. Eur J Anaesthesiol 2015; 32: 712-7. doi: 10.1097/EJA.0000000000000268