Introduction Enhanced recovery after surgery (ERAS) pathways have become standard of care, as they reduce perioperative complications and accelerate recovery. Optimal postoperative pain management is considered a prerequisite to enhancing recovery after surgery because it facilitates ambulation and rehabilitation.¹ However, postoperative pain continues to be inadequately managed. One of the major reasons for inadequate pain control includes inappropriate clinical application of current knowledge.

Because pain is a complex phenomenon, a multimodal approach has been recommended.² Although optimal multimodal analgesic regimen remains controversial, it is well accepted that combination of paracetamol (acetaminophen) and non-steroidal anti-inflammatory drugs (NSAIDs) or cyclooxygenase (COX)-2 specific inhibitor should be administered unless there are contraindications. In addition, local and/or regional analgesia is recommended. The choice of the regional analgesia technique should be procedure specific. Furthermore, analgesic adjuncts such as ketamine, dexmedetomidine, and lidocaine infusions have been evaluated as components of multimodal analgesic regimen and/or opioid-free anesthesia.³ The aim of this pro/con discussion is to present the current evidence on the role of epidural analgesia and intravenous lidocaine infusion as components of multimodal analgesia technique for enhanced recovery.

Epidural Analgesia Epidural analgesia provides excellent dynamic pain relief and has been shown to reduce postoperative morbidity and mortality.^{4 5} Advantages of epidural analgesia include reduced pulmonary, cardiovascular, gastrointestinal, and venous thromboembolic complications. Given these benefits thoracic epidural has been recommended in patients with significant comorbid conditions including cardiovascular disease and chronic obstructive pulmonary disease.⁶ Therefore, epidural analgesia has been considered as a gold standard for patients undergoing major thoraco-abdominal surgery.^7-9

However, in recent years the clinical benefits of epidural analgesia have been questioned.^10-13 This probably is due to implementation of ERAS pathways, improved surgical techniques, improved postoperative care (e.g., avoidance of nasogastric tubes and drains), improved pulmonary physiotherapy, early oral intake and early mobilization. A systematic review of randomized trials in patients undergoing laparoscopic colonic surgery revealed that pain scores in patients receiving optimal multimodal analgesia were within an acceptable range, suggesting that epidural analgesia may not be necessary for laparoscopic procedures.¹⁴ Also, there were no differences between the epidural analgesia and the non-epidural analgesia groups with respect to return of bowel function, pulmonary function, length of stay, and quality of life. Other studies in patients undergoing laparoscopic colorectal surgery also found that epidural analgesia increased the incidence of urinary infection and longer hospital length of stay^15-17 without providing any analgesic benefits over conventional analgesic regimen. Also, epidural analgesia did not reduce post-discharge opioid requirements¹⁸ or postopeerative venous thromboembolism.¹⁹

Epidural analgesia is limited by a significant failure rate for catheter placement and malfunction as well as adverse effects related to sympathetic and motor blockade. In addition, use of epidural opioids can increase postoperative pruritis, nausea, and urinary retention. Also, epidural analgesia can delay ambulation due to the presence of catheters/pumps and difficulties in catheter management due to routine use of VTE prophylaxis.Also, epidural analgesia is invasive, labor-intensive, and expensive.^{20 21}

Given the lack of clinical benefits and the potential for increased complications including delayed ambulation, epidural analgesia is being replaced with more distal regional analgesia techniques such as interfascial plane blocks and/or surgical site infiltration.

Intravenous Lidocaine Infusion Lidocaine has analgesic, anti-hyperalgesic, and anti-inflammatory effects. It also has anti-neoplastic properties, and therefore may provide benefits in patients undergoing cancer surgery.²² Lidocaine can reduce nociception and/or cardiovascular responses to surgical stress. Also, perioperative (intraoperative and immediate postoperative) intravenous lidocaine infusion has been found to reduce pain scores and opioid requirements. In addition to improved pain control, some studies have reported beneficial effects on the gastrointestinal tract (decrease in postoperative ileus, shortening of both the time to first flatus and the time to first bowel movement, decrease in postoperative nausea and vomiting).^23-26 These benefits are observed only in patients undergoing abdominal surgery (laparoscopic and open approaches), but not for any other surgical procedures, although the reason for this specificity is poorly understood.

Overall, intraopertive lidocaine infusion has been used widely as a component of multimodal analgesic technique, particularly in patients undergoing abdmonial surgery. Also, intravenous lidocaine infusion could be recommended in patients undergoing open abdominal surgery with contraindications to basic analgesics (e.g. paracetamol and NSAIDs). Furthermore, lidociane infusion may be suitable for patients at high risk of postoperative pain, however, the evidence for this is lacking.

Although the exact mechanism of action of lidocaine infusion are not well understood,²² the plasma concentrations of lidocaine infusion are like those obtained during epidural administration, which may be its mechanism of action.²⁷Therefore, intravenous lidocaine infusion has been labelled as ‘the poor man’s epidural.’

A recent study found that lidocaine infusion provides clinically meaningful difference in postoperative pain.²⁸ However, almost 10% of patients experienced symptoms consistent with local anesthetic toxicity (LAST) including one patient having cardiac arrest who recovered after receiving intravenous lipid emulsion. The potential for LAST increases with the use of local/regional analgesia techniques, which are increasingly being used in current clinical practice. Therefore, some suggest that lidocaine infusion should be considered as a ‘high-risk’ approach for pain management.^{29 30}

Significant caution is advised to prevent LAST. It is recommended that the lidocaine infusion dose should be calculated based on Ideal body weight, not actual body weight. Lidocaine infusion should not be used in patients weighing <40 kg. The loading dose should be ≤1.5 mg/kg, given over 10 min followed by infusion rate of ≤1.5 mg/kg/h for maximum of 24 h. Total lidocaine dose infused should be <120 mg/h. Intravenous lidocaine should be avoided when regional analgesic blocks are used. If regional analgesia technique is planned, the choice of loco/regional blocks may become limited with the use of lidocaine infusion. It is recommended to avoid a regional analgesia technique with high risk of LAST based on local anesthetic absorption characteristics (e.g. intercostal, paravertebral, or fascial plane blocks, and midline surgeries needing bilateral blockade) or characteristics of surrounding structures. Choose techniques where the minimum effective dose is small, such as selective root blocks of the brachial plexus. Also, continuous catheter techniques should be avoided when using lidocaine infusion.

Lidocaine metabolism can be affected by the duration and direct effects of GA and surgery on liver blood flow. Vigilance is needed in patients with existing comorbidity. When administered on the wards, patients should be managed in a monitored high dependency unit. Also, lidocaine infusion should be administered through a dedicated intravenous cannula using a suitable infusion device. There should be a separate lidocaine monitoring chart. Physician and staff should be educated regarding patient susceptibility and selection as well as infusion preparation and infusion pump programing.

Conclusions In summary, the role of epidural analgesia in current clinical practice of enhanced recovery after surgery is diminishing. Peripheral regional blocks such as interfascial plane blocks and local infiltration analgesia. Intravenous lidocaine infusion has been shown to influence postoperative outcomes after abdominal surgery. However, the optimal duration of administration appears to be for 24 h. Also, there are concerns of LAST particularly with concomitant use of local/regional analgesia techniques. Therefore, it is imperative to follow rigorous precautions for prevention as well as early diagnosis and management of LAST.

References

1. Joshi GP, Kehlet H. Postoperative pain management in the era of ERAS: an overview. Best Pract Res Anaestheisiol 2019;33:259-67.

2. Joshi GP. Rational multimodal analgesia for perioperative pain management. Curr Pain Headache Rep. 2023;27:227-37.

3. Shanthanna H, Ladha KS, Kehlet H, Joshi GP. Perioperative opioid administration. Anesthesiology 2021;134:645-59.

4. Popping DM, Elia N, Marret E, et al. Protective effects of epidural analgesia on pulmonary complications after abdominal and thoracic surgery: a meta-analysis. Arch Surg 2008;143:990-9.

5. Rodgers A, Walker N, Schug S, et al. Reduction of postoperative mortality with epidural or spinal anaesthesia: results from overview of randomized trials. Br Med J 2000;321:1493-7.

6. van Lier F, van der Geest PJ, Hoeks SE, et al. Epidural analgesia is associated with improved health outcomes of surgical patients with chronic obstructive pulmonary disease. Anesthesiology 2011;115:315-21.

7. Joshi GP, Bonnet F, Shah R, et al. A systematic review of randomized trials evaluating regional techniques for postthoracotomy analgesia. Anesth Analg 2008;107:1026-40.

8. Elsaharydah A, Zuo LW, Minhajuddin A, Joshi GP. Effects of epidural analgesia on the recovery after open colorectal surgery. Proc Bayl Univ Med Cent 2017;30:255-8.

9. Freise H, Van Aken HK. Risks and benefits of thoracic epidural anaesthesia. Br J Anaesth 2011;107:859-68.

10. Rigg JR, Jamrozik K, Myles PS, et al. Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial. Lancet 2002;359:1276-82.

11. Christie W, McCabe S. Major complications of epidural analgesia after surgery: results of a six-year survey. Anaesthesia 2007;62:335-41.

12. Low J, Johnston N, Morris C. Epidural analgesia: first do no harm. Anaesthesia 2008;63:1-3.

13. Kehlet H, Joshi GP. Systematic reviews and meta-analyses of randomized controlled trials on perioperative outcomes: an urgent need for critical reappraisal. Anesth Analg 2015;121:1104-7.

14. Joshi GP, Bonnet F, Kehlet H, et al. Evidence-based postoperative pain management after laparoscopic colorectal surgery. Colorectal Dis. 2013;15:146-55.

15. Halabi WJ, Jafari MD, Nguyen VQ, et al. A nationwide analysis of the use and outcomes of epidural analgesia in open colorectal surgery. J Gastrointest Surg 2013;17:1130-7.

16. Halabi WJ, et al. Epidural analgesia in laparoscopic colorectal surgery: a nationwide analysis of use and outcomes. JAMA Surg 2014;149:130-6.

17. ERAS Compliance Group. The impact of enhanced recovery protocol complicance on elective colorectal cancer resection: results from an international registry. Ann Surg 2015;261:1153-9.

18. Ladha KS, et al. Impact of perioperative epidural placement on postdischarge opioid use in patients undergoing abdominal surgery. Anesthesiology 2016;124.

19. Turan A, et al. Association of neuraxial anesthesia with postoperative venous thromoboembolism after noncardiac surgery: a propensity-matched analysis of ACS-NSQIP database. Anesth Analg 2019;128:494-501.

20. Rawal N. Epidural technique for postoperative pain: gold standard no more? Reg Anesth Pain Med 2012;37:310-7.

21. Wildsmith JA. Continuous thoracic epidural block for surgery: gold standard or debased currency? Br J Anaesth 2012;109:9-12.

22. Hermanns H, Hollmann MW, Stevens MF, et al. Molecular mechanisms of action of systemic lidocaine in acute and chronic pain: a narrative review. Br J Anaesth 2019;123:335-49.

23. Dunn LK, Durieux ME. Perioperative use of intravenous lidocaine. Anesthesiology. 2017;126:729-37.

24. Sun Y, Li T, Wang N, Yun Y, Gan TJ. Perioperative systemic lidocaine for postoperative analgesia and recovery after abdominal surgery: a meta-analysis of randomized controlled trials. Dis Colon Rectum. 2012;55:1183-94.

25. Rollins KE, Javanmard-Emamghissi H, Scott MJ, Lobo DN. The impact of peri-operative intravenous lidocaine on postoperative outcome after elective colorectal surgery: a meta-analysis of randomised controlled trials. Eur J Anaesthesiol 2020;37:1–12.

26. Yang W, Yan S, Yu F, Jiang C. Appropriate duration of perioperative intravenous administration of lidocaine to provide satisfactory analgesia for adult patients undergoing colorectal surgery: a meta-analysis of randomized controlled trials. Anesth Analg 2023;136:494-506.

27. Hollmann MW, Strümper D, Durieux ME. The poor man’s epidural: systemic local anesthetics for improving postoperative outcomes. Med Hypotheses 2004;63:386-9.

28. De Oliveira K, Eipe N. Intravenous lidocaine for acute pain: a single-institution retrospective study. Drugs Real World Outcomes 2020;7:205-12.

29. Foo I, Macfarlane AJR, Srivastava D, et al. The use of intravenous lidocaine for postoperative pain and recovery: international consensus statement on efficacy and safety. Anaesthesia 2021;76:238-50.

30. Shanthanna H, Weinburg G. Intravenous lidocaine, regional blockade, or both: considerations for multiple interventions involving local anaesthetics. Br J Anaesth 2021;127:497-501.