Pain relief after colonic surgery. Has the epidural had it’s day?

Dr Anton Krige

Epidural analgesia (EA) grew in popularity through the nineties with several studies and systematic reviews [1,2] reporting superior analgesic efficacy compared to high dose opiate. A systematic review followed suggesting EA reduced morbidity following major abdominal surgery [3] and a Cochrane Review [4] demonstrated a reduction in GI paralysis.

In recent years Enhanced Recovery Programs (ERP) have become widely established in the UK, with early mobilisation a key component. Effective pain relief is obviously pivotal to achieving early mobilisation, and EA remains the recommended technique in the ERAS Society guidelines for colonic and rectal surgery [5,6], as well as in the latest NHS ERP generic pathway [7], both published in 2012.

However a gradual paradigm shift away from EA is taking place both internationally, largely in Australasia, as well as in the UK.

There are a variety of factors contributing to this change in clinical practice.

The first was the publication over 10 years ago now of the MASTERS Trial [8], which with 915 patients recruited remains the largest RCT investigating EA for abdominal surgery. This multi-centre trial across Australasia & SE Asia was designed to determine if EA reduced mortality and major morbidity in high-risk major abdominal surgery. It failed to do so, and mortality was in fact non-significantly higher in the morphine arm, with only a reduction in respiratory failure in the high-risk respiratory disease group reaching significance in favour of EA. Enthusiasts interpreted this as confirmation of the value of EA, but the study was widely considered to refute earlier small trials showing improved outcomes with EA.

This month has seen the publication of controversial data from a previous randomised trial (POISE study) challenging the role of EA in reducing morbidity, indicating instead that it may in fact increase morbidity [9]. This study leaves us with more questions than answers in this regard.

NAP3 [10] provided accurate data on neurological complications following central neuraxial blocks, and although the incidence is extremely low, it is greatest in the group receiving thoracic EA for major surgery.

Furthermore technological advances in portable ultrasound have led to a variety of abdominal wall blocks (postero-lateral, subcostal & oblique subcostal TAP as well as rectus sheath blocks), either singe shot or catheter based. Multi-holed catheters have become available to effectively deliver preperitoneal continuous wound infusions of local anaesthetic. These techniques ensure somatic analgesia, dependant on choosing the correct approach for the nature of the incision. Transdermal low dose opiate provides effective and efficient management of the remaining visceral pain, this is short-lived in nature, with any breakthrough pain managed with oral morphine.

Aside from the new array of interventions available to anaesthetists, the past 10 years have seen equally rapid changes in surgical approaches, with laparoscopic approach now the most common, and many of the remaining open procedures performed via transverse incisions. These all have a lower analgesic requirement than the traditional open midline approach.

In fact, it is increasingly clear that for laparoscopic approaches EA is not only unnecessary, but actually lengthens hospital stay as compared to morphine PCA or spinal diamorphine [11], and in my clinical experience the same seems to hold true for open surgery with a transverse incision. Spinal diamorphine seems to provide the best combination of pain experience and duration of hospital stay with the added advantage of single administration.

Adjuvant analgesic therapies may hold additional benefits i.e. gabapentin, ketamine, lidocaine and corticosteroids, with the optimum route, timing and dosages still to be elucidated.

Finally, the failure rate of EA, reported as 20-50% in trials, and the peri-operative hypotension seen in 60% of thoracic EA have added to disillusionment with EA. Hypotension is associated with fluid overload, and vasopressor requirement, which increases stay in high care facilities and healthcare management time.

Our growing armamentarium provides the ability to select horses for courses dependant on the aforementioned factors.

EA still occupies a niche for the foreseeable future for specific colorectal operations e.g. APR due to the combination of incisions, or patients e.g. those with chronic pain conditions or multiple previous abdominal surgery and scarring.

Future trials should compare all new analgesic techniques to EA, and define the role of the alternative adjuvant agents to determine if they warrant widespread use outside of research settings.

  1. Block BM, Liu SS, Rowlingson AJ, Cowan AR, Cowan Jr JA, Wu CL. Efficacy of postoperative epidural analgesia: a meta-analysis. JAMA 2003;290(18):2455-63
  2. Werawatganon T, Charuluxananan S. Patient controlled intravenous opioid analgesia versus continuous epidural anal- gesia for pain after intra-abdominal surgery. Cochrane Database of Systematic Reviews 2005, Issue 1. Art. No.: CD004088.
  3. Rodgers A, Walker N, Schug S et al. Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview randomised trials. MJ 2000;321:1–12
  4. Jørgensen H, Wetterslev J, Møiniche S, Dahl JB. Epidural local anaesthetics versus opioid-based analgesic regimens for postoperative gastrointestinal paralysis, PONV and pain after abdominal surgery. Cochrane Database of Systematic Reviews 2001, Issue 1. Art. No.: CD001893.
  5. Gustafsson U, Scott M, Schwenk M, et al. Guidelines for Perioperative Care in Elective Colonic Surgery: Enhanced Recovery After Surgery (ERASÒ) Society Recommendations. World J Surg (2013) 37:259–284
  6. Nygren J, Thacker J, Carli F et al. Guidelines for Perioperative Care in Elective Rectal/Pelvic Surgery: Enhanced Recovery After Surgery (ERASÒ) Society Recommendations. World J Surg (2013) 37:285–305
  7. Fulfilling the potential: A better journey for patients and a better deal for the NHS. Published on behalf of the Enhanced Recovery Partnership by NHS Improvement 2012.
  8. Rigg JR, Jamrozik K, Myles PS, Silbert BS, Peyton PJ, Parsons RW, et al. Epidural anaesthesia and analgesia and outcome of major surgery: a randomised trial. Lancet 2002;359(9314):1276-82
  9. Leslie K, Myles P, Devereaux P, et al. Neuraxial block, death and serious cardiovascular morbidity in the POISE trial. Br J Anaesth 2013; 111: 382–90
  10. Cook TM,Counsell D, Wildsmith JAW. On behalf of the Royal College of Anaesthetists Third National Audit Project. Major complications of central neuraxial block: report on the 3rd National Audit Project of the Royal College of Anaesthetists. Br J Anaesth 2009; 102: 179–90
  11. Levy B, Scott M, Fawcett W, Fry C and Rockall T. Randomized clinical trial of epidural, spinal or patient-controlled analgesia for patients undergoing laparoscopic colorectal surgery. British Journal of Surgery 2011; 98: 1068–1078

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