Analgesia for Major Abdominal Surgery

 

This post serves as handout for my lecture of the above title I delivered at the Norwich Anaesthesia Update on the 8th December 2016.

Introduction

As William Pollard said:

“Learning and innovation go hand in hand. The arrogance of success is to think that what you did yesterday will be sufficient for tomorrow.”

The two key components required to deliver successful ERAS are early mobilisation and early nutrition (assuming high quality surgery). Both of these are influenced directly by the anaesthetist’s fluid management and provision of effective analgesia.

Effective analgesia

The most effective analgesic option is not necessarily the option with the best pain relief efficacy but rather the one that allows optimal respiratory function and early mobilisation.

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Attributes required:

  • Minimal adverse effects
    • no prolonged hypotension
    • no nausea and vomiting
    • no motor blockade
  • Easy to deploy at scale
  • High level of staff delivery compliance
  • Minimal attachments – portability
  • Cost-effective

Surgical Developments

Laparoscopic surgery

  • Open surgery involves a variety of approaches.
  • Rapid increase transverse approaches and the use of harmonic scalpels for open colorectal surgery – both reduce analgesic requirements.
  • Rapid increase laparoscopic approaches – now 48% of major colorectal and 50% increase over past 5 years (National Bowel Cancer Audit).
  • Robotic surgery increasing and moving from urological across to colorectal surgery.

These newer surgical approaches are game-changers for our analgesic strategies as they induce minimal somatic pain and we are mostly treating the visceral pain, which although intense initially, subsides within 12 to 24 hours.

Analgesic Developments

At the same time we have had a rapid expansion in our analgesic armamentarium. At the turn of the century either thoracic epidural analgesia or morphine PCA’s dominated. Since then, thanks to ultrasound, old techniques have been resurrected and existing techniques have found wider application.

Key primary techniques:

  • Thoracic Epidural Analgesia (TEA)
  • Spinal Opiate
  • Rectus Sheath Catheters (RSC)
  • Continuous Wound Infusion Catheters (CWIC)
  • Thoracic Paravertebral Blocks (TPVB)
  • Quadratus Lumborum Blocks (QLB)
  • TAP Blocks

I will not be discussing the final 3 techniques (TPVB, QLB or TAP Blocks) as although all of these have proven efficacy they either require experts, greater invasiveness or excessive complexity (to cover the entire abdomen with TAP blocks requires 4 injections & 2 catheters) hence not fulfilling my criteria of delivery at scale enabling easy standardisation. I will instead focus on the first four key techniques: TEA, Spinal Opiate, RSC & CWI along with non-opioid adjuvants, with a particular focus on Lidocaine Infusions.

Packages/Bundles of Analgesia:

Each primary technique needs to be delivered as an entire package or bundle of care with simple analgesia as the foundation and the addition of non-opioid adjuvants. We also find transdermal fentanyl patches a usual addition to our bundle.

Non-opioid Adjuvants:

Gabapentin

  • Extensive evidence for opiate sparing properties & safety (1-5).
  • Cost-effective
  • All of our major surgery patients receive a pre-op dose (300mg) & 300mg in divided doses for 3 days post-op (modest dosaging for acute pain however older patients have experienced dizziness with larger doses in our experience) (6)

Evidence:

  1.  Mathiesen O, Møiniche S, Dahl JB. Gabapentin and postoperative pain: a qualitative and quantitative systematic review, with focus on procedure. BMC Anesthesiology. 2007;7(1):6–15.
  2.  Tiippana EM, Hamunen K, Kontinen VK, Kalso E. Do surgical patients benefit from perioperative gabapentin/pregabalin? A systematic review of efficacy and safety. Anesthesia & Analgesia. 2007 Jun;104(6):1545–56–tableofcontents.
  3. Efficacy of Pregabalin in Acute Postoperative Pain Under Different Surgical Categories: A Meta-Analysis. 2015 Nov;94(46):e1944.

  4. Arumugam S, Lau csm, Chamberlain RS. Use of preoperative gabapentin signi cantly reduces postoperative opioid consumption: a meta-analysis. Journal of Pain Research 2016:9 631–640

  5. Dauri M, Faria S, Gatti A, Celidonio L, Carpenedo R, Sabato AF. Gabapentin and Pregabalin for the Acute Post-operative Pain Management. A Systematic-narrative Review of the Recent Clinical Evidences. Current Drug Targets, 2009, 10, 716-733

  6. Perioperative gabapentinoids: choice of agent, dose, timing, and effects on chronic postsurgical pain. 2013 Nov;119(5):1215–21.

Ketamine

  • Extensive  evidence (1-3) for  efficacy via a variety of
    • routes,
    • timing (pre-, intra- & post-op),
    • boluses or infusions.
  • The simplest strategy = 0.5mg/kg bolus intra-operatively.
  • Reduction in inflammatory response is an additional benefit (4).
  • Animal models (5) suggest possible reduction in gut reperfusion injury which may be particularly useful following extended pneumoperitoneum.

Evidence:

  1. Perioperative ketamine for acute postoperative pain. 2006 Jan 25;(1):CD004603.

  2. Ketamine as adjuvant analgesic to opioids: a quantitative and qualitative systematic review. 2004 Aug;99(2):482–95.

  3. Intravenous sub-anesthetic ketamine for perioperative analgesia. 2016 Apr;32(2):160–7.

  4. Does intraoperative ketamine attenuate inflammatory reactivity following surgery? A systematic review and meta-analysis. 2012 Oct;115(4):934–43.

  5. Ketamine anesthesia reduces intestinal ischemia/reperfusion injury in rats. 2008 Sep 7;14(33):5192–6.

IV Lidocaine Infusions

See section following Spinal Opiate.

Fentanyl Patches

  • Very useful either for stepping down from epidurals or to provide visceral analgesia for the other primary techniques.
  • Eliminate the issue of non-compliance with drug administration where regularly prescribed analgesics as frequently treated as PRN drugs.
  • Limit the dosage to 12mcg patches for those over 70 years old &/or

Anti-emmetics

  • Be aggressive.
  • Audits continue to report up to 60% of colorectal surgery patients experiencing PONV. This is a major obstacle to ERAS success.
  • Along with multimodal antie-emmetics intra-operatively  – cyclizine, ondansetron and dexamethazone.
  • Buccastem as a regular administration for 2 days of post-operative prophylaxis. Efficacious, cost-effectiveness & not reliant on gut function.

Primary Techniques

Thoracic Epidural Analgesia

  • Current gold standard although but this is under threat.
  • This Cochrane review (1)  is one of many demonstrating analgesic supremacy over morphine PCA & we all know nothing can beat the way a patient with a good epidural appears in theatre recovery.
  • That’s not the full story. Marret’s metanalysis (2) shows that this doesn’t translate into shorter hospital stays,
  • Nor does it lead to any survival advantage in updated meta-analysis (3) which includes the Peyton & Park studies that were powered for mortality.
  • And the beneficial effects of modulating the stress response appears to be short-lived in more recent studies (4) – glucose and cortisol rise were reduced in a epidural group compared to a morphine group at the end of surgery but no difference by 24 hours and no difference at all for cytokine response. Therefore unlikely to be of much clinical significance.
  • Epidural failure rates are a well known problem – quoted as 32% across a range of studies (5)
  • And attempts to keep them working incur significant healthcare worker time shown here by Tileul (6) comparing epidurals, PCAs & CWICs.
  • I won’t dwell on NAP-3 (7). As we know nerve injuries are rare but the bulk occur in peri-operative TEAs & of course most of the alternatives don’t have this risk at all.
  • I’m sure those of you who do POCU or critical care ward rounds also frequently encounter, as I do, the irritation of prolonged stays due to vasopressor dependency (roughly 20% of patients).
  • And even worse patients being drowned on the wards in attempts to manage the hypotension.

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  • In this large ER cohort study (8) excessive fluid had the strongest association with morbidity it’s a really important issue.
  • Our decisions should be patient-centered but unfortunately patient experience is generally ignored in quantitative research. Our as yet unpublished nested qualitative study within our RCT comparing TEA to RSC (TERSC) (9) involved patents being interviewed in their homes a month after surgery regarding their experiences and acceptability of the techniques. Several TEA patients reported high levels of anxiety building up to the epidural as well as significant discomfort during insertion and feelings of claustrophobia.

Evidence:

  1. Patient controlled intravenous opioid analgesia versus continuous epidural analgesia for pain after intra-abdominal surgery. 2005 Jan 25;(1):CD004088
  2. Meta-analysis of epidural analgesia versus parenteral opioid analgesia after colorectal surgery. 2007 Jun;94(6):665–73.

  3. Neuraxial anesthesia for the prevention of postoperative mortality and major morbidity: an overview of cochrane systematic reviews. 2014 Sep;119(3):716–25.

  4. Thoracic epidural analgesia inhibits the neuro-hormonal but not the acute inflammatory stress response after radical retropubic prostatectomy. 2013 May;110(5):747–57.

  5. Failed epidural: causes and management. 2012 Aug;109(2):144–54.

  6. Cost-effectiveness analysis comparing epidural, patient-controlled intravenous morphine, and continuous wound infiltration for postoperative pain management after open abdominal surgery. 2012 Jun;108(6):998–1005.

  7. NAP3
  8. Adherence to the enhanced recovery after surgery protocol and outcomes after colorectal cancer surgery. 2011 May;146(5):571–7.

  9. Thoracic Epidural analgesia versus Rectus Sheath Catheters for open midline incisions in major abdominal surgery within an enhanced recovery programme (TERSC): study protocol for a randomised controlled trial. 2014 Oct 21;15:400.

Spinal Opiate

  • Spinal opiate is a very attractive alternative. The skill set is inherent so it’s easy to deploy at scale. The rare but serious complications are less common than with epidurals (NAP3) and it’s single shot with no ongoing management requirements. The key indication is laparoscopic surgery or open surgery via transverse incisions.
  • Spinal morphine has shown efficacy over parenteral opiate for laparoscopic abdominal surgery. A Canadian study (1) randomized 50 patients to IT morphine + PRN oxycodone or morphine PCA and the intrathecal group had better pain control and less opiate consumption in the 1st 24 hrs, however 2 patients had excessive sedation and respiratory depression.
  • My personal experience is entirely with intrathecal diamorphine where we see these adverse events extremely rarely – we have experience of several thousand patients in this context (in fact morphine PCA has the highest incidence in our database).
  • Virlos et al (2) published a cohort study of 175 patients comparing spinal diamorphine to epidurals for laparoscopic colorectal surgery and not only did the spinal group have better pain relief but also shorter hospital stays & no adverse events despite using up to 1.5mg.
  • Subsequently the Royal Surrey (3) randomised 99 patients, in a practice-changing study, between epidurals, spinal diamorphine and morphine PCAs with all patients experiencing a robust ERP. Both spinal & epidural groups had better pain scores than the PCA group. However the epidural group fared worse than both the spinal and PCA groups when it came to the primary outcome measure of time to fitness for discharge – probably in part related to their slower return of bowel function. Spinals therefore gave the best of both worlds & for us is the technique of choice for laparoscopic colorectal surgery & in fact any laparoscopic major abdominal surgery.

Evidence:

  1. Spinal analgesia for laparoscopic colonic resection using an enhanced recovery after surgery programme: better analgesia, but no benefits on postoperative recovery: a randomized controlled trial. 2012 May;108(5):850–6.

  2. Short-term outcomes with intrathecal versus epidural analgesia in laparoscopic colorectal surgery. 2010 Sep;97(9):1401–6.

  3. Randomized clinical trial of epidural, spinal or patient-controlled analgesia for patients undergoing laparoscopic colorectal surgery. 2011 Aug;98(8):1068–78.

Lidocaine Infusions

  • Lidocaine infusions are a fascinating non-opioid adjuvant. I’ve been following this development for a few years but only recently introduced it into my own practice & I’m currently protocolising it locally.
  • There are multiple metanalyses (1-4) all demonstrating significant opiate sparing effects & also a reduction in N&V, ileus rates & hospital LOS following abdominal surgery. The gut effects are a direct effect on the gut smooth muscle in addition to the opiate sparing effects.
  • Specifically in the context of laparoscopic colorectal surgery this RCT (5) involving 64 patients randomized them between iv lidocaine or placebo with both groups receiving a fixed rate fentanyl infusion & PRN tramadol. The lidocaine group had better pain scores at rest & movement as well as a quicker return of bowel function & a shorter hospital stay.
  • Interestingly a Korean RCT (6) recruited gastrectomy patients & only infused lidocaine or placebo intra-operatively yet the analgesic advantage stretched out to 24 hrs along with a reduction in inflammatory response (CRP).
  • The dosage regimen from Ottawa Hospital of a 1-2mg/kg bolus followed by a 1-2mg/kg/hr infusion is very simple to implement and shown to be safe with extensive pharmacokinetic modelling. They have extensive experience over several years providing these infusions for several days post-op on general surgical wards.
  • A similar regimen has been adopted as part of the Scottish Laparoscopic Colorectal ERP.
  • I see this, & any other laparoscopic abdominal surgery, where spinal diamorphine is our technique of choice as it’s niche, whereas other surgical approaches involve techniques employing LA infusions therefore preventing use.

Evidence:

  1. Meta-analysis of intravenous lidocaine and postoperative recovery after abdominal surgery. 2008 Nov;95(11):1331–8.

  2. Impact of intravenous lidocaine infusion on postoperative analgesia and recovery from surgery: a systematic review of randomized controlled trials. 2010 Jun 18;70(9):1149–63.

  3. Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery. 2015 Jul 16;(7):CD009642.

  4. Efficacy and safety of intravenous lidocaine for postoperative analgesia and recovery after surgery: a systematic review with trial sequential analysis. 2016 Jun;116(6):770–83.

  5. Intravenous lidocaine for post-operative pain relief after hand-assisted laparoscopic colon surgery: a randomized, placebo-controlled clinical trial. 2014 Apr;18(4):373–80.

  6. Intraoperative systemic lidocaine for pre-emptive analgesics in subtotal gastrectomy: a prospective, randomized, double-blind, placebo-controlled study. 2014 Jun;57(3):175–82.

Rectus Sheath Catheters (RSC)

  • This is truly resurgence of a forgotten technique, which was originally described by Carl Ludwig Schleich in 1899, & was used to provide abdominal wall relaxation until the emergence of muscle relaxants, thus preceding epidural analgesia by many decades.
  • As you can see in this video LA is injected in the space between the rectus muscle & the posterior rectus sheath and this provides sensory dermatomal blockade of the entire abdominal wall.
  • The catheters can either be placed surgically at the end, which work, but observational data suggest not quite as well as Ultrasound guided insertion pre-op. Possible reasons include the benefit of pre-emptive analgesia, LA leakage when surgically placed if space dissected open, the surgical technique may result in placement in the space between peritoneum & sheath rather than muscle & sheath.
  • We use very small accurate portable pumps carried in sling bags over patient’s shoulders together with bags of 0.2% ropivacaine. We set the pump to deliver a 40ml bolus 4 hourly equally to both catheters via a Y-connector. Staff or patient can press the delivery button & the bolus is then delivered over 24 minutes with a 4 hour lock-out in place. Anecdotally I found inferior results when using the same dosage but delivered as continuous infusions which is likely due to a bolus needed to burst the space open and achieve a nerve block whilst the LA likely just remains at the end of the catheter during a slow continuous infusion.
  • A cohort study from Devon (1) using US guided RSC showed similar pain relief to epidurals for open colorectal surgery but less hypotension.
  • And another cohort study from Somerset (2) comparing surgically placed RSC to epidurals reported equivalent analgesia but faster recovery.
  • In a series of 200 consecutive RSC (3) for major urological surgery consistently low pain score & low morphine consumption were reported.
  • An Egyptian RCT (4) of 60 open midline colorectal patients compared RSC to CWIC & found significantly better pain relief, less rescue analgesia & less morphine consumption in favour of RSC. This is very relevant to the next section.
  • To date their have been a lack of RCT comparing RSC to epdurals. Exeter have completed one with over 80 patients but not yet reported to my knowledge & we will soon be completing our TERSC study (5) of 132 patients in January 2017 with reporting to follow later in 2017.

Evidence:

  1. Ultrasonography guided rectus sheath catheters versus epidural analgesia for open colorectal cancer surgery in a single centre. 2013 Nov;95(8):591–4.

  2. Rectus sheath catheters provide equivalent analgesia to epidurals following laparotomy for colorectal surgery. 2015 Oct;97(7):530–3.

  3. Use of rectus sheath catheters for pain relief in patients undergoing major pelvic urological surgery. 2014 Feb;113(2):246–53.

  4. Postoperative analgesia of ultrasound guided rectus sheath catheters versus continuous wound catheters for colorectal surgery: A randomized clinical trial. Egypt J Anaesth (2016), http://dx.doi.org/10.1016/j.egja.2016.02.001
  5. Thoracic Epidural analgesia versus Rectus Sheath Catheters for open midline incisions in major abdominal surgery within an enhanced recovery programme (TERSC): study protocol for a randomised controlled trial. 2014 Oct 21;15:400.

Continuous Wound Infusion (CWI)

  • The 1st reports of LA wound infusion via polythene tubes go back to the 50’s, with RCT’s appearing in the 80’s, elastomeric pumps in the 90’s and better designed trials appearing since the millennium.
  • Advantages
    • Simplicity of placement & management.
    • Can be used for any sort of incision, providing the surgeon places the catheter in the correct tissue plane i.e. pre-peritoneal rather than inter-muscular.
  • Disadvantages
    • Potentially needing more than 1 pump for certain incisions.
    • Usually need a morphine PCA as well so an additional pump to complicate mobilisation.
    • Only the wound is anaesthetized, as opposed to abdominal wall blocks which provide wider coverage thereby analgesing drains & stomas as well.
    • This in turn leads to higher iv opiate requirement in the 1st 24 hrs, compared to say RSC, as we saw e.g. earlier Egyptian study.
    • Cost with these roughly double the price of a RSC kit.
  • Modern CWIC are multi-holed wound soaker catheters which come in different lengths to choose according to wound length. These guarantee even distribution of LA throughout the length of the catheter & wound. The most common regimen is to inject a 10ml bolus of 0.2% ropivacaine down the catheter following by 10mls/hr via a small portable pump (we use the same device as for RSC) or elastomeric devices.
  • There have been plenty of proof of concept studies for midline incisions but these 2 recent RCTs compared CWI to TEA for open colorectal surgery with midline incisions. They reported contrasting results with the Italian study (1) in favour of CWI & the Canadian study (2) in favour of TEA however the methodology was quite different. Both used the standard CWIC regimen above. However the Italian study compared to a suboptimal fixed rate epidural at 10mls/hr using plain ropivacaine & a morphine PCA for breakthrough while the Canadian study compared to an optimised PCEA using a bupivacaine/fentanyl mixture. Clearly very different comparisons. My personal bias combining the Egyptian study, these 2 studies, the disadvantages above & my own experience is to favour RSC over CWIC for midline incisions.
  • My practice to date has been to reserve CWIC for rescue when laparoscopic liver resections are converted to open or epidural placement fails or is contra-indicated/refused. Following very favourable results I am considering moving this to my primary technique.
  • And it turns out this is a burgeoning area of research with 3 recent relevant RCT. The 1st RCT from Edinburgh (3) compared CWI to TEA for open liver resections. 65 patients were randomised and blinded to their group allocation. Although the epidural group had lower pain scores, when it came to the primary outcome of hospital length of stay, this was significantly better in the CWI group illustrating the point that effective analgesia wins over perfectly efficacious analgesia. This was despite a greater number of major resections and longer operating time in the CWI group.
  • The 2nd study is also from Edinburgh (4). This time unblinded with 49 recruited to TAP block followed by CWI & 44 to TEA. Again pain scores were similar but interestingly the TEA group required more opiate after day 1 & the primary outcome of fitness to D/C from hospital was significantly in favour of CWI again. This was in part due to significantly greater time on HDU due to vasopressor dependency in 20% of TEA patients. There was no difference in inflammatory response or haemodynamic responses during surgery.
  • And finally we have a recent Dutch study (5) from 2 centres which included open liver and pancreatic surgery. It was an unblinded non-inferiority comparison of a composite outcome combining pain scores, opiate side effects & patient satisfaction. 55 & 47 patients were analysed in CWI & TEA groups respectively & non-inferiority was established. Again they reported a greater need for vasopressors intra- & post-operatively.

Evidence:

  1. The postoperative analgesic efficacy of preperitoneal continuous wound infusion compared to epidural continuous infusion with local anesthetics after colorectal cancer surgery: a randomized controlled multicenter study. 2012 Dec;115(6):1442–50.

  2. Epidural versus continuous preperitoneal analgesia during fast-track open colorectal surgery: a randomized controlled trial. 2013 Mar;118(3):622–30.

  3. Randomized clinical trial of local infiltration plus patient-controlled opiate analgesia vs. epidural analgesia following liver resection surgery. 2012 Sep;14(9):611–8.

  4. Randomized clinical trial of perioperative nerve block and continuous local anaesthetic infiltration via wound catheter versus epidural analgesia in open liver resection (LIVER 2 trial). 2015 Dec;102(13):1619–28.

Recommendations

  • Spinal diamorphine possibly combined with IV Lidocaine infusion for major laparoscopic abdominal surgery, open transverse incisions and robotics.
  • Consider RSC for open midline surgery,
  • CWI for other incisions  – in particular open liver surgery.
  • Thoracic Epidurals still have an important role but I think in the future they will be used more selectively e.g. complicated abdomens, young inflammatory bowel disease patients, anorectal surgery (particularly ELAPSE) and chronic pain patients.
  • Maximally use anti-emmetics, simple analgesia & non-opioid adjuvants (gabapentin & ketamine) in a standardised fashion & consider transdermal fentanyl patches to control visceral pain & to aid step down from epidurals.

Take Home Message

Choose the most effective form of analgesia to meet the requirements of the patient & the surgical approach. This is not always the option with the best pain scores.

As George Bernard Shaw said:

“Progress is impossible without change, and those who cannot change their minds cannot change anything.”

 

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