Case: Prevention of chronic post-operative pain

With Professor Harald Breivik  |  13 Mar 2015  |  Print

Case: Prevention of chronic post-operative pain

Professor Harald Breivik is emeritus professor of anaesthesiology, Universitetet i Oslo, Norway. He is also editor-in-chief of the Scandinavian Journal of Pain.

Scenario

A 35-year-old woman is scheduled for removal of a painful (possibly infected) breast tumor. She has a history of migraine headaches, endometriosis and had several episodes of non-specific low back pain lasting several months each time. She is due to receive chemotherapy soon after removal of her breast tumor. She is nervous, having catastrophizing thoughts about not surviving surgery and about already having metastasis, and she has been told that there is a real risk of having chronic and difficult-to-treat pain after her surgery.

Q. What should we do to reduce her risk of developing chronic pain after this operation?

A. This patient has most of the well-documented risk factors for persistent neuropathic-type pain after breast surgery, chronic post-operative pain (CPP):[1–4]

  • Pain in the surgical area
  • Chronic pain conditions not related to the area of surgery
  • Extreme stress and nervousness about the outcome of the operation, with catastrophizing thoughts
  • Requires chemotherapy and possibly radiation therapy after removal of the breast tumor.

This patient needs all the measures we can offer her that are documented to have at least some effect on the risk of developing CPP: before surgery a thorough explanation of the approach to pain management is important for alleviating her severe anxiety. I would give her pregabalin 300 mg before surgery and continue with 150mg twice daily after surgery and for the next two weeks. I would offer paravertebral blocks of Th1-Th5 using lidocaine 20 mg/mL with adrenaline 5 µg/mL, 5 mL at each level (four levels) making sure the blocks are placed on the correct side. An even better alternative is a high thoracic epidural anaesthesia which can be continued as epidural analgesia after surgery for as long as necessary, using bupivacaine 1mg/ml plus fentanyl 2 microgram/ml and adrenaline 2 µg/mL at 5-10 mL/h. With paravertebral and epidural block she does not need a general anesthetic. But for her comfort and because of her hypervigilant state of mind, I would give her ketamine after she is asleep with 70% nitrous oxide as both reduce the risk of CPP.

For induction of anesthesia I would give a bolus of lidocaine 100 mg IV, which also reduces risk of CPP, before the induction agents, maintaining general anesthesia with nitrous oxide 70% in the inhaled gas mixture. I would give her one bolus of ketamine 0.5 mg/kg after induction and two more boluses during surgical anesthesia. I might even consider an IV infusion of ketamine at 2 µg/kg/min for the day of surgery and the next two postoperative days. At start of surgery, I would give her dexamethasone 16 mg IV. Dexamethasone 16 mg prevents postoperative nausea, reduces the risk of CPP and is a potent analgesic with duration of action of up to 72 hours.

I would consider with the surgeon the increased risk of chronic pain if an axillary lymph node dissection is performed, as compared with sentinel node biopsy,[2,3] and discuss the importance of keeping the surgery as ‘atraumatic’ as possible.

After surgery, I would keep her pain-free, preferably by means of an epidural infusion of local anaesthetic plus fentanyl and adrenaline (see above), for at least two days. If this approach is not possible, I would give her appropriate pharmacotherapy with multimodal analgesia using paracetamol 1 g IV three times daily, ketorolac 30mg IV twice daily and IV patient-controlled analgesia with morphine or oxycodone as required to maintain a VAS score (0-10) below 3-4 while moving the shoulder and arm on the operated side; although methadone may be preferable, given as a 20mg IV bolus at the start of surgery, with an immediate postoperative booster bolus dose of 2-3 mg IV, as necessary.

Dextromethadone in racemic methadone tablets is an NMDA-antagonist, which may be the reason why methadone has a superior effect on neuropathic pain compared with pure mu-opioid-receptor agonists such as morphine.

The many drugs proposed here may seem like ‘overkill’. But please remember that approximately 30-50% of patients like her have CPP five years after tumor removal.[1,4] This patient has more significant risk factors for CPP than the ‘average’ breast cancer patient. Severe CPP could destroy her quality of life for the remainder of her life. It is therefore vitally important for her that we do everything that has some evidence for effectiveness in reducing the risk of CPP. I have seen too many sad cases of such patients being neglected as a result of physicians’ lack of knowledge or experience with CPP.

The treatment options described in this case scenario are based on the global literature on reduction of CPP and the long clinical experience of the author. Not all the medications listed are licensed for use in the settings described and physicians should consult the relevant SPCs prior to prescribing

References:

  1. 1. Rashiq S, Dick BD. Post-surgical pain syndromes: a review for the non-pain specialist. Can J Anaesth 2014;61:123-130.
  2. 2. Haroutiunian S, Nikolajsen L, et al. The neuropathic component in persistent postsurgical pain: a systematic literature review. Pain 2013;154:95-102.
  3. 3. Kehlet H, Jensen TS, Woolf CJ. Persistent postsurgical pain: risk factors and prevention. Lancet 2006;367:1618-1625.
  4. 4. Sipilä R, Estlander AM, et al. Development of a screening instrument for risk factors of persistent pain after breast cancer surgery. Br J Cancer 2012;107:1459-1466.

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