Put in my two penny worth and a penny for your thoughts…
The Spinal DOPS. This is an assessment most Palliative Medicine trainees get flustered and frustrated about, me included. If you are unaware it is a Direct Observational Procedure which needs to be signed off to complete the palliative curriculum and gain the converted consultanthood. It is frustrating become large swathes of the country do not do it, to be frank, the vast majority have little to no access to it. Needless-to-say it is there, looming, dipping and dopping away in the to do list.
In the process of trying to gain this ethereal mystical assessment I was at the pain clinic and you may be surprised that I began to learn one or two things. Namely Spinal analgesia is actually quite good, and just maybe we should be doing a wee bit more.
I read the British Pain Society’s review (1, also web-link below) and this is truly excellent, so I won’t bore you with my placid attempt at summarising the literature, but I will say a few salient points. There are only really three indications for spinal / Intrathecal drug administration…
- Chronic non-malignant pain. – Of which there ain’t much evidence, One small RCT and numerous prospective studies supports the efficacy of intrathecal opioids. However there have been large scale RCTs with snail juice (ziconotide) which showed limited short term efficacy. (Snail talk for another post I think)
- Pain associated with Cancer. – There has only been one RCT (2), the results are glowing with everything better F.A.B. There is also evidence from Mr Cochrane indirectly (3) of which I learnt about intracerebroventricular drug administration (the oldest operation in the world with a twist) Overall evidence appears to supports the use of intrathecal opioid therapy for pain that has not been adequately controlled by our regular treatments.
- Spasticity – Of which there is cracking evidence with intrathecal baclofen in multiple sclerosis (MS), cerebral palsy, and spinal cord injury
So; if it works well, the remit defined, evidence is as sound as the rest of palliative care and the skills in place (lots of folk are putting in baclofen pumps for MS), why are we not doing it a wee bit more?
Maybe we don’t need it? Well, the landmark paper (4) looking at 10-year view of the effectiveness of the WHO analgesic ladder disagrees, suggesting there is a clear percentage (around 10%) of which the WHO elevator doesn’t fully cut the mustard. Folk have many suggestions (5,6,7) to modify the WHO staircase, all with putting interventional procedures in various positions on the WHO escalator. But all agree we need something.
Aww complications you say? What about granulomas, the intractable itch, the danger of dose conversions? What about the under reported endocrine effects including hypogonadotrophic hypogonadism, loss of libido and hypocortisism? Well, I say these are concerns, sure, but not as dangerous or harmful as we first perceive.
The rate of diagnosis of intrathecal granulomas in a UK centre was 7%, the equivalent to 0.009 events per patient year (8) and the recommendations are to be aware and avoid high dosages and high concentrations of opioids solutions. It seems more likely to occur the longer it is in for, and remember most of this info is from baclofen pumps. If the doses are reduced they have been shown to reduce the incidence of granuloma formation (9). A nifty chart has been made…
What about the procedure I hear you cry, well, in a multi-centre study with cancer and non-cancer pain patients, procedure related complications occurred at a rate of 0.29 events per patient year and catheter related complications at a rate of 0.05 events per patient year (10). The rate of complications / side-effects in a non-cancer study with a 13-year follow-up was 0.111 events per patient year. i.e. not much really. There appears less of a side effect profile than traditional opioid administration (less constipation etc.).
Now I know there are a lot of barriers to us using a relative unknown, both in our minds and practically, both within the medics and nurses having to learn and practice new skills, but surely if we truly want the best evidence based treatment for our patients should we not be intrathcaling Mrs Thrice opioid switch? Are we missing a trick here?
Folk often cite the paper “Patient-controlled spinal opiate analgesia in terminal cancer. Has its time really arrived?” (11) which states there is a multifactorial 30% failure rate with intrathecal pumps, but this was published in 1992, in which I was still in single fingers. Maybe, just maybe the time has now come?
As I continued to chat with the chronic pain (anaesthetic) consultant he reflected upon his past ways, which were very interventional and giving bonkers amounts of opioids for chronic pain, this has strongly fallen out of favour. The whole chronic pain profession has moved towards ‘softer’ less interventional foci such as psychology (ACT, CBT etc.), mindfulness and how to live with pain. He mirrors this thought with palliative care and the impression of it being ‘hand holding’ historically but is now moving slowly to be more interventional. “We both started the wrong way around.” He said.
He wishes palliative care just hurries up a little because this spinal intervention is just a good idea for our palliative patients.
Needless to say I’d better get my DOPS.
- Intrathecal drug delivery for the management of pain and spasticity in adults; recommendations for best clinical practice, British Pain Society, Dec 2015 https://www.britishpainsociety.org/static/uploads/resources/files/itdd_2015_pro_v3.pdf
- Smith TJ, Staats PS, Deer T, Stearns LJ, Rauck RL, Boortz-Marx RL, Buchser E, Catala E, Bryce DA, Coyne PJ, Pool GE, Implantable Drug Delivery Systems Study Group. Randomized clinical trial of an implantable drug delivery system compared with comprehensive medical management for refractory cancer pain: impact on pain, drug-related toxicity, and survival. J Clin Oncol 2002; 20(19):4040-4049.
- Ballantyne JC, Carwood CM. Comparative e cacy of epidural, subarachnoid and intracerebroventricular opioids in patients with pain due to cancer. Cochrane Database Syst Rev 2005; (1):CD005178. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD005178/abstract
- Zech DF, Grond S, Lynch J, Hertel D, Lehmann KA.. Validation of the World Health Organisation guidelines for cancer pain relief: a 10 year prospective study. Pain 1995; 63(1): 65-7
- Natoli S, Lazzari M, Dauri M. Open questions in the treatment of cancer pain: time for strong evidence-based approach? Expert Opin Pharmacother. 2015;16(1):1–4.
- Pergolizzi JV, Raffa RB. The WHO pain ladder: do we need another step? Pract Pain Manage. 2014;14(1):1–16.
- Vargas-Schaffer G. Is the WHO analgesic ladder still valid? Can Fam Physician. 2010;56(6):514–517.
- Duarte RV, Raphael JH, Southall JL, Baker C, Hanu-Cernat D. Intrathecal in ammatory masses: is the yearly opioid dose increase an early indicator? Neuromodulation 2010; 13(2):109-113.
- McMillan MR, Doud T, Nugent W. Catheter-associated masses in patients receiving intrathecal analgesic therapy. Anesth Analg 2003; 96(1):186-190.
- Follett KA, Naumann CP. A prospective study of catheter-related complications of intrathecal drug delivery systems. J Pain Symptom Manage 2000; 19: 209-215.
- Duarte RV, Raphael JH, Sparkes E, Southall JL, LeMarchand K, Ashford RL. Long-term intrathecal drug administration for chronic non- malignant pain. J Neurosurg Anesthesiol 2012; 24(1):63-70.
- Chrubasik J, Chrubasik S, Martin E. Patient-controlled spinal opiate analgesia in terminal cancer. Has its time really arrived? Drugs 1992; 43 (6): 799-804.