EAHP 2012 Report – Pain management: a dual perspective

by Zara Qadir – Even with international guidelines for pain treatment, therapy has to be individualised for patients and pharmacists can play an important role in the management of various types of acute and chronic painful conditions. At the EAHP congress, Lona Christrup, a Professor in Clinical Pharmacy at the University of Copenhagen in Denmark, gave delegates an insight into optimising pain treatment, whilst Dr Chantal Wood, Head of the Pain Unit of Robert Debré in France, provided a paediatrician’s perspective of assessing and managing pain in children.

 

“By any reasonable code, freedom from pain should be a basic human right, limited only by our knowledge to achieve it.” Leibeskind and Melzack, 1988.

 

“We still have some obstacles to overcome to help all patients suffering from pain towards freedom from pain, and there is a lot of research to be done yet,” commented Professor Christrup. “As pharmacists, we can only be involved in the physical dimension of pain as that is where analgesics work but there are a lot of other dimensions.”

Classifying pain is complex, and pain can be categorised as temporal, etiological, or physiological [see Table 1: Classification of Pain]. “There are lots of ways we can classify pain, and most have been described as we want to know the best way to treat pain in the individual patient,” commented Professor Christrup.

 

Table 1: Classification of Pain:

 

 

“Pathophysiological classification of pain is one of the most important for pharmacists,” emphasised Professor Christrup, “because that is where we can use our skills in pharmacology to guide the doctors to treatment”. Pathophysiological pain can be divided into three types: (1.) nociceptive caused by tissue damage, which is either somatic or visceral, (2.) neuropathic caused by damage to the central nervous system) and (3.) sensitisation. Neuropathic and sensitisation pain were distinguished a year ago under new guidelines. Differentiating between the different types of pain is important for pharmacists [see Figure 2: Descriptive words to describe pain].

 

Table 2: Words used to describe pain

 

 

The ultimate goal of a good pharmacokinetic/pharmacodynamics model for pain has not been reached. Treatment has to be individualised and requires pharmaceutical skills to decide upon treatment either with non-opioids, opioids, adjuvant analgesics and dual action analgesics. Professor Chirstrup gave some recommendations. Amongst the non-opioids, NSAIDs are recommended for pain as they have analgesic effect (centrally mediated) and anti-inflammatory effect (peripherally-mediated). However, NSAIDs have a number of gastrointestinal side effects so are a less desirable option as a long-term approach to pain management. Christrup explained that there is ‘individual response for every patient and across every opioid’.

Professor Christrup advised treatment for the different pathophysiological pain. “Normally, we say that nociceptive inflammatory pain should be treated with NSAIDs, and if the pain is intense, you can add-on opioids. However, if the individual has nociceptive non-inflammatory pain, we would advise treatment with paracetamol as the side effects are minimal,” explained Professor Christrup.  “Neuropathic and sensitisation pain are the most difficult types to treat as you often need antidepressants and anticonvulsants, and even opioids.” Professor Christrup strongly stipulated that if a patient has to be switched to a new opioid, a pharmacist should refer the patient to a pain specialist.

Lona Christrup concluded her presentation with some pertinent closing remarks. “Treatment with analgesics is always a balance between analgesics and side effects, and it’s an individual balance, and we need to take the patients’ wishes into account. Some patients might want to be totally free of pain and will accept the side effects. Where as others, prefer to have a little bit of pain but get rid of the side effects.”

 

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The assessment of pain also plays a crucial role in investigating and diagnosing pain, although there are many factors involved in this process that influence the information that is elicited from patients. Dr. Chantal Wood began her presentation by stressing the importance of taking a multi-disciplinary and biopsychosocial approach, and introduced two case studies to illustrate effective pain management in children. Her take-home message was to “adapt your approach to your patient and adopt a multi-model method.”

The first case, Dr. Wood introduced was a five-year old boy with leukeamia, who presented with procedural pain and refused his needle infusions. Dr. Wood outlined some of the tools that can be used to assess the child’s pain. The first step was to identify the pyschological factors (e.g. anxiety/depression or needle-phobia).

From the age of 3 or 4 years, self-assessment tools can be used (FPS-R, Poker Chip, VAS, NRS). However, assessment of a young child’s pain can be challenging, and some tools are more accurate than others. Certain scales are only recommended for older children e.g. Visual Analogue Scale (8+ years). Adults also use scales differently to adults. For example, adults tend to avoid the ends of the scale, whilst children are more predisposed to pick the end. Children can use metaphorical analogies for example, ‘It was as if I was ‘stung by a wasp’ or ‘stubbed my toe’ etc.

“For a 5-year old, the six-face facial pain¹ scale is one of the best scales that can be used in children. It is recommended in children between 4 and 12 years old,” advised Dr Wood. Drawing body outlines also gives an accurate indication of the source of the underlying pain. For example, bilateral and symmetrical drawings are often indicative of muscle pain.

Dr Wood did advise delegates to be careful, as self-reporting measures in young children (3 and 7 years old) can prove unreliable, and should therefore be supported by behavioural measures as secondary outcome. ‘If you are dealing with chronic pain, don’t think that one simple assessment scale will show the dimensions of chronic pain. Several scales are best,” emphasised Dr Wood. A new scale, Face, Legs, Activity, Cry, Consolability scale or FLACC scale has been recommended for use in assessing pain for children (and disabled children) between the ages of 2 months to 7 years. Dr. Wood offered the advice from a Von Baeyer² study, “for brief painful events, use FLACC or CHEOPS. For post-operative pain, use FLACC. No single scale is broadly recommended across all context.”

When choosing a treatment for post-operative pain, Dr. Wood advised that it is important to access the length of time it takes for the therapy to become effective. Another consideration for children with leukaemia, is that procedures are performed correctly³ as implicit (unconscious) and explicit (conscious) memory of pain can play a role in anticipating procedures. Hence, distraction is also important for managing pain in children. “Expectations of the hyper-analgesia pain modify the way we live the pain⁴,” explained Dr. Wood.

The second case study was a 14-year old boy who had surgery for tonsillitis and appendicitis, and was suffering abdominal pain. For teenage patients, Dr. Wood emphasised the importance of taking a clear pain history/observation and assessment. Questions that can be illuminating include: ‘What is the pain history in their family?’ ‘When does the pain happen?’ and ‘What are the triggers?’ After body-line drawings and a clinical examination, Dr Wood diagnosed the boy with myofascial pain, and gave recommendations for the pharmaceutical issues: “to reduce the pain, improve sleep, improve daily living activities and educate the patient and family.”

 

References:

1.   Facial Pain, Whaley LF, Wong DL. Nursing Care of Infants and Children. 3rd ed.  St. Louis, MO: Mosby; 1987.

2.   Von Baeyer CL. et al. (2009) Three new datasets supporting use of the Numerical Rating Scale (NRS-11) for children’s self-reports of pain intensity. Pain 143(3):223–227.

3.   Weisman S.J. et al. (1998). Consequences of Inadequate Analgesia During Painful Procedures in Children. Arch Pediatr Adol Med 152. 147. (http://archpedi.ama-assn.org/cgi/content/abstract/152/2/147)

4.   Goffaux P. et al. (2007). Descending analgesia – When the spine echoes what the brain expects. Pain 130: 137-143. (http://www.painjournalonline.com/article/S0304-3959(06)00643-9/abstract)