Evidence-based guidelines on the use of opioids in chronic non-cancer pain--a consensus statement by the Pain Association of Singapore Task Force

<p><b>INTRODUCTION</b>While opioids are effective in carefully selected patients with chronic non-cancer pain (CNCP), they are associated with potential risks. Therefore, treatment recommendations for the safe and effective use of opioids in this patient population are needed.</p><p><b>MATERIALS AND METHODS</b>A multidisciplinary expert panel was convened by the Pain Association of Singapore to develop practical evidence-based recommendations on the use of opioids in the management of CNCP in the local population. This article discusses specific recommendations for various common CNCP conditions.</p><p><b>RESULTS</b>Available data demonstrate weak evidence for the long-term use of opioids. There is moderate evidence for the short-term benefit of opioids in certain CNCP conditions. Patients should be carefully screened and assessed prior to starting opioids. An opioid treatment agreement must be established, and urine drug testing may form part of this agreement. A trial duration of up to 2 months is necessary to determine efficacy, not only in terms of pain relief, but also to document improvement in function and quality of life. Regular reviews are essential with appropriate dose adjustments, if necessary, and routine assessment of analgesic efficacy, aberrant behaviour and adverse effects. The reasons for discontinuation of opioid therapy include side effects, lack of efficacy and aberrant drug behaviour.</p><p><b>CONCLUSION</b>Due to insufficient evidence, the task force does not recommend the use of opioids as first-line treatment for various CNCP. They can be used as secondor third-line treatment, preferably as part of a multimodal approach. Additional studies conducted over extended periods are required.</p>

Percutaneous T2 and T3 Radiofrequency Sympathectomy for Complex Regional Pain Syndrome Secondary to Brachial Plexus Injury: A Case Series

Complex regional pain syndrome secondary to brachial plexus injury is often severe, debilitating and difficult to manage. Percuteneous radiofrequency sympathectomy is a relatively new technique, which has shown promising results in various chronic pain disorders. We present four consecutive patients with complex regional pain syndrome secondary to brachial plexus injury for more than 6 months duration, who had undergone percutaneous T2 and T3 radiofrequency sympathectomy after a diagnostic block. All four patients experienced minimal pain relief with conservative treatment and stellate ganglion blockade. An acceptable 6 month pain relief was achieved in all 4 patients where pain score remained less than 50% than that of initial score and all oral analgesics were able to be tapered down. There were no complications attributed to this procedure were reported. From this case series, percutaneous T2 and T3 radiofrequency sympathectomy might play a significant role in multi-modal approach of CRPS management.

Pain prevalence in Singapore

<p><b>UNLABELLED</b>The prevalence of chronic pain is well described in various parts of the world; primarily in Western societies such as Europe, America and Australia. Little is known of the prevalence of chronic pain within Asia or Southeast Asia. In view of the cultural and genetic variation in pain causation, manifestation and reporting, the findings of previous studies cannot be translated to Asian countries. Prevalence studies needed to be carried out to quantify the magnitude and impact of chronic pain within Asian countries to properly allocate precious health funds to deal with this important healthcare issue. We report the findings of the prevalence study within one Asian country: Singapore.</p><p><b>OBJECTIVE</b>To determine the prevalence and impact of chronic pain in adult Singaporeans.</p><p><b>MATERIALS AND METHODS</b>Two sets of questionnaires were designed. The first, a screening questionnaire, to identify the prevalence of chronic pain, and should there be chronic pain; the second, a detailed questionnaire was administered, to characterise the features and the impact of pain. A cross-sectional sampling of Singapore adults were achieved using a computer-based multi-step random sampling of listed telephones numbers. The questionnaires were administered via telephone by a trained interviewer with the aid of a computer-assisted telephone interview system.</p><p><b>RESULTS</b>A total of 4141 screening and 400 detailed questionnaires were completed. The prevalence of chronic pain, defined as pain of at least 3 months' duration over the last 6 months was 8.7% (n = 359). There was a higher prevalence in females (10.9%) and with increasing age. In particular, pain prevalence increased steeply beyond the age of 65 years old. There was a significant impact on work and daily function of those with chronic pain.</p><p><b>CONCLUSION</b>Though the prevalence of chronic pain was marginally lower compared other studies, the impact of pain was just as significant. In a rapidly ageing population such as Singapore, chronic pain is an important emerging healthcare problem which will likely exert increasing toll on the existing social infrastructure within the next 5 to 10 years.</p>