Description of a mechanistic approach to pain management in advanced cancer. Preliminary report

Abstract

A mechanistic approach to advanced cancer pain management is proposed, based on the clinically perceived anatomical and pathophysiological mechanisms of pain generation. It is an extension of the World Health Organisation (WHO) analgesic ladder in which severity of pain is the principal determinant of analgesic choice. The mechanistic categories are: superficial somatic, deep somatic, visceral and neurogenic (mixed or pure, i.e., nociceptive component present or absent). Allocation of pain to the different categories is based on clinical history, physical findings and investigations to establish the site and extent of active primary or metastatic tumor deposits, and evidence of previous response to medication. Drug choice sequence is determined by the dominant pain mechanism judged to be present and not the severity of the pain. In order to describe this approach, mechanisms of pain, disease distribution and drug treatment have been analysed in the first 20 consecutive patients who consented to enter a longitudinal pain description and evaluation study on admission to an inpatient hospice unit. Despite a high exclusion rate from research standard monitoring due to severity of illness and related factors, the majority of eligible patients approached to enter the study did so, and the pain scoring was well tolerated. The implications of this for future research and clinical practice are discussed. In 6 patients only 1 pain mechanism was identified (visceral 4, deep somatic 2). Two mechanisms were present in 8 patients and 3 mechanisms in 6 patients. The deep somatic mechanism was identified in 15 patients, visceral mechanism in 13, neurogenic in 10 and superficial somatic in 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Pain treatment and outcomes for patients with advanced cancer who receive follow-up care at home

“…A mechanistic approach to advanced cancer pain has been proposed based on the choice of a drug sequence; the choice is made according to the dominant pain mechanism rather than the pain intensity and potency of drugs 10. In the current study, pain relief was not associated with pain mechanism, and this approach was equally effective regardless of the pain syndrome, although OEI was higher in the presence of complex neuropathic syndromes.…”

“…Controversies exist regarding the use of the second analgesic ladder proposed by WHO, as no significant differences in pain relief between nonopioids alone and nonopioids plus MPOs have been reported 9. Finally, a mechanistic approach has been proposed, based on a selective drug administration sequence according to the pain mechanism rather than a stepwise fashion based on the overall severity of pain and potency of drugs 10. This prospective study included a large population of patients with advanced cancer who received follow‐up at home to provide information on the effectiveness, safety, and feasibility in terms of incidence and intensity of adverse effects of a pain management based on the WHO method at home.…”

A validation study of the WHO analgesic ladder: a two-step vs three-step strategy

“…In particular, some authors have questioned the real usefulness of step II, proposing the use of strong opioids when NSAIDs become ineffective [2,4,8,9,14,15,20,25].…”

Prospective audit of short‐term concurrent ketamine, opioid and anti‐inflammatory (‘triple‐agent’) therapy for episodes of acute on chronic pain

“…The WHO ladder takes no account of pain mechanism(s) (somatic, visceral or neuropathic) 10 , or of the emerging experimental and clinical evidence of central nervous system plasticity, in particular the phenomenon of central sensitization. The clinical manifestations of central sensitization include ongoing and escalating pain, hyperalgesia, allodynia and relative opioid insensitivity.…”