The Polyanalgesic Consensus Conference (PACC)®: Intrathecal Drug Delivery Guidance on Safety and Therapy Optimization When Treating Chronic Noncancer Pain

An Algorithmic Overview of Advanced Pain Therapies: A Narrative Review

PURPOSE OF REVIEW

Quickly referenceable, streamlined, algorithmic approaches for advanced pain management are lacking for patients, trainees, non-pain specialists, and interventional specialists. This manuscript aims to address this gap by proposing a comprehensive, evidence-based algorithm for managing neuropathic, nociceptive, and cancer-associated pain. Such an algorithm is crucial for pain medicine education, offering a structured approach for patient care refractory to conservative management.

RECENT FINDINGS

A comprehensive literary review with PubMed and regulatory documents from the United States Food and Drug Administration were searched for a variety of interventions. Pain syndromes were categorized into nociceptive and neuropathic pain, and an algorithm was constructed. Serving as an educational tool for patients, trainees, and non-pain specialists, and as an accessible reference for pain specialists, this algorithm bridges knowledge gaps, promotes interdisciplinary collaboration, and streamlines the learning curve for new practitioners. The strength of this algorithm lies in integrating extensive clinical data, emphasizing the latest clinical evidence, and providing a structured decision-making pathway.

The Diagnosis and Treatment of Neuropathic Pain

BACKGROUND

The reported prevalence of neuropathic pain in the general population in Germany is from 6.9% to 10%. There are both medical and surgical treatment options.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, with consideration of clinical trials, meta-analyses, and guidelines.

RESULTS

Neuropathic pain is diagnosed when pain of the appropriate character is accompanied by further features such as hypesthesia/anesthesia, allodynia, or hyperalgesia. It is generally treated initially with drugs (antidepressant drugs, anticonvulsant drugs, opioids, topical agents, and others); the number needed to treat (NNT) is between 7 and 8 for gabapentin and 3.6 for amitryptiline, as estimated in meta-analyses. For nerve compression and entrapment syndromes, surgical decompression is a treatment directed against the cause of the problem, which can therefore be curative. Microvascular decompression (MVD) is often used to treat supposed compression syndromes of cranial nerves, above all classic trigeminal neuralgia; according to a meta-analysis, MVD brings about a pain-free state in 92.9% [89.1; 96.8] of patients after 5 months to 5 years of follow-up. Ablative surgical procedures are used for symptom control in patients with refractory and/or cancer-related pain. Further symptomdirected treatment options for medically intractable neuropathic pain include neuromodulatory techniques, which involve minimally invasive electrical stimulation of neural structures, and the chronic intrathecal application of drugs such as opioids and ziconotide.

CONCLUSION

The treatment of neuropathic pain can be either cause-directed or symptom-directed, depending on its origin. Multidisciplinary collaboration can facilitate both the diagnostic evaluation and the selection of the optional modality and timing of treatment.

A perspective: neuraxial therapeutics in pain management: now and future

The neuraxial delivery of drugs for the management of pain and other spinal pathologies is widely employed and is the subject of a large volume of ongoing research with several thousand papers appearing in the past 5 years alone on neuraxial delivery. Several learned texts have been recently published. A number of considerations have contributed to this widespread interest in the development of the use of neuraxial therapeutics to manage pain. In the following section, major topics relevant to spinal encoding and in the use of neuraxial therapeutics are considered by the Frontiers in Pain Research editors of the research topic: "Neuraxial Therapeutics in Pain Management: Now and Future". This paper seeks to serve as a perspective to encourage the submission of manuscripts reflecting research in this exciting area.

Neuromodulation for Neuropathic Pain Syndromes

OBJECTIVE

This article reviews the principles, applications, and emerging trends of neuromodulation as a therapeutic approach for managing painful neuropathic diseases. By parsing evidence for possible mechanisms of action and clinical trial outcomes for various diseases, this article focuses on five common therapy modalities: cutaneous, peripheral nerve, spinal cord, and brain stimulation, and intrathecal drug delivery.

LATEST DEVELOPMENTS

Recent advances in both invasive and noninvasive neuromodulation for pain have introduced personalized and closed-loop techniques, integrating real-time feedback mechanisms and combining therapies to improve physical and psychosocial function. Novel stimulation waveforms may influence distinct neural tissues to rectify pathologic pain signaling.

ESSENTIAL POINTS

With appropriate patient selection, peripheral nerve stimulation or epidural stimulation of the spinal cord can provide enduring relief for a variety of chronic pain syndromes. Newer technology using high frequencies, unique waveforms, or closed-loop stimulation may have selective advantages, but our current understanding of therapy mechanisms is very poor. For certain diagnoses and patients who meet clinical criteria, neuromodulation can provide profound, long-lasting relief that significantly improves quality of life. While many therapies are supported by data from large clinical trials, there is a risk of bias as most clinical studies were funded by device manufacturers or insurance companies, which increases the importance of real-world data analysis. Emerging methods like invasive or noninvasive brain stimulation may help us dissect basic mechanisms of pain processing and hold promise for personalized therapies for refractory pain syndromes. Finally, intrathecal delivery of drugs directly to segments of the spinal cord can also modify pain signaling to provide therapy for severe pain syndromes.

Multidimensional Analysis of Quality of Life in Patients with Chronic Non-Cancer Pain and Short- and Long-Term Intrathecal Analgesic Therapy

Background: Intrathecal drug delivery (IDD) is part of the fourth analgesic step. Evidence on the quality of life of patients with refractory chronic non-cancer pain (CNCP) using these devices and their long-term outcomes is scarce. This study aims to evaluate patients with IDD to assess their HRQoL. Additionally, the study seeks to understand the patients' satisfaction with the treatment and changes in pain magnitude over time. Methods: Adult patients with CNCP and intrathecal drug delivery systems (IDDS) were included. The study population was divided into two groups: less than and more than 15 years of treatment. HRQoL was analyzed using validated questionnaires. Pain reduction was assessed using the visual analog scale (VAS), and treatment satisfaction was evaluated using the Patient Global Impression of Improvement scale. Results: The results indicate a poor HRQoL in IDD patients, with better scores in the group with ≥15 years of treatment. Pain reduction was similar in both groups, and patients reported a positive satisfaction level with the treatment. Conclusions: HRQoL in CNCP patients is severely affected. Long-term IDD patients have a similar or even better HRQoL in some respects compared to those with shorter follow-ups. IDD patients experienced pain reduction, with most feeling better or much better.

Intrathecal drug delivery for the management of pain and spasticity in adults: British Pain Society's recommendations for best clinical practice

The British Pain Society updated their recommendations on intrathecal drug delivery (ITDD) for the management of pain and spasticity in adults. The recommendations are primarily evidence based but where necessary comprise the consensus opinion of the working group. The recommendations are accompanied by information for patients and their carers, intended to inform and support patients in their decision making. The updated guidance includes recent evidence base of ITDD use in pain and spasticity, address the issues of drug pump compatibility following the latest manufacturer and Medicines and Healthcare products Regulatory Agency (MHRA) recommendations as well as provide an update on the indications and complication management particularly endocrine complications and intrathecal granuloma formation.