Evaluation of Fixed Intrathecal Bupivacaine Infusion Doses in the Oncologic Population

The Polyanalgesic Consensus Conference (PACC)®: Updates on Clinical Pharmacology and Comorbidity Management in Intrathecal Drug Delivery for Cancer Pain

INTRODUCTION

The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on using intrathecal drug delivery in chronic pain treatment. This Polyanalgesic Consensus Conference (PACC)® project's scope is to provide evidence-based guidance for clinical pharmacology and best practices for intrathecal drug delivery for cancer pain.

MATERIALS AND METHODS

Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Meeting Abstracts, and Scopus from 2017 (when the PACC last published guidelines) to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations were based on the strength of evidence, and when evidence was scant, recommendations were based on expert consensus.

RESULTS

The PACC evaluated the published literature and established evidence- and consensus-based expert opinion recommendations to guide best practices in treating cancer pain. Additional guidance will occur as new evidence is developed in future iterations of this process.

CONCLUSIONS

The PACC recommends best practices regarding the use of intrathecal drug delivery in cancer pain, with an emphasis on managing the unique disease and patient characteristics encountered in oncology. These evidence- and consensus-based expert opinion recommendations should be used as a guide to assist decision-making when clinically appropriate.

Intrathecal Drug Delivery System in Prepontine Cistern for Patients with Intractable Craniofacial Cancer Pain: A Multicenter Retrospective Study

BACKGROUND

Patients with craniofacial cancer frequently suffer from severe pain. The traditional intrathecal, oral, or intravenous analgesics could only provide insufficient pain relief with many side effects. Thus, a more effective analgesia approach is required. This study aimed to investigate the safety and efficacy of placing the catheter of an intrathecal morphine pump in the prepontine cistern for the treatment of craniofacial cancer pain.

METHODS

We performed a retrospective study of patients with primary or metastatic craniofacial cancer pain who received the catheter placement of an intrathecal morphine pump into the prepontine cistern in eleven medical centers from September 2019 to December 2023. Friedman test and pairwise signed-rank test were used to evaluate the difference in numeric rating scale (NRS) scores, the number of breakthrough pain episodes, dose of intrathecal morphine, and dose of systemic morphine equivalents (oral, patch, intravenous) from preoperative period to postoperative days 1, 7, and 30. P values were corrected for multiple comparisons using Bonferroni test.

RESULTS

The study included 33 patients. The median (interquartile range [IQR]) of NRS scores at days 1, 7, and 30 postimplant were 2.0 (1.0-3.5), 2.0 (1.0-2.0), and 1.0 (1.0-2.0), respectively, which was significantly lower than that before surgery (median, 8.0; IQR, 7.0-10.0; all P < .001). Compared to baseline number/d of breakthrough pain episodes (median, 6.0; IQR, 4.5-10.0), there was a progressive decrease in the number/d of breakthrough pain episodes at day 1, day 7, and day 30 postimplant, and the median (IQR) were 1.0 (0.0-3.0), 2.0 (0.0-3.0), and 0.0 (0.0-1.2), respectively (all P < .001). Approximately 78.8% and 96.7% of patients reported pain relief >50% at days 1 and 30 postimplant, respectively. Compared with that at day 1 postimplant, the proportion of patients with a pain relief rate >75% at day 30 postimplant also increased with continued intrathecal treatment. Compared to the dose of baseline systemic morphine equivalents (median, 228 mg.d-1; IQR, 120-408 mg.d-1), the dose of systemic morphine equivalents reduced significantly from 0(0-120) mg.d-1 at day 1 postimplant (P = .001), to 0 (0-0) mg.d-1 at days 7 and 30 postimplant (both P < .001). Few patients reported perioperative adverse events, including nausea, constipation, hypotension, urinary retention, dry mouth, headache, and sedation. No severe adverse events occurred.

CONCLUSIONS

Placing the catheter tip of an intrathecal morphine pump into the prepontine cistern could effectively relieve refractory craniofacial cancer pain with an extremely low total morphine dose requirement and few adverse events. This procedure could be considered in patients with severe refractory craniofacial cancer pain.

Safety and Efficacy of Surgical Implantation of Intrathecal Drug Delivery Pumps in Patients With Cancer With Refractory Pain

BACKGROUND AND OBJECTIVES

Pain management in patients with cancer is a critical issue in oncology palliative care as clinicians aim to enhance quality of life and mitigate suffering. Most patients with cancer experience cancer-related pain, and 30%-40% of patients experience intractable pain despite maximal medical therapy. Intrathecal pain pumps (ITPs) have emerged as an option for achieving pain control in patients with cancer. Owing to the potential benefits of ITPs, we sought to study the long-term outcomes of this form of pain management at a cancer center.

METHODS

We retrospectively reviewed medical records of all adult patients with cancer who underwent ITP placement at a tertiary comprehensive cancer center between 2013 and 2021. Baseline characteristics, preoperative and postoperative pain control, and postoperative complication rate data were collected.

RESULTS

A total of 193 patients were included. We found that the average Numerical Rating Scale (NRS) score decreased significantly by 4.08 points (SD = 2.13, P < .01), from an average NRS of 7.38 (SD = 1.64) to an average NRS of 3.27 (SD = 1.66). Of 185 patients with preoperative and follow-up NRS pain scores, all but 9 experienced a decrease in NRS (95.1%). The median overall survival from time of pump placement was 3.62 months (95% CI: 2.73-4.54). A total of 42 adverse events in 33 patients were reported during the study period. The 1-year cumulative incidence of any complication was 15.6% (95% CI: 10.9%-21.1%) and for severe complication was 5.7% (95% CI: 3.0%-9.7%). Eleven patients required reoperation during the study period, with a 1-year cumulative incidence of 4.2% (95% CI: 2.0%-7.7%).

CONCLUSION

Our study demonstrates that ITP implantation for the treatment of cancer-related pain is a safe and effective method of pain palliation with a low complication rate. Future prospective studies are required to determine the optimal timing of ITP implantation.

Differences in efficacy and safety between intrathecal infusion devices in cancer pain

BACKGROUND

Intrathecal infusion therapy is widely accepted for cancer pain patients when conventional analgesic treatments are not sufficient. There are different types of devices for carrying out this therapy: partially externalized devices (PED), used when life expectancy is under 3 months, and totally implanted devices (TID), when it is larger. Our objective is to compare the efficacy, functionality, and complication rate in both types.

METHODS

We included 132 patients with mild-severe cancer pain, treated with intrathecal infusion therapy by fixed flow devices, PED, or TID, during the study time. Demographic, physical oncologic, and pain control data of the patients were recorded prior to starting therapy and at months 1, 3, and 6. Functionality status and complications were also collected from the patient's medical records and clinical files.

RESULTS

Pain control improved after starting therapy, with an overall reduction of 4.75 points in VAS score at 1 month in the both groups, without significant differences between them, keeping it at 3 months and 6. 33.3% of the patients developed complications and were more frequent in the PED group, being catheter dislocation the most common. Patients with TID required more often hospital admission to solve the complication.

CONCLUSIONS

Intrathecal infusion therapy has been shown to be a very effective and safe therapy for the treatment of moderate to severe oncologic pain. There are no significant differences between PED and TID in terms of degree of pain control, therapeutic success, efficacy on episodic or nocturnal pain, or the presence of serious complications.

Predictive factors for efficacy and safety of intrathecal infusion devices for oncological pain

Introduction

In an important percentage of intrathecal infusion therapy, the pain after implantation of a spinal device does not improve. Our objective is to identify factors that can predict therapeutic success and complications, developing a predictive model based on univariate and multivariate analyses.

Methods

Retrospective observational study, including 132 patients with oncological pain who were implanted with a fixed-flow device for intrathecal infusion. Four time points were established for data collection and, in addition to demographic and anthropometric data, variables related to oncologic pain pathology, initiation of therapy, pain control and complications were collected. Based on univariate and multivariate analyses, we performed predictive models on efficacy and complications.

Results

The mean baseline pain intensity was VAS 7.78, and when comparing the values before implantation with those at month 1, we observed an overall decrease of 4.75 points, maintained at months 3 and 6. Nocturnal pain progressively decreased in incidence from 50.0% before implantation to 21.8%, 9.1% and 4.3% at 1, 3 and 6 months. Episodic pain was present in 90.1% of the patients before implantation (7.79 episodes/day), and at 6 months the incidence remained at 53.8%. Most of the patients (66.6%) had no complications related to therapy. We constructed a highly significant multivariate model for the efficacy of the therapy with a predictive capacity of 30.2% and composed of factors: absence of nocturnal pain before implantation and clinical improvement on day 2 after implant. Regarding the prediction of complications, it was not possible to achieve a significantly multivariate effective model.

Conclusion

We identify two factors that predict therapeutic success in a multivariate model: the absence of nocturnal pain before implantation and the improvement of pain on the second day after implantation.

Refractory Cancer Pain and Intrathecal Therapy: Critical Review of a Systematic Review

This critical review assessed the advantages of invasive procedures that were recently included in systematic reviews, to evaluate whether the definition of refractory pain condition was correctly followed to select patients for invasive interventions and to analyze how data were positively interpreted. A total of 21 studies were selected for the purpose of this review. Three were randomized controlled studies, ten were prospective studies, and eight were retrospective studies. Analysis of these studies showed evident lack of proper assessment before implantation for different reasons. These included an optimistic interpretation regarding the outcomes, poor consideration of complications, and inclusion of patients with short survival. Moreover, the indication of intrathecal therapy as a condition in which a patient has failed to respond to multiple therapies provided by a pain or palliative care physician or at sufficient doses for adequate durations, as suggested by a recent research group, has been disregarded. Regretfully, this can discourage the use of intrathecal therapy in patients who are unresponsive to multiple opioid strategies subtrahend a potent means to be used in a very selective population.

Controversies in intrathecal drug delivery for cancer pain

Pain and suffering related to cancer are challenging issues that continue to deserve consideration for treatment optimization. Advances in analgesic management and control of the underlying cancer have improved symptom management, yet many patients still suffer from uncontrolled pain. Intrathecal drug delivery has an established role in the management of refractory cancer pain, but there are significant knowledge gaps in our understanding and application of this therapy. This review addresses several areas of controversy, including the importance of intrathecal catheter tip location, the necessity of an intrathecal trial and the role of intrathecal ziconotide and local anesthetics. In each area, the evidence is discussed, with an emphasis on presenting practical clinical guidance and highlighting deficiencies in our knowledge that are worthy of future investigation.

Effectiveness and Safety of Intrathecal Drug Delivery Systems for the Management of Cancer Pain: A Systematic Review and Meta-Analysis

OBJECTIVES

Intrathecal drug delivery systems (IDDS) and spinal cord stimulation (SCS) have been proposed and assessed for the management of cancer pain; however, such treatments remain underused. We conducted a systematic review to evaluate the effectiveness and safety of IDDS and SCS for cancer pain.

MATERIALS AND METHODS

Electronic databases MEDLINE, CENTRAL, EMBASE, and WikiStim were searched from 1988 to March 2021. Randomized controlled trials and observational studies of adults with pain related to cancer or its treatment who received an implantable IDDS or SCS were eligible for inclusion. The primary outcome of the review was change in pain intensity from baseline to the last available follow-up, measured using a visual analog scale or numerical rating scale. The protocol for this review is registered on PROSPERO (CRD42021240717).

RESULTS

A total of 22 studies (24 reports) included a total of 3043 participants who received either IDDS or SCS for cancer pain. Eight studies reporting data for 405 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction at the latest posttreatment follow-up time compared with baseline (mean difference [MD], -3.31; 95% CI, -4.18 to -2.45; p < 0.001). Six studies reporting data for 325 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction up to one month after treatment compared with baseline (MD, -3.53; 95% CI, -4.06 to -3.00; p < 0.001). A meta-analysis including studies of participants with either an IDDS or an SCS device showed similar results. Improvements in other outcomes following implantation of IDDS also were observed. Postdural puncture headache was the most reported complication, whereas urinary retention, nausea, and vomiting were commonly reported side effects.

CONCLUSION

Our findings suggest that IDDS is effective in reducing pain intensity for patients with cancer pain when compared with pretreatment.

The American Society of Pain and Neuroscience (ASPN) Best Practices and Guidelines for the Interventional Management of Cancer-Associated Pain

Moderate to severe pain occurs in many cancer patients during their clinical course and may stem from the primary pathology, metastasis, or as treatment side effects. Uncontrolled pain using conservative medical therapy can often lead to patient distress, loss of productivity, shorter life expectancy, longer hospital stays, and increase in healthcare utilization. Various publications shed light on strategies for conservative medical management for cancer pain and a few international publications have reviewed limited interventional data. Our multi-institutional working group was assembled to review and highlight the body of evidence that exists for opioid utilization for cancer pain, adjunct medication such as ketamine and methadone and interventional therapies. We discuss neurolysis via injections, neuromodulation including targeted drug delivery and spinal cord stimulation, vertebral tumor ablation and augmentation, radiotherapy and surgical techniques. In the United States, there is a significant variance in the interventional treatment of cancer pain based on fellowship training. As a first of its kind, this best practices and interventional guideline will offer evidenced-based recommendations for reducing pain and suffering associated with malignancy.