Neuraxial (epidural and intrathecal) opioids for intractable pain

Efficacy of epidural analgesia for intractable cancer pain: A systematic review

BACKGROUND

Epidural analgesia is a common technique for managing perioperative and obstetric pain. Patients with cancer who cannot tolerate opioids or not responding to conventional treatment may benefit from epidural analgesia. Therefore, this systematic review aimed to analyze the efficacy and safety of epidural analgesia in patients with intractable cancer pain.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials to identify studies on patients with cancer who received epidural analgesia. We assessed the quality of all included studies using the risk-of-bias tool or Newcastle-Ottawa scale. The primary outcome was pain relief after epidural analgesia, and the secondary outcome was quality of life, analgesic consumption, and adverse events. The studies were grouped based on the medications used for epidural analgesia. A descriptive synthesis was performed following the Synthesis Without Meta-analysis reporting guideline.

RESULTS

Our systematic review included nine randomized controlled trials (n = 340) and 15 observational studies (n = 926). Two randomized controlled trials suggested that epidural opioids were not superior to systemic opioids in relieving pain. Epidural opioids combined with local anesthetics or adjuvants, including calcitonin, clonidine, ketamine, neostigmine, methadone, and dexamethasone, offered better analgesic effects. No significant difference in pain relief between an intermittent bolus and a continuous infusion of epidural morphine was observed. Epidural opioids had more analgesic effects on nociceptive pain than neuropathic pain. The methods used to evaluate the quality of life and the corresponding results were heterogeneous among studies. Six observational studies demonstrated that some patients could have decreased opioid consumption after epidural analgesia. Adverse events, including complications and drug-related side effects, were reported in 23 studies. Five serious complications, such as epidural abscess and hematoma, required surgical management. The heterogeneity and methodological limitations of the studies hindered meta-analysis and evidence-level determination.

CONCLUSION

Coadministration of epidural opioids, local anesthetics, and adjuvants may provide better pain relief for intractable cancer pain. However, we must assess the patients to ensure that the benefits outweigh the risks before epidural analgesia. Therefore, further high-quality studies are required.

Intrathecal drug delivery for cancer pain at the end of life: a case study

Two-thirds of patients with advanced cancer have pain and, of these, approximately 10-20% do not respond to conventional pain management approaches. This case study concerns a hospice patient who received intrathecal drug delivery for intractable cancer pain at the end of life. This involved working in partnership with a hospital-based interventional pain team. Despite side-effects and complications associated with intrathecal drug delivery and the requirement for inpatient nursing care, intrathecal drug delivery was the best option for the patient. The case identifies the importance of a patient-centred approach to decision-making, effective partnerships between hospice and acute hospital teams, and nurse education as key factors contributing to the provision of safe and effective intrathecal drug delivery.

The Ramifications of Opioid Utilization and Outcomes of Alternative Pain Control Strategies for Total Knee Arthroplasties

Morbidity and mortality related to opioid use has generated a public health crisis in the United States. Total knee arthroplasty (TKA) is an increasingly common procedure and is often accompanied by post-operative opioid utilization. Unfortunately, post-operative opioid usage after TKA has been shown to lead to higher rates of complications, longer hospital stays, increased costs, and more frequent need for revision surgery. Pre-operative opioid utilization has been shown to be one of the most important predictors of post-operative opioid usage. Additional risk factors for continued post-operative opioid utilization after TKA include pre-operative substance and tobacco use as well as higher post-operative prescription dosages, younger age, female gender, and Medicaid insurance. One method for mitigating excessive post-operative opioid utilization are Enhanced Recovery After Surgery (ERAS) protocols, which include a multidisciplinary approach that focuses on perioperative factors to optimize patient recovery and function after surgery. Additional strategies include multimodal pain regimens with epidural anesthetics, extended duration local anesthetics and adjuvants, and ultrasound guided peripheral nerve blocks. In recent years, opioid prescribing duration limitations have also been put into place by state and federal government, hospital systems, and ambulatory surgery centers making effective acute pain management imperative for all stakeholders. In this regard, as rates of TKA continue to increase across the United States, multidisciplinary efforts by all stakeholders are needed to ensure adequate pain control while preventing the negative sequalae of opioid medications.

PALLIATIVE TREATMENT OF INTRACTABLE CANCER PAIN

In 10% to 30% cancer-pain cases standard analgesic therapy fails to provide effective pain relief. Interventional techniques, such as peripheral nerve blocks, neuraxial analgesia along with neurolytic blocks may be used for such refractory pain. Peripheral nerve blocks can be used when pain occurs in the territory of one or more peripheral nerves, but rarely as main therapy. Neuraxial analgesia is a valid option for progressive cancer pain, and healthcare possibilities and costs call into question the utility of intrathecal infusion pumps. Neurolysis is the targeted destruction of a nerve or nerve plexus, using chemicals, radiofrequency ablation (RFA), cryoablation, and neurosurgical procedures; however, it rarely completely eliminates pain because patients frequently experience coexisting somatic and neuropathic pain as well. Complex conditions of palliative patients along with limited high-quality randomized controlled trials limit the use of interventional procedures. Even so, some cancer patients benefit from interventional procedures to achieve pain alleviation and consequently improve quality of life.

The Options for Neuraxial Drug Administration

Neuraxial drug administration, i.e., the injection of drugs into the epidural or intrathecal space to produce anesthesia or analgesia, is a technique developed more than 120 years ago. Today, it still is widely used in daily practice in anesthesiology and in acute and chronic pain therapy. A multitude of different drugs have been introduced for neuraxial injection, only a part of which have obtained official approval for that indication. A broad understanding of the pharmacology of those agents is essential to the clinician to utilize them in a safe and efficient manner. In the present narrative review, we summarize current knowledge on neuraxial anatomy relevant to clinical practice, including pediatric anatomy. Then, we delineate the general pharmacology of neuraxial drug administration, with particular attention to specific aspects of epidural and intrathecal pharmacokinetics and pharmacodynamics. Furthermore, we describe the most common clinical indications for neuraxial drug administration, including the perioperative setting, obstetrics, and chronic pain. Then, we discuss possible neurotoxic effects of neuraxial drugs, and moreover, we detail the specific properties of the most commonly used neuraxial drugs that are relevant to clinicians who employ epidural or intrathecal drug administration, in order to ensure adequate treatment and patient safety in these techniques. Finally, we give a brief overview on new developments in neuraxial drug therapy.

Care and management of patients receiving epidural analgesia

Epidural analgesia continues to have an important role in the management of acute pain in post-operative settings. Although its use in clinical practice has declined, it continues to demonstrate superior analgesia effect compared with parenteral opioids. However, despite these benefits, epidural analgesia requires additional monitoring to ensure the timely identification of significant complications, such as haematoma and abscess. This article details the nursing care and management of adults receiving epidural analgesia in post-operative settings. It also outlines the main complications that may occur and how these can be managed.

Cancer pain: where are we now?

Increasing numbers of those living with and beyond cancer presents a clinical challenge for pain specialists. A large proportion of these patients experience pain secondary to their disease or its treatment, impeding rehabilitation and significantly impacting upon their quality of life. The successful management of this pain presents a considerable challenge. This review aims to outline current concepts and treatment options, while considering nuances within pain assessment and the use of large-scale data to help guide further advances.

Brief review: Neuraxial analgesia in refractory malignant pain

PURPOSE

This narrative review aims to inform health care practitioners of the current literature surrounding the use of intrathecal (IT) and epidural analgesia in cancer patients with refractory pain at end of life. Topics discussed and reviewed include: patient selection, treatment planning, procedure, equipment, medications, complications, policies and procedures, as well as directions for future research.

PRINCIPAL FINDINGS

Cancer pain is inadequately treated in an estimated 10% of patients with malignant pain despite the implementation of the World Health Organization three-step analgesic ladder. This has prompted some to advocate for the addition of a fourth step that would include neuraxial interventions. There is moderate evidence supporting the safety and efficacy of IT drug therapy in cancer patients with refractory pain. A detailed assessment and interdisciplinary team approach is necessary to develop and implement care plans for patients requiring neuraxial analgesia. Neuraxial analgesia can significantly improve pain and reduce side effects, but this must be balanced against the increased complexity of care and the risk of uncommon but serious complications.

CONCLUSION

Neuraxial drug delivery gives clinicians more options to manage refractory pain at end of life and should be offered to patients with intractable cancer pain. Teams should be interprofessional with clear delineation of roles and responsibilities. They should discuss advanced discharge planning with the patient prior to implantation as well as provide on-call support.