Epidural Infusion of Morphine and Levobupivacaine through a Subcutaneous Port for Cancer Pain Management

Effectiveness of epidural morphine for the treatment of cancer pain in patients with gastrointestinal neoplasm-a systematic review

One-third of cancer pain patients do not experience adequate pain relief using analgesic ladder by the World Health Organization. Interventional procedures, such as epidural morphine, have been considered. This study aimed to review the literature comparing the effects of epidural administration of morphine with the oral route. This systematic review included randomized controlled trials (RCTs) conducted with patients with gastrointestinal neoplasm. A search was conducted on PubMed, EMBASE, Web of Science, Scopus, Cochrane Library, and CINAHL databases to identify studies published up to May 2023. The retrieved study was evaluated using the Risk of Bias 2 (RoB 2) tool and qualitatively synthesized. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach (Prospero: CRD42021264728). Only one RCT, a crossover trial, was included in this systematic review. The study was conducted with ten participants (one withdrawal) and reported a statistically significant difference between both subcutaneous and epidural morphine solutions and oral morphine. The adverse events were not described. The included study presents some concerns of bias and low certainty of evidence on the effectiveness and security of epidural morphine administration. The available literature does not suffice to elucidate whether morphine administration via the epidural route is more effective than other routes. Further RCTs are necessary to improve the level of evidence on the effectiveness and risk-benefit of epidural morphine in the management of cancer pain in gastrointestinal neoplasm patients.

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.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Continuous Cervical Epidural Analgesia in Metastatic Spinal Cord Compression

Metastatic spinal cord compression is a devastating complication of cancer. Patients may often require high doses of opioids that may cause side effects, myoclonus being one such. A 63-year-old male suffering from malignant spinal cord compression was admitted to our institution. The primary team managed him conservatively with pharmacotherapy with no relief of pain, and he experienced myoclonus and sedation as adverse effects. A continuous cervical epidural catheter with local anesthetic infusion was inserted for 5 days to control his pain. This relieved his pain, which was sustained even after we removed the epidural catheter on day 5, for up to 64 days until the time of his death. Continuous cervical epidural local anesthetic infusions may help with refractory pain by deafferentation of noxious stimuli. Central neuraxial blocks may be a valuable rescue in selected patients.

Anatomic variations of cervical and high thoracic ligamentum flavum

BACKGROUND

Epidural blocks are widely used for the management of acute and chronic pain. The technique of loss of resistance is frequently adopted to determine the epidural space. A discontinuity of the ligamentum flavum may increase the risk of failure to identify the epidural space. The purpose of this study was to investigate the anatomic variations of the cervical and high thoracic ligamentum flavum in embalmed cadavers.

METHODS

Vertebral column specimens of 15 human cadavers were obtained. After vertebral arches were detached from pedicles, the dural sac and epidural connective tissue were removed. The ligamentum flavum from C3 to T6 was directly examined anteriorly.

RESULTS

The incidence of midline gaps in the ligamentum flavum was 87%-100% between C3 and T2. The incidence decreased below this level and was the lowest at T4-T5 (8%). Among the levels with a gap, the location of a gap in the caudal third of the ligamentum flavum was more frequent than in the middle or cephalic portion of the ligamentum flavum.

CONCLUSIONS

The cervical and high thoracic ligamentum flavum frequently has midline intervals with various features, especially in the caudal portion of the intervertebral space. Therefore, the ligamentum flavum is not always reliable as a perceptible barrier to identify the epidural space at these vertebral levels. Additionally, it may be more useful to insert the needle into the cephalic portion of the intervertebral space than in the caudal portion.