Stability and Tolerability of High Concentrations of Intrathecal Bupivacaine and Opioid Mixtures in Chronic Noncancer Pain: An Open-Label Pilot Study

Catheter Tip-Associated Mass With Continuous Infusion of Sufentanil for Persistent Spinal Pain Syndrome Type 2: A Case Report Including Histopathologic Examination and Review of the Associated Basic and Clinical Research

OBJECTIVES

Intrathecal opioids delivered by implanted pumps are used to treat malignant or nonmalignant chronic pain. In this study, we 1) review a case in which intrathecal infusions of sufentanil along with other adjuvants were used and after an extended period led to an intrathecal mass and 2) compared and contrasted the potential mechanisms for these phenomena.

MATERIALS AND METHODS

A woman aged 66 years with a history of scoliosis and multiple spine surgeries was treated with an implantable drug delivery system for treating persistent pain after laminectomy. The patient received intrathecal medication comprising sufentanil, bupivacaine, and clonidine.

RESULTS

Intrathecal therapy over approximately ten years served to reduce pain and improve function over the treatment period. After the extended treatment interval, the patient developed an intrathecal mass that was associated with impairment. The mass was surgically removed. Systematic histopathology revealed the space-occupying mass to largely comprise fibroblasts and some inflammatory cells embedded in a collagen mass located proximally to the catheter tip.

CONCLUSIONS

To our knowledge, this is the first published case report of sufentanil causing this complication. The science and mechanism of intrathecal catheter tip-associated mass formation and associated clinical research correlates are reviewed in detail, and explanations for this phenomenon are proposed based on histochemical analysis of the patient's pathology findings.

Intrathecal pain pump causing delayed acute flaccid paralysis: A case report and review of the literature

Patients with intrathecal catheters for pain medication infusion should be aware of the possible complication of acute flaccid paralysis. While exceedingly rare, it should prompt immediate medical attention to rule out compressive pathology requiring intervention.

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.

Intrathecal Co-administration of Morphine Facilitated the Anti-nociceptive of Bupivacaine in a Rat Model of Acute Postoperative Pain

Introduction: Bupivacaine is one of the commonly used agents for spinal anaesthesia. Moreover, co-administration with morphine can likely increase its anti-nociceptive effect bringing about a reduction in the required dose of bupivacaine. Though this has been observed clinically, preclinical studies on the efficacy of this drug combination are lacking.

Methods: Sprague Dawley rats, previously implanted with intrathecal catheters, were administered either bupivacaine (30 mcg) or morphine (30 mcg) or both bupivacaine and morphine (15 mcg each). These doses were determined following prior evaluation of different doses of bupivacaine (3, 10 and 30 mcg). Rats were subjected to hind paw incision under isoflurane anaesthesia, 15 min after drug administration. Anti-nociception was evaluated by estimating mechanical allodynia in a fixed peri-incisional area using von Frey filaments. This was done 4 h after the incision.

Results: Both bupivacaine and morphine attenuated allodynia though morphine was more effective. Co-administration of both drugs at half the doses increased the antinociceptive effect of bupivacaine to the 30 mcg dose level.

Conclusion: The underlying reason for this enhanced anti-nociception could be the different neural mechanisms responsible for anti-nociception. Local anaesthetics inhibit the generation of action potentials by blocking sodium channels whereas opioids like morphine act through G-protein coupled mu opioid receptor-linked closure of calcium channels in presynaptic terminals. In conclusion, the addition of morphine can facilitate bupivacaine’s anti-nociceptive effect following intrathecal administration. This information could have clinical relevance in the treatment of postoperative pain.

Bupivacaine reduces GlyT1 expression by potentiating the p-AMPKα/BDNF signalling pathway in spinal astrocytes of rats

Bupivacaine, a local anaesthetic, is widely applied in the epidural or subarachnoid space to clinically manage acute and chronic pain. However, the underlying mechanisms are complex and unclear. Glycine transporter 1 (GlyT1) in the spinal cord plays a critical role in various pathologic pain conditions. Therefore, we sought to determine whether bupivacaine exerts its analgesic effect by regulating GlyT1 expression and to determine the underlying mechanisms of regulation. Primary astrocytes prepared from the spinal cord of rats were treated with bupivacaine. The protein levels of GlyT1, brain-derived neurotrophic factor (BDNF) and phosphorylated adenosine 5′-monophosphate (AMP)-activated protein kinase α (p-AMPKα) were measured by western blotting or immunofluorescence. In addition, 7,8-dihydroxyflavone (7,8-DHF, BDNF receptor agonist) and AMPK shRNA were applied to verify the relationship between the regulation of GlyT1 by bupivacaine and the p-AMPKα/BDNF signalling pathway. After treatment with bupivacaine, GlyT1 expression was diminished in a concentration-dependent manner, while the expression of BDNF and p-AMPK was increased. Moreover, 7,8-DHF decreased GlyT1 expression, and AMPK knockdown suppressed the upregulation of BDNF expression by bupivacaine. Finally, we concluded that bupivacaine reduced GlyT1 expression in spinal astrocytes by activating the p-AMPKα/BDNF signalling pathway. These results provide a new mechanism for the analgesic effect of intrathecal bupivacaine in the treatment of acute and chronic pain.

Triple Intrathecal Combination Therapy for End-Stage Cancer-Related Refractory Pain: A Prospective Observational Study with Two-Month Follow-Up

INTRODUCTION

In cancer-related pain refractory to systemic opioids, intrathecal (IT) administration of morphine can be a useful strategy. In clinical practice, IT morphine is usually combined with other drugs with different mechanisms of action, in order to obtain a synergistic analgesic effect. However, the discussion on efficacy and safety of IT combination therapy is still ongoing. The aim of this observational study was to report the effects of an IT combination of low doses of ziconotide, morphine, and levobupivacaine in end-stage cancer refractory pain.

METHODS

Sixty adult patients, 21 females and 39 males, were enrolled to an IT device implant. The mean visual analogue scale of pain intensity (VASPI) score was 88 ± 20 mm. All patients started with a triple combination therapy: the initial IT dose of morphine was calculated for each patient based on the equivalent daily dose of morphine; an oral/IT ratio of 400/1 was used. For ziconotide, a standard slow titration schedule was started at 1.2 μg/day and the initial dose of levobupivacaine was 3 mg/day.

RESULTS

The initial IT mean doses of morphine, ziconotide, and levobupivacaine were 0.8 ± 0.3 mg/day, 1.2 mcg/day and 3 mg/day, respectively. At day 2, a significant reduction in VASPI score was registered (49 ± 17, p < 0.001), and this significant reduction persisted at 56 days (mean VASPI score 44 ± 9, p < 0.001), with mean doses of morphine 2 ± 1 mg/day, ziconotide 2.8 ± 1 mcg/day, and levobupivacaine 3.8 ± 2 mg/day. Very few adverse effects (AEs) were observed. Patients' satisfaction was very high during the entire study period.

CONCLUSIONS

Our results, within the limit of the study design, suggest that the IT combination of ziconotide, morphine, and levobupivacaine, at low doses, allows safe and rapid control of refractory cancer pain, with high levels of patient satisfaction.

Evaluation of Fixed Intrathecal Bupivacaine Infusion Doses in the Oncologic Population

OBJECTIVES

Intrathecal drug delivery systems (IDDS) are an important method of pain control for patients with refractory oncologic pain. Local anesthetics such as bupivacaine have been infused either alone or with opioids. While effective, bupivacaine can cause adverse effects such as numbness, weakness, and urinary retention. This study looks to establish a safe and efficacious fixed bupivacaine dosing algorithm in intrathecal pumps for cancer patients.

MATERIALS AND METHODS

A bupivacaine dosing algorithm was developed using data from 120 previous patients who underwent IDDS placement at Memorial Sloan Kettering Cancer Center. The outcomes were then evaluated for 43 subsequent patients who were treated with bupivacaine IDDS according to our aforementioned algorithm.

RESULTS

Our data show that in patients treated with our bupivacaine guideline, visual analog pain scale scores decreased by 59% and oral morphine equivalence decreased by 70% from the period between IDDS implantation until discharge from the MSKCC hospital. However, 16.3% of our patients had bupivacaine-related side effects.

CONCLUSIONS

For oncological patients, our data and experience support the initiation of intrathecal bupivacaine at the following doses: 5 mg/day for catheter tips in the cervical spine, 8 mg/day for catheter tips at T1-4, and 10 mg/day for catheter tips at T5-8. Given the higher likelihood of adverse effects in catheters at T9-12 and the lumbar spine, we start at 8 mg/day with close follow-up of the patient. Initiating these doses allow our patients to safely reach adequate analgesia faster, with a shorter hospitalization and quicker return to anti-cancer therapy.

Cancer- and Non-cancer Related Chronic Pain: From the Physiopathological Basics to Management

The prevalence of chronic pain is between 33% to 64% and is due to cancer pain, but it has also been observed in non-cancer patients. Chronic pain is associated with lower quality of life and higher psychological distress and depressive/anxiety disorders in patients without a history of disorder. In this study we evaluated in clinical practice the effectiveness of the intrathecal pump in 140 patients who underwent pain therapy at our Center. These patients were consecutively enrolled from January 2010 to July 2018. Follow-up was carried out over these eight years regarding the infusion modalities. Pain relief was obtained in 71 (50,7%) patients out of the 140 that experienced satisfactory pain control globally. Intrathecal therapy is one of the best options for chronic severe refractory pain. The greatest advantage of this therapy is due to the possibility of treating the pain with minimal dosages of the drug, avoiding the appearance of troublesome side effects.

Toxic Myelitis and Arachnoiditis After Intrathecal Delivery of Bupivacaine via an Implanted Drug Delivery System: Case Report and Review of the Literature

The off-label usage of amino-amide anesthetics in intrathecal drug delivery systems (IDDS) for the treatment of chronic non-malignant and malignant pain is supported in the polyanalgesic consensus guidelines as a second-line adjunctive therapy. Although strong evidence for its clinical efficacy is lacking, its clinical safety profile has been well established within established dosing parameters. Despite the rarity of neurological adverse reactions to intrathecal bupivacaine, whether given as regional anesthesia or intrathecal therapy, neurologic morbidity associated with its administration is well documented. The etiology of adverse reactions is often difficult to definitively identify, especially given the variabilities associated with compounding errors in the formulation, solvent contamination, and mechanical factors. We present a rare case of toxic myelitis and arachnoiditis resulting in paraplegia two months after the addition of bupivacaine to the intrathecal analgesic regimen and discuss possible etiological factors with a review of the literature.

Polyanalgesic Consensus Conference 2012: recommendations for the management of pain by intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel

INTRODUCTION

The use of intrathecal (IT) infusion of analgesic medications to treat patients with chronic refractory pain has increased since its inception in the 1980s, and the need for clinical research in IT therapy is ongoing. The Polyanalgesic Consensus Conference (PACC) panel of experts convened in 2000, 2003, and 2007 to make recommendations on the rational use of IT analgesics based on preclinical and clinical literature and clinical experiences.

METHODS

The PACC panel convened again in 2011 to update the standard of care for IT therapies to reflect current knowledge gleaned from literature and clinical experience. A thorough literature search was performed, and information from this search was provided to panel members. Analysis of published literature was coupled with the clinical experience of panel members to form recommendations regarding the use of IT analgesics to treat chronic pain.

RESULTS

After a review of literature published from 2007 to 2011 and discussions of clinical experience, the panel created updated algorithms for the rational use of IT medications for the treatment of neuropathic pain and nociceptive pain.

CONCLUSIONS

The advent of new algorithmic tracks for neuropathic and nociceptive pain is an important step in improving patient care. The panel encourages continued research and development, including the development of new drugs, devices, and safety recommendations to improve the care of patients with chronic pain.