Bupivacaine administered intrathecally versus rectally in the management of intractable rectal cancer pain in palliative care

Integration of Solid-Phase Extraction and Reversed-Phase Chromatography in Single Protein-Coated Columns for Direct Injection of Bupivacaine in Human Serum

A rapid, reliable and precise integrated solid-phase extraction (SPE) and reversed-phase liquid chromatography method was developed and validated to determine bupivacaine in human serum using single protein-coated analytical columns. The protein-coated columns were packed with four different sorbents: TSK-ODS, LiChrosorb RP-8, LiChrosorb RP-2 and μ-Bondapak CN-bonded silica. The method involved direct injection of serum sample onto the columns for trapping of the analyte, clean-up from weakly retained serum endogenous components, as well as the final separation. The protein-coated columns operated in two different chromatographic modes. Serum proteins were extracted and cleaned up by SPE, whereas the final separation of bupivacaine was based on reversed-phase chromatography. The protein-coated TSK-ODS column resulted in more accurate peak integration and more reproducible results. A linear relationship between the concentrations of drug and peak areas was confirmed in the range of 100-2000 ng/mL. Detection and quantification limits were 24.85 and 85.36 ng/mL, respectively. The average recovery for bupivacaine ranged from 96.48% to 98.81%. The present methodology was successfully applied, with a high degree of confidence, to analyze clinical samples obtained from patient receiving 0.5% bupivacaine therapy.

Management of Malignant Rectal Pain and Tenesmus: A Systematic Review

Background: Malignant rectal pain (MRP) and tenesmus cause significant morbidity for cancer patients at all stages of disease. There is little evidence to guide management of these symptoms. Objective: The objective of this review was to summarize the existing evidence base for palliative management of MRP and tenesmus outside of standard oncologic or surgical management. Design: A systematic review of PubMed and Embase was conducted according to PRISMA guidelines using preselected search terms for publications between 1980 and January 2017. Setting/Subjects: Studies that described management for patients with tenesmoid pain from malignant tumors of the rectum, anus, or perineum were identified. Measurements: The primary outcome was response of pain to treatment. Results: The search produced 1412 titles. Twenty articles met criteria for inclusion in the review, including 11 case series and 9 case reports. A variety of treatments were found with most patients receiving interventional procedures, but overall evidence to support any particular intervention is limited and of poor quality. Conclusions: This review highlights the limited current evidence base for medical and interventional treatments for MRP and tenesmus. Further study is needed to clarify the best approach to managing these challenging symptoms.

Rectal enema of bupivacaine in cancer patients with tenesmus pain - case series

Introduction: Rectal tenesmus pain in cancer patients most frequently appears in patients with colon cancer, and as a consequence of radiotherapy of the hypogastrium region. Treatment with opioids and adjuvant analgesics is often ineffective. Patients and methods: Here, we report on two female patients diagnosed with colon and ovary cancer, respectively, who had very severe tenesmus pain (numerical rating scale 8-10) despite using high doses of opioids, including methadone with corticosteroids, anticonvulsants, antidepressants and ketamine. Results: In both patients, bupivacaine was administered via a rectal enema. In the first patient, bupivacaine was administered at a dose of 100 mg 0.1% (100 mL), and subsequently 100 mg 0.2% (50 mL), leading to effective analgesia for 8 and 12 hrs, respectively. In the second patient, 100 mg 0.1% (100 mL) was initially administered, followed by 100 mg 0.2% (50 mL), leading to effective analgesia for 12 and 17 hrs, respectively, with only dull abdominal pain reported that was relieved by 100 mg IV ketoprofen and complete disappearance of tenesmus pain. Rectal bupivacaine administration did not cause neurologic adverse effects, heart function disturbances or decreased blood pressure. A volume of 50 mL was enough to cover a painful area in the colon. Initial bupivacaine concentrations in the blood serum did not exceed 50 ng/mL and eventually dropped to 20 ng/mL and below. Conclusions: Administration of 100 mg bupivacaine as a rectal enema is safe and provides effective analgesia, and this procedure may be conducted in hospital departments and out-patient clinics. Furthermore, this procedure in the case of pain recurrence, can be repeated, and by providing effective pain relief often allows time for the patient to be transferred to a specialized pain center.

A systematic review of the effectiveness of palliative interventions to treat rectal tenesmus in cancer

BACKGROUND

Rectal tenesmus is a distressing symptom in patients with advanced cancer and challenging to treat. There is lack of consensus on the appropriate management of tenesmus in this patient population.

AIM

To identify and examine the effectiveness of interventions to palliate rectal tenesmus caused by advanced cancer when surgery, radiotherapy or chemotherapy are no longer treatment options.

DESIGN

A systematic review of the literature following standard systematic review methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance.

DATA SOURCES

A comprehensive search of the electronic databases MEDLINE, EMBASE and the Cochrane Library was conducted from date of inception to April 2016. PubMed 'related articles' search, grey literature search and hand-searches of the bibliographies of relevant papers and textbooks were also performed. Non-cancer patients were excluded. Any studies involving surgery or radiotherapy to treat tenesmus were excluded. Studies involving interventions to treat pelvic pain syndromes without specific outcome measures on severity of tenesmus were excluded. The quality of the studies was assessed using a National Institute for Health and Clinical Excellence-recommended quality assessment tool.

RESULTS

From 861 studies, 9 met full criteria and were selected. All were case series investigating the use of pharmacological interventions (diltiazem, nifedipine, methadone, mexiletine hydrochloride, lidocaine and bupivacaine), anaesthetic interventions (lumbar sympathectomy, neurolytic superior hypogastric plexus block), and endoscopic laser interventions. The included studies showed substantial heterogeneity, and therefore, a meta-analysis was not feasible.

CONCLUSION

From this review, we identified a significant gap in research into the palliation of rectal tenesmus. A multimodal approach may be necessary due to the complexity of the pathophysiology of tenesmus. Future research should focus on randomised controlled trials of drug therapies whose potential effectiveness is suggested by case series.