Clinical experience with intrathecal bupivacaine in combination with opioid for the treatment of chronic pain related to failed back surgery syndrome and metastatic cancer pain of the spine

Abstract Background context: Bupivacaine is a local anesthetic agent of the amide class. This drug has been used in many clinical situations including intrathecal infusion. The literature regarding intrathecal bupivacaine is limited to small case studies, and anecdotal reports. This article examines a large patient group receiving bupivacaine with opioids over an extended period of time and analyzes efficacy and safety. The patients had pain related to failed back surgery syndrome or metastatic cancer to the spine. Purpose: The purpose of this study was to determine the efficacy and safety of intrathecal bupivacaine combined with opioids for treatment of pain of spinal origin when opioids alone were inadequate. The secondary purpose of this study was to determine if the combination of bupivacaine and opioids created a neurological safety risk. Study design/setting: The study design was retrospective, and involved consecutive medical records review by a disinterested third party. Patient sample: One hundred nine consecutive patients were studied for a total of 6,780 patient weeks of bupivacaine/opioid infusion. These data were compared with a comparable time in the opioid alone treatment arm. The population included 84 noncancer patients and 25 cancer patients. Outcome measures: The primary outcome measure was pain relief obtained by a group of patients with a combination of bupivacaine and opioids as compared with opioid alone when delivered by intrathecal infusion. The visual analog scale was used to measure pain levels. Secondary objectives included measuring the amount of oral and transdermal medication required (opioid and nonopioid), emergency visits, routine office visits and patient satisfaction. These secondary objectives give a measure of health-care utilization. We also reviewed neurological complications during the combined arm of treatment. Methods: The study was done retrospectively with 109 consecutive patients. Patient chart reviews were used to determine the visual analog scales, amount of oral opioids, oral nonopioid adjuvant and patient safisfaction ratings. Patient satisfaction and pain rating was measured by a visual analog scale. Other factors recorded were emergency room visits, doctor's visits (other than the primary pain physician) and pain center visits. We also reviewed records for neurological deficits in the opioid arm and the combined arm. The t test was used to analyze statistical significance. Results: The findings suggested that in the combination arm the pain relief was significantly better (p=.008), the number of oral opioids used were significantly less (p=.008), the number of oral nonopioid adjuvants were reduced, the number of doctor's visits were less in the combined arm (p=.008), the number of pain clinic visits were less (p=.03), the number of emergency visits were significantly less (p=.01) and patient satisfaction was better (p=.003). The total dose of morphine was reduced by 23% in the combined arm (p=.005). During the course of treatment with intrathecal bupivacaine, there were no irreversible complications. Conclusion: Bupivacaine, when used in combination with opioids, is a helpful and safe method of treatment in a select population of patients who have not responded to intrathecal opioids alone.