F. Michael Ferrante

Radiofrequency sacroiliac joint denervation for sacroiliac syndrome

Background and Objectives Radiofrequency (RF) denervation of the sacroiliac (SI) joint has been advocated for the treatment of sacroiliac syndrome, yet no clinical studies or case series support its use. Methods We report the results of a consecutive series of 50 SI joint RF denervations performed in 33 patients with sacroiliac syndrome. All patients underwent diagnostic SI joint injections with local anesthetic before denervation. Changes in visual analog pain scores (VAS), pain diagrams, physical examination (palpation tenderness over the joint, myofascial trigger points overlying the joint, SI joint pain provocation tests, and range of motion of the lumbar spine), and opioid use were assessed pre- and postdenervation. Results The criteria for successful RF denervation were at least a 50% decrease in VAS for a period of at least 6 months; 36.4% of patients (12 of 33) met these criteria. Failure of denervation correlated with the presence of disability determination and pain on lateral flexion to the affected side. The average duration of pain relief was 12.0 ± 1.2 months in responders versus 0.9 ± 0.2 months in nonresponders (P ≤ .0001). A positive response was associated with an atraumatic inciting event. Successful denervation was associated with a change in the pain diagram and a reduction in the pattern of referred pain, a normalization of SI joint pain provocation tests, and a reduction in the use of opioids. Conclusions This study suggests that RF denervation of the SI joint can significantly reduce pain in selected patients with sacroiliac syndrome for a protracted time period. Moreover, certain abnormal physical findings (i.e., SI joint pain provocation tests) revert to normal for the duration of the analgesia.

Evidence-Based Review of the Literature on Intrathecal Delivery of Pain Medication

Evidence-based medicine depends on the existence of controlled clinical trials that establish the safety and efficacy of specific therapeutic techniques. Many interventions in clinical practice have achieved widespread acceptance despite little evidence to support them in the scientific literature; the critical appraisal of these interventions based on accumulating experience is a goal of medicine. To clarify the current state of knowledge concerning the use of various drugs for intraspinal infusion in pain management, an expert panel conducted a thorough review of the published literature. The exhaustive review included 5 different groups of compounds, with morphine and bupivacaine yielding the most citations in the literature. The need for additional large published controlled studies was highlighted by this review, especially for promising agents that have been shown to be safe and efficacious in recent clinical studies.

Clinical guidelines for intraspinal infusion: Report of an expert panel

Consensus guidelines developed by an expert panel are helpful to clinicians when there is variation in practice and lack of a firm evidence base for an intervention, such as intraspinal therapy for pain. An internet-based survey of practitioners revealed remarkable variation in practice patterns surrounding intraspinal therapy. This prompted an interdisciplinary panel with extensive clinical experience in intraspinal infusion therapy to evaluate the results of the survey, the systematic reviews of the literature pertaining to this approach, and their own clinical experience with long-term spinal infusions. The panel proposed a scheme for the selection of drugs and doses for intraspinal therapy, and suggested guidelines for administration that would increase the likelihood of a successful outcome. These expert panel guidelines were designed to provide an initial structure for clinical decision making that is based on the best available evidence and the perspectives of experienced clinicians.

Evidence against trigger point injection technique for the treatment of cervicothoracic myofascial pain with botulinum toxin type a

Background:Traditional strategies for myofascial pain relief provide transient, incomplete, variable, or unpredictable outcomes. Botulinum toxin is itself an analgesic but can also cause sustained muscular relaxation, thereby possibly affording even greater relief than traditional therapies. Methods:The study goal was to determine whether direct injection of botulinum toxin type A (BoNT-A) into trigger points was efficacious for cervicothoracic myofascial pain, and if so, to determine the presence or absence of a dose–response relation. One hundred thirty-two patients with cervical or shoulder myofascial pain or both and active trigger points were enrolled in a 12-week, randomized, double-blind, placebo-controlled trial. After a 2-week washout period for all medications, patients were injected with either saline or 10, 25, or 50 U BoNT-A into up to five active trigger points. The maximum doses in each experimental group were 0, 50, 125, and 250 U per patient, respectively. Patients subsequently received myofascial release physical therapy and amitriptyline, ibuprofen, and propoxyphene–acetaminophen napsylate. Follow-up visits occurred at 1, 2, 4, 6, 8, and 12 weeks. Outcome measures included visual analog pain scores, pain threshold as measured by pressure algometry, and rescue dose use of propoxyphene–acetaminophen napsylate. Results:No significant differences occurred between placebo and BoNT-A groups with respect to visual analog pain scores, pressure algometry, and rescue medication. Conclusions:Injection of BoNT-A directly into trigger points did not improve cervicothoracic myofascial pain. The role of direct injection of trigger points with BoNT-A is discussed in comparison to other injection methodologies in the potential genesis of pain relief.

Mortality Associated with Implantation and Management of Intrathecal Opioid Drug Infusion Systems to Treat Noncancer Pain

Background:In 2006, the authors observed a cluster of three deaths, which circumstances suggested were opioid-related, within 1 day after placement of intrathecal opioid pumps for noncancer pain. Further investigation suggested that mortality among such patients was higher than previously appreciated. The authors performed investigations to quantify that mortality and compare the results to control populations, including spinal cord stimulation and low back surgery. Methods:After analyzing nine index cases–three sentinel cases and six identified by a prospective strategy–the authors used epidemiological methods to investigate whether mortality rates reflected patient- or therapy-related differences. Mortality rates after intrathecal opioid therapy and spinal cord stimulation were derived by correlating Medtronic device registration data with deidentified data from the Social Security Death Master File. Aggregate demographic and comorbidity data were obtained from Medicare and United Healthcare population databases to examine the influence of demographics and comorbidities on mortality. Results:Device registration and Social Security analyses revealed an intrathecal opioid therapy mortality rate of 0.088% at 3 days after implantation, 0.39% at 1 month, and 3.89% at 1 yr–a higher mortality than after spinal cord stimulation implants or after lumbar diskectomy in community hospitals. Demographic, illness profile, and mortality analyses of large databases suggest, despite limitations, that excess mortality was related to intrathecal opioid therapy, and could not be fully explained by other factors. These findings were consistent with the nine index cases that revealed that respiratory arrest caused or contributed to death in all patients. No device malfunctions associated with overinfusion were identified among cases where data were available. Conclusions:Patients with noncancer pain treated with intrathecal opioid therapy experience increased mortality compared to similar patients treated by using other therapies. Respiratory depression as a consequence of intrathecal drug overdosage or mixed intrathecal and systemic drug interactions is one plausible, but hypothetical mechanism. The exact causes for patient deaths and the proportion of those deaths attributable to intrathecal opioid therapy remain to be determined. These findings, although based on incomplete information, suggest that it may be possible to reduce mortality in noncancer intrathecal opioid therapy patients.

Extramedullary Intrathecal Catheter Granuloma Adherent to the Conus Medullaris Presenting as Cauda Equina Syndrome

EXTRAMEDULLARY intrathecal granuloma formation is a rare complication of morphine administration via implanted drug delivery systems. 1-5 We present a unique case of a granuloma adherent to the conus medullaris presenting as cauda equina syndrome. Practitioners should not assume that implantation of intrathecal catheters with their tips located at or below the conus medullaris will eliminate all risk of neurologic sequelae associated with inflammatory granulomas.

Intrathecal Bupivacaine for Chronic Pain: A Review of Current Knowledge

Objective. This article presents an overview of the use of intrathecal bupivacaine (with and without opioid), focusing on laboratory data and clinical use for chronic pain. Some background on epidural use is included to support the intrathecal literature.

Subarachnoid and epidural neurolysis

In many cases, treatment of severe cancer pain remains a great clinical challenge. Spinal (epidural and subarachnoid) neurolysis remains the treatment of choice for a minority of patients with cancer-related pain. Because of the risk of severe complications many practitioners are reluctant to employ these techniques. When used appropriately, in carefully selected patients, they can be an effective means of relieving suffering. The purpose of this article is to review the techniques of subarachnoid and epidural neurolysis for the treatment of cancer-related pain so that more clinicians may become familiar and comfortable with its use. An understanding of the material presented should help the practitioner maximize benefit for his patients and minimize the possibility of complications or litigation.

PERIOPERATIVE DRUGS AND POSTOPERATIVE PAIN MANAGEMENT

Laboratory research efforts over the last two decades have resulted in dramatic advances in understanding of the pharmacologic mechanisms of nociception (see the article by Sorkin). Clinical studies have demonstrated how these new concepts can be effectively applied and point to the benefits of suppressed physiologic responses and improved outcome that may be achieved with aggressive multimodal treatment of postoperative pain. This explosion of knowledge has produced a vast, potentially confusing array of interventions from which the practicing clinician must choose. This article presents the foundations for rational application of combined pharmacologic analgesic therapy, also known as balanced analgesia, 26 based on current understanding of the anatomy, physiology, and pharmacology of nociception and the neuroendocrine stress response to injury.