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The field of neurostimulation for the treatment of chronic pain is a rapidly developing area of medicine. Although neurostimulation therapies have advanced significantly as a result of technologic improvements, surgical planning, device placement, and postoperative care are of equal importance to optimize outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for these often-overlooked areas of neurostimulation practice.Authors were chosen based on their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from the last NACC publication in 2017 to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on evidence strength and consensus when evidence was scant.This NACC project provides guidance on preoperative assessment, intraoperative techniques, and postoperative management in the form of consensus points with supportive evidence. These results are based on grade of evidence, strength of consensus, and expert opinion.The NACC has given guidance for a surgical plan that encompasses the patient journey from the planning stage through the surgical experience and postoperative care. The overall recommendations are designed to improve efficacy and the safety of patients undergoing these neuromodulation procedures and are intended to apply throughout the international community.

Sacroiliac joint disease is a prominent diagnosis across the world. A novel fixation technique employing a posterior approach, single point, bone allograft transfixation has proven to be helpful anecdotally. The purpose of this is study is to investigate prospectively the safety and efficacy of this approach.A multicenter, prospective, single arm study was performed after patient identification and treatment with the novel posterior fusion, single-point transfixation system and followed for 24 months. Target enrollment is 100 patients. Interim results on the first 69 consecutive patients at 6 months is presented. Primary endpoint at 6-month analysis was Pain Intensity reduction by visual analogue scale and functional improvement by Oswestry Disability Index. Adverse events were assessed for safety analysis.In total, 69 patients were identified for this analysis. At 6 months, a mean improvement of 34.9 was identified by a reduction in VAS and functional improvement was demonstrated by a mean reduction in ODI of 17.7. There were three adverse events, all unrelated to the device.The posterior single point transfixation is safe and efficacious for the treatment of sacroiliac joint dysfunction with statistical improvements in pain and function.

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A-). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).

Supplemental digital content is available in the text., Background Over the past 2 decades, the use of intravenous ketamine infusions as a treatment for chronic pain has increased dramatically, with wide variation in patient selection, dosing, and monitoring. This has led to a chorus of calls from various sources for the development of consensus guidelines. Methods In November 2016, the charge for developing consensus guidelines was approved by the boards of directors of the American Society of Regional Anesthesia and Pain Medicine and, shortly thereafter, the American Academy of Pain Medicine. In late 2017, the completed document was sent to the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters, after which additional modifications were made. Panel members were selected by the committee chair and both boards of directors based on their expertise in evaluating clinical trials, past research experience, and clinical experience in developing protocols and treating patients with ketamine. Questions were developed and refined by the committee, and the groups responsible for addressing each question consisted of modules composed of 3 to 5 panel members in addition to the committee chair. Once a preliminary consensus was achieved, sections were sent to the entire panel, and further revisions were made. In addition to consensus guidelines, a comprehensive narrative review was performed, which formed part of the basis for guidelines. Results Guidelines were prepared for the following areas: indications; contraindications; whether there was evidence for a dose-response relationship, or a minimum or therapeutic dose range; whether oral ketamine or another N-methyl-d-aspartate receptor antagonist was a reasonable treatment option as a follow-up to infusions; preinfusion testing requirements; settings and personnel necessary to administer and monitor treatment; the use of preemptive and rescue medications to address adverse effects; and what constitutes a positive treatment response. The group was able to reach consensus on all questions. Conclusions Evidence supports the use of ketamine for chronic pain, but the level of evidence varies by condition and dose range. Most studies evaluating the efficacy of ketamine were small and uncontrolled and were either unblinded or ineffectively blinded. Adverse effects were few and the rate of serious adverse effects was similar to placebo in most studies, with higher dosages and more frequent infusions associated with greater risks. Larger studies, evaluating a wider variety of conditions, are needed to better quantify efficacy, improve patient selection, refine the therapeutic dose range, determine the effectiveness of nonintravenous ketamine alternatives, and develop a greater understanding of the long-term risks of repeated treatments.

Intrathecal delivery of alpha(2)-adrenergic agonists produces an analgesic effect. However, hemodynamic side effects limit their clinical usage. To more fully characterize the effects on heart rate and arterial blood pressure of alpha(2)-adrenergic agonists, clonidine and tizanidine were injected intrathecally in conscious dogs. Both compounds produced a potent inhibition of thermal foot-withdrawal latencies at 1000 micrograms, which was blocked by the alpha(2)-adrenergic antagonist yohimbine. Tizanidine (250-500 micrograms) did not change heart rate. Clonidine (500 -2000 micrograms) and tizanidine (1000-2000 micrograms) decreased heart rate. The tizanidine effect was inhibited by yohimbine and the alpha(2)/imidazoline antagonist idazoxan, as well as the parasympathetic blocker glycopyrrolate. No drug completely inhibited the clonidine-induced bradycardia. Clonidine had a biphasic effect on arterial blood pressure, a decrease at 500 micrograms and an increase at 2000 micrograms. Tizanidine decreased arterial blood pressure at all doses. The results indicate that, while the analgesic effects of both drugs are similar, the hemodynamic responses differ. While the decrease in heart rate with tizanidine is consistent with alpha(2)-adrenergic binding and vagal action, the bradycardia induced by clonidine is more complex. In addition, the increased arterial blood pressure with high doses of clonidine, which is suggestive of a peripheral vasoconstrictive effect, does not occur with tizanidine.

Current IASP diagnostic criteria for CRPS have low specificity, potentially leading to overdiagnosis. This validation study compared current IASP diagnostic criteria for CRPS to proposed new diagnostic criteria (the "Budapest Criteria") regarding diagnostic accuracy. Structured evaluations of CRPS-related signs and symptoms were conducted in 113 CRPS-I and 47 non-CRPS neuropathic pain patients. Discriminating between diagnostic groups based on presence of signs or symptoms meeting IASP criteria showed high diagnostic sensitivity (1.00), but poor specificity (0.41), replicating prior work. In comparison, the Budapest clinical criteria retained the exceptional sensitivity of the IASP criteria (0.99), but greatly improved upon the specificity (0.68). As designed, the Budapest research criteria resulted in the highest specificity (0.79), again replicating prior work. Analyses indicated that inclusion of four distinct CRPS components in the Budapest Criteria contributed to enhanced specificity. Overall, results corroborate the validity of the Budapest Criteria and suggest they improve upon existing IASP diagnostic criteria for CRPS. (C) 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Objectives. This study seeks to identify characteristics of the chronic pain patient population that may increase vulnerability to vicariously experienced psychological trauma. Design. Characteristics, including demographics and psychological measures, were evaluated by modeling change in visit rates to a university pain center immediately after the terrorist attacks of September 11, 2001. Setting. University pain center. Patients. A total of 570 patients with chronic pain. Outcome Measures. Visit rates, psychologists evaluation of depression, Beck Depression Inventory. Results. Evaluation of psychological measures showed that depression was the most effective predictor of the postattack visit rate increase in chronic pain patients. The visit rate for nondepressed patients did not change significantly after the attacks, but approximately doubled for depressed patients. A more detailed analysis, performed by categorizing patients into one of four levels of depression, found that patients classified as “Mild to Moderately” depressed were most likely to show an increase in visits after the attacks. Conclusions. Chronic pain patients represent a vulnerable population, and the current study posits the possibility of predicting the most vulnerable individuals within that population. With information commonly contained in medical records, target populations may be identified for potential psychological trauma intervention to reduce the sequelae of vicariously experienced psychological trauma.

ContextControlling postoperative pain after knee replacement while reducing opiod-induced adverse effects and improving outcomes remains an important challenge.ObjectiveTo assess the effect of combined preoperative and postoperative administration of a selective inhibitor of cyclooxygenase 2 on opioid consumption and outcomes after total knee arthroplasty (TKA).Design, Setting, and PatientsRandomized, placebo-controlled, double-blind trial conducted June 2001 through September 2002, enrolling 70 patients aged 40 to 77 years and undergoing TKA at a university hospital in the United States.InterventionsPatients were randomly assigned to receive 50 mg of oral rofecoxib at 24 hours and at 1 to 2 hours before TKA, 50 mg daily for 5 days postoperatively, and 25 mg daily for another 8 days, or matching placebo at the same times.Main Outcome MeasuresPostoperative outcomes including postsurgical analgesic consumption and pain scores achieved, nausea and vomiting, joint range of motion, sleep disturbance, patient satisfaction with analgesia, and hematologic and coagulation parameters.ResultsTotal epidural analgesic consumption and in-hospital opioid consumption were less in the group receiving rofecoxib compared with the group receiving placebo (P.05 for both intraoperative and postoperative blood loss).ConclusionPerioperative use of an inhibitor of cyclooxygenase 2 is an effective component of multimodal analgesia that reduces opioid consumption, pain, vomiting, and sleep disturbance, with improved knee range of motion after TKA.

The short duration of epidural fentanyl has limited its direct comparison with epidural morphine in previous reports. The following study was performed of continuous postoperative epidural infusions at 5 ml/hr fentanyl 10 micrograms/ml (n = 59) or morphine 0.1 mg/ml (n = 48), both with bupivacaine 0.1%, in patients having cesarean sections. Postoperative evaluations included the frequency and magnitude of clinically evident respiratory depression, the adequacy of analgesia, nausea, pruritus, the ability to ambulate, and other side effects for 24 hours. Analgesia and the number of supplemental narcotic injections needed were similar in both groups. The incidence of nausea and pruritus was significantly less in the patients receiving fentanyl. No patient developed respiratory depression in either group. Patient and staff acceptance of the continuous epidural technique was excellent because there were only minor catheter-related problems associated with its use. It is concluded that continuous epidural fentanyl combined with bupivacaine offers excellent postoperative analgesia with minimal side effects.

Twenty-one hundred eighty two consecutive lumbar epidural injections were studied to determine the incidence of inadvertent subdural block retrospectively. A subdural block is defined as an extensive neural block in the absence of subarachnoid puncture, that is out of proportion to the amount of local anesthetic injected. Subdural injection is a complication of epidural block that probably occurs more frequently than previously recognized. An earlier report has estimated the incidence of subdural block to be 0.1%. This study, however, reports an incidence of 0.82% from a sample size of 2182 patients. Cadaveric dissection was also performed, further clarifying the presence and anatomic position of the subdural space.