The Use of Contrast Agents in Interventional Pain Procedures: A Multispecialty and Multisociety Practice Advisory on Nephrogenic Systemic Fibrosis, Gadolinium Deposition in the Brain, Encephalopathy After Unintentional Intrathecal Gadolinium Injection, and Hypersensitivity Reactions.

This Practice Advisory presents a comprehensive and evidence-based set of position statements and recommendations for the use of contrast media in interventional pain procedures. The advisory was established by an international panel of experts under the auspices of 11 multinational and multispecialty organizations based on a comprehensive review of the literature up to December 31, 2019. The advisory discusses the risks of using gadolinium-based contrast agents. These include nephrogenic systemic fibrosis, gadolinium brain deposition/retention, and encephalopathy and death after an unintentional intrathecal gadolinium injection. The advisory provides recommendations on the selection of a specific gadolinium-based contrast agent in patients with renal insufficiency, those who had multiple gadolinium-enhanced magnetic resonance imaging examinations, and in cases of paraspinal injections. Additionally, recommendations are made for patients who have a history of mild, moderate, or severe hypersensitivity reactions to contrast medium.

Mixing Studies in Patients With Prolonged Activated Partial Thromboplastin Time or Prothrombin Time.

BACKGROUND: Patients presenting for surgery may have isolated or combined prolonged activated partial thromboplastin time (aPTT) and/or prothrombin time (PT). In patients not receiving anticoagulants or with no identifiable cause for abnormal clot formation, a mixing study is performed. The index of circulating anticoagulant (ICA) has been used to predict the presence of an inhibitor, usually a lupus anticoagulant. METHODS: We retrospectively reviewed the results of mixing studies performed at Northwestern Memorial Hospital, between January 1, 2010 and February 29, 2012. We determined the number of samples that normalized or remained prolonged, the clotting factors associated with prolonged test results, and the presence of coagulation inhibitors. We calculated the ICA in the samples with prolonged aPTT and PT to determine its ability to predict a lupus anticoagulant. The primary comparison of interest was the diagnostic utility of the ICA at cutoff values of 11% for predicting the presence of lupus anticoagulant. RESULTS: There were 269 mixing studies performed: 131 samples with prolonged aPTT; 95 with prolonged PT; and 43 with both prolonged aPTT and prolonged PT. Of the samples with a prolonged aPTT, 55 of 131 (42%) normalized, 36 of 131 (27%) partially corrected, and 40 of 131 (31%) remained prolonged. Thirty-three of 95 samples (35%) with prolonged PT normalized, while 62 of 95 (65%) remained prolonged. Eight of 43 (19%) mixing studies of patients with prolonged PT and aPTT normalized; the aPTT normalized, but the PT remained prolonged in 17 of 43 (39%); the PT normalized, but the aPTT remained prolonged in 7 of 43 (16%); and both tests remained prolonged in 11 of 43 (26%) samples. Prolongations in the aPTT were primarily associated with low activities of CF XII, while the majority of the prolongations in PT were secondary to low activities in CF VII. Combined prolongations were secondary to deficiencies in both the intrinsic and extrinsic as well as the common pathways. An ICA >11% had 100% (95% CI, 59%-100%) sensitivity, 53% (95% CI, 35%-70%) specificity, and 77% (95% CI, 62%-92%) accuracy in predicting the presence of lupus anticoagulant in patients with prolonged aPTT. CONCLUSIONS: Normalization of the aPTT and PT in a mixing study was associated with low clotting factor activity. The ICA may be helpful in predicting the presence of a lupus anticoagulant. As anesthesiologists take ownership of the perioperative surgical home, we need to understand the clinical implications of the results of mixing studies.

Consistent Definitions of Clinical Practice Guidelines, Consensus Statements, Position Statements, and Practice Alerts.

An evidence-based approach to clinical decision-making for optimizing patient care is desirable because it promotes quality of care, improves patient safety, decreases medical errors, and reduces health care costs. Clinical practice recommendations are systematically developed documents regarding best practice for specific clinical management issues, which can assist care providers in their clinical decision-making. However, there is currently wide variation in the terminology used for such clinical practice recommendations. The aim of this article is to provide guidance to authors, reviewers, and editors on the definitions of terms commonly used for clinical practice recommendations. This is intended to improve transparency and clarity regarding the definitions of these terminologies.

Development, Reporting, and Evaluation of Clinical Practice Guidelines.

Clinical practice parameters have been published with greater frequency by professional societies and groups of experts. These publications run the gamut of practice standards, practice guidelines, consensus statements or practice advisories, position statements, and practice alerts. The definitions of these terms have been clarified in an accompanying article. In this article, we present the criteria for high-quality clinical practice parameters and outline a process for developing them, specifically the Delphi method, which is increasingly being used to build consensus among content experts and stakeholders. Several tools for grading the level of evidence and strength of recommendation are offered and compared. The speciousness of categorizing guidelines as evidence-based or consensus-based will be explained. We examine the recommended checklist for reporting and appraise the tools for evaluating a practice guideline. This article is geared toward developers and reviewers of clinical practice guidelines and consensus statements.

Alternatives to Opioids in the Pharmacologic Management of Chronic Pain Syndromes: A Narrative Review of Randomized, Controlled, and Blinded Clinical Trials.

Chronic pain exerts a tremendous burden on individuals and societies. If one views chronic pain as a single disease entity, then it is the most common and costly medical condition. At present, medical professionals who treat patients in chronic pain are recommended to provide comprehensive and multidisciplinary treatments, which may include pharmacotherapy. Many providers use nonopioid medications to treat chronic pain; however, for some patients, opioid analgesics are the exclusive treatment of chronic pain. However, there is currently an epidemic of opioid use in the United States, and recent guidelines from the Centers for Disease Control (CDC) have recommended that the use of opioids for nonmalignant chronic pain be used only in certain circumstances. The goal of this review was to report the current body of evidence-based medicine gained from prospective, randomized-controlled, blinded studies on the use of nonopioid analgesics for the most common noncancer chronic pain conditions. A total of 9566 studies were obtained during literature searches, and 271 of these met inclusion for this review. Overall, while many nonopioid analgesics have been found to be effective in reducing pain for many chronic pain conditions, it is evident that the number of high-quality studies is lacking, and the effect sizes noted in many studies are not considered to be clinically significant despite statistical significance. More research is needed to determine effective and mechanism-based treatments for the chronic pain syndromes discussed in this review. Utilization of rigorous and homogeneous research methodology would likely allow for better consistency and reproducibility, which is of utmost importance in guiding evidence-based care.

Back Pain and Neuraxial Anesthesia.

The incidence of back pain after neuraxial anesthesia in the adult population is not different from that after general anesthesia. The pain is usually mild, localized in the low back, rarely radiates to the lower extremities, and has a duration of only a few days. The risk factors for development of back pain include the lithotomy position, multiple attempts at block placement, duration of surgery longer than 2.5 hours, body mass index ≥32 kg/m, and a history of back pain. However, there is no permanent worsening of preexisting back pain after neuraxial anesthesia. The back pain has been attributed to tears in the ligaments, fascia, or bone with localized bleeding; immobility of the spine; relaxation of the paraspinal muscles under anesthesia; flattening of the normal lumbar convexity; and stretching and straining of the lumbosacral ligaments and joint capsules. The addition of an anti-inflammatory drug to the local anesthetic used for skin infiltration may decrease the incidence and severity of back pain. The use of spinal or epidural anesthesia in the adult, non-obstetric and obstetric populations should depend on the advantages offered by the technique and not on the occurrence of back pain after the procedure. Additional studies are needed to confirm the efficacy of epidural dexamethasone, or other steroids, or the addition of an anti-inflammatory drug to the local anesthetic infiltration for the prevention of back pain after neuraxial anesthesia. Future studies should involve a physician with expertise in the evaluation of chronic low back pain to help identify the cause of the back pain and institute appropriate treatment(s).

Safeguards to prevent neurologic complications after epidural steroid injections: consensus opinions from a multidisciplinary working group and national organizations.

BACKGROUND: Epidural corticosteroid injections are a common treatment for radicular pain caused by intervertebral disc herniations, spinal stenosis, and other disorders. Although rare, catastrophic neurologic injuries, including stroke and spinal cord injury, have occurred with these injections. METHODS: A collaboration was undertaken between the U.S. Food and Drug Administration Safe Use Initiative, an expert multidisciplinary working group, and 13 specialty stakeholder societies. The goal of this collaboration was to review the existing evidence regarding neurologic complications associated with epidural corticosteroid injections and produce consensus procedural clinical considerations aimed at enhancing the safety of these injections. U.S. Food and Drug Administration Safe Use Initiative representatives helped convene and facilitate meetings without actively participating in the deliberations or decision-making process. RESULTS: Seventeen clinical considerations aimed at improving safety were produced by the stakeholder societies. Specific clinical considerations for performing transforaminal and interlaminar injections, including the use of nonparticulate steroid, anatomic considerations, and use of radiographic guidance are given along with the existing scientific evidence for each clinical consideration. CONCLUSION: Adherence to specific recommended practices when performing epidural corticosteroid injections should lead to a reduction in the incidence of neurologic injuries.

Neuropathic pain and pharmacological treatment.

Neuropathic pain is a serious chronic condition strongly affecting quality of life, which can be relieved but cannot be cured. Apart from symptomatic management, treatment should focus on the underlying disorder. The estimated prevalence is at least 1% to 5% of the general population. Neuropathic pain is characterized both by spontaneous and evoked pain. A diagnosis of neuropathic pain can usually be established based solely on history and neurological examination. Ancillary investigations may include EMG and computerized tomography/magnetic resonance imaging scans, depending on the localization of the suspected lesion. A limited number of agents, primarily directed at symptom control, are currently approved for use in neuropathic pain. A mechanism-based approach to pharmacological intervention supports the use of polypharmacy in neuropathic pain.

Literature review of spinal hematoma case reports: causes and outcomes in pediatric, obstetric, neuraxial and pain medicine cases.

BACKGROUND: The risk of spinal epidural hematoma (SEH) has been described in the literature but the impact in various patient populations has not been assessed in the same study. We identified the risk factors for SEH and calculated the OR for recovery in the pediatric, adult and obstetric (OB) patients based on the degree of neurological deficit before surgery. METHODS: Adult non-OB cases were categorized whether they were on anticoagulants or not; SEH was related to neuraxial or pain procedure; or whether there was adherence to the American Society of Regional Anesthesia (ASRA) guidelines. Eligible cases were identified through PubMed and Embase searches in the English literature from 1954 to July 2022. RESULTS: A total of 940 cases were evaluated. In the pediatric cases, SEH was typically spontaneous, related to coagulopathy or athletic trauma. OB cases were spontaneous or related to neuraxial injections. Among adults on anticoagulant(s), SEH was mostly spontaneous with no related etiology or related to neuraxial procedure. SEH occurred despite adherence to the ASRA guidelines. Among non-OB adults not on anticoagulants, SEH was due to trauma, neuraxial injections, surgery or other causes. Neurological recovery was related to the degree of neurological deficit before surgery. CONCLUSIONS: Our data show a preponderance of spontaneous SEH in all patient populations. SEH developed even though the ASRA guidelines were followed, especially in patients on multiple anticoagulants. Patients with less impairment prior to surgery had a higher likelihood of complete recovery, regardless of the interval between surgery and onset of symptoms.

Infectious complications following regional anesthesia: a narrative review and contemporary estimates of risk.

INTRODUCTION: Infectious complications following regional anesthesia (RA) while rare, can be devastating. The objective of this review was to estimate the risk of infectious complications following central neuraxial blocks (CNB) such as epidural anesthesia (EA), spinal anesthesia (SA) and combined spinal epidural (CSE), and peripheral nerve blocks (PNB). MATERIALS AND METHODS: A literature search was conducted in PubMed, Embase and Cochrane databases to identify reference studies reporting infectious complications in the context of RA subtypes. Both prospective and retrospective studies providing incidence of infectious complications were included for review to provide pooled estimates (with 95% CI). Additionally, we explored incidences specifically associated with spinal anesthesia, incidences of central nervous system (CNS) infections and, the incidences of overall and CNS infections following CNB in obstetric population. RESULTS: The pooled estimate of overall infectious complications following all CNB was 9/100 000 (95% CI: 5, 13/100 000). CNS infections following all CNB was estimated to be 2/100 000 (95% CI: 1, 3/100 000) and even rarer following SA (1/100 000 (95% CI: 1, 2/100 000)). Obstetric population had a lower rate of overall (1/100 000 (95% CI: 1, 3/100 000)) and CNS infections (4 per million (95% CI: 0.3, 1/100 000)) following all CNB. For PNB catheters, the reported rate of infectious complications was 1.8% (95% CI: 1.2, 2.5/100). DISCUSSION: Our review suggests that the risk of overall infectious complications following neuraxial anesthesia is very rare and the rate of CNS infections is even rarer. The infectious complications following PNB catheters seems significantly higher compared with CNB. Standardizing nomenclature and better reporting methodologies are needed for the better estimation of the infectious complications.

Use of corticosteroids for adult chronic pain interventions: sympathetic and peripheral nerve blocks, trigger point injections - guidelines from the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, the American Society of Interventional Pain Physicians, the International Pain and Spine Intervention Society, and the North American Spine Society.

BACKGROUND: There is potential for adverse events from corticosteroid injections, including increase in blood glucose, decrease in bone mineral density and suppression of the hypothalamic-pituitary axis. Published studies note that doses lower than those commonly injected provide similar benefit. METHODS: Development of the practice guideline was approved by the Board of Directors of American Society of Regional Anesthesia and Pain Medicine with several other societies agreeing to participate. The scope of guidelines was agreed on to include safety of the injection technique (landmark-guided, ultrasound or radiology-aided injections); effect of the addition of the corticosteroid on the efficacy of the injectate (local anesthetic or saline); and adverse events related to the injection. Based on preliminary discussions, it was decided to structure the topics into three separate guidelines as follows: (1) sympathetic, peripheral nerve blocks and trigger point injections; (2) joints; and (3) neuraxial, facet, sacroiliac joints and related topics (vaccine and anticoagulants). Experts were assigned topics to perform a comprehensive review of the literature and to draft statements and recommendations, which were refined and voted for consensus (≥75% agreement) using a modified Delphi process. The United States Preventive Services Task Force grading of evidence and strength of recommendation was followed. RESULTS: This guideline deals with the use and safety of corticosteroid injections for sympathetic, peripheral nerve blocks and trigger point injections for adult chronic pain conditions. All the statements and recommendations were approved by all participants after four rounds of discussion. The Practice Guidelines Committees and Board of Directors of the participating societies also approved all the statements and recommendations. The safety of some procedures, including stellate blocks, lower extremity peripheral nerve blocks and some sites of trigger point injections, is improved by imaging guidance. The addition of non-particulate corticosteroid to the local anesthetic is beneficial in cluster headaches but not in other types of headaches. Corticosteroid may provide additional benefit in transverse abdominal plane blocks and ilioinguinal/iliohypogastric nerve blocks in postherniorrhaphy pain but there is no evidence for pudendal nerve blocks. There is minimal benefit for the use of corticosteroids in trigger point injections. CONCLUSIONS: In this practice guideline, we provided recommendations on the use of corticosteroids in sympathetic blocks, peripheral nerve blocks, and trigger point injections to assist clinicians in making informed decisions.

Advances in topical analgesics.

PURPOSE OF REVIEW: The recent increase in opioid consumption in the modern world prompted pain physicians to find new and improved solutions to tackle chronic, refractory pain syndromes. Topical analgesics are emerging as a valued multimodal analgesic arm in the fight against chronic pain. RECENT FINDINGS: New and improved topical formulations have emerged as effective tools to treat chronic refractory pain. In addition to formulations manufactured by the pharmaceutical industry, there has been a recent interest in mixed topical products by local, regional and national compounding pharmacies. This review will focus on advances in topical analgesics, especially their role as an effective analgesic in nociceptive and neuropathic refractory pain states. We will explore topical analgesics' mechanisms of action and their efficacy as opioid-sparing formulations. SUMMARY: This review will allow physicians to understand the role of topical agents in the treatment of intractable pain syndromes. Increasing medical providers' familiarity with these agents will allow their incorporation as part of a complex analgesic regimen for an improved pain management plan benefiting the patient population at large.

Neuropathic pain: treatment guidelines and updates.

PURPOSE OF REVIEW: The purpose of this review is to provide an update on the diagnosis, treatment, and prevention of neuropathic pain. RECENT FINDINGS: Neuropathic pain can be debilitating, leading to poor quality of life and functional status. Neuropathic pain results from numerous mechanisms of nerve injury including infectious diseases, complication of medical diseases, and mechanical damage. As a result of the lack of class I evidence for the treatment of numerous neuropathic pain conditions, those diseases without such evidence are often managed, as though neuropathic pain is a singular condition. In diseases such as diabetes, HIV, and herpes infections, the resultant neuropathic pain is often modifiable with prevention strategies. In one of the more prevalent neuropathic pain conditions, radiculopathy, the commonly used treatments lack sufficient evidence to explain their widespread use. SUMMARY: The literature reveals that neuropathic pain is underdiagnosed and often undertreated or treated with ineffective or untested modalities. Evolving definitions of neuropathic pain has broadened the range of therapeutic approaches and brought current treatment paradigms under increased scrutiny. The lack of a mechanism-based approach to treatment may be responsible for the lackluster responses seen in most neuropathic pain conditions.