John C. Rowlingson

Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition).

The actual incidence of neurologic dysfunction resulting from hemorrhagic complications associated with neuraxial blockade is unknown. Although the incidence cited in the literature is estimated to be less than 1 in 150,000 epidural and less than 1 in 220,000 spinal anesthetics, recent epidemiologic surveys suggest that the frequency is increasing and may be as high as 1 in 3000 in some patient populations. Overall, the risk of clinically significant bleeding increase with age, associated abnormalities of the spinal cord or vertebral column, the presence of an underlying coagulopathy, difficulty during needle placement, and an indwelling neuraxial catheter during sustained anticoagulation (particularly with standard heparin or low-molecular weight heparin). The need for prompt diagnosis and intervention to optimize is also consistently reported. In response to these patient safety issues, the American Society of Regional Anesthesia and Pain Medicine (ASRA) convened its Third Consensus Conference on Regional Anesthesia and Anticoagulation. Practice guidelines or recommendations summarize evidence-based reviews. However, the rarity of spinal hematoma defies a prospective randomized study, and there is no current laboratory model. As a result, the ASRA consensus statements represent the collective experience of recognized experts in the field of neuraxial anesthesia and anticoagulation. These are based on case reports, clinical series, pharmacology, hematology, and risk factors for surgical bleeding. An understanding of the complexity of this issue is essential to patient management.

Regional anesthesia in the anticoagulated patient: Defining the risks (the second ASRA Consensus Conference on Neuraxial Anesthesia and Anticoagulation)

Neuraxial anesthesia and analgesia provide several advantages over systemic opioids, including superior analgesia, reduced blood loss and need for transfusion, decreased incidence of graft occlusion, and improved joint mobility following major knee surgery. 1-4 New challenges in the management of patients undergoing neuraxial block have arisen over the last 2 decades, as medical standards for the prevention of perioperative venous thromboembolism were established. 5,6 Concern for patient safety in the presence of potent antithrombotic drugs has resulted in avoidance of regional anesthesia. Indeed, perioperative anesthesia and analgesia are often determined by the antithrombotic agent. 7 Conversely, although the anesthesia community is well aware of the potential for spinal bleeding, other specialties have only recently become cognizant of the risk, as documented by case reports

Regional anesthesia in the anticoagulated patient: Defining the risks

umerous studies have documented the safety of neuraxial anesthesia and analgesia in the anticoagulated patient. Patient management is based on ppropriate timing of needle placement and catheter removal relative to the iming of anticoagulant drug administration. Familiarity with the pharmacology f hemostasis-altering drugs, the clinical studies involving patients undergoing euraxial blockade while receiving these medications, as well as the case reports f spinal hematoma will guide the clinician in management decisions. New challenges in the management of the anticoagulated patient undergoing euraxial blockade have arisen as medical standards for the prevention of periperative venous thromboembolism were established. Likewise, as more efficaious anticoagulants and antiplatelet agents have been introduced, patient mangement has become more complex. In response to these patient safety issues, the merican Society of Regional Anesthesia and Pain Medicine (ASRA) convened its econd Consensus Conference on Neuraxial Anesthesia and Anticoagulation. It is mportant to note that although the consensus statements are based on a thorugh evaluation of the available information, in some cases, data are sparse. ariances from recommendations contained in this document may be acceptable ased on the judgment of the responsible anesthesiologist. The consensus stateents are designed to encourage safe and quality patient care, but cannot guarntee a specific outcome. They are also subject to timely revision as justified by volution of information and practice. Finally, the current information focuses on

Epidural analgesic techniques in the management of cervical pain

The injection of depot steroids into the cervical epidural space can maximize the conservative management of patients with cervical radiculopathy. We retrospectively studied 25 patients wtih cervical radiculopathy who received a total of 45 epidural injections of steroids. Sixty-four percent of the patients had a good or excellent response to cervical epidural steroid injection, whereas other conservative treatment modalities had not helped them. The patients history and a description of the pain and the corresponding neurological abnormalities present were of value in the selection of patients who were most likely to respond favorably to epidural steroids, whereas laboratory studies were not as useful. Anesthesiologists, many already familiar with the use of epidural steroid injection in the treatment of low back pain, should add to their armamentarium the use of such techniques in the management of patients with acute and chronic cervical radiculopathy.

Epidural steroid effects on nerves and meninges.

There have been encouraging reports of symptomatic improvement in patients with low back pain following injection of a mixture of a local anesthetic and a corticosteroid into the lumbar epidural space. However, there is a lack of animal or human studies which examined possible long-term effects of this combination on the exposed neural tissues. This study evaluated by both light and electron microscopy the effect of triamcinolone diacetate in vehicle and of the vehicle itself (both in 2% lidocaine) in 48 cats after percutaneous epidural injections were done at the lumbosacral space. When the animals were killed at 30 or 120 days, specimens of the spinal root, the root exit zone, and the meninges at the level of injection and level above and below were obtained. Because all of the histologic findings were found to be mild, it is concluded that local anesthetic-steroid combinations do not cause significant damage to neural tissues.

Intravenous lidocaine is as effective as epidural bupivacaine in reducing ileus duration, hospital stay, and pain after open colon resection: a randomized clinical trial.

Background: Both postoperative epidural analgesia and intravenous (IV) infusion of local anesthetic have been shown to shorten ileus duration and hospital stay after colon surgery when compared with the use of systemic narcotics alone. However, they have not been compared directly with each other. Methods: Prospective, randomized clinical trial was conducted comparing the 2 treatments in open colon surgery patients. Before induction of general anesthesia, patients were randomized either to epidural analgesia (bupivacaine 0.125% and hydromorphone 6 &mgr;g/mL were started at 10 mL/hr within 1 hr of the end of surgery) or IV lidocaine (1 mg/min in patients <70 kg, 2 mg/min in patients ≥70 kg). Markers of return of bowel function, length of stay, postoperative pain scores, systemic analgesic requirements, and adverse events were recorded and compared between the 2 groups in an intent-to-treat analysis. Results: Study enrollment took place from April 2005 to July 2006. Twenty-two patients were randomized to IV lidocaine therapy and 20 patients to epidural therapy. No statistically significant differences were found between groups in time to return of bowel function or hospital length of stay. The median pain score difference was not statistically significant. No statistically significant differences were found in pain scores for any specific postoperative day or in analgesic consumption. Conclusions: No differences were observed between groups in terms of return of bowel function, duration of hospital stay, and postoperative pain control, suggesting that IV infusion of local anesthetic may be an effective alternative to epidural therapy in patients in whom epidural anesthesia is contraindicated or not desired.

Lidocaine as an Analgesic for Experimental Pain

The purpose of this study was to evaluate the analgesic contribution of intravenously administered lidocaine and to correlate it with blood levels of the drug. In a double-blind manner, 14 healthy male volunteers received saline solution or lidocaine, 0.2 per cent, at three increasingly greater rates of infusion on two separate days. Experimental pain was produced by means of the submaximal tourniquet-induced ischemia test of Beecher and Smith. The times to the onset of ischemic (threshold) and unbearable (tolerance) pain were recorded for three control trials to two tests for the same end points during each infusion rate. Between the two ischemic trials, while the test solution continued to be infused, venous blood samples were drawn and analyzed for lidocaine by gas chromatography. No statistically significant difference in analgesia between the control and lidocaine values for threshold or tolerance was observed at blood levels from 1 to 3 μg/ml. The data suggest that lidocaine at these blood levels produces sedation but not analgesia.

Cognitive Deficits in Chronic Pain Patients With and Without History of Head/Neck Injury: Development of a Brief Screening Battery

The incidence of cognitive deficits in chronic pain patients with a history of major or minor head/neck injury (HI) and without a history of major or minor head/neck injury (NHI) was examined. As an alternative to more costly and time-consuming assessment instruments, a brief screening battery was employed which tested for problems in concentration and attention. Based on a limited subsample, 100% accuracy was obtained in predicting deficits later confirmed by full neuropsychological testing. Results indicated significantly higher incidence of difficulties in sustained attention and rapid problemsolving ability in the HI group than in the NHI group. These difficulties are discussed in the context of recent evidence that the incidence of subtle but possibly lasting cognitive deficits is greater than had been earlier recognized with minor head trauma. Implications of the type of deficits noted, their clinical presentation, and suggestions for their detection and clinical management in chronic pain patients are discussed.

The Balans chair and its semi-kneeling position: an ergonomic comparison with the conventional sitting position.

Recently, the Balans chair has been introduced with claims that, because of its semi-kneeling position, individuals will experience decreased low-back pain (LBP) as well as improvement in circulation. This study investigated the validity of these claims. Twenty healthy subjects were randomly assigned to one of two groups. Group 1 subjects sat in the Balans chair for a 30-minute study period and then sat in a conventional office chair for an additional 30-minute period. Group 2 subjects were studied in the reverse seating order. Parameters studied were cervical and lumbar paraspinous surface EMG, and pedal cutaneous blood flow measured by laser-Doppler flowimetry. In addition, a questionnaire comparing the comfort of the two chairs was completed at the end of the study session. Comfort ratings showed an overall preference for the conventional chair. Increased cervical (P = .004) and lumbar muscle EMG measurements were noted after sitting in the Balans chair. Pedal cutaneous blood flow was increased by 15% in the Balans chair (P = .001). The data do not support the manufacturers claim that the Balans chair is likely to decrease complaints of LBP.

Publishing studies that involve "off-label" use of drugs: formalizing Regional Anesthesia and Pain Medicine's policy.

The US Food and Drug Administration (FDA) or its counterpart regulatory agencies worldwide approve the human use of drugs, biologics, and devices. Approval of drugs is granted only for those specific indications for which the agent was tested in preclinical and clinical trials. The FDA approval process includes the creation of a Blabel,[ a detailed document that specifies the indications, dosing, route of administration, and patient populations for which use of the product is approved. When a drug is used outside the indications specified on the label, its use is termed Boff-label.[ For example, fentanyl use is Bon-label[ for intravenous administration, but off-label for intrathecal administration because when fentanyl was presented to the FDA for approval, requisite studies were presented only for its intravenous, but not its intrathecal, use. For the off-label use of a drug to gain on-label status, the FDA requires that specific conditions must be met. Expanding a drug’s label to include new indications and/or routes of administration may or may not necessitate that the drug undergo additional preclinical and clinical testing to gain approval for the new indication. Any change in drug label can be sought only by a pharmaceutical company, not by an individual. From a practical standpoint, physicians knowingly or unknowingly consider a drug’s label on a daily basis. For the individual practicing physician, the absence of formal approval by the FDA does not represent a major impediment to the off-label use of any drug in actual clinical practice. Although pharmaceutical companies cannot promote or otherwise discuss with physicians the offlabel uses of their product, they may supply supporting educational information if it is directly requested by the prescriber. Importantly, the physician is free to use any drug for off-label indications as part of the practice of medicine as long as the use is based on sound clinical judgment and reasonable scientific rationale. Indeed, many, if not most, drugs in anesthesiology and pain medicine are used in an off-label manner; the FDA recognizes that such use is permissible and typically within the standard of care. For example, we administer fentanyl into the intrathecal space, perform spinal anesthesia with 0.5% bupivacaine labeled Bnot for spinal use,[ and use gabapentin as part of our multimodal analgesia regimenVall well-accepted practices, but all explicitly off-label. Would you be just as comfortable with a less widely accepted practice, such as admixing dexamethasone to prolong peripheral nerve local anesthetic blockade or adding midazolam to increase the duration of spinal anesthesia based on our current evidence? Do you, in fact, know whether these off-label uses were preceded by adequate preclinical and clinical neurotoxicity testing? Would you feel any better if you had read a small human study that concluded the drug used in this manner was Bsafe and efficacious,[ but which made no mention of neurotoxicity studies or the lack thereof? All drugs have the potential to cause toxicity. Sometimes, serious toxicity becomes apparent in preliminary animal studies, sometimes in early clinical trials, and occasionally only after widespread clinical use of the drug. Thus, case reports and small-scale clinical studies cannot be relied on to establish a drug’s safety. NeurotoxicityVthe potential for a drug to injure a peripheral nerve or the spinal cordVis a serious concern in regional anesthesia and pain medicine. What then should be a journal’s responsibility to publish an otherwise scientifically sound study if it involves the off-label use of a potentially neurotoxic drug, even if that drug has been approved for other uses for decades? If the journal publishes the study, even with an accompanying editorial that addresses the implications for patient safety, is not the journal effectively blessing a new clinical indication for the drug? Furthermore, if the study was approved by the investigator’s institutional review board (IRB) or research ethics committee, is it ethical for the journal to withhold the study’s results from the EDITORIAL