Michael F. Mulroy

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

ASRA practice advisory on local anesthetic systemic toxicity.

The American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity assimilates and summarizes current knowledge regarding the prevention, diagnosis, and treatment of this potentially fatal complication. It offers evidence-based and/or expert opinion-based recommendations for all physicians and advanced practitioners who routinely administer local anesthetics in potentially toxic doses. The advisory does not address issues related to local anesthetic-related neurotoxicity, allergy, or methemoglobinemia. Recommendations are based primarily on animal and human experimental trials, case series, and case reports. When objective evidence is lacking or incomplete, recommendations are supplemented by expert opinion from the Practice Advisory Panel plus input from other experts, medical specialty groups, and open forum. Specific recommendations are offered for the prevention, diagnosis, and treatment of local anesthetic systemic toxicity.

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

Systemic toxicity and cardiotoxicity from local anesthetics: Incidence and preventive measures

Central nervous system toxicity from unintentionally high blood levels has been a significant concern and risk with local anesthetics since their discovery. Cardiotoxicity associated with toxic blood levels of long-acting local anesthetics1 has heightened concern about systemic blood levels in the last 20 years. This review will discuss the apparent incidence of systemic toxicity, the situations in which it occurs, some of the other risks of regional anesthesia, and appropriate safety steps to reduce the frequency of both systemic reactions and cardiotoxicity.

Fentanyl Prolongs Lidocaine Spinal Anesthesia Without Prolonging Recovery

Lidocaine spinal anesthesia is a popular anesthetic for short procedures due to its brief duration.The addition of fentanyl may improve the quality and duration of lidocaine spinal anesthesia. Eight volunteers received plain lidocaine 5% in dextrose (50 mg) both with and without 20 micro gram of fentanyl in a randomized, double-blind, cross-over fashion. Sensory analgesia was assessed with pinprick, cold, touch, transcutaneous electrical stimulation equivalent to surgical incision, and duration of tolerance of pneumatic thigh tourniquet. Motor block was assessed with isometric force dynamometry. Regression of pinprick, touch, and cold was prolonged with fentanyl. Duration of tolerance of electrical stimulation at the umbilicus, hip, knee, and ankle was increased with fentanyl (181% increase from plain lidocaine on average; P < 0.01). Duration of tolerance of tourniquet-induced pain was increased by an average of 48% with addition of fentanyl (P = 0.02). Neither motor block nor time to void was prolonged with fentanyl. Pruritus occurred in all subjects receiving fentanyl but was treated easily and were well tolerated. We recommend the addition of 20 micro gram of fentanyl to lidocaine spinal anesthesia as a means to improve duration of sensory anesthesia without prolonging recovery of motor function or time to micturition. (Anesth Analg 1995;80:730-4)

Ambulatory surgery patients may be discharged before Voiding after short-acting spinal and epidural anesthesia

Background Voiding before discharge is usually required after outpatient epidural or spinal anesthesia because of concern about bladder overdistention and dysfunction. Shorter duration spinal and epidural anesthesia may allow return of bladder function before overdistention occurs in low-risk patients (those younger than age 70, not having hernia, rectal, or urologic surgery, and without a history of voiding difficulty), and predischarge voiding may not be necessary. Methods After institutional review board approval and informed consent, 201 low-risk ambulatory patients were prospectively studied in either a standard or accelerated pathway after undergoing spinal or epidural anesthesia with procaine, lidocaine, 2-chloroprocaine, or less than 7 mg bupivacaine; epinephrine was not used in any anesthetic. Standard pathway patients (n = 70) were required to void before discharge. Accelerated pathway (n = 131) patients were not required to void. (After randomization of an initial 163 patients to one of the two tracks, 38 additional patients were assigned to the accelerated pathway.) If accelerated pathway patients voided, they were discharged when all other discharge criteria were met. If they did not spontaneously void after block resolution, a bladder ultrasound (BUS) was performed. If the BUS indicated a urine volume of less than 400 ml, the patients were discharged and instructed to return to the emergency department if they were unable to void within 8 h of discharge. If the BUS indicated a urine volume of greater than 400 ml, the patients were reassessed in 1 h and were discharged if they could void spontaneously. If they could not void spontaneously, they were catheterized to facilitate discharge. All patients were contacted the next day to assess the return of normal bladder function. Results All standard pathway patients voided without difficulty, and were discharged in 153 ± 49 (SD) min. 62 patients in the accelerated pathway voided spontaneously after resolution of their block and were discharged in 127 ± 41 min. 46 patients were discharged with a BUS less than 400 ml in 120 ± 42 min. 23 patients had a BUS greater than 400 ml: of these, 20 patients voided within an hour and were discharged in 162 ± 45 min. Three were catheterized after 1 h, and were discharged in 186 ± 61 min. Mean discharge time for all patients in the accelerated pathway was 22 min shorter than the standard pathway (P = 0.002). No patients had difficulty voiding or returned to the hospital for urinary problems. None reported new urologic symptoms. Conclusions Delay of discharge after outpatient spinal or epidural anesthesia with short-duration drugs for low-risk procedures is not necessary, and may result in prolonged discharge times.

The Effect of Single-Injection Femoral Nerve Block Versus Continuous Femoral Nerve Block After Total Knee Arthroplasty on Hospital Length of Stay and Long-Term Functional Recovery Within an Established Clinical Pathway

Total knee arthroplasty (TKA) may result in severe pain, and single-injection femoral nerve blocks (SFNB) have been demonstrated to have a limited duration of analgesia. Continuous femoral nerve blocks (CFNB) can prolong the analgesic duration of SFNB. We prospectively randomized 36 patients undergoing TKA to CFNB versus SFNB and evaluated the effect on hospital length of stay (LOS) as the primary outcome within a standardized clinical pathway. Secondary outcomes included visual analog scale (VAS) pain scores, opioid consumption, and long-term functional recovery at 12 wk. Mean VAS resting scores were significantly lower among patients who received CFNB versus SFNB: first day (1.7 vs 3.3 [P = 0.002]) and second day (0.9 vs 3.2 [P < 0.0001]) after surgery. Mean maximal VAS scores during physical therapy were significantly lower among patients who received CFNB versus SFNB: first day (4.7 vs 6.3 [P = 0.01]) and second day (3.9 vs 6.1 [P = 0.0005]) after surgery. Mean oxycodone consumption was significantly lower among patients who received CFNB versus SFNB: 15 mg versus 40 mg (P = < 0.0001) on the first day after surgery; 20 mg versus 43 mg (P = 0.0004) on the second day after surgery. There was no difference in hospital LOS (3.8 vs 3.9 days) or long-term functional recovery (117° versus 113° knee flexion at 12 wk) between the two groups. The lack of effect provided by increased duration of analgesia (from CFNB) after TKA may now have minimal impact on hospital LOS and long-term functional recovery in the contemporary healthcare environment within the United States.

A comparison of spinal, epidural, and general anesthesia for outpatient knee arthroscopy.

We compared general, epidural, and spinal anesthesia for outpatient knee arthroscopy (excluding anterior cruciate ligament repairs). Forty-eight patients (ASA physical status I–III) were randomized to receive either propofol-nitrous oxide general anesthesia with a laryngeal mask airway with anesthetic depth titrated to a bispectral index level of 40–60, 15–20 mL of 3% 2-chloroprocaine epidural, or 75 mg of subarachnoid procaine with 20 &mgr;g fentanyl. All patients were premedicated with <0.035 mg/kg midazolam and <1 &mgr;g/kg fentanyl and received intraarticular bupivacaine and 15–30 mg of IV ketorolac during the procedure. Recovery times, operating room turnover times, and patient satisfaction were recorded by an observer using an objective scale for recovery assessment and a verbal rating scale for satisfaction. Statistical analysis was performed with analysis of variance and &khgr;2. Postanesthesia care unit discharge times for the general and epidural groups were similar (general = 104 ± 31 min, epidural = 92 ± 18 min), whereas the spinal group had a longer recovery time (146 ± 52 min) (P = 0.0003). Patient satisfaction was equally good in all three groups (P = 0.34). Room turnover times did not differ among groups (P = 0.16). There were no anesthetic failures or serious adverse events in any group. Pruritus was more frequent in the spinal group (7 of 16 required treatment) than in the general or epidural groups (no pruritus) (P < 0.001). We conclude that epidural anesthesia with 2-chloroprocaine provides comparable recovery and discharge times to general anesthesia provided with propofol and nitrous oxide. Spinal anesthesia with procaine and fentanyl is an effective alternative and is associated with a longer discharge time and increased side effects. Implications For outpatient knee arthroscopy, anesthesia can be provided adequately with regional or general anesthesia. Epidural and general anesthesia provide equal recovery times and patient satisfaction, whereas spinal anesthesia may prolong recovery and have increased side effects. The choice of anesthesia may depend primarily on the patient’s interest in being alert or asleep during the procedure.

American Society of Regional Anesthesia and Pain Medicine Checklist for Managing Local Anesthetic Systemic Toxicity: 2012 Version

Abstract In 2010, the American Society of Regional Anesthesia and Pain Medicine (ASRA) issued a practice advisory on local anesthetic systemic toxicity (LAST). The executive summary of this work contained a document that was intended to serve as a checklist for the management of LAST. Based on testing the checklist during a simulated episode of LAST, ASRA has issued an updated version that should replace the previous 2010 version. Electronic copies of the ASRA Checklist, suitable for lamination and inclusion in a local anesthetic toxicity kit, are available from the ASRA Web site (www.asra.com).