Regional Anesthesia Complications and Contraindications.

Regional anesthesia has a strong role in minimizing post-operative pain, decreasing narcotic use and PONV, and, therefore, speeding discharge times. However, as with any procedure, regional anesthesia has both benefits and risks. It is important to identify the complications and contraindications related to regional anesthesia, which patient populations are at highest risk, and how to mitigate those risks to the greatest extent possible. Overall, significant complications secondary to regional anesthesia remain low. While a variety of different regional anesthesia techniques exist, complications tend to fall within 4 broad categories: block failure, bleeding/hematoma, neurological injury, and local anesthetic toxicity.

Local Anesthetics, Local Anesthetic Systemic Toxicity (LAST), and Liposomal Bupivacaine.

Local anesthetics have played a vital role in the multimodal analgesia approach to patient care by decreasing the use of perioperative opioids, enhancing patient satisfaction, decreasing the incidence of postoperative nausea and vomiting, decreasing the length of hospital stay, and reducing the risk of chronic postsurgical pain. The opioid-reduced anesthetic management for perioperative analgesia has been largely successful with the use of local anesthetics during procedures such as peripheral nerve blocks and neuraxial analgesia. It is important that practitioners who use local anesthetics are aware of the risk factors, presentation, and management of local anesthetic systemic toxicity (LAST).

Local Anesthetic Systemic Toxicity (LAST): More Common Than You Think.

The number of anesthetic body procedures in the United States is rapidly increasing, with many being performed on an outpatient basis. These procedures are advertised as being safe, and many times the serious complications may not be discussed. Although local anesthetic systemic toxicity is a rare complication, it is associated with an increase in morbidity. The emergency department staff should be aware of the possibility of this rare complication, as well as the variety of resulting symptoms (from minor to severe), potential sequelae, and appropriate management for patients who have undergone an outpatient anesthetic body procedure. Multiple factors contribute to the development of local anesthetic systemic toxicity, resulting in life-threatening effects on the neurologic and cardiovascular systems. Also, the site of administration, along with the local anesthetic agent used, can impact the risk of the development of local anesthetic systemic toxicity. To minimize the risk and ensure the best possible outcome for these patients, emergency department staff must be highly aware of the mechanisms, risk factors, prevention, and management/treatment of local anesthetic systemic toxicity.

Local Anesthetic Systemic Toxicity in Cardiac Surgery Patient with Erector Spinae Plane Catheter: A Case Report.

Regional anesthesia nerve blocks are increasingly used for patients undergoing cardiac surgery as part of multimodal pain management. Though rare, local anesthetic systemic toxicity (LAST) is a severe complication that requires vigilant monitoring. We present a case of a postcardiac surgery patient who developed LAST multiple days after surgery from lidocaine via an erector spinae plane catheter. This episode was determined to be a result of impaired lidocaine metabolism from liver shock caused by worsening pulmonary hypertension. Even under continuous monitoring, patients with cardiac or liver dysfunction are at increased risk of complications from local anesthetics.

Using part of the initial analgesic dose as the epidural test dose did not delay the onset of labor analgesia: a randomized controlled clinical trial.

BACKGROUND: Epidural test dose for labor analgesia is controversial and varies widely in clinical practice. It is currently unclear whether using a portion of the initial dose for analgesia as the test dose delays the onset time of analgesia, compared to the traditional test dose. METHODS: One hundred and twenty-six parturients who chose epidural analgesia during labor were randomly assigned to two groups. The first dose in group L was 3 ml 1.5% lidocaine, and in the RF group was 10 ml 0.1% ropivacaine combined with 2 µg/ml fentanyl. After 3 min of observation, both groups received 8 ml 0.1% ropivacaine combined with 2 µg/ml fentanyl. The onset time of analgesia, motor and sensory blockade level, numerical pain rating scale, patient satisfaction score, and side effects were recorded. RESULTS: The onset time of analgesia in group RF was similar to that in group L (group RF vs group L, 7.0 [5.0-9.0] minutes vs 8.0 [5.0-11.0] minutes, p = 0.197). The incidence of foot numbness (group RF vs group L, 34.9% vs 57.1%, p = 0.020) and foot warming (group RF vs group L, 15.9% vs 47.6%, p < 0.001) in group RF was significantly lower than that in group L. There was no difference between the two groups on other outcomes. CONCLUSIONS: Compared with 1.5% lidocaine 3 ml, 0.1% ropivacaine 10 ml combined with 2 µg/ml fentanyl as an epidural test dose did not delay the onset of labor analgesia, and the side effects were slightly reduced. CLINICAL TRIAL REGISTRATION: http://www.chictr.org.cn (ChiCTR2100043071).

Lipid emulsion treatment for local anesthetic systemic toxicity in pediatric patients: A systematic review.

BACKGROUND: Local anesthetic systemic toxicity (LAST) is rare, but fatal; the current widely used treatment is lipid emulsion (LE). The goal of this study was to analyze and review case reports on LE treatment for LAST in pediatric patients. METHODS: We performed a systematic review using case reports on LE treatment for LAST in pediatric patients, searching PubMed and Scopus databases to March 2023 using the following keywords: ("local anesthetic toxicity" OR "local anesthetic systemic toxicity" OR LAST") AND ("newborn" OR "infant" OR "child" OR "children" OR "adolescent" OR "pediatric") AND ("lipid emulsion" OR "Intralipid"). RESULTS: Our search yielded 21 cases, revealing that nearly 43% patients with LAST were less than 1 year old, and most cases were caused by bupivacaine (approximately 67% cases). "Inadvertent intravascular injection" by anesthesiologists and "overdose of local anesthetics" mainly by surgeons were responsible for 52% and 24% cases of LAST, respectively. LAST occurred in the awake state (52%) and under general anesthesia (48%), mainly causing seizures and arrhythmia, respectively. Approximately 55% of patients received LE treatment in <10 minutes after LAST, mainly improving cardiovascular symptoms. A 20% LE (1.5 mL/kg) dose followed by 0.25 mL/kg/minutes dose was frequently used. LE and anticonvulsants were mainly used in the awake state, whereas LE with or without vasopressors was mainly used under general anesthesia. LE treatment led to full recovery from LAST in 20 cases; however, 1 patient died due to underlying disease. CONCLUSION: Consequently, our findings reveal that LE is effective in treating pediatric LAST.

Dose safety and pharmacodynamics of subcutaneous bupivacaine in a novel extended-release microparticle formulation: A phase 1, dose-ascending study in male volunteers.

A novel microparticle-based extended-release local anaesthetic containing a bupivacaine/poly-lactic-co-glycolic acid (PLGA; LIQ865A) or plain bupivacaine (LIQ865B) was examined in a first-in-human trial. The objectives were to examine the dose safety/tolerability and pharmacodynamics. Randomized subcutaneous injections of LIQ865A (n = 16) or LIQ865B (n = 12) and diluent, contralaterally, were administered in a dose-ascending manner (150- to 600-mg bupivacaine). Subjects were admitted 24 h post-injection and followed for 30 days post-injection. The risk ratios (RRs; 95% CI) of erythematous reactions for LIQ865A versus diluent was 9.00 (1.81-52.23; P = 0.006) and for LIQ865B versus diluent 2.50 (0.69-9.94; P = 0.37). The RR for the development of hematomas (LIQ865A versus diluent) were 3.25 (1.52-8.16; P = 0.004) and 4.00 (0.72-24.89; P = 0.32) (LIQ865B versus diluent). Subcutaneous indurations persisting for 4-13 weeks were seen in 6/16 subjects receiving LIQ865A. One subject receiving LIQ865A (600-mg bupivacaine) developed intermittent central nervous system (CNS) symptoms of local anaesthetic systemic toxicity (85 min to 51 h post-injection) coinciding with plasma peak bupivacaine concentrations (490-533 ng/ml). Both LIQ865 formulations demonstrated dose-dependent hypoesthesia and hypoalgesia. The duration of analgesia ranged between 37 and 86 h. The overall number of local adverse events, however, prohibits clinical application without further pharmacological modifications.

Complications and side effects of Wide-Awake Local Anaesthesia No Tourniquet (WALANT) in upper limb surgery: a systematic review and meta-analysis.

PURPOSE: Wide-Awake Local Anaesthesia No Tourniquet (WALANT), a groundbreaking anaesthetic technique resurging in practice, warrants a comprehensive safety analysis for informed adoption. Our study aimed to identify complications/side effects of WALANT upper limb procedures through a systematic review and meta-analysis. METHODS: This PROSPERO-registered study was performed with strict adherence to PRISMA guidelines. Embase, OVIDMedline, Cochrane, Web of Science, and Scopus databases were searched until February 2023. Inclusion criteria involved English articles, reporting complications/side effects in primary WALANT upper limb surgeries. Outcomes included all complications and side effects, data on the anaesthetic mixture, publication year/location, study type, and procedures performed. The meta-analysis employed the Freeman-Tukey Double Arcsine Transformation, computed I2 statistics, and utilized common or random effects models for pooled analysis. RESULTS: 2002 studies were identified; 79 studies met the inclusion criteria representing 15,595 WALANT patients. A total of 301 patients had complications, and the meta-analysis using a random effects model provided a complication rate of 1.7% (95% CI: 0.93-2.7%). The most reported complications were superficial infection (41%, n = 123/300), other/specified (12%, n = 37/300), and recurrent disease (6.7%, n = 20/300). A decade-by-decade analysis revealed no statistically significant difference in complication rates spanning the last three decades (p = 0.42). Adding sodium bicarbonate to the anaesthetic solution significantly reduced postoperative complications (p = 0.025). CONCLUSION: WALANT has a low overall complication rate of 1.7%, with no significant temporal variation and a significant reduction in complications when sodium bicarbonate is added to the anaesthetic solution. Our findings support the safety of WALANT in upper limb procedures. REGISTRATION: PROSPERO: CRD42023404018.

Efficacy and safety of ketamine as an adjuvant to regional anesthesia: A systematic review and meta-analysis of randomized controlled trials.

STUDY OBJECTIVE: To identify whether adding ketamine to the local anesthetics (LA) in the regional anesthesia could prolong the duration of analgesia. DESIGN: A Systematic review and meta-analysis of randomized controlled trials. SETTING: The major dates were obtained in the operating room and the postoperative recovery ward. PATIENTS: A total of 1011 patients at ASA physical status I and II were included in the analysis. Procedure performed including cesarean section, orthopedic, radical mastectomy, urological or lower abdominal surgery and intracavitary brachytherapy implants insertion. INTERVENTIONS: After an extensive search of the electronic database, patients received regional anesthesia combined or not combined general anesthesia and with or without adding ketamine to LA were included in the analysis. The regional anesthesia includes spinal anesthesia, brachial plexus block, pectoral nerve block, transversus abdominis plane block and femoral and sciatic nerve block. MEASUREMENT: The primary outcome was the duration of analgesia. Secondary outcomes were the duration and onset time of motor and sensory block as well as the ketamine-related adverse effect. Data are expressed in mean differences in continuous data and odds ratios (OR) for dichotomous data with 95% confidence intervals. The risk of bias of the included studies was evaluated using the revised Cochrane risk of bias tool for randomized trials. The quality of evidence for each outcome was rated according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) Working Group system. MAIN RESULT: Twenty randomized controlled trials were included in the analysis. When ketamine was used as an adjuvant to LA, the duration of analgesia could be prolonged(172.21 min, 95% CI, 118.20 to 226.22; P<0.00001, I2 = 98%), especially in the peripheral nerve block(366.96 min, 95% CI, 154.19 to 579.74; P = 0.0007, I2 = 98%). Secondary outcomes showed ketamine could prolong the duration of sensory block(29.12 min, 95% CI, 10.22 to 48.01; P = 0.003, I2 = 96%) but no effect on the motor block(6.94 min, 95% CI,-2.65 to 16.53;P = 0.16, I2 = 84%), the onset time of motor and sensory block (motor onset time, -1.17 min, 95% CI, -2.67 to 0.34; P = 0.13, I2 = 100%; sensory onset time, -0.33 min, 95% CI,-0.87 to 0.20; P = 0.23, I2 = 96%) as well as the ketamine-related adverse effect(OR, 1.97, 95% CI,0.93 to 4.17;P = 0.08, I2 = 57%). CONCLUSION: This study indicates that ketamine could be an ideal adjuvant to local anesthetics regardless of the types of anesthesia. Overall, the quality of the evidence is low.

[Principles of the pharmacology of local anesthetics]. / Grundlagen der Pharmakologie von Lokalanästhetika.

The development of local anesthetics revolutionized the performance of painful interventions. Local anesthetics have an effect on voltage-gated sodium channels in nerve fibers and modulate the conduction of impulses. With respect to the chemical structure, local anesthetics can be divided into amide and ester types. The structural differences of local anesthetics have an influence on the duration of action, the degradation pathways and specific side effects. Severe adverse events include cardiotoxicity and neurotoxicity. In addition to basic measures, such as the monitoring and securing of vital parameters, lipid infusion represents a treatment option in cases of intoxication. The recent developments of local anesthetics are particularly concerned with the reduction of toxicity and prolonging the duration of action.

Local anesthetics allergy in children: Evaluation of diagnostic tests with Real-Life data.

BACKGROUND: Local anesthetic (LA) drugs are commonly used in clinical practice to provide effective analgesia, including in dentistry and minor surgical procedures. The perception of a high risk of allergy in daily applications leads to the referral of atopic patients and those with other drug allergies to allergy clinics for the evaluation of allergic reactions to LA. The aim of this study was to determine who should be referred to the allergy clinic for LA allergy testing, assess the frequency of LA allergy in pediatric patients, and identify the negative predictive value of skin tests in diagnosis. METHODS: January 2017-July 2023, the clinical and laboratory data, as well as the results of drug allergy tests, of patients referred to our pediatric allergy clinic by dentists and physicians performing minor surgical procedures with suspected LA allergy were retrospectively evaluated. RESULTS: Our study included a total of 153 patients, comprising 84 girls (54.9%) and 69 boys (45.1%), with a mean age of 8.9 (±3.3) years. The most common reason for referral was a history of non-LA drug allergies (n = 66, 43.2%), followed by asthma (n = 25, 16.3%). Hypersensitivity reactions (HRs) with LA were most commonly associated with articaine (n = 7, 4.8%), followed by lidocaine (n = 6, 4.1%). When intradermal tests were evaluated, 17 patients (11.1%) had a positive test result. The positivity for lidocaine was 70.6% (n = 12), and prilocaine was 29.4% (n = 5). Subcutaneous provocation was administered to 109 patients (71.2%), and one patient exhibited local erythema and swelling with prilocaine. CONCLUSION: Although LA allergy is a rare occurrence, consultations of this nature are frequently requested from allergy clinics in real life. Considering the negative predictive value of skin tests performed with LA drugs, the reaction rate appears to be low in patients with atopy or other drug allergies. It is crucial for all relevant healthcare professionals to be knowledgeable about the appropriate approach to suspected LA allergies to avoid unnecessary tests. To the best of our knowledge, our study is the most comprehensive work in the literature that evaluates the results of diagnostic tests in children referred with a suspicion of LA allergy.

Safety and Complications of Landmark-based Paravertebral Blocks: A Retrospective Analysis of 979 Patients and 4983 Injections.

OBJECTIVE: This study aimed to determine the incidence of complications after landmark-based paravertebral blocks for breast surgery. METHODS: The medical records of patients who received a paravertebral block for breast surgery between 2019 and 2022 were reviewed. Patient age, sex, type of procedure, number of injections, volume of injected anesthetic, and possible complications were noted. A record was identified as a possible serious block-related complication if there was concern or treatment for local anesthetic systemic toxicity, pneumothorax, altered mental status, or intrathecal/epidural spread. Other complications recorded were immediate postblock hypotension and nausea/vomiting requiring treatment and unanticipated postsurgical admission. Patients receiving ultrasound-guided paravertebral blocks were excluded from this study. RESULTS: Over a 3-year period, 979 patients received paravertebral blocks using the landmark technique for breast surgery, totaling 4983 injections. Overall, 6 patients required assessment for postblock issues (0.61%), including hypotension (2 patients), nausea (3 patients), and hypotension + altered mental status (1 patient). This latter patient was identified as having a serious complication related to the paravertebral block (0.1%). This patient had unintentional intrathecal spread and altered mental status that required mechanical ventilation. The incidence of block-related hypotension and nausea requiring treatment was thus 0.31% and 0.31% respectively. Four patients required unanticipated admission, but none were for block-related reasons. No patients in this study were found to have local anesthetic systemic toxicity or pneumothorax. CONCLUSION: Our study suggests that landmark-based paravertebral blocks for breast surgery result in a very low complication rate and are a safe technique for postsurgical analgesia.

Efficacy and safety of epidural block with lidocaine for refractory severe plaque psoriasis: An open-label pilot study in real world setting.

Epidural block using lidocaine, a non-selective blocker of voltage-gated sodium channels (Nav), has demonstrated efficacy in the treatment of severe plaque psoriasis in a limited number of cases. This study aimed to evaluate the effectiveness and safety of epidural lidocaine block in adult patients with severe, treatment-resistant plaque psoriasis. This was an open-label pilot study. Patients with severe plaque-type psoriasis unresponsive to at least one systemic treatment were enrolled for a 1-week epidural lidocaine block and followed up for 48 weeks. Thirty-six patients participated, with 32 completing the study. At the 12-week mark, there was a remarkable 59% improvement in the mean Psoriasis Area Severity Index (PASI) score (P < 0.001). By week 48, 28 out of 32 patients (87%) achieved PASI 75, while 18 out of 32 (56%) reached PASI 90. Within 7 days, 20 out of 21 patients (95%) reported a reduction in itch, with a mean itch reduction of 82% at day 1 and 94% at day 7. Notably, no severe side effects were observed. Epidural lidocaine block proved to be an effective and safe long-term treatment option for individuals with refractory severe plaque psoriasis.

Intravenous lipid emulsion for local anaesthetic systemic toxicity in pregnant women: a scoping review.

BACKGROUND: Local anaesthetic systemic toxicity (LAST) is a rare but life-threatening complication that can occur after local anaesthetic administration. Various clinical guidelines recommend an intravenous lipid emulsion as a treatment for local anaesthetic-induced cardiac arrest. However, its therapeutic application in pregnant patients has not yet been established. This scoping review aims to systematically identify and map the evidence on the efficacy and safety of intravenous lipid emulsion for treating LAST during pregnancy. METHOD: We searched electronic databases (Medline, Embase and Cochrane Central Register Controlled Trials) and a clinical registry (lipidrescue.org) from inception to Sep 30, 2022. No restriction was placed on the year of publication or the language. We included any study design containing primary data on obstetric patients with signs and symptoms of LAST. RESULTS: After eliminating duplicates, we screened 8,370 titles and abstracts, retrieving 41 full-text articles. We identified 22 women who developed LAST during pregnancy and childbirth, all presented as case reports or series. The most frequent causes of LAST were drug overdose and intravascular migration of the epidural catheter followed by wrong-route drug errors (i.e. intravenous anaesthetic administration). Of the 15 women who received lipid emulsions, all survived and none sustained lasting neurological or cardiovascular damage related to LAST. No adverse events or side effects following intravenous lipid emulsion administration were reported in mothers or neonates. Five of the seven women who did not receive lipid emulsions survived; however, the other two died. CONCLUSION: Studies on the efficacy and safety of lipids in pregnancy are scarce. Further studies with appropriate comparison groups are needed to provide more robust evidence. It will also be necessary to accumulate data-including adverse events-to enable clinicians to conduct risk-benefit analyses of lipids and to facilitate evidence-based decision-making for clinical practice.

Efficacy of intraoperative systemic lidocaine on quality of recovery after laparoscopic colorectal surgery: a randomized controlled trial.

INTRODUCTION: Many clinical trials have demonstrated the benefits of intraoperative systemic lidocaine administration in major abdominal surgeries. We tested the hypothesis that systemic lidocaine is associated with an enhanced early quality of recovery in patients following laparoscopic colorectal resection. PATIENTS AND METHODS: We randomly allocated 126 patients scheduled for laparoscopic colorectal surgery in a 1:1 ratio to receive either lidocaine (1.5 mg kg-1 bolus over 10 min, followed by continuous infusion at 2 mg kg-1 h-1 until the end of surgery) or identical volumes and rates of saline. The primary outcome was the Quality of Recovery-15 score assessed 24 h after surgery. Secondary outcomes were areas under the pain numeric rating scale curve over time, 48-h morphine consumption, and adverse events. RESULTS: Compared with saline, systemic lidocaine improved the Quality of Recovery-15 score 24 h postoperatively, with a median difference of 4 (95% confidence interval: 1-6; p = 0.015). Similarly, the area under the pain numeric rating scale curve over 48 h at rest and on movement was reduced in the lidocaine group (p = 0.004 and p < 0.001, respectively). However, these differences were not clinically meaningful. Lidocaine infusion reduced the intraoperative remifentanil requirements but not postoperative 48-h morphine consumption (p < 0.001 and p = 0.34, respectively). Additionally, patients receiving lidocaine had a quicker and earlier return of bowel function, as indicated by a shorter time to first flatus (log-rank p < 0.001), yet ambulation time was similar between groups (log-rank test, p = 0.11). CONCLUSIONS: In patients undergoing laparoscopic colorectal surgery, intraoperative systemic lidocaine resulted in statistically but not clinically significant improvements in quality of recovery (see Graphical Abstract).Trial registration: Chinese Clinical Trial Registry; ChiCTR1900027635.

Systemic lidocaine failed to clinically improve the overall quality of recovery following laparoscopic colorectal resection.Systemic lidocaine reduced intraoperative remifentanil and time to first flatus but not postoperative 48-h morphine consumption.No differences emerged in patient-reported outcomes like opioid side effects, mobility, or satisfaction between groups postoperatively.