Challenges in Differentiating Fat Embolism Syndrome and Local Anesthetic Toxicity: A Case Report

Local anaesthetic systemic toxicity

Local anesthetic systemic toxicity (LAST) is a rare but potentially life-threatening complication associated with the use of local anesthetics. Prompt recognition and effective management are critical to preventing severe outcomes. However, studies have shown that healthcare workers' knowledge regarding LAST remains limited, especially in surgical settings where local anesthetics are frequently used. This study is to assess the current state and associated factors of knowledge regarding LAST among healthcare workers in the surgical departments of a hospital under the Ho Chi Minh City Department of Health. A cross-sectional study was conducted from April 2024 to May 2025, involving 260 healthcare workers across 11 clinical departments. Data were collected using a structured, self-administered questionnaire developed based on national guidelines for LAST diagnosis and management. Nearly half of the participants (48.8%, 127/260) reported having prescribed or administered local anesthetics. Among those with direct experience using local anesthetics, lidocaine was the most commonly used agent (88.2%, 112/127). The majority of participants (81.9%, 213/260) correctly recognized that local anesthetic systemic toxicity (LAST) may occur even when local anesthetics are administered within recommended dosage ranges. However, only 22.3% (58/260) perceived themselves as knowledgeable about LAST. Regarding lipid emulsion therapy, 33.8% (88/260) reported having heard of 20% lipid emulsion therapy, whereas 43.9% (114/260) had never heard of this intervention. The most frequently identified early signs of LAST were tachycardia (64.6%, 168/260) and hypertension (34.2%, 89/260). Healthcare workers in surgical departments demonstrated insufficient knowledge regarding local anesthetic toxicity, particularly in recognizing early symptoms and understanding the use of lipid emulsion therapy as a treatment strategy. Targeted training programs are warranted to enhance competency in LAST management and improve patient safety.

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. 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"). 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. Consequently, our findings reveal that LE is effective in treating pediatric LAST.

Background:Local anesthetics are widely used by non-anesthesiologists to provide analgesia. Penile nerve blocks are used for analgesia during urological surgery. Local anesthetic systemic toxicity (LAST), which is rare but likely fatal, is often caused by a penile nerve block. However, there has been no analysis of cases of LAST induced by a penile nerve block. This Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review aimed to analyze case reports involving LAST induced by a penile nerve block, with a particular focus on the presumed causes, local anesthetics, and lipid emulsion treatment.Methods:Relevant case reports included in PubMed from inception to December 31, 2024, were retrieved using the keywords “penile nerve block,” “dorsal penile nerve block,” “penile block,” “local anesthetic toxicity,” “local anesthetic systemic toxicity,” and “local anesthetic overdose.”Results:Eleven case reports including 19 patients were obtained. The main presumed causes of penile nerve block-induced LAST were overdose (47.4%) and inadvertent intravascular absorption (47.4%) of local anesthetics. The main local anesthetics associated with overdose and inadvertent intravascular absorption were lidocaine (77.8%) and bupivacaine (88.9%), respectively. Of the patients, 89.5% had risk factors for LAST. Of the patients with LAST, 31.6% received lipid emulsion plus supportive treatment. The age distribution of patients with penile nerve block-induced LAST was as follows: <1 year (73.7%), ≥1 year to <19 years (15.8%), and ≥19 years (10.5%). A penile nerve block was used for circumcision in 84.2% of the cases. The most common symptoms of penile nerve block-induced LAST were cardiovascular symptoms (52.6%) and central nervous system symptoms (42.1%). The negative aspiration technique was used to prevent LAST in 47.4% of patients. All patients recovered from LAST.Conclusion:LAST in infants and neonates receiving a penile nerve block for circumcision is mainly caused by lidocaine overdose or inadvertent intravascular absorption of bupivacaine. The following measures should be considered to prevent LAST: adherence to the maximum recommended dose of local anesthetics; awareness of LAST risk factors; slow injection of the local anesthetic with minimal pressure and negative aspiration; and lipid emulsion preparation.

ESRA19-0693 Paediatric regional anaesthesia and last

This article provides a concise overview of local anesthetic systemic toxicity, its history, mechanisms, risk factors, prevention, clinical presentation, and treatment, with a special emphasis on issues specific to the geriatric population. The authors used MEDLINE, Scopus, and Google Scholar to search for original research articles (human and animal studies), registries data, case reports, review articles, and pertinent online publications using the combinations of the following search terms: local anesthetics, local anesthetic systemic toxicity, intralipid, lipid emulsion, Exparel, ultrasound-guidance, regional anesthesia, lidocaine, bupivacaine, ropivacaine, cocaine, procaine, tetracaine, levobupivacaine, liposomal bupivacaine, lignocaine. Local anesthetic systemic toxicity continues to occur despite the use of putatively less cardiotoxic formulations of local anesthetics and more common use of ultrasound guidance. The elderly appear to be at a disproportionately increased risk for toxicity owing to the presence of relevant comorbidities and decreased muscle mass. Examination of recent case reports involving patients over the age of 65years demonstrates that inadvertent overdosing is responsible for some cases of local anesthetic systemic toxicity. Elderly patients are at increased risk of local anesthetic systemic toxicity. When considering use of local anesthetics in older patients, special attention should be paid to the presence of systemic disease and muscle wasting. The safety of regional anesthesia and multi-modal analgesia among these at-risk patients will be improved by educating physicians and staff to recognize and manage local anesthetic systemic toxicity.

Background and objectives: Local anesthetic systemic toxicity (LAST) in children is extremely rare, occurring at an estimated rate of 0.76 cases per 10,000 procedures. However, among reported cases of LAST in the pediatric population, infants and neonates represent approximately 54% of reported LAST cases. We aim to present and discuss the clinical case of LAST with full clinical recovery due to accidental levobupivacaine intravenous infusion in a healthy 1.5-month-old patient, resulting in cardiac arrest necessitating resuscitation. Case presentation: A 4-kilogram, 1.5-month-old female infant, ASA I, presented to the hospital for elective herniorrhaphy surgery. Combined anesthesia was planned, involving general endotracheal and caudal anesthesia. After anesthesia induction, cardiovascular collapse was noticed, resulting in bradycardia and later cardiac arrest with EMD (Electromechanical Dissociation). It was noticed that during induction, levobupivacaine was accidentally infused intravenously. A local anesthetic was prepared for caudal anesthesia. LET (lipid emulsion therapy) was started immediately. Cardiopulmonary resuscitation was carried out according to the EMD algorithm, which lasted 12 min until spontaneous circulation was confirmed and the patient was transferred to the ICU. In ICU, the girl was extubated the second day, and the third day she was transferred to the regular pediatric unit. Finally, the patient was discharged home after a total of five days of hospitalization with full clinical recovery. A four-week follow-up has revealed that the patient recovered without any neurological or cardiac sequelae. Conclusions: The clinical presentation of LAST in children usually begins with cardiovascular symptoms because pediatric patients are already under general anesthesia when anesthetics are being used, as was the case in our case. Treatment and management of LAST involve cessation of local anesthetic infusion, stabilization of the airway, breathing, and hemodynamics, as well as lipid emulsion therapy. Early recognition of LAST as well as immediate CPR if needed and targeted treatment for LAST can lead to good outcomes.

Objective: to assess comprehension of local anaesthetic systemic toxicity among clinical practitioners.&#x0D; Study Design: Cross-sectional study.&#x0D; Place and Duration of Study: Tertiary Care Institute, from Dec 2019 to Mar 2020.&#x0D; Methodology: Methodology constituted of a web-based questionnaire. A pilot study carried out at 15-20 participants forquestionnaire validation and reviewed by independent experts for face validity, a final questionnaire comprised of 10 multiple-choice questions in addition to demographic profile.&#x0D; Results: A total of 950 participants participated in the study and data was extracted from their responses. Out of 738 (77.8%) participants declared that they are unaware of local anaesthetic systemic toxicity complication, 26 (2.7%) encountered local anaesthetic systemic toxicity and 185 (19.5%) never experienced. Ninety (9.5%) were aware of the availability and utilization of 'Lipid Emulsion' therapy to treat ‘Local Anaesthetic Systemic Toxicity’ (LAST).&#x0D; Conclusion: Although clinicians have significant awareness level regarding local anaesthetic toxicity but unfortunately compliance with management of this life-threatening complication is deficient.

With increases in use of regional anesthesia, local anesthetic systemic toxicity (LAST) has been a topic of interest and debate. Despite many years of research, the exact cause and best treatment of LAST (particularly local anesthetic cardiotoxicity) remain unclear. This review will summarize what is known and what remains uncertain about LAST and its treatment, including information published in the past 12-18 months. Several authorities, including the American Society of Regional Anesthesia and Pain Medicine, have published guidelines on prevention and treatment of LAST. Experimental data continue to add to better understanding of LAST and its treatment. The data are not entirely consistent, but themes include continued evidence to support the ideas that LAST cardiotoxicity occurs primarily at sodium channels, lipid emulsion is a reasonably well tolerated and effective treatment, and there may be qualitative differences in cardiotoxicity caused by low and high-potency local anesthetics. Regarding mechanism(s) of LAST, the evidence remains mixed, but it is likely that local anesthetic cardiotoxicity primarily arises from a blockade of sodium channels. As for treatment, in addition to ventilation, oxygenation, and chest compressions, lipid emulsion therapy should be a primary element in the treatment of cardiovascular LAST. The use of epinephrine and vasopressin should be tailored to specifics of an episode of LAST, and doses should be kept as low as possible while still achieving the desired effects.

Local anesthetic systemic toxicity in the pediatric patient.

With the increased utilization of regional anesthesia as part of a multimodal analgesic regimen in enhanced recovery after surgery protocols, the pain practitioner must be aware of the diagnosis and management of local anesthetic systemic toxicity (LAST). The mainstay of treatment for LAST is the administration of intravenous lipid emulsion (ILE) therapy, which is provided as an initial bolus followed by an infusion. ILE works by several mechanisms, which include both a redistribution of local anesthetic from areas of toxicity to areas of metabolism and direct cardiotonic and vasoactive effects. LAST differs from other advanced cardiac life support (ACLS) scenarios as resuscitation is often prolonged, and several common code medications such as epinephrine and vasopressin should have dose reductions or be omitted entirely. The American Society of Regional Anesthesia and Pain Medicine (ASRA) maintains a checklist for the treatment of LAST, last updated in 2017. The checklist describes the diagnosis and management of suspected LAST, several risk-reducing measures to prevent LAST, and a proposed LAST rescue kit that should be readily available whenever local anesthetic is used.

Enthusiasm for regional anesthesia has been driven by multimodal benefits to patient outcomes. Despite widespread awareness and improved techniques (including the increasing use of ultrasound guidance for block placement), intravascular sequestration and the attendant risk of local anesthetic systemic toxicity (LAST) remains. Intravenous lipid emulsion (ILE) for the treatment of LAST has been endorsed by anesthetic regulatory societies on the basis of animal study and human case report data. The accumulated mass of reporting now permits objective interrogation of published literature. Although incompletely elucidated the mechanism of action for ILE in LAST seemingly involves beneficial effects on initial drug distribution (i.e., pharmacokinetic effects) and positive cardiotonic and vasoactive effects (i.e., pharmacokinetic effects) acting in concert. Recent systematic review by collaborating international toxicologic societies have provided reserved endorsement for ILE in bupivacaine-induced toxicity, weak support for ILE use in toxicity from other local anesthetics, and largely neutral recommendation for all other drug poisonings. Work since publication of these recommendations has concluded that there is a positive effect on survival for ILE when animal models of LAST are meta-analyzed and evidence of a positive pharmacokinetic effect for lipid in human models of LAST. Lipid emulsion remains first-line therapy (in conjunction with standard resuscitative measures) in LAST. Increasing conjecture as to the clinical efficacy of ILE in LAST, however, calls for high-quality human data to refine clinical recommendations.

Intravenous lipid emulsion (ILE; Intralipid) therapy, a standard treatment in local anesthetic toxicity, has demonstrated therapeutic efficacies for a number of different drug class-mediated toxicities. Some of these varied drug groups include antipsychotics, antidepressants, antiarrhythmics, and calcium channel blockers. To meet the objective of describing the growing number of indications for Intralipid therapy and any diverse effects and/or failures of Intralipid therapy in reversing multiple drug toxicities, we queried several Internet search engines with the key words "intravenous lipid emulsion therapy," "Intralipid," "lipid emulsion," and "local anesthetic systemic toxicity," resulting in the identification of 31 case reports for descriptive analysis. These case reports included 49 separate drug overdose cases involving ten separate drug classes which were successfully reversed with Intralipid. The education of clinicians regarding the beneficial and varied roles of Intralipid therapy in different clinical settings is warranted, particularly in terms of the potential for Intralipid therapy to reverse the toxicities of non-local anesthetic drugs.

The practice of regional anesthesia has been revitalized of late with the popularization of ultrasound-guided techniques. Advocates must be vigilant for the effects of unintentionally high blood levels of local anesthetic. Systemic local anesthetic toxicity, though rare, is a potentially devastating occurrence. This narrative review summarizes the effects of local anesthetic toxicity. We highlight how these toxic effects have motivated the search for a safe and long-acting local anesthetic. We outline current prevention and treatment options and appraise an emerging therapy in light of unfolding evidence. A search of the English language literature was conducted using the PubMed database from the National Library of Medicine. Bibliographies of retrieved articles were used to retrieve additional articles. The advent of multiple safety steps has led to a dramatic reduction in the incidence of local anesthetic toxicity over the past 30 years. Rising plasma levels of local anesthetic lead to a progressive spectrum of neurological and cardiac effects. Seizure activity may herald the onset of myocardial depression and ventricular arrhythmias that are often refractory to treatment. In addition to specific measures, such as lipid emulsion therapy, general supportive measures are warranted, for example, Advanced Life Support Guidelines. Vigilance during the performance of regional anesthesia and immediate intervention at the earliest sign of toxicity improve the chances of successful treatment.

Local anesthetic systemic toxicity is a systemic adverse reaction to the administration of a local anesthetic. Children are at particular risk for local anesthetic systemic toxicity given their smaller body weight. In cases of cardiac arrest from local anesthetic systemic toxicity, prolonged chest compressions or extracardiac membrane oxygenation may be indicated because cardiac toxicity may last for several hours. Under general anesthesia, some of the early central nervous system signs of local anesthetic systemic toxicity, such as altered consciousness and seizures, may be masked, and the first indicator of local anesthetic systemic toxicity may be hemodynamic instability or cardiac arrest. Nevertheless, in a multicenter database of more than 100,000 consecutive pediatric regional anesthetics, local anesthetic systemic toxicity did not occur more often in pediatric patients undergoing regional anesthesia under general anesthesia compared with patients undergoing regional anesthesia awake or under sedation, and was overall very rare (2.2/10,000 and 15.2/10,000, respectively). In cases of cardiac arrest from local anesthetic systemic toxicity, prolonged chest compressions or extracardiac membrane oxygenation (ECMO) may be required because toxicity may last for several hours or more. Aggressive resuscitation and early administration of intralipid are the most important steps.