Clinical Presentation of Local Anesthetic Systemic Toxicity: A Review of Published Cases, 1979 to 2009

Approach to Altered Mental Status in Pregnancy and Postpartum

The evaluation and diagnosis of altered mental status in the pregnant or postpartum patient largely parallels the approach used for any other patient; however, there are several critical differences including that some neuroobstetric diagnoses require emergent delivery of the fetus. Being familiar with the physiological changes and medical complications of pregnancy and delivery is therefore essential. This review first addresses pregnancy-specific disorders that may result in altered mental status, such as the hypertensive disorders of pregnancy and pregnancy-related metabolic and endocrinopathies. The focus then shifts to the complex physiologic changes in pregnancy and how these changes contribute to the distinct epidemiology of pregnancy-related cerebrovascular complications like intracranial hemorrhage, ischemic stroke, and reversible cerebral vasoconstriction syndrome. Medical disorders that are not unique to pregnancy, such as infections and autoimmune conditions, may present de novo or worsen during pregnancy and the peripartum period and require a thoughtful approach to diagnosis and management. Finally, the unique nervous system complications of obstetric anesthesia are explored. In each section, there is a focus not only on diagnosis and syndrome recognition but also on the emergent treatment needed to reverse these complications, bearing in mind the unique physiology of the pregnant patient.

Serum Levels of Bupivacaine After Bilateral Ultrasound-Guided Deep Parasternal Intercostal Plane Block in Cardiac Surgery with Median Sternotomy

OBJECTIVE

To evaluate systemic levels of bupivacaine after bilateral ultrasound-guided deep parasternal intercostal plan (PIP) block in cardiac surgical patients undergoing median sternotomy.

DESIGN

Prospective, observational study SETTING: Single institution; academic university hospital PARTICIPANTS: Twenty-eight adult patients undergoing cardiac surgery with median sternotomy received a PIP block with 2.5 mg/kg bupivacaine with or without dexamethasone and dexmedetomidine.

MEASUREMENTS

Arterial blood samples were analyzed for total serum bupivacaine concentration at 5, 15, 30, 45, 60, 90, 120, and 150 minutes after placement of PIP. Local anesthetic volume, local anesthetic adjuncts, time to extubation, postoperative pain scores, and opioid consumption were recorded.

MAIN RESULTS

The mean peak bupivacaine concentration was 0.60 ± 0.62 µg/mL, and the mean time to maximum concentration (Tmax) was 16.92 ± 12.97 minutes. Two patients (7.1%) had a concentration >2.0 µg/mL within 15 minutes of block placement. The mean Tmax of bupivacaine was significantly greater in patients who did not receive additives compared to those patients who did (22.86 ± 14.77 minutes v 10.0 ± 5.22 minutes; p = .004). The times to extubation and postoperative pain were not improved with additives.

CONCLUSIONS

Bilateral PIP placed at the end of cardiac surgery resulted in low systemic bupivacaine levels. The inclusion of additives shortened Tmax without improving outcome.

Efficacy, Safety, and Pharmacokinetics of CPL-01, an Investigational Long-Acting Ropivacaine, in Bunionectomy: Results of a Phase 2b Study

CPL-01 (ropivacaine extended-release injection) is formulated to safely provide postoperative analgesia and reduce opioid use. Participants undergoing unilateral distal first metatarsal bunionectomy with osteotomy were randomized to receive either CPL-01 (200 mg in Cohort 1, 300 mg in Cohort 2), ropivacaine HCl (50 mg in Cohort 1, 75 mg in Cohort 2), or volume-matched placebo into the surgical site prior to closure. Participants remained in an inpatient setting for 72 hours to assess efficacy (Numeric Rating Scale [NRS] scores for pain with activity adjusted for opioid usage and rescue medication usage), safety and pharmacokinetics. Seventy-three participants were randomized and treated, and 71 participants completed the study. Participants who received 300 mg CPL-01 had a mean (SD) area under the curve from 0 to 72 hours (AUC0-72) of the NRS score with activity of 356.9 (132.82), which was lower than placebo, indicating less pain. Participants who received CPL-01 300 mg also had numerically lower mean total opioid consumption. CPL-01 was safe and well-tolerated, with no evidence of increased AEs in one group versus another. Infiltration of CPL-01 had no impact on wound or bone healing. CPL-01 showed predictable and consistent extended-release pharmacokinetics, with no indication of "dose-dumping." Ropivacaine HCl delivered 94.3-99.7% of its ropivacaine dose in the first 24 hours, the 300 mg CPL-01 dose delivered 38.5%. While this Phase 2b study was small, results demonstrated the safety, efficacy, and extended-release characteristics of this long-acting ropivacaine formulation in this surgical model, supporting further development of CPL-01 in Phase 3 clinical studies.

Local Anesthetic Systemic Toxicity in Pregnancy: A Retrospective Cohort Analysis

Introduction Local anesthetic systemic toxicity (LAST) is a rare complication of regional anesthesia. Pregnancy is a risk factor due to gestational physiologic changes. Labor and disorders of pregnancy can mask or delay symptoms of LAST, slowing appropriate intervention. This study examines LAST within a larger cohort and identifies features that help distinguish LAST in pregnant women from LAST in nonpregnant patients. Methods The TriNetX database was used to compare pregnant and nonpregnant patients with LAST from 2013 to 2023. Cohorts were matched on age, race, obesity status, diabetes, metabolic disorders, local anesthetic type, and cardiovascular, liver, kidney, and respiratory disease. Outcomes included prodromal symptoms of LAST and symptoms of cardiac and central nervous system excitation and depression. Results Matching occurred for 276 pregnant and 276 nonpregnant patients. Pregnant cohorts had a significantly higher risk of cardiac depression (risk ratio (RR)=1.96 (95% confidence interval (CI): 1.44-2.66), p<0.01) and significantly lower risk of cardiac excitation (RR=0.38 (95% CI: 0.22-0.63), p<0.01), prodromal symptoms (RR=0.17 (95% CI: 0.09-0.33), p<0.01), central nervous system excitation (RR=0.44 (95% CI: 0.21-0.90), p=0.02), and central nervous system depression (RR=0.24 (95% CI: 0.13-0.48), p<0.01) than nonpregnant cohorts. Conclusion Pregnant patients with LAST were more likely to exhibit cardiac depression and less likely to manifest prodromal symptoms, cardiac excitation, and central nervous system excitation and depression than nonpregnant patients. Physiological changes during pregnancy and prompt detection and treatment may explain these differences. These findings highlight the variable nature of LAST and how pregnancy may influence its clinical presentation.

CPL-01, an investigational long-acting ropivacaine, demonstrates safety and efficacy in open inguinal hernia repair

BACKGROUND

There is an unmet medical need for effective nonopioid analgesics that can decrease pain while reducing systemic opioid use. CPL-01, an extended-release injectable formulation of ropivacaine, is designed to safely provide analgesia and reduce or eliminate opioid use in the postoperative period.

METHODS

Subjects undergoing open inguinal hernia with mesh were prospectively randomized to 1 of 3 doses of CPL-01 (10, 20, or 30 ml of 2% CPL-01, n = 14, 12, and 14, respectively), Naropin (150 mg, n = 40), or saline placebo (n = 13) infiltrated into the surgical site prior to closure. Pain and rescue medication usage was assessed, and Numeric Rating Scale (NRS) pain scores were adjusted for opioid usage using windowed worst observation carried forward (wWOCF) imputation. The primary efficacy endpoint was the mean area under the curve (AUC) of the NRS pain intensity scores with activity.

RESULTS

Ninety-three subjects were treated, and 91 subjects completed 72 h of post-operative monitoring. Subjects who received the highest dose of CPL-01 in Cohort 3 showed a clinically meaningful reduction in postoperative pain intensity scores, which was the lowest value for any treatment in all cohorts, showing a trend towards statistical significance as compared to the pooled placebo group (p = 0.08), and numerically better than the 40 subjects who received Naropin. Opioid use through 72 h in subjects who received CPL-01 in Cohort 3 was approximately half of that shown in the placebo and Naropin groups; approximately 2/3 of the CPL-01 subjects (9/14) required no opioids at all through the first 72 h after the operation. More CPL-01 subjects avoided severe pain and were ready for discharge earlier than other groups. CPL-01 was safe and well-tolerated, with no clinically meaningful safety signals, and showed predictable and consistent extended-release pharmacokinetics.

CONCLUSION

Results suggest that CPL-01 may be the first long-acting ropivacaine to address postoperative pain while reducing the need for opioids.

Lidocaine-Associated CNS Toxicity at Therapeutic Dosage: A Case Report and Literature Review

Lidocaine is a commonly used anesthetic. High doses or intravenous administration of lidocaine, as well as other local anesthetics, may result in systemic effects involving the cardiovascular and neurologic systems. Typically, effects are dependent on the serum concentrations of the offending agent. This is a case where a patient presented with symptoms of systemic lidocaine toxicity despite therapeutic dosage and an undetectable serum lidocaine concentration. A 47-year-old Caucasian male received a lumbar medial branch injection of lidocaine and presented with symptoms of perioral numbness, seizure-like activity, and confusion. The patient had a workup, including a CT head without acute findings and an undetectable serum lidocaine level. Due to symptoms consistent with systemic local anesthetic toxicity, intravenous lipid emulsion (ILE) was administered with resolution and without recurrence of symptoms. There should be a low threshold of suspicion for local anesthetic systemic toxicity when patients have neurologic or cardiovascular symptoms following exposure. Toxicity may be present despite therapeutic dosages and low serum concentrations. ILE may be beneficial and should be considered.

Local anesthetic dosing and toxicity of adult truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Anesthesiologists frequently use truncal catheters for postoperative pain control but with limited characterization of dosing and toxicity.

OBJECTIVE

We reviewed the published literature to characterize local anesthetic dosing and toxicity of paravertebral and transversus abdominis plane catheters in adults.

EVIDENCE REVIEW

We searched the literature for bupivacaine or ropivacaine infusions in the paravertebral or transversus abdominis space in humans dosed for 24 hours. We evaluated bolus dosing, infusion dosing and cumulative 24-hour dosing in adults. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 121 and 108 papers for ropivacaine and bupivacaine respectively with a total of 6802 patients. For ropivacaine and bupivacaine, respectively, bolus dose was 1.4 mg/kg (95% CI 0.4 to 3.0, n=2978) and 1.0 mg/kg (95% CI 0.18 to 2.1, n=2724); infusion dose was 0.26 mg/kg/hour (95% CI 0.06 to 0.63, n=3579) and 0.2 mg/kg/hour (95% CI 0.06 to 0.5, n=3199); 24-hour dose was 7.75 mg/kg (95% CI 2.1 to 15.7, n=3579) and 6.0 mg/kg (95% CI 2.1 to 13.6, n=3223). Twenty-four hour doses exceeded the package insert recommended upper limit in 28% (range: 17%-40% based on maximum and minimum patient weights) of ropivacaine infusions and 51% (range: 45%-71%) of bupivacaine infusions. Toxicity occurred in 30 patients and was associated with high 24-hour dose, bilateral catheters, cardiac surgery, cytochrome P-450 inhibitors and hypoalbuminemia.

CONCLUSION

Practitioners frequently administer ropivacaine and bupivacaine above the package insert limits, at doses associated with toxicity. Patient safety would benefit from more specific recommendations to limit excessive dose and risk of toxicity.

[Principles of the pharmacology of local anesthetics]

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.

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.

Local anesthetic dosing and toxicity of pediatric truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Despite over 30 years of use by pediatric anesthesiologists, standardized dosing rates, dosing characteristics, and cases of toxicity of truncal nerve catheters are poorly described.

OBJECTIVE

We reviewed the literature to characterize dosing and toxicity of paravertebral and transversus abdominis plane catheters in children (less than 18 years).

EVIDENCE REVIEW

We searched for reports of ropivacaine or bupivacaine infusions in the paravertebral and transversus abdominis space intended for 24 hours or more of use in pediatric patients. We evaluated bolus dosing, infusion dosing, and cumulative 24-hour dosing in patients over and under 6 months. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 46 papers with 945 patients.Bolus dosing was 2.5 mg/kg (median, range 0.6-5.0; n=466) and 1.25 mg/kg (median, range 0.5-2.5; n=294) for ropivacaine and bupivacaine, respectively. Infusion dosing was 0.5 mg/kg/hour (median, range 0.2-0.68; n=521) and 0.33 mg/kg/hour (median, range 0.1-1.0; n=423) for ropivacaine and bupivacaine, respectively, consistent with a dose equivalence of 1.5:1.0. A single case of toxicity was reported, and pharmacokinetic studies reported at least five cases with serum levels above the toxic threshold.

CONCLUSIONS

Bolus doses of bupivacaine and ropivacaine frequently comport with expert recommendations. Infusions in patients under 6 months used doses associated with toxicity and toxicity occurred at a rate consistent with single-shot blocks. Pediatric patients would benefit from specific recommendations about ropivacaine and bupivacaine dosing, including age-based dosing, breakthrough dosing, and intermittent bolus dosing.

Neurological Complications of Local Anesthesia in Dentistry: A Review

Local anesthesia is a technique that temporarily desensitizes a specific body area, typically for a surgical procedure, dental work, or pain management. It is described as a sensation loss in a specific area of the body due to depression of excitation in the nerve endings or due to the inhibition of the conduction process within the peripheral nerves. It allows for safer and more comfortable medical procedures, reducing the need for general anesthesia and facilitating faster recovery. Local anesthesia is generally safe, but like any medical intervention, it carries potential risks and side effects. The complications related to local anesthetics can be assessed in terms of neurological, vascular, local, systemic, and neurological. In this review article, we discussed the neurological complications of local anesthesia related to the ophthalmic nerve, maxillary nerve, mandibular nerve, branches of the trigeminal nerve, and facial nerve. These include diplopia, ptosis, paralysis of the eye, blindness, paresthesia, trismus, soft tissue lesions, edema, hematoma, facial blanching, infection, allergy, overdose, neuralgia, facial palsy, etc.

Adverse Outcomes in Topical Lidocaine Exposure: A Pediatric Case Series From the United States National Poison Data System

To examine the clinical outcomes of topical lidocaine exposures in pediatric patients reported to the National Poison Data System (NPDS). We performed a retrospective review of the NPDS in pediatric patients with topical lidocaine toxicity from 2000 to 2020. Specific data analyzed were age, exposure chronicity, medical outcome, clinical effects, treatments, and disposition. Narrative case records were requested from poison centers. Of 37 cases identified, mean age was 5 years with age distribution of 1- to 0 days (n = 8), 1 to 24 months (n = 11), and 2-18 years (n = 18). Exposure chronicity was acute in 33 (89.2%) or chronic in 4 (10.8%). Moderate effects were seen in 25 (67.6%), major effects in 10 (27%), and 2 deaths (5.4%). The most common clinical effects included cyanosis (29.7%), seizures (18.9%), central nervous systems (CNS) depression (13.5%), drowsiness/lethargy (13.5%), and tachycardia (10.8%). The most common treatments were dilution/irrigation (35.1%), intravenous (IV) fluids (29.7%), oxygen (29.7%), methylene blue (27%), benzodiazepines (13.5%), and intubation (10.8%). Non-intensive care unit (ICU) disposition occurred for 23 patients (62.2%) and ICU admission for 14 (37.8%). Case details were requested for 37 cases, 16 cases (43.2%) were provided. Of the 2 deaths, 1 had significant cardiac history. The most common use of topical lidocaine was at home prior to a dermatologic procedure (37.5%). Topical lidocaine can induce serious outcomes resulting in ICU level care or death; however, moderate/major effects were well tolerated without comorbidities. Most patients discharged home. Given frequent use of topical, especially in outpatient settings, greater vigilance should be taken with prescriptions, instructions for use, and anticipatory guidance.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

[Principles of the pharmacology of local anesthetics]

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 systemic toxicity in children: analysis of the French pharmacovigilance database

PURPOSE

To characterize clinical profile of pediatric local anesthetic (LA) systemic toxicity (LAST) and to identify determinants of life-threatening outcomes.

METHODS

Spontaneous reports notified to the French Pharmacovigilance Network were retrieved and followed by a case-by-case review, according to the following criteria: LA as suspected drug, age < 18 years, adverse drug reactions related to nervous system, cardiac, respiratory, psychiatric or general disorders. Multivariate logistic regression analysis was performed to identify factors leading to life-threatening reaction (i.e. continuous seizures or cardiorespiratory arrest).

RESULTS

Among 512 cases retrieved, 64 LAST cases were included (neonates 11%, infants 30%, children 36%, adolescents 23%) mainly involving lidocaine (47%), lidocaine + prilocaine (22%) and ropivacaine (14%). Toxicity profiles were neurological (58%), cardiac (11%) or mixed (20%) and 7 patients (11%) developed methemoglobinemia. LAST was life-threatening for 23 patients (36%) and 2 patients died. Doses were above recommendations in 26 patients (41%) and were not different between life-threatening and non-life-threatening cases. The context of use (general and orthopedic surgery, p = 0.006) and the type of LA agent (lidocaine, p = 0.016) were independently associated with a life-threatening outcome.

CONCLUSION

In this national retrospective analysis, LAST in children appear to be a rare event. Neurological and cardiac signs were the most frequently reported reactions. LAST in children can be life-threatening, even at therapeutic doses. Although a fatal outcome may anecdotally occur, the vast majority of patients recovered after appropriate medical care.

Lipid emulsion for xenobiotic overdose: PRO

Infusion of lipid emulsion for drug overdose arose as a treatment for local anaesthetic systemic toxicity (LAST) initially based on laboratory results in animal models with the subsequent support of favourable case reports. Following successful translation to the clinic, practitioners also incorporated lipid emulsion as a treatment for non-local anaesthetic toxicities but without formal clinical trials. Recent clinical trials demonstrate a benefit of lipid emulsion in antipsychotic, pesticide, metoprolol and tramadol overdoses. Formal trials of lipid emulsion in LAST may never occur, but alternative analytic tools indicate strong support for its efficacy in this indication; for example, lipid emulsion has obviated the need for cardiopulmonary bypass in most cases of LAST. Herein, we describe the pre-clinical support for lipid emulsion, evaluate the most recent clinical studies of lipid emulsion for toxicity, identify a possible dose-based requirement for efficacy and discuss the limitations to uncontrolled studies in the field.

Ultrasound-Guided Paravenous Saphenous Nerve Block for Lower Extremity Abscess Incision and Drainage in a Male Adolescent

ABSTRACT

The use of ultrasound-guided regional anesthesia is growing as a modality for analgesia provision within the pediatric emergency department. We present a case in which a paravenous saphenous nerve block was used for anesthesia during incision and drainage of a lower extremity abscess. We further review the technique and literature concerning this straightforward and effective procedure.

[Forensic medical assessment of lidocaine and bupivacaine systemic toxicity]

THE AIM OF THE STUDY

Was to assess the lidocaine and bupivacaine systemic toxicity in forensic medical practice. The number of patients' clinical observations equal three with local anesthetic systemic toxicity (LAST) from the practice of forensic medical experts were studied, and a search of scientific publications for the last 5 years in PubMed database was conducted. The amount of publications, describing cases with LAST, equal four were selected. Differential diagnostic features between LAST and anaphylaxis were considered. The literature data about relationship between lidocaine's concentration in the blood serum and clinical features are shown. The forensic medical assessment of LAST is proposed.

Enhanced Recovery After Aesthetic Breast Surgery Under Sedation, Intercostal Block and Tumescent Anaesthesia: A Prospective Cohort Study of the Early Postoperative Phase

BACKGROUND

Comfort and recovery are major concerns of patients seeking aesthetic surgery. This study aimed to assess postoperative pain and recovery after outpatient breast surgery under sedation, intercostal block, and local anaesthesia.

METHODS

This prospective cohort study included all consecutive patients who underwent aesthetic breast surgery between April 2021 and August 2022. Epidemiological data, anaesthesia, pain, and patients' satisfaction were systematically assessed with standardized self-assessment questionnaires.

RESULTS

Altogether, 48 patients [median (IQR) age: 30 (36-25)] were included. The most frequent surgery was mastopexy. 69% of surgeries involved additional procedures. The mean intercostal block and local anaesthesia time was 15 min. Patients received a median (IQR) of 19 (34-2) mg/kg lidocaine and 2.3 (2.5-2.0) mg/kg ropivacaine. The median (IQR) consumption of propofol and alfentanil was, respectively, 4.89 (5.48-4.26) mg/kg/h and 0.27 (0.39-0.19) µg/kg/min. No conversion to general anaesthesia or unplanned hospital admission occurred. Patients were discharged after a median (IQR) of 2:40 (3:43-1:58) hours. Within the first 24 postoperative hours, 17% required once an antiemetic medication and 38% an opioid. Patients were very satisfied with the anaesthesia and 90% of the patients had not wished more analgesia in the first 24 h.

CONCLUSIONS

Aesthetic breast surgery under sedation, intercostal block, and tumescent anaesthesia can safely be performed as an ambulatory procedure and is associated with minimal intra- and postoperative opioid consumption and high patient satisfaction. These data may be used to inform patients and clinicians and improve the overall quality of care.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Perioperative intravenous lidocaine use in children

Perioperative pain management impacts patient morbidity, quality of life, and hospitalization cost. In children, it impacts not only the child, but the whole family. Adjuncts for improved perioperative analgesia continue to be sought to minimize adverse side effects associated with opioids and for those in whom regional or neuraxial anesthesia is not suitable. The use of ketamine and alpha agonists may be useful in these settings but have noted adverse effects including hallucinations, hemodynamic instability, and excessive sedation. One alternative is intravenous lidocaine. Despite its off-label use, intravenous lidocaine has demonstrated anti-neuropathic, anti-hyperalgesic, and anti-inflammatory actions and is an emerging technique. Multiple studies in adults have demonstrated beneficial effects of perioperative intravenous lidocaine including improved perioperative analgesia with reduced postoperative opioid use, improved gastrointestinal function, earlier mobilization, and reduction in hospital length of stay. Despite the limited pediatric literature, some of these findings have been replicated. Large-scale trials providing evidence for the pediatric pharmacokinetics and high-quality safety data with respect to intravenous lidocaine are still however lacking. To date, dose ranges studied in the pediatric population have not been associated with serious side effects and current data suggests perioperative intravenous lidocaine in a subgroup of pediatric surgical patients seems well-tolerated and beneficial.

A Myriad of Symptoms After Spinal Anesthesia: A Case Report of Local Anesthetic Systemic Toxicity

Local anesthetics are widely used by various medical professionals. Although their usefulness is unquestionable, as with any medication, there is a possibility of iatrogenic effects. When local anesthetic systemic toxicity occurs, it might be a life-threatening condition. Knowing its existence and how to act when it arises is crucial. The clinical presentation is wide-ranging, but globally it affects the neurological and cardiovascular system, with cardiac arrest being the extreme of its presentation. The treatment is mainly supportive with an attempt to reverse the effects of the anesthetic by administering a lipid emulsion. Here, we present a clinical case of difficult management with many complications.

Plasma bupivacaine levels (total and free/unbound) during epidural infusion in liver resection patients: a prospective, observational study

INTRODUCTION

Liver resection patients may be at an increased risk of local anesthetic (LA) toxicity because the liver is essential for metabolizing LA and producing proteins (mainly α1-acid glycoprotein (AAG)) that bind to it and reduce the free (and pharmacologically active/toxic) levels in circulation. The liver resection itself, manipulation during surgery, and pre-existing liver disease may all interfere with normal hepatic protein synthesis and result in an attenuation of the increased AAG (a positive acute-phase protein) that normally occurs postoperatively. The purpose of this study was to determine whether the AAG response is attenuated postoperatively following liver resection and whether patients approach toxicity thresholds with continuous postoperative epidural infusion of bupivacaine.

METHODS

Prospective, observational study with blood drawn preoperatively, in the postanesthetic care unit, on postoperative day (POD) 2, and prior to discontinuation of epidural analgesia on POD3/POD4. Plasma was analyzed for total and unbound bupivacaine via liquid chromatography-mass spectrometry and AAG via ELISA. Signs/symptoms of local anesthetic systemic toxicity (LAST), pain, and sedation scores were also recorded.

RESULTS

For the 19 patients completed, total plasma bupivacaine was correlated with total administered, but unbound levels were not associated with the total administered. Unlike non-hepatectomy surgery where unbound LA plasma levels remain stable (or decrease) with continuous postoperative epidural administration, we observed an overall increase. Several patients approached toxicity thresholds and 47% reported at least one symptom of LAST, but no epidurals were discontinued because of LAST. In contrast to the AAG response reported following major non-liver surgery where AAG levels increase twofold, we observed a reduction until POD2 and the magnitude was proportional to resection weight.

DISCUSSION

Our results are supported by the literature in suggesting that major liver resection patients may be at an increased vulnerability for LAST. Factors such as the extent of liver disease, resection and intraoperative blood loss should be considered when using continuous postoperative epidural infusion of bupivacaine and vigilance should be used in monitoring, for signs/symptoms of LAST, even for those subtle and non-specific. Future research will be required to verify these findings.

TRIAL REGISTRATION NUMBER

NCT03145805.

Local Anesthesia in Interventional Radiology

Interventional radiology is an evolving field that treats a variety of diseases. Local anesthetics is an important component of pain management during interventional radiologic procedures. It is highly effective and generally safe for routine procedures. However, local anesthetics can be associated with painful initial injection, allergic reactions, and rare but potentially devastating systemic toxicities. Recent evidence has shown that buffered solution and warm local anesthetics may reduce injection discomfort and improve clinical efficacy. Sensible safety practices and prompt recognition/treatment of the systemic toxicity are of paramount importance to provide safe local anesthesia. Interventional radiologists should be familiar with the basic pharmacology, common local anesthetics, optimizing strategies, complications, and management to provide safe and effective local anesthesia for patients.

Local anesthetic systemic toxicity: A narrative review for emergency clinicians

INTRODUCTION

Emergency clinicians utilize local anesthetics for a variety of procedures in the emergency department (ED) setting. Local anesthetic systemic toxicity (LAST) is a potentially deadly complication.

OBJECTIVE

This narrative review provides emergency clinicians with the most current evidence regarding the pathophysiology, evaluation, and management of patients with LAST.

DISCUSSION

LAST is an uncommon but potentially life-threatening complication of local anesthetic use that may be encountered in the ED. Patients at extremes of age or with organ dysfunction are at higher risk. Inadvertent intra-arterial or intravenous injection, as well as repeated doses and higher doses of local anesthetics are associated with greater risk of developing LAST. Neurologic and cardiovascular manifestations can occur. Early recognition and intervention, including supportive care and intravenous lipid emulsion 20%, are the mainstays of treatment. Using ultrasound guidance, aspirating prior to injection, and utilizing the minimal local anesthetic dose needed are techniques that can reduce the risk of LAST.

CONCLUSIONS

This focused review provides an update for the emergency clinician to manage patients with LAST.

A Case of Late-Onset Local Anesthetic Toxicity Observed as Seizure Activity

Most of the local anesthetic toxicity cases develop within the first five minutes of peripheral block administration. Late local anesthetic toxicity has been rarely reported in the literature. However, it is an important life-threatening problem that can lead to seizures, hemodynamic collapse, and cardiac arrest if it is ignored and not considered. Here we present the case of an 18-year-old male patient who had ultrasonography-guided infraclavicular brachial plexus block administration with a 30 mL local anesthetic. The patient had convulsions 210 minutes after the block administration and was treated with intravenous diazepam. Intraoperative and postoperative courses were uneventful. He had no neurologic signs or symptoms afterward. All laboratory tests and radiologic investigation tests were normal. This report demonstrates that late local anesthetic toxicity is still possible after several hours of the uneventful peripheral neural blockade, although it is rarely reported.

Sudden quadriparesis after non-overdose local anesthesia

Background

A well-known anesthetic, lidocaine is the most widely used local anesthetic. Local anesthetic systemic toxicity (LAST) is a life-threatening event with common and prominent presentations of central nervous system (CNS) toxicity and cardiovascular toxicity. The most frequent and prominent early warning signs and symptoms of LAST are central nervous system symptoms. While rare, cases quadriparesis after the administration of lidocaine has been reported.

Case presentation

In this paper, we report a very rare case of quadriparesis after local anesthesia administration for vocal cord cyst-removal surgery, which dramatically improved after treatment. LAST can occur during various routes of lidocaine administration, such as local spray. A possible mechanism of our case could be the local diffusion of lidocaine to the spinal cord, which caused the symptoms to mimic anterior cord syndrome.

Conclusions

Our case presented a favorable outcome following the administration of intravenous lipid emulsion (ILE) for non-over dose local anesthetic drug induced spinal cord inhibition symptoms. These findings highlight the need for further research on the use of ILE to reverse LAST and other adverse effects of local anesthetics.

Local Anesthetic Plasma Concentrations as a Valuable Tool to Confirm the Diagnosis of Local Anesthetic Systemic Toxicity? A Report of 10 Years of Experience

Background: Local anesthetic systemic toxicity (LAST) has been reported as a serious complication of local anesthetic (LA) peripheral injection. The signs and symptoms of LAST are highly variable, and the challenge remains to confirm its diagnosis. In this context, the determination of LA plasma concentration appears as a valuable tool to confirm LAST diagnosis. The aims of this study were to describe observed LA concentrations in patients suspected with LAST and their contribution to diagnostic confirmation. Methods: We retrospectively reported suspected LAST in patients for which at least one plasma LA concentration was determined to confirm diagnosis of LAST. Data collection came from our pharmacological laboratory’s database. Clinical signs and symptoms of toxicity, their onset time and observed LA concentrations were used to confirm LAST diagnosis. Results: 33 patients who presented with suspected LAST after ropivacaine and/or lidocaine administration were included. Prodromal symptoms were observed in 13 patients. Isolated central nervous system (CNS) toxicity occurred in 11 patients, and combined CNS and cardiovascular toxicity occurred in 12. One, two or three venous plasma samples were performed in 11, 3 and 19 patients, respectively. Toxic plasma LA concentrations were observed in three patients, receiving peripheral LA injection using lidocaine (16.1 µg/mL) and ropivacaine (4.2 and 4.8 µg/mL). Conclusion: This study presents an important biological and clinical dataset of patients who presented with suspected LAST. Plasma LA concentrations could bring valuable information in the diagnosis of LAST but requires rigorous sample protocols.

Retrospective Single-Center Comparative Analysis of Ultrasound-Guided Versus Non-ultrasound-Guided Nerve Blocks in Extremity Surgeries

OBJECTIVES

Although ultrasound-guided peripheral nerve blocks have become increasingly popular, it is arguable at present whether ultrasound guidance is a necessary tool for peripheral nerve blocks. The purpose of this study was to assess the significance of ultrasound-guided peripheral nerve blocks in reducing complications.

METHODS

From January 2013 to January 2019, 17,823 patients who underwent peripheral nerve blocks with/without ultrasound guidance were reviewed, recording data on their age, sex, height, weight, American Society of Anesthesiologists, block type, operation type, operation duration, and complications. The patients were divided into 2 groups: 9372 cases with ultrasound guidance (US Group) and 8451 cases without ultrasound guidance (No-US Group). To control selection bias, a total of 16,236 patients were finally included in this study after 1:1 propensity score matching, including 8118 cases in the US Group and 8118 cases in the No-US Group. Outcome measures included local anesthetic systemic toxicity (LAST), nerve injury, incomplete block anesthesia (IBA), local hematoma, and infection at the block site.

RESULTS

Baseline characteristics of patients were similar between the two groups (P >.05, respectively). Our study revealed that the incidence of infection was similar between the two groups (P >.05). However, the incidences of LAST, nerve injury, IBA, and local hematoma in the US Group were significantly lower than those in the No-US Group (P <.05, respectively).

CONCLUSIONS

Our findings suggest that ultrasound-guided peripheral nerve blocks are associated with fewer complications and higher success rates, compared with the paresthesia approach.

Epinephrine and Dexamethasone as Adjuvants in Upper Extremity Peripheral Nerve Blocks in Pediatric Patients

Introduction: Regional anesthesia in children in recent years has been accepted worldwide. The increased interest in it is partly due to the use of ultrasonography which provides confidence and accuracy to the anesthesiologic team. Adjuvants are used to extend the duration of the sensory and motor blocking, limiting the cumulative dose of local anesthetics. The use of adjuvants in peripheral nerve blocks in the pediatric population is still under research. Aim: To observe the effect of epinephrine and dexamethasone as adjuvants to local anesthetics in peripheral upper extremity nerve blocks in pediatric patients. Materials and methods: The study included 63 patients, aged group 4-14 years, admitted to the University Clinic of Pediatric Surgery for surgical treatment of upper limb fractures in the period of January 2020 until March 2021. Patients were randomized into three groups, and all patients in the groups received analgo-sedation prior to peripheral nerve block. Patients in group 1 (21 patients) received supraclavicular, or interscalene block with 2 ml lidocaine 2% and bupivacaine 0.25% (max 2mg/kg) with a total volume of 0.5ml/kg. In group 2, the patients (21) received 25 μg of epinephrine in 2 ml of 2% solution of lidocaine and 0.25% bupivacaine (max 2 mg/kg) with a total volume of 0.5 ml/kg, and in group 3, the patients (21) received 2% lidocaine 2ml and 0.25% bupivacaine (max 2mg/kg) in combination with 2mg dexamethasone with a total volume of 0.5ml/kg. Results: Results showed that in patients in group 1, the average duration of the sensory block was 7 hours, while the duration of the motor block was 5 hours and 30 minutes. In group 2 (epinephrine), the durations of both sensory and motor block were prolonged for about 30 minutes on average compared to the first group. In group 3 (dexamethasone) the duration of the sensory and motor block was significantly longer compared with the first two groups (p<0.0001). Conclusion: Epinephrine and dexamethasone prolong the duration of action of local anesthetics in peripheral nerve blocks of the upper extremity in pediatric patients and thus reduce the need for analgesics in the postoperative period.

Asystolic Cardiac Arrest Associated With Unstable Bradycardia During Augmentation Mammaplasty: A Case Report

Cardiac arrest is a rare but reported complication during breast augmentation surgery. It is even more rare in a reportedly healthy patient without preexisting cardiac disease. The authors present the case of a healthy 34-year-old female who underwent elective bilateral augmentation mammaplasty and experienced unanticipated asystolic cardiac arrest intraoperatively following general anesthesia supplemented by a regional pectoral (pec I) nerve block. The performing plastic surgeon provided cardiopulmonary resuscitation while the anesthesiologist initiated a rescue protocol per Advanced Cardiac Life Support (ACLS) guidelines. Fortunately, the patient was resuscitated in a timely manner and had a successful return of spontaneous circulation within 1 minute. This case report serves to briefly review the literature and recommendations on proper resuscitation of cardiac arrest per ACLS protocols as well as discuss unstable bradycardia in otherwise healthy patients undergoing breast augmentation surgery. Plastic surgeons and anesthesiologists who perform this procedure should be aware of the possible, rare but serious progression to asystole as well as the proper resuscitative measures to take should they be required.

LEVEL OF EVIDENCE 5

Local anesthetic systemic toxicity in children: a review of recent case reports and current literature

BACKGROUND

Local anesthetic systemic toxicity (LAST) in children occurs at an estimated rate of 8 per 100 000 blocks (95% CI 0.3 to 1.6). Due to the potential lethality of this iatrogenic complication, a better clarity of risk factors, clinical presentation, and prognosis may be clinically useful for contemporary treatment and prevention.

METHODS

An extensive literature search and detailed analysis of reported cases of LAST in patients less than 18 years of age published between April 2014 and August 2019 was performed. Clinical patterns were summarized.

RESULTS

Thirty-two cases of LAST were described in 17 published articles and 2 additional cases reported to lipidrescue.org, for a total of 34 cases. Three patients did not meet the inclusion criteria. Thirty-one cases were included in the analysis.

DISCUSSION

Infants represented a disproportionately large number of reports of LAST. The majority of local anesthetic doses were within currently published guidelines. Among the reported cases, penile and caudal blocks were the most commonly associated with LAST. Needle aspiration and test dosing with epinephrine failed to predict LAST with certainty. When LAST presented with severe cardiac compromise, intravenous lipid emulsion was given within 10 min in 43% of cases (13 of 30 reported cases). The vast majority of children were under general anesthesia when local anesthetic medications were administered. In children under general anesthesia, LAST presented with cardiac manifestations in 90% of cases (19 of 21 cases). There were no deaths or long-term morbidity reported.

Vorteile, Sicherheit und Nebenwirkungen der Tumeszenz‐Lokalanästhesie bei dermatologischen Operationen an Säuglingen

Die Tumeszenz-Lokalanästhesie (TLA) spielt bei dermatochirurgischen Eingriffen eine wichtige Rolle. Die TLA bietet etliche Vorteile, wie lang anhaltende Betäubung, reduzierte Blutung während der Operation und Vermeidung möglicher Komplikationen einer Vollnarkose. Einfache Durchführung, günstiges Risikoprofil und breites Indikationsspektrum sind weitere Gründe dafür, dass TLA zunehmend auch bei Säuglingen eingesetzt wird. Es gibt nicht nur viele Indikationen für chirurgische Exzisionen im Säuglingsalter, wie angeborene Naevi, sondern es hat auch erhebliche Vorteile, wenn diese Exzisionen in einem frühen Alter durchgeführt werden. Dazu zählen die geringere Größe der Läsionen sowie die unproblematische Wundheilung und Geweberegeneration im Säuglingsalter. Dennoch müssen hinsichtlich der Anwendung der TLA bei Säuglingen einige Aspekte berücksichtigt werden, darunter die Dosierung, eine veränderte Plasmaproteinbindung und die Notwendigkeit einer adäquaten und lang anhaltenden Schmerzkontrolle.

Local Anesthetic-Induced Central Nervous System Toxicity during Interscalene Brachial Plexus Block: A Case Series Study of Three Patients

Local anesthetics are commonly administered by nuchal infiltration to provide a temporary interscalene brachial plexus block (ISB) in a surgical setting. Although less commonly reported, local anesthetics can induce central nervous system toxicity. In this case study, we present three patients with acute central nervous system toxicity induced by local anesthetics applied during ISB with emphasis on neurological symptoms, key neuroradiological findings and functional outcome. Medical history, clinical and imaging findings, and outcome of three patients with local anesthetic-induced toxic left hemisphere syndrome during left ISB were analyzed. All patients were admitted to our neurological intensive care unit between November 2016 and September 2019. All three patients presented in poor clinical condition with impaired consciousness and left hemisphere syndrome. Electroencephalography revealed slow wave activity in the affected hemisphere of all patients. Seizure activity with progression to status epilepticus was observed in one patient. In two out of three patients, cortical FLAIR hyperintensities and restricted diffusion in the territory of the left internal carotid artery were observed in magnetic resonance imaging. Assessment of neurological severity scores revealed spontaneous partial reversibility of neurological symptoms. Local anesthetic-induced CNS toxicity during ISB can lead to severe neurological impairment and anatomically variable cerebral lesions.

Benefits, safety and side effects of tumescent local anesthesia in dermatologic surgery in infants

Tumescent local anesthesia (TLA) plays an important role in dermatosurgical procedures. TLA has several benefits such as long-lasting anesthesia, reduced bleeding during surgery and the avoidance of general anesthesia-associated complications. Convenience and a favorable risk profile along with a broad spectrum of indications are further reasons why TLA is increasingly applied in infants as well. There are not only a variety of indications for surgical excisions in infancy, such as congenital nevi, but also substantial benefits when performing these excisions at an early age. These include the smaller size of the lesions as well as the unproblematic wound healing and tissue regeneration in infancy. Nevertheless, several aspects need to be considered when applying TLA in infants including dosing, altered plasma protein binding and the need for adequate and long-lasting pain control.

Updates in our understanding of local anaesthetic systemic toxicity: a narrative review

Despite advances in clinical practice, local anaesthetic systemic toxicity continues to occur with the therapeutic use of local anaesthesia. Patterns of presentation have evolved over recent years due in part to the increasing use of ultrasound which has been demonstrated to reduce risk. Onset of toxicity is increasingly delayed, a greater proportion of clinical reports are secondary to fascial plane blocks, and cases are increasing where non-anaesthetist providers are involved. The evolving clinical context presents a challenge for diagnosis and requires education of all physicians, nurses and allied health professionals about these changing patterns and risks. This review discusses: mechanisms; prevention; diagnosis; and treatment of local anaesthetic systemic toxicity. The local anaesthetic and dose used, site of injection and block conduct and technique are all important determinants of local anaesthetic systemic toxicity, as are various patient factors. Risk mitigation is discussed including the care of at-risk groups, such as: those at the extremes of age; patients with cardiac, hepatic and specific metabolic diseases; and those who are pregnant. Advances in the changing clinical landscape with novel applications and settings for the use of local anaesthesia are also described. Finally, we signpost future directions to potentially improve the management of local anaesthetic systemic toxicity. The utility of local anaesthetics remains unquestionable in clinical practice, and thus maximising the safe and appropriate use of these drugs should translate to improvements in patient care.

Care and management of patients receiving epidural analgesia

Epidural analgesia continues to have an important role in the management of acute pain in post-operative settings. Although its use in clinical practice has declined, it continues to demonstrate superior analgesia effect compared with parenteral opioids. However, despite these benefits, epidural analgesia requires additional monitoring to ensure the timely identification of significant complications, such as haematoma and abscess. This article details the nursing care and management of adults receiving epidural analgesia in post-operative settings. It also outlines the main complications that may occur and how these can be managed.

Intraoperative Cardiac Arrest

Cardiac arrest in the operating room and in the immediate postoperative period is a potentially catastrophic event that is almost always witnessed and is frequently anticipated. Perioperative crises and perioperative cardiac arrest, although often catastrophic, are frequently managed in a timely and directed manner because practitioners have a deep knowledge of the patient's medical condition and details of recent procedures. It is hoped that the approaches described here, along with approaches for the rapid identification and management of specific high-stakes clinical scenarios, will help anesthesiologists continue to improve patient outcomes.

Adverse Drug Reaction: Midazolam-Induced Extrapyramidal Symptoms: A Case Report

Midazolam is commonly used for sedation during procedures because of its relative safety and predictability. Still, some rare undesirable medication reactions have been described. We report a case in which midazolam given before a peripheral nerve block caused acute onset dyskinetic extrapyramidal symptoms. These symptoms ultimately resolved following reversal of the midazolam with flumazenil. Given the widespread and multidisciplinary use of midazolam, practitioners should be aware of the potential for rare adverse reactions and be prepared to manage these scenarios.

Local Anesthetic Toxicity in the Geriatric Population

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 65 years 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.

Ultrasound-Guided Posterior Tibial Nerve Block for Plantar Foot Foreign Body Removal

Ultrasound-guided regional anesthesia is a growing modality within the pediatric emergency department. Here we present a case where a posterior tibial nerve block was used for anesthesia during foreign body removal from the plantar foot. We further review the technique and literature regarding this straightforward and highly effective procedure.

Resuscitation Following a Bupivacaine Injection for a Cervical Paravertebral Block

Background

Cardiac arrest related to nerve blockade using a local anaesthetic is a rare event. We report a case of bupivacaine severe cardiovascular toxicity following cervical paravertebral nerve block.

Case presentation

A 44-year-old female was admitted to Republican Vilnius University Hospital, with symptoms of sustained severe pain in her neck that radiated to both arms. Multiple cervical intervertebral hernias with spinal stenosis were confirmed by magnetic resonance imaging. Following infiltration of the subcutaneous tissue with a 0.5 % bupivacaine solution, an 18-gauge spinal needle was used to perform the paravertebral block at the C6 level. Bupivacaine was injected in incremental doses to a total of 10 mL. Rapid loss of consciousness and cardiovascular collapse suggested a neuraxial injection of bupivacaine. Long-lasting cardiopulmonary resuscitation, including chest compressions, defibrillation attempts for refractory ventricular fibrillation, medications, mechanical ventilation, and intravenous lipid emulsion infusion, was successful. No severe adverse outcomes other than acute kidney injury and chest pain related to prolonged chest compressions were documented.

Conclusions

This case report emphasizes the necessity of ensuring adequate safety precautions to avoid local anaesthetic systemic toxicity. Lipid emulsion preparations should be available in all hospital settings where local anaesthetics are used for regional anaesthesia or pain management.

A Review of Regional Anesthesia in Infants

Regional anesthesia provides effective anesthesia and pain relief in infants with age-specific data attesting to safety and efficacy. Regional anesthesia decreases exposure to opioids and general anesthetic agents and associated adverse drug effects, suppresses the stress response, and provides better hemodynamic stability compared to general anesthesia. Regional anesthesia can prevent long-term behavioral responses to pain. As a result, the overall number and variety of nerve blocks being used in infants is increasing. While neuraxial blocks are the most common blocks performed in infants, the introduction of ultrasound imaging and a better safety profile has advanced the use of peripheral nerve blocks. Infant-specific pharmacokinetic and pharmacodynamic data of local anesthetic medications are reviewed including risk factors for the accumulation of high serum levels of unbound, pharmacologically active drug. Bupivacaine accumulates with continuous infusion and 2-chloroprocaine can be used as an alternative. Local anesthetic systemic toxicity has the highest incidence in infants less than 6 months of age and is associated with bolus dosing and penile nerve blocks. Local anesthetic toxicity is treated by securing the airway, suppression of seizure activity and implementation of cardiopulmonary resuscitation. Administration of intralipid (intravenous lipid emulsion) is initiated at the first sign of toxicity. A high level of expertise in regional anesthesia is needed when treating infants due to their unique development.

Pain Management for Orthopedic Injuries

Pain management in acute orthopedic injury needs to be tailored to the presentation and patient. Subjective and objective assessment, in conjunction with pathophysiology, should be used to provide symptom control. Ideally, treatment should be administered in an escalating fashion, attempting to manage pain with the lowest dose of the safest medication available. There are also adjunctive therapies, including those that are nonpharmacologic, that can provide additional relief.