Use of Intralipid in an infant with impending cardiovascular collapse due to local anesthetic toxicity

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.

Mechanisms and Efficacy of Intravenous Lipid Emulsion Treatment for Systemic Toxicity From Local Anesthetics

Local anesthetics are widely used clinically for perioperative analgesia to achieve comfort in medical treatment. However, when the concentration of local anesthetics in the blood exceeds the tolerance of the body, local anesthetic systemic toxicity (LAST) will occur. With the development and popularization of positioning technology under direct ultrasound, the risks and cases of LAST associated with direct entry of the anesthetic into the blood vessel have been reduced. Clinical occurrence of LAST usually presents as a series of severe toxic reactions such as myocardial depression, which is life-threatening. In addition to basic life support (airway management, advanced cardiac life support, etc.), intravenous lipid emulsion (ILE) has been introduced as a treatment option in recent years and has gradually become the first-line treatment for LAST. This review introduces the mechanisms of LAST and identifies the clinical symptoms displayed by the central nervous system and cardiovascular system. The paper features the multimodal mechanism of LAST reversal by ILE, describes research progress in the field, and identifies other anesthetics involved in the resuscitation process of LAST. Finally, the review presents key issues in lipid therapy. Although ILE has achieved notable success in the treatment of LAST, adverse reactions and contraindications also exist; therefore, ILE requires a high degree of attention during use. More in-depth research on the treatment mechanism of ILE, the resuscitation dosage and method of ILE, and the combined use with other resuscitation measures is needed to improve the efficacy and safety of clinical resuscitation after LAST in the future.

Complications in paediatric regional anaesthesia: a narrative review

Paediatric anaesthesia and paediatric regional anaesthesia are intertwined. Currently, almost all paediatric patients posted for surgery could and should be given a regional block unless and until contraindicated. This is because the scope, techniques, and their benefits have a wide range and complications are rare. The first report that used regional anaesthesia in children was in 1898, and over the last 120 years it has been developed with many scholars’ wisdom, ideas and publications. Paediatric regional anaesthesia (PRA) has many advantages but requires experience and expertise. For a long-time, exclusively landmark-guided techniques were used and gradually the development of new techniques such as the use of neuro-stimulator and ultrasound-guided (USG) blocks developed into PRA. Especially, the application of ultrasonography (US) has revolutionised the practice of PRA. Few limitations of regional anaesthesia can be tackled by the use of US, leading to shorter time to perform the block, reduced time for block onset and use of a smaller volume of local anaesthetic. Life threatening complications of regional anaesthesia are rare and the riskbenefit ratio is favourable. However, a thorough insight into RA complications, no matter how rare they are, is essential for safe practice. This is because they can be life-threatening, and no matter how small the percentage is, when complications occur, for that individual patient statistics is irrelevant.

Literature review of the evidence regarding intravenous lipid administration in drug-induced cardiotoxicity

Introduction: Intravenous lipid emulsion (ILE) administration is capable of reversing the acute cardiac and neurological toxicity caused by local anesthetic agents. In recent years, ILE has also been explored as a potential antidote for cardiotoxicity caused by non-anesthetic agents too. Areas covered: The potential mechanisms, safety, and efficacy of this approach are considered. Data were sought from published reports listed in PubMed and EMBASE, and abstracts of meetings of the North American Congress of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. There were reports involving 298 patients where ILE has been administered for severe drug toxicity. Clinical improvement was observed in 57 of 59 patients with local anesthetic toxicity (96.6%); there were 239 patients where toxicity was due to non-anesthetic agents, and ILE apparently improved clinical outcome in 215 (72.1%). Expert opinion: Response rates were similar between ILE treated toxicity caused by lipid soluble and non-lipid soluble drugs. Potential adverse effects of ILE include interference with laboratory assays, acute pancreatitis, and adult respiratory distress syndrome, although the rate of occurrence is difficult to ascertain.

Awake caudal anaesthesia in neonates/young infants for improved patient safety

Caudal epidural block in a conscious infant is a recognised technique that allows the avoidance of general anaesthesia and risks associated with it. It is also technically easier to perform reliably compared with an awake subarachnoid block in skilled hands.1 While local anaesthetic systemic toxicity is a rare complication of caudal anaesthesia, this case illustrates the potential for caudal anaesthesia done awake in enhancing patient safety through early recognition of local anaesthetic systemic toxicity.

Giving Priority to Lipid Administration Can Reduce Lung Injury Caused by Epinephrine in Bupivacaine-Induced Cardiac Depression

BACKGROUND AND OBJECTIVES

Epinephrine is usually administered in concert with a lipid emulsion during local anesthetic toxicity. However, the timing and role of epinephrine administration in combination with a lipid emulsion remain unclear. Specifically, the temporal association of epinephrine and lipid emulsion administration with related changes in pulmonary vascular pressures that may lead to pulmonary edema and hemorrhage needs to be determined.

METHODS

This study consisted of 2 parts, experiments A and B. In experiment A, 24 adult male Sprague-Dawley rats were randomly divided into 3 groups (n = 8) to receive 1 of 3 treatments. All rats were anesthetized with an intraperitoneal injection of chloral hydrate, and anesthesia was maintained by sevoflurane. Each treatment group was initially given an infusion of bupivacaine (15 mg/kg) in order to produce cardiac depression. Group 1 (A-LEN) received a 30% lipid infusion (3 mL/kg) followed by a rapid epinephrine bolus (10 μg/kg), which was then followed by a normal saline infusion (3 mL/kg). Group 2 (A-NEL) first received a normal saline infusion (3 mL/kg) followed by a rapid epinephrine bolus, which was then followed by a 30% lipid emulsion. Group 3 (A-NEN, considered a control group) first received a normal saline infusion (3 mL/kg) followed by a rapid epinephrine bolus (10 μg/kg), which was then followed by another normal saline infusion (3 mL/kg). Lipid and normal saline infusions were administered over 1 minute, whereas epinephrine was injected rapidly. The continuous monitoring of blood pressure, heart rate, pulmonary arterial pressure, and pulmonary venous pressure occurred for 30 minutes. After the 30-minute monitoring period, lung tissue was sampled, and bronchoalveolar lavage fluid was collected. In experiment B, the experimental model and resuscitation protocol were similar to experiment A (B-LEN and B-NEL groups). In this arm of the experiment, bupivacaine concentrations of cardiac tissue were determined after the second minute of normal saline infusion.

RESULTS

The A-LEN group produced the best rate pressure product when compared with the A-NEL or A-NEN group (P = 0.045, P = 0.011, respectively). In regard to pulmonary venous pressure, the A-LEN group was lower than the A-NEL or A-NEN group (P = 0.031, P = 0.006, respectively). Animals in the A-NEL and A-NEN groups rapidly developed pulmonary edema after infusion of epinephrine. The wet-to-dry ratio of the lungs in the A-LEN group was lower than that of the lungs in the A-NEL group (P = 0.024).The lung permeability index of the A-LEN group was lower than that of the A-NEL group (P = 0.011). In experiment B, concentrations of bupivacaine in cardiac tissue and plasma of the B-LEN group were lower than those of the B-NEL group (P = 0.001, P = 0.03, respectively).

CONCLUSIONS

Giving priority to the administration of a lipid emulsion before the administration of epinephrine can reduce lung injury in bupivacaine-induced cardiac depression in rats.

Systematic review of the effect of intravenous lipid emulsion therapy for local anesthetic toxicity

BACKGROUND

Following national and regional recommendations, intravenous lipid emulsion (ILE) has become established in clinical practice as a treatment for acute local anesthetic (LA) toxicity, although evidence of efficacy is limited to animal studies and human case reports. A collaborative lipid emulsion workgroup was therefore established by the American Academy of Clinical Toxicology to review the evidence on the effect of ILE for LA toxicity.

METHODS

We performed a systematic review of the literature published through 15 December 2014. Relevant articles were determined based on pre-defined inclusion and exclusion criteria. Pre-treatment experiments, pharmacokinetic studies not involving toxicity and studies that did not address antidotal use of ILE were excluded.

RESULTS

We included 113 studies and reports. Of these, 76 were human and 38 animal studies. One publication included both a human case report and an animal study. Human studies included one randomized controlled crossover trial involving 16 healthy volunteers. The subclinical LA toxicity design did not show a difference in the effects of ILE versus saline. There was one case series and 73 case reports of ILE use in the context of toxicity (83 patients) including CNS depression or agitation (n = 45, 54%), seizures (n = 49, 59%), hypotension, hypertension, EKG changes, arrhythmias (n = 39, 47%), cardiac arrest (n = 18, 22%), cardiopulmonary resuscitation, and/or requirement for endotracheal intubation and/or mechanical ventilation (n = 35, 42%). There were 81 (98%) survivors including 63 (76%) with no reported sequelae from the LA poisoning or ILE, although the presence or absence of sequelae was not reported in 15 (18%) cases. Animal studies included 29 randomized controlled studies, three observational studies, five case series, and one case report; bupivacaine was used in 29 of these reports (76%). Of 14 controlled experiments in animals, eight showed improved survival or time to return of spontaneous circulation and five no benefit of ILE versus saline or non-ILE treatments. Combining ILE with epinephrine improved survival in five of the six controlled animal experiments that studied this intervention. The studies were heterogeneous in the formulations and doses of ILE used as well as the doses of LA. The body of the literature identified by this systematic review yielded only a very low quality of evidence.

CONCLUSION

ILE appears to be effective for reversal of cardiovascular or neurological features in some cases of LA toxicity, but there is currently no convincing evidence showing that ILE is more effective than vasopressors or to indicate which treatment should be instituted as first line therapy in severe LA toxicity.

Differential effects of short- and long-term bupivacaine treatment on α1-adrenoceptor-mediated contraction of isolated rat aorta rings and the reversal effect of lipid emulsion

AIM

Arterial function is significantly influenced by bupivacaine at both clinically relevant concentrations and toxic concentrations, but the underlying mechanisms are not fully understood. In the present study we investigated the role of α1-adrenoceptors in bupivacaine effects on isolated rat aortas.

METHODS

Isolated aortic rings were prepared from rats and suspended in an organ bath. Phenylephrine (Phe)-induced vasoconstriction and acetylcholine (ACh)-induced vasodilation were recorded through an isometric force transducer connected to a data acquisition system.

RESULTS

Administration of bupivacaine (30-300 μmol/L) produced mild vasoconstriction, and this response declined with repeated administrations. Treatment of the aortic rings with bupivacaine (3-30 μmol/L) for 20 min enhanced Phe-induced vasoconstriction, while treatment for 40 min suppressed Phe-induced vasoconstriction. Both the short- and long-term bupivacaine treatment suppressed ACh-induced vasodilation. Incubation of the aortic rings with 0.2%-0.6% lipid emulsion (LE) for 100 min significantly increased the pD2 and Emax values of Phe-induced vasoconstriction, and incubation with 0.4% LE for 100 min reversed the inhibition of bupivacaine on vasoconstriction induced by Phe (30 μmol/L). In contrast, incubation with LE suppressed ACh-induced vasodilation, even at a lower concentration and with a 5-min incubation.

CONCLUSION

Bupivacaine exerts dual effects on α1-adrenoceptor-mediated vasoconstriction of isolated rat aortic rings: short-term treatment enhances the response, while long-term treatment inhibits it; the inhibition may be reversed via long-term incubation with LE.

Pre-treatment of bupivacaine-induced cardiovascular depression using different lipid formulations of propofol

BACKGROUND

Pre-treatment with lipid emulsions has been shown to increase lethal doses of bupivacaine, and the lipid content of propofol may alleviate bupivacaine-induced cardiotoxicity. The aim of this study is to investigate the effects of propofol in intralipid or medialipid emulsions on bupivacaine-induced cardiotoxicity.

METHODS

Rats were anaesthetised with ketamine and were given 0.5 mg/kg/min propofol in intralipid (Group P), propofol in medialipid (Group L), or saline (Group C) over 20 min. Thereafter, 2 mg/kg/min bupivacaine 0.5% was infused. We recorded time to first dysrhythmia occurrence, respective times to 25% and 50% reduction of the heart rate (HR) and mean arterial pressure, and time to asystole and total amount of bupivacaine consumption. Blood and tissue samples were collected following asystole.

RESULTS

The time to first dysrhythmia occurrence, time to 25% and 50% reductions in HR, and time to asystole were longer in Group P than the other groups. The cumulative bupivacaine dose given at those time points was higher in Group P. Plasma bupivacaine levels were significantly lower in Group P than in Group C. Bupivacaine levels in the brain and heart were significantly lower in Group P and Group L than in Group C.

CONCLUSION

We conclude that pre-treatment with propofol in intralipid, compared with propofol in medialipid or saline, delayed the onset of bupivacaine-induced cardiotoxic effects as well as reduced plasma bupivacaine levels. Further studies are needed to explore tissue bupivacaine levels of propofol in medialipid and adapt these results to clinical practice.

Phenylephrine as a simulated intravascular epidural test dose in pediatrics: a pilot study

BACKGROUND

A test dose is used to detect intravascular injection during neuraxial block in pediatrics. Accidental intravascular epidural local anesthetic injection might be unrecognized in anesthetized children leading to potential life-threatening complications. In children, sevoflurane anesthesia blunts the hemodynamic response when intravascular cathecolamines are administered. No studies have explored the hemodynamics and the criteria for a positive test dose result following phenylephrine in sevoflurane anesthetized children.

METHODS

Healthy children undergoing minor procedures were randomly assigned to receive intravenous placebo, or 5 μg∙kg(-1) phenylephrine (n = 11/group) during sevoflurane anesthesia. Hemodynamic response was assessed using electrocardiography, pulse oxymetry and non-invasive blood pressure monitoring for 5 min following drug administration in anesthetized patients.

RESULTS

All patients receiving phenylephrine showed a decreased heart rate (HR) but not all of them met the positive criterion for test dose response. Overall, at 1 min, patients receiving phenylephrine showed a 25% decrease in HR from the baseline while an increase in blood pressure was noticed in 54% of patients receiving phenylephrine.

DISCUSSION

Phenylephrine might be a future indicator of positive intravascular test dose. Further investigation is needed to find out the phenylephrine dose that elicits a reliable hemodynamic response and whether phenylephrine needs to be dose age-adjusted in order to appreciate relevant hemodynamic changes in children receiving neuraxial blocks undergoing general anesthesia.

Intravenous lipid emulsion to reverse acute drug toxicity in pediatric patients

OBJECTIVE

To identify and summarize published cases in which intravenous lipid emulsion was used to treat pediatric patients with acute drug toxicities.

DATA SOURCES

PubMed, SCOPUS, and EMBASE were searched up to December 2012 for relevant publications using the terms fat emulsion, lipid emulsion, Intralipid, Liposyn, Medialipide, Medialipid, lipid rescue, ILE, IVLE, IFE, IVFE, or lipid and intoxication, overdose, poisoning, toxicity, resuscitation, antidote, and rescue that were limited to reports in humans aged 18 years or younger.

STUDY SELECTION AND DATA EXTRACTION

A publication was included if an intravenous lipid emulsion was used to treat acute-onset drug toxicity as reported in prospective or retrospective observational studies, case reports, and abstracts for patients aged 18 years or younger.

DATA SYNTHESIS

Fourteen case reports were identified in which intravenous lipid emulsion was used to treat toxicities due to local anesthetics and other medications (amitriptyline, diltiazem, bupropion, dosulepin, lamotrigine, quetiapine, and verapamil). Thirteen cases demonstrated a beneficial response in reversing systemic toxicity; 1 of these patients developed hypertriglyceridemia and pancreatitis. The dosage regimens used in this series were dissimilar.

CONCLUSIONS

There is an increasing interest in use of intravenous lipid emulsions to treat life-threatening toxicity from several lipophilic drugs in adults and children. Although most of the literature describes adult cases, intravenous lipid emulsion has been used in neonates and adolescents, with generally positive outcomes. Given the life-threatening, sometimes near-death situations in which an intravenous lipid emulsion is typically used after conventional resuscitation is unsuccessful and the dramatic positive response to this therapy in most published cases, its use likely will continue. Continued reporting of pediatric cases will guide the optimal use and safety profile of intravenous lipid emulsion for the emergent reversal of drug toxicity.

Intravenous lipid administration for drug-induced toxicity: a critical review of the existing data

Following the discovery that administration of intravenous lipid emulsion (ILE) may reverse the cardiac and neurological toxicity of certain local anesthetic agents, ILE's potential role has recently been explored in the setting of toxicity attributed to a variety of different drugs. The potential mechanisms, safety and efficacy of this approach are considered in this review. Data are reviewed from 76 published reports involving ILE administration for severe drug toxicity, including 55 where toxicity was due to nonanesthetic agents. ILE was reported to exert a positive therapeutic effect in only a proportion of the reported cases, with greatest evidence of efficacy concerning local anesthetic agents. Administration has typically involved bolus administration followed by continuous maintenance infusion, and a number of different mechanisms are proposed, from preferential partitioning of the drug from cardiac tissue to the circulating lipid fraction and direct inotropic effects related to carnitine pathways and fatty acid oxidative metabolism. No major adverse effects have been encountered, but too few data exist to adequately address the safety profile of ILE.

Intravenous Lipid Emulsion for the Treatment of Drug Toxicity

Intravenous lipid emulsion (ILE) has emerged as a powerful antidote for the treatment of drug toxicity in the past decade. Initial efficacy of ILE was shown in the setting of local anesthetic systemic toxicity (LAST), but recent case reports suggest its consideration in a variety of other drug toxicities. In this review, we will summarize the experimental evidence as well as the clinical experience in using ILE as an antidote. Specifically, we will look at the evidence for using ILE in LAST as well as toxicity due to beta-blockers, calcium-channel blockers, and tricyclic antidepressants. We will also review the current dosing recommendations as well as potential side effects of ILE as an antidote.

ECMO for Cardiac Rescue after Accidental Intravenous Mepivacaine Application

Mepivacaine is a potent local anaesthetic and used for infiltration and regional anaesthesia in adults and pediatric patients. Intoxications with mepivacaine affect mainly the CNS and the cardiovascular system. We present a case of accidental intravenous mepivacaine application and intoxication of an infant resulting in seizure, broad complex bradyarrhythmia, arterial hypotension and finally cardiac arrest. The patient could be rescued by prolonged resuscitations and a rapid initiation of ECMO and survived without neurological damage. The management strategies of this rare complication including promising other treatment options with lipid emulsions are discussed.

Tricyclic antidepressant overdose in a toddler treated with intravenous lipid emulsion

We report a case that involves the use of intravenous lipid emulsion as an antidote for a drug overdose involving a 20-month-old girl who had ingested a potentially lethal amount of the tricyclic antidepressant (TCA) dothiepin. The patient's condition continued to deteriorate despite implementation of standard pediatric treatment recommendations for TCA toxicity. Administration of intravenous lipid emulsion in addition to standard therapy (including sodium bicarbonate) and direct-current cardioversion for ventricular arrhythmia led to a successful outcome. The case report is followed by a review of the current evidence underlying this novel therapy and the background on its use. TCA toxicity is addressed specifically.

Comparison of epinephrine vs lipid rescue to treat severe local anesthetic toxicity - an experimental study in piglets

OBJECTIVES

Local anesthetic (LA) intoxication with severe hemodynamic compromise is a potential catastrophic event. Lipid resuscitation has been recommended for the treatment of LA-induced cardiac arrest. However, there are no data about effectiveness of Intralipid for the treatment of severe cardiovascular compromise prior to cardiac arrest. Aim of this study was to compare effectiveness of epinephrine and Intralipid for the treatment of severe hemodynamic compromise owing to bupivacaine intoxication.

METHODS

  Piglets were anesthetized with sevoflurane, intubated, and ventilated. Bupivacaine was infused with a syringe driver via a central venous catheter at a rate of 1 mg·kg(-1) ·min(-1) until invasively measured mean arterial pressure (MAP) dropped to 50% of the initial value. Bupivacaine infusion was then stopped, and epinephrine 3 μg·kg(-1) (group 1), Intralipid(®) 20% 2 ml·kg(-1) (group 2), or Intralipid 20% 4 ml·kg(-1) (group 3) was immediately administered. Survival, hemodynamic course, and ET(CO2) were recorded.

RESULTS

  Twenty-one piglets (3 × 7), with median age of 26 days (19-43) and weighing 4.9 kg (4.3-5.8), were investigated. All animals in group 1 (100%) but only four of seven (57%) piglets in group 2 and group 3, respectively, survived. Normalization of hemodynamic parameters (HR, MAP) and ET(CO2) was fastest in group 1 with all piglets achieving HR and MAP values at or above baseline within 1 min.

CONCLUSION

  For the treatment of severe hemodynamic compromise owing to bupivacaine intoxication in piglets, first-line rescue with epinephrine was more effective than Intralipid with regard to survival as well as normalization of hemodynamic parameters and ET(CO2) .

Partition constant and volume of distribution as predictors of clinical efficacy of lipid rescue for toxicological emergencies

CONTEXT

Lipid infusion is useful in reversing cardiac toxicity of local anesthetics, and recent reports indicate it may be useful in resuscitation from toxicity induced by a variety of other drugs. While the mechanism behind the utility of lipid rescue remains to be fully elucidated, the predominant effect appears to be creation of a "lipid sink".

OBJECTIVE

Determine whether the extraction of drugs by lipid, and hence the clinical efficacy of lipid rescue in toxicological emergencies can be predicted by specific drug properties.

MATERIALS AND METHODS

Each drug investigated was added individually to human drug-free serum. Intralipid® was added to this drug-containing serum, shaken and then incubated at 37°C. The lipid was removed by ultracentrifugation and the concentration of drug remaining in the serum was measured by high-pressure liquid chromatography.

RESULTS

In this in vitro model, the ability of lipid emulsion to bind a drug was largely dependent upon the drug's lipid partition constant. Additionally, using a multiple linear regression model, the prediction of binding could be improved by combining the lipid partition constant with the volume of distribution together accounting for approximately 88% of the variation in the decrease in serum drug concentration with the administration of lipid emulsion.

CONCLUSIONS

The lipid partition constant and volume of distribution can likely be used to predict the efficacy of lipid infusion in reversing the cardiac toxicity induced by anesthetics or other medications.

Regional anaesthesia and analgesia in the neonate

A large number of published studies have shown that the use of diverse regional anaesthetic techniques is associated with high-quality pain relief following the different types of surgery and painful procedures that are commonly performed in neonatal patients. Apart from pain, few studies have examined other outcomes in this setting. Some data suggest a benefit with regional anaesthesia. In a retrospective study, Bosenberg et al. found that the use of epidural analgesia in neonatal patients undergoing tracheo-oesophageal fistula repair resulted in a reduced need for postoperative mechanical ventilation. Furthermore, epidural analgesia was found to be associated with a significant and beneficial modification of the neuroendocrine surgical stress response after major abdominal surgery in infants when compared to postoperative morphine infusions. The use of local anaesthetics in association with neonatal circumcision has also shown a benefit as neonates not treated with eutectic mixture of lidocaine and prilocaine (EMLA) or a penile block had an exaggerated pain response to later vaccinations as compared with neonates treated with a local anaesthetic technique. Finally, safety data generated from large, prospective studies and audits clearly show that the use of paediatric regional anaesthetic techniques is associated with adequate safety also in neonatal patients. In conclusion, a large variety of local and regional anaesthetic techniques can be safely used in neonatal patients. The use of such techniques must obviously be associated with sufficient knowledge about the various techniques, as well as adherence to adequate dosage guidelines and other safety precautions. However, if these prerequisites are met, regional anaesthesia may offer great advantages to our smallest and most vulnerable patients.

Clinical presentation of local anesthetic systemic toxicity: a review of published cases, 1979 to 2009

The classic description of local anesthetic systemic toxicity (LAST) generally described in textbooks includes a series of progressively worsening neurologic symptoms and signs occurring shortly after the injection of local anesthetic and paralleling progressive increases in blood local anesthetic concentration, culminating in seizures and coma. In extreme cases, signs of hemodynamic instability follow and can lead to cardiovascular collapse. To characterize the clinical spectrum of LAST and compare it to the classic picture described above, we reviewed published reports of LAST during a 30-year period from 1979 to 2009. Ninety-three cases were identified and analyzed with respect to onset of toxicity and the spectrum of signs and symptoms. Sixty percent of cases followed the classic pattern of presentation. However, in the remainder of cases, symptoms were substantially delayed after the injection of local anesthetic, or involved only signs of cardiovascular compromise, with no evidence of central nervous system toxicity. Although information gained from retrospective case review cannot establish incidence, outcomes, or comparative efficacies of treatment, it can improve awareness of the clinical spectrum of LAST and, theoretically, the diagnosis and treatment of affected patients. The analytic limitations of our method make a strong case for developing a prospective, global registry of LAST as a robust alternative for educating practitioners and optimizing management of LAST.