Update on Local Anesthetic Toxicity, Prevention and Treatment During Regional Anesthesia in Infants and Children

Local Anesthetic Systemic Toxicity in an Infant Following a Caudal Block: A Case Report and Review of Literature

Local anesthetic systemic toxicity (LAST) is a rare but serious complication of regional anesthesia, particularly in neonates and infants due to their immature hepatic metabolism, reduced protein-binding capacity, and increased vascular absorption. We report the case of a two-month-old ex-premature infant who developed ventricular fibrillation following a caudal block with bupivacaine during hernia repair and circumcision. Despite negative aspiration tests, systemic absorption of bupivacaine led to toxic plasma concentrations, resulting in sudden cardiovascular collapse without preceding neurological symptoms, a presentation typical in pediatric LAST. Immediate resuscitation, including cardiopulmonary resuscitation, epinephrine, and lipid emulsion therapy, successfully restored normal cardiac rhythm. This case underscores the importance of vigilance, strict adherence to weight-based dosing, and the availability of lipid emulsion therapy in pediatric anesthesia while emphasizing prevention through careful technique, monitoring, and the use of ultrasound guidance to minimize the risk of this life-threatening complication.

Super-refractory status epilepticus, rhabdomyolysis, central hyperthermia and cardiomyopathy attributable to spinal anesthesia: a case report and review of literature

BACKGROUND

There are only six past reports of super-refractory status epilepticus induced by spinal anesthesia. None of those patients have died. Only < 15 mg of bupivacaine was administered to all six of them and to our case. Pathophysiology ensuing such cases remains unclear.

CASE PRESENTATION

A 27 year old gravida 2, para 1, mother at 37 weeks of gestation came to the operating theater for an elective cesarean section. She had no significant medical history other than controlled hypothyroidism and one episode of food allergy. Her current pregnancy was uneventful. Her American Society of Anesthesiologists (ASA) grade was 2. She underwent spinal anesthesia and adequate anesthesia was achieved. After 5-7 min she developed a progressive myoclonus. After delivery of a healthy baby, she developed generalized tonic clonic seizures that continued despite the induction of general anesthesia. She had rhabdomyolysis, one brief cardiac arrest and resuscitation, followed by stress cardiomyopathy and central hyperthermia. She died on day four. There were no significant macroscopic or histopathological changes in her brain that explain her super refractory status epilepticus. Heavy bupivacaine samples of the same batch used for this patient were analyzed by two specialized laboratories. National Medicines Quality Assurance Laboratory of Sri Lanka reported that samples failed to confirm United States Pharmacopeia (USP) dextrose specifications and passed other tests. Subsequently, Therapeutic Goods Administration of Australia reported that the drug passed all standard USP quality tests applied to it. Nonetheless, they have detected an unidentified impurity in the medicine.

CONCLUSIONS

After reviewing relevant literature, we believe that direct neurotoxicity by bupivacaine is the most probable cause of super-refractory status epilepticus. Super-refractory status epilepticus would have led to her other complications and death. We discuss probable patient factors that would have made her susceptible to neurotoxicity. The impurity in the drug detected by one laboratory also would have contributed to her status epilepticus. We propose several possible mechanisms that would have led to status epilepticus and her death. We discuss the factors that shall guide investigators on future such cases. We suggest ways to minimize similar future incidents. This is an idiosyncratic reaction as well.

Disposition of levobupivacaine during intraoperative continuous caudal epidural analgesia in a preterm neonate

BACKGROUND

Continuous caudal epidural analgesia used intraoperatively in children is an effective and safe technique. However, in preterm neonates, developmental factors may significantly affect levobupivacaine disposition, leading to variable pharmacokinetics, pharmacodynamics, and potential large-variable systemic toxicity of local anesthetics.

OBJECTIVE

To our knowledge, this is the first case report describing the disposition of levobupivacaine used for intraoperative caudal epidural analgesia in a preterm neonate treated for the postoperative pain profile.

METHOD

4-days old neonate (postmenstrual age 35+5, weight 2140 g) with congenital anal atresia received continuous caudal epidural long-term analgesia (loading dose 1.694 mg/kg, initial infusion 0.34 mg/kg/hour) before correction surgery. The blood samples were obtained at 1.0, 1.5, 6.5, 12, and 36.5 h after the start of epidural infusion. The pharmacokinetic profile of levobupivacaine was determined by using the Stochastic Approximation Expectation Maximization algorithm. COMFORT and NIPS pain scores were used for the assessment of epidural analgesia.

RESULTS

The levobupivacaine absorption rate constant, apparent volume of distribution, apparent clearance, and elimination half-life were 10.8 h-1, 0.9 L, 0.086 L/h, and 7.3 h, respectively.

CONCLUSION

The results confirm our hypothesis of altered pharmacokinetics in the preterm neonate. Therefore, levobupivacaine therapy in these patients should be carefully monitored. Since therapeutic drug monitoring of levobupivacaine is not established in clinical routines, we suggest monitoring the intraoperative pain profile using validated scores.

TRIAL REGISTRATION

EudraCT number: 2020-000595-37.

Regional anesthesia for pain control in children with solid tumors-a review of case reports

Introduction

Around seventy percent of all childhood cancer patients suffer from severe pain. This pain can arise from various sources, including tumors themselves, pain caused by metastasizing tumor cells or as the outcome of therapy meant to deal with tumors. If managed inadequately, such pain can lead to many hazardous sequelae. However, there are extreme cases when pain does not respond to standard treatment. For such cases, regional anesthesia or nerve blocks are utilized as the utmost pain control measure. Blocks are used to treat pain in patients who no longer respond to conventional opioid-based treatment or whose worsened condition makes it impossible to receive any other therapy. The data regarding the use of regional anesthesia for such cases in the children population is limited.

Methods

For this review we searched for case reports in Scopus and PubMed from inception to 2023. The descriptive search items included terms related to childhood cancer and the description of each block. The inclusion criteria for review include children (0-18 years old) receiving oncology-related surgical procedures or palliative care. The data collection was limited to solid tumor-related cases only. We analyzed a total of 38 studies that included case reports and one retrospective study.

Results and discussion

It was concluded that nerve blocks, although rarely performed, are a safe and efficient way of pain control in children with solid tumors. The major settings for block performance are postoperative pain control and palliative care. We observed that block indication and its outcomes depend on unique health circumstances in which they should be performed. Patients with similar diagnoses had differing outcomes while receiving the same block treatment.

Advances in Anesthesia for Shoulder Surgery: A Comprehensive Review of Dexmedetomidine-Enhanced Interscalene Brachial Plexus Block

Surgical procedures on the shoulder pose distinctive challenges in managing pain during the perioperative period, underscoring the importance of exploring innovative anesthesia techniques. This comprehensive review article delves into integrating dexmedetomidine, an alpha-2 adrenergic agonist, within interscalene brachial plexus blocks for shoulder surgery. The review initiates by underscoring the pivotal role of effective anesthesia in shoulder surgery and elucidates the rationale behind investigating dexmedetomidine as an adjunct. It meticulously examines the anatomy and physiology of the brachial plexus, emphasizing its critical significance in shoulder surgery. Furthermore, the article expounds on dexmedetomidine's mechanisms of action and pharmacokinetics, encompassing its safety profile and potential side effects. The conventional interscalene brachial plexus block techniques, along with their limitations and challenges, are discussed, laying the foundation for the integration of dexmedetomidine. The review subsequently delves into exploring the role of dexmedetomidine in regional anesthesia, covering previous studies, mechanisms of action, and the potential advantages of incorporating it into nerve blocks. The review's core concentrates on the practical application of dexmedetomidine-enhanced interscalene brachial plexus blocks. This includes discussions on administration techniques, dosage guidelines, and compelling evidence supporting its utilization. Clinical scenarios where this approach proves most advantageous are thoroughly explored, comparing its effectiveness with traditional techniques in terms of pain control and patient outcomes. A comprehensive examination of relevant clinical trials and case studies highlights the evidence supporting its efficacy. The review also underscores safety considerations associated with dexmedetomidine. It proposes strategies for mitigating risks to ensure patient safety. Insights into future directions and research are provided, encompassing ongoing studies, areas necessitating further investigation, and potential refinements in technique. Finally, the article summarizes key findings, emphasizing the practicality of dexmedetomidine-enhanced interscalene brachial plexus blocks in shoulder surgery and its far-reaching implications for clinical practice and patient care.

Regional anesthesia for geriatric population

Advancements in modern health care over 20 years have substantially increased the average lifespan in developed countries, and the fastest growing population is the elderly population. The proportion of people in Saudi Arabia aged 60 or more is predicted to be 25 percent of the total population of 40 million by the end of 2050. Moreover, the number of people aged 80 or more is expected to reach 1.6 million or 4 percent of the total population in the same period. Improvements in surgical techniques, anesthesia, and intensive care units make surgical interventions in older and sicker patients possible. It is estimated that over half of the population older than 65 years will require surgical intervention at least once during the remainder of their lives. Therefore, elderly patients are becoming an even larger part of anesthetic practice. Regional anesthesia (RA) is frequently used in elderly patients, especially during orthopedic surgery, genitourologic and gynecologic procedures, and hernia repair. Although age can no longer be considered a contraindication to anesthesia and surgery, anesthesia-related morbidity and mortality remain higher among elderly than among young adult surgical patients. Undoubtedly, peripheral nerve (PN) blocks improve analgesia and reduce opioid consumption and their associated side effects. This is beneficial in the perioperative care of elderly patients who may have less physiologic reserve to withstand the side effects of general anesthesia (GA).

Safety of local anesthetics in cervical nerve root injections: a narrative review

Severe neurological adverse events have been reported after fluoroscopically guided cervical nerve root injections. Particulate corticosteroids inadvertently injected intraarterially and iatrogenic vertebral artery trauma have been implicated in these outcomes. This has raised concern for the potential consequences of including local anesthetic with these injections. As a result, some providers have now discontinued the routine administration of local anesthetic with corticosteroid when performing cervical nerve root injections. At present, there is no consensus regarding whether the use of local anesthetic in this context is safe. Here, the current literature is synthesized into a narrative review aiming to clarify current perspectives of the safety of local anesthetics in cervical nerve root injections.

Neurological Complications of Regional Anesthesia: An Updated Review with Clinical Guidelines

The main purpose of this article is to present the neurological complications of regional anesthesia. Our analysis may help clinicians determine when regional anesthesia can be administered safely and in which patients it needs additional precautions. Regional anesthesia has a major role in anesthesia practice. Here, we focus especially on the most common neurological complications: epidural hematoma, post-anesthesia headaches, and peripheral nerve function defect. We investigated risk factors of these states and propose ways of reducing the risks. This work is based on the available literature and the authors' experience. The research process involved using relevant keywords in various electronic databases, resulting in the selection of 32 articles published between 1989 and 2022. This manuscript provides an overview and analysis of the existing literature related to neurological complications of regional anesthesia. We believe that our article provides up-to-date information on the most common regional anesthesia complications, emphasizing differences concerning children and pregnant women and provides important guidance for clinicians in preparing for and performing anesthesia.

Postoperative Apnea in a Neonate Following an Epidural Bolus Dose Through a High Thoracic Epidural Catheter

Regional anesthesia is being used more frequently in the practice of pediatric anesthesia including neonates and infants. While generally safe and effective, adverse effects may occur related to catheter placement or its subsequent use. We present the rare occurrence of high motor blockade with apnea following the administration of a bolus dose of the local anesthetic agent, 2-chloroprocaine, into the thoracic epidural catheter of a 4-week-old, 2.2-kg former premature neonate. The patient had an epidural catheter that had been threaded from the caudal space to the thoracic level to provide analgesia following an abdominal surgical procedure. Subsequent investigation with a standard chest radiograph revealed a higher than intended placement of the epidural catheter (T4 instead of T8-10) which resulted in a transient high motor blockade with apnea. The epidural infusion was discontinued and assisted ventilation was provided by bag-valve-mask ventilation. Immediately, the heart rate and oxygen saturation returned to baseline values, and within 5 min the patient became more active, spontaneous ventilation resumed, and a strong cry was noted. The epidural catheter was removed and the remainder of the postoperative course was unremarkable. Adverse effects of epidural anesthesia in neonates are discussed and options for identifying the correct placement of a thoracic epidural catheter are reviewed.