Malignant hyperthermia 2020: Guideline from the Association of Anaesthetists

Successful Treatment Without Using Dantrolene Sodium on a Child Occurring Malignant Hyperthermia During Induction of General Anesthesia: A Case Report

Malignant hyperthermia (MH) is a fatal hyperthermia with a high mortality, which usually occurs during induction of general anesthesia. Dantrolene sodium is a wonder drug currently used for treating malignant hyperthermia. However, preparing, storing, and maintaining dantrolene sodium are crucially expensive, thus making it financially unsatisfactory and difficult for clinicians to acquire in time. Monitoring patients' condition closely and intervening promptly when early signs of malignant hyperthermia occur can effectively prevent the condition from worsening and win over time for the arrival of dantraline sodium. This article is to report a case in which we successfully rescued a child occurring malignant hyperthermia without using dantrolene sodium.

Remimazolam-based total intravenous anesthesia in a patient with a confirmed diagnosis of malignant hyperthermia: a case report

BACKGROUND

Malignant hyperthermia (MH) is a rare, life-threatening disorder of calcium homeostasis in skeletal muscle cells that is triggered by volatile anesthetics and succinylcholine, leading to a hypermetabolic reaction. The pathogenic ryanodine receptor 1 (RYR1) gene variant is critical. Patients susceptible to MH should avoid triggering agents, and total intravenous anesthesia (TIVA) is preferred. Remimazolam is safe in patients with suspected MH.

CASE PRESENTATION

We present the first case of remimazolam treatment in a genetically confirmed patient with MH without MH development. A 72-year-old man with a family history of MH underwent remimazolam-based TIVA. After informed consent was obtained, a muscle biopsy and genetic testing were performed. Intraoperatively and postoperatively, the patient exhibited no signs of MH. An enhanced function of the RYR1 channel into releasing calcium was indicated, and the genetic testing revealed a pathogenic variant of RYR1.

CONCLUSIONS

Remimazolam-based TIVA is safe in patients confirming the diagnosis of MH.

Diagnosis and rescue of malignant hyperthermia induced by anesthesia during radical surgery in a cervical cancer patient using the National Remote Emergency System: A case report

RATIONALE

Malignant hyperthermia (MH) is a rare yet serious medical complication that typically arises following general anesthesia or the administration of specific anesthetics. Due to the infrequency of MH, anesthesiologists often lack sufficient expertise in identifying and managing it, leading to misdiagnosis and inappropriate treatment. There is an urgent need to enhance the diagnosis and management of MH through the utilization of relevant tools.

PATIENT CONCERNS

In this case, a 52-year-old woman underwent radical cervical cancer surgery under general anesthesia, with no family or significant medical history. She experienced a gradual increase in end-tidal carbon dioxide (ETCO2) to a maximum of 75 mm Hg and a rise in body temperature from 36.5 to 37.5 °C in a very short period, as well as a blood gas analysis showing a pH of 7.217.

DIAGNOSIS

The anesthesiologist immediately used The WeChat applet-based National Remote Emergency System for Malignant Hyperthermia (MH-NRES), and the score was 40, which indicated that the patient was very likely to have MH.

INTERVENTIONS

We immediately discontinued sevoflurane and switched total intravenous anesthesia to maintain general anesthesia, with a rapid intravenous infusion of dantrolene sodium.

OUTCOMES

The ETCO2 and the temperature quickly dropped to normal, followed by successful completion of the surgery, and the patient was discharged 8 days after surgery.

LESSONS

The experience can provide a basis use of MH-NRES and improve the ability of anesthesiologists to deal with intraoperative MH as well as increase the survival probability of patients.

Nanotherapeutics for Alleviating Anesthesia-Associated Complications

Current management of anesthesia-associated complications falls short in terms of both efficacy and safety. Nanomaterials with versatile properties and unique nano-bio interactions hold substantial promise as therapeutics for addressing these complications. This review conducts a thorough examination of the existing nanotherapeutics and highlights the strategies for developing prospective nanomedicines to mitigate anesthetics-related toxicity. Initially, general, regional, and local anesthesia along with the commonly used anesthetics and related prevalent side effects are introduced. Furthermore, employing nanotechnology to prevent and alleviate the complications of anesthetics is systematically demonstrated from three aspects, that is, developing 1) safe nano-formulization for anesthetics; 2) nano-antidotes to sequester overdosed anesthetics and alter their pharmacokinetics; 3) nanomedicines with pharmacodynamic activities to treat anesthetics toxicity. Finally, the prospects and challenges facing the clinical translation of nanotherapeutics for anesthesia-related complications are discussed. This work provides a comprehensive roadmap for developing effective nanotherapeutics to prevent and mitigate anesthesia-associated toxicity, which can potentially revolutionize the management of anesthesia complications.

Epidemiological and clinical features of malignant hyperthermia: A scoping review

Malignant hyperthermia (MH) is a potentially fatal inherited pharmacogenetic disorder related to pathogenic variants in the RYR1, CACNA1S, or STAC3 genes. Early recognition of the occurrence of MH and prompt medical treatment are indispensable to ensure a positive outcome. The purpose of this study was to provide valuable information for the early identification of MH by summarizing epidemiological and clinical features of MH. This scoping review followed the methodological framework recommended by Arksey and O'Malley. PubMed, Embase, and Web of science databases were searched for studies that evaluated the epidemical and clinical characteristics of MH. A total of 37 studies were included in this review, of which 26 were related to epidemiology and 24 were associated with clinical characteristics. The morbidity of MH varied from 0.18 per 100 000 to 3.9 per 100 000. The mortality was within the range of 0%-18.2%. Identified risk factors included sex, age, disorders associated with MH, and others. The most frequent initial clinical signs included hyperthermia, sinus tachycardia, and hypercarbia. The occurrence of certain signs, such as hypercapnia, delayed first temperature measurement, and peak temperature were associated with poor outcomes. The epidemiological and clinical features of MH varied considerably and some risk factors and typical clinical signs were identified. The main limitation of this review is that the treatment and management strategies were not assessed sufficiently due to limited information.

Ventilatory failure in chronic neuromuscular disease

Patients with neuromuscular diseases (NMD) can present to the neurologist with symptoms and signs of respiratory failure, either acutely or as an insidious process in the outpatient setting. Since the advent of non-invasive ventilation, the outcomes of patients with ventilatory failure due to NMD have dramatically improved. However, the natural history of different NMDs requires a nuanced approach to respiratory investigation and management. Respiratory failure dictates the prognosis of many NMDs and timing the most appropriate investigation and referral to ventilation services is crucial in optimising care.

Comparison of Transcriptomic Changes in Survivors of Exertional Heat Illness with Malignant Hyperthermia Susceptible Patients

Exertional heat illness (EHI) is an occupational health hazard for athletes and military personnel-characterised by the inability to thermoregulate during exercise. The ability to thermoregulate can be studied using a standardised heat tolerance test (HTT) developed by The Institute of Naval Medicine. In this study, we investigated whole blood gene expression (at baseline, 2 h post-HTT and 24 h post-HTT) in male subjects with either a history of EHI or known susceptibility to malignant hyperthermia (MHS): a pharmacogenetic condition with similar clinical phenotype. Compared to healthy controls at baseline, 291 genes were differentially expressed in the EHI cohort, with functional enrichment in inflammatory response genes (up to a four-fold increase). In contrast, the MHS cohort featured 1019 differentially expressed genes with significant down-regulation of genes associated with oxidative phosphorylation (OXPHOS). A number of differentially expressed genes in the inflammation and OXPHOS pathways overlapped between the EHI and MHS subjects, indicating a common underlying pathophysiology. Transcriptome profiles between subjects who passed and failed the HTT (based on whether they achieved a plateau in core temperature or not, respectively) were not discernable at baseline, and HTT was shown to elevate inflammatory response gene expression across all clinical phenotypes.

Description of the Content and Quality of Publicly Available Information on the Internet About Inhaled Volatile Anesthesia and Total Intravenous Anesthesia: Descriptive Study

BACKGROUND

More than 300 million patients undergo surgical procedures requiring anesthesia worldwide annually. There are 2 standard-of-care general anesthesia administration options: inhaled volatile anesthesia (INVA) and total intravenous anesthesia (TIVA). There is limited evidence comparing these methods and their impact on patient experiences and outcomes. Patients often seek this information from sources such as the internet. However, the majority of websites on anesthesia-related topics are not comprehensive, updated, and fully accurate. The quality and availability of web-based patient information about INVA and TIVA have not been sufficiently examined.

OBJECTIVE

This study aimed to (1) assess information on the internet about INVA and TIVA for availability, readability, accuracy, and quality and (2) identify high-quality websites that can be recommended to patients to assist in their anesthesia information-seeking and decision-making.

METHODS

Web-based searches were conducted using Google from April 2022 to November 2022. Websites were coded using a coding instrument developed based on the International Patient Decision Aids Standards criteria and adapted to be appropriate for assessing websites describing INVA and TIVA. Readability was calculated with the Flesch-Kincaid (F-K) grade level and the simple measure of Gobbledygook (SMOG) readability formula.

RESULTS

A total of 67 websites containing 201 individual web pages were included for coding and analysis. Most of the websites provided a basic definition of general anesthesia (unconsciousness, n=57, 85%; analgesia, n=47, 70%). Around half of the websites described common side effects of general anesthesia, while fewer described the rare but serious adverse events, such as intraoperative awareness (n=31, 46%), allergic reactions or anaphylaxis (n=29, 43%), and malignant hyperthermia (n=18, 27%). Of the 67 websites, the median F-K grade level was 11.3 (IQR 9.5-12.8) and the median SMOG score was 13.5 (IQR 12.2-14.4), both far above the American Medical Association (AMA) recommended reading level of sixth grade. A total of 51 (76%) websites distinguished INVA versus TIVA as general anesthesia options. A total of 12 of the 51 (24%) websites explicitly stated that there is a decision to be considered about receiving INVA versus TIVA for general anesthesia. Only 10 (20%) websites made any direct comparisons between INVA and TIVA, discussing their positive and negative features. A total of 12 (24%) websites addressed the concept of shared decision-making in planning anesthesia care, but none specifically asked patients to think about which features of INVA and TIVA matter the most to them.

CONCLUSIONS

While the majority of websites described INVA and TIVA, few provided comparisons. There is a need for high-quality patient education and decision support about the choice of INVA versus TIVA to provide accurate and more comprehensive information in a format conducive to patient understanding.

Temperature control in sepsis

Fever can be viewed as an adaptive response to infection. Temperature control in sepsis is aimed at preventing potential harms associated with high temperature (tachycardia, vasodilation, electrolyte and water loss) and therapeutic hypothermia may be aimed at slowing metabolic activities and protecting organs from inflammation. Although high fever (>39.5°C) control is usually performed in critically ill patients, available cohorts and randomized controlled trials do not support its use to improve sepsis prognosis. Finally, both spontaneous and therapeutic hypothermia are associated with poor outcomes in sepsis.

Suspected Malignant Hyperthermia in a Brain-Dead Donor During Anesthesia for Organ Procurement Surgery: A Case Report

We report an unusual case of highly suspected malignant hyperthermia after inducing anesthesia in a brain-dead 18-year-old male patient undergoing organ procurement surgery. The patient was administered desflurane (3 vol%) and rocuronium bromide (50 mg) to induce and maintain general anesthesia. He experienced hypercapnia and tachycardia within 5 minutes of anesthesia induction; however, his body temperature rapidly rose only after 15 minutes. The volatile anesthetic was discontinued, and dantrolene was administered at a low dose (1 mg/kg) to avert possible hepatotoxic effects on the donor liver. Fortunately, the clinical course of the brain-dead donor until the organs were harvested and the liver transplantation outcome of the recipient was favorable. A comprehensive understanding of the pathophysiology of brain death, organ transplantation, and malignant hyperthermia is essential to respond promptly and appropriately. Based on our experience, low-dose dantrolene may be clinically used in brain-dead donors while accounting for its potential hepatotoxic effects.

A WeChat applet-based national remote emergency system for malignant hyperthermia in China: a usability study

BACKGROUND

Malignant hyperthermia (MH) is a rare anesthetic emergency with a high mortality rate in China. We developed a WeChat applet-based National Remote Emergency System for Malignant Hyperthermia (MH-NRES) to provide a real-time emergency system to help Chinese anesthesiologists deal with MH crises. However, it is imperative that close attention should be paid to the usability of the applet.

PURPOSE

The objectives of this study were to (1) evaluate the usability of the applet-based MH-NRES for anesthesiologists; and (2) to test the validity and reliability of a modified mHealth app usability questionnaire.

METHODS

A modified User Version of the Mobile Application Rating Scale (uMARS) was designed. Together with System Usability Scale (SUS) and Post-Study System Usability Questionnaire (PSSUQ), another two well-validated questionnaires, uMARS were then used to evaluate the usability of MH-NRES. The Cronbach alpha of the total score and the subscales of uMARS was calculated to evaluate the internal consistency. The correlation coefficients among three questionnaires were calculated.

RESULTS

In this study, 118 anesthesiologists provided responses to the questionnaire. The overall mean uMARS score was 4.43 ± 0.61, which ranged from 3 to 5. The mean PSSUQ score were in good to excellent range with mean of 6.02 ± 0.97, which ranged from 3.19 to 7. The overall SUS score was 76.0 ± 17.6, which ranged from 45 to 100. The total uMARS score had excellent internal consistency (Cronbach alpha = 0.984). uMARS and its subscales were strongly correlated with PSSUQ (coefficient 0.758-0.819, P < 0.001) and SUS (coefficient 0.535-0.561, P < 0.001), respectively.

CONCLUSIONS

Data obtained from the usability evaluation questionnaires in this study indicated a high quality of the MH-NRES on the ease of use, satisfaction and perceived usefulness, which suggest this system might be a useful tool for anesthesiologists' education and management of MH crises. Future feedback from high-fidelity simulation and clinical scenarios are need for further usability evaluation of this system.

A case report of Andersen-Tawil syndrome misdiagnosed with myodystrophy

Andersen-Tawil syndrome (ATS) is a rare periodic paralysis caused by the KCNJ2 gene mutation. Here, we report on an ATS patient misdiagnosed with myodystrophy. A 66-year-old man presented with a 60-year history of episodic weakness in the proximal muscles of the upper and lower limbs. The man has been diagnosed with muscle pathology and has undergone genetic examinations in many hospitals since childhood. We conducted a correct diagnosis in combination with the patient's history, electrical physiology, and genetic analysis and identified a heterozygous KCNJ2 gene variant (c.220A > G; p.T74A). Patients with ATS can develop permanent myasthenia characterized by chronic progressive myopathy. ATS patients should also pay special attention to the risks of anesthesia in surgery, including malignant hyperthermia (MH), muscle spasms affecting tracheal intubation or ventilation, and ventilator weakness. Early diagnosis and therapy could help delay the onset of myasthenia and prevent risks associated with anesthesia accidents.

Real Evidence and Misconceptions about Malignant Hyperthermia in Children: A Narrative Review

Malignant hyperthermia is a rare but life-threatening pharmacogenetic disorder triggered by exposure to specific anesthetic agents. Although this occurrence could affect virtually any patient during the perioperative time, the pediatric population is particularly vulnerable, and it has a five-fold higher incidence in children compared to adults. In the last few decades, synergistic efforts among leading anesthesiology, pediatrics, and neurology associations have produced new evidence concerning the diagnostic pathway, avoiding unnecessary testing and limiting false diagnoses. However, a personalized approach and an effective prevention policy focused on clearly recognizing the high-risk population, defining perioperative trigger-free hospitalization, and rapid activation of supportive therapy should be improved. Based on epidemiological data, many national scientific societies have produced consistent guidelines, but many misconceptions are common among physicians and healthcare workers. This review shall consider all these aspects and summarize the most recent updates.

Multi-omic molecular profiling and network biology for precision anaesthesiology: a narrative review

Technological advancement, data democratisation, and decreasing costs have led to a revolution in molecular biology in which the entire set of DNA, RNA, proteins, and various other molecules - the 'multi-omic' profile - can be measured in humans. Sequencing 1 million bases of human DNA now costs US$0.01, and emerging technologies soon promise to reduce the cost of sequencing the whole genome to US$100. These trends have made it feasible to sample the multi-omic profile of millions of people, much of which is publicly available for medical research. Can anaesthesiologists use these data to improve patient care? This narrative review brings together a rapidly growing literature in multi-omic profiling across numerous fields that points to the future of precision anaesthesiology. Here, we discuss how DNA, RNA, proteins, and other molecules interact in molecular networks that can be used for preoperative risk stratification, intraoperative optimisation, and postoperative monitoring. This literature provides evidence for four fundamental insights: (1) Clinically similar patients have different molecular profiles and, as a consequence, different outcomes. (2) Vast, publicly available, and rapidly growing molecular datasets have been generated in chronic disease patients and can be repurposed to estimate perioperative risk. (3) Multi-omic networks are altered in the perioperative period and influence postoperative outcomes. (4) Multi-omic networks can serve as empirical, molecular measurements of a successful postoperative course. With this burgeoning universe of molecular data, the anaesthesiologist-of-the-future will tailor their clinical management to an individual's multi-omic profile to optimise postoperative outcomes and long-term health.

Polyetherimide- and folic acid-modified Fe3 O4 nanospheres for enhanced magnetic hyperthermia performance

Recent studies have highlighted the development prospects of magnetic hyperthermia in cancer therapy. A few studies on the application of Fe₃ O₄ nanospheres for the magnetic hyperthermia of gynecological malignancies have achieved certain efficacy, but there was no visible progress currently. In this work, Fe₃ O₄ nanospheres modified with polyetherimide (PEI) and folic acid (FA) were synthesized using a hydrothermal method for possible utility in biocompatible and active tumor-targeting magnetic induction hyperthermia. The PEI- and FA-coated Fe₃ O₄ nanospheres showed high crystallinity, well-dispersed spherical structures and ideal M_s value. As a result, the designed Fe₃ O₄ @ PEI@FA nanospheres achieved higher specific absorption rate (SAR) values at 360 kHz and 308 Oe, as well as excellent biocompatibility in Hela, SKOV3, HEC-1-A and NIH3T3 cells. These nanospheres can be used as an optimal heating agent for the magnetic hyperthermia treatment of gynecological cancers.

Oral Dantrolene for Myopathic Symptoms in Malignant Hyperthermia-Susceptible Patients: A 25-Year Retrospective Cohort Study of Adverse Effects and Tolerability

BACKGROUND

Patients susceptible to malignant hyperthermia (MH) may experience disabling manifestations of an unspecified myopathy outside the context of anesthesia, including myalgia, fatigue, or episodic rhabdomyolysis. Clinical observations suggest that oral dantrolene may relief myopathic symptoms in MH-susceptible (MHS) patients. However, high-dose oral dantrolene has been associated with severe hepatotoxicity.

METHODS

In a retrospective database review (1994-2018), we investigated a cohort of patients who were diagnosed as MHS by a positive caffeine-halothane contracture test (CHCT), had myopathic manifestations, and received oral dantrolene. Our aim was to investigate the occurrence of serious adverse effects and the adherence to oral dantrolene therapy. We also explored factors associated with self-reported clinical improvement, considering as nonresponders patients with intolerable adverse effects or who reported no improvement 8 weeks after starting treatment.

RESULTS

Among 476 MHS patients with positive CHCT, 193 had muscle symptoms, 164 started oral dantrolene, 27 refused treatment, and 2 were excluded due to abnormal liver function before starting therapy. There were no serious adverse effects reported. Forty-six of 164 patients (28%; 95% confidence interval [CI], 22%-35%) experienced mild to moderate adverse effects. Twenty-two patients (22/164, 13%; 95% CI, 9%-19%) discontinued treatment, among which 16 due to adverse effects and 6 due to lack of improvement. One hundred forty-two patients (87%; 95% CI, 80%-90%) adhered to therapy and reported improvement of myalgia (n = 78), fatigue (n = 32), or rhabdomyolysis/hiperCKemia (n = 32). The proportion of responders was larger among patients with MH history than among those referred due to a clinical myopathy with nonpertinent anesthetic history (97% vs 79%, respectively; 95% CI of the difference, 8.5-28; P < .001). Patients with a sarcoplasmic reticulum Ca2+ release channel ryanodine receptor gene ( RYR1 ) variant had higher odds of responding to dantrolene treatment (OR, 6.4; 95% CI, 1.3-30.9; P = .013). Dantrolene median dose was 50 (25-400) and 200 (25-400) mg·day -1 in responders and nonresponders, respectively.

CONCLUSIONS

We found that oral dantrolene produced no serious adverse effects within the reported dose range, and was well tolerated by most MH-susceptible patients presenting myopathic symptoms. Our study provides dosing and adverse effect data as a basis for further randomized controlled clinical trials to determine the efficacy of oral dantrolene for symptomatic relief in MHS-related myopathies.

Cognitive aids in the management of clinical emergencies: a systematic review

Clinical emergencies can be defined as unpredictable events that necessitate immediate intervention. Safety critical industries have acknowledged the difficulties of responding to such crises. Strategies to improve human performance and mitigate its limitations include the provision and use of cognitive aids, a family of tools that includes algorithms, checklists and decision aids. This systematic review evaluates the usefulness of cognitive aids in clinical emergencies. Following a systematic search of the electronic databases, we included 13 randomised controlled trials, reported in 16 publications. Each compared cognitive aids with usual care in the context of an anaesthetic, medical, surgical or trauma emergency involving adults. Most trials used only clinicians in the development and testing of the cognitive aids, and only some trials provided familiarisation with the cognitive aids before they were deployed. The primary outcome was the completeness of care delivered to the patient. Cognitive aids were associated with a reduction in the incidence of missed care steps from 43.3% to 11% (RR (95%CI) 0.29 (0.15-0.16); p < 0.001), and the quality of evidence was rated as moderate. The use of cognitive aids was related to decreases in the incidence of errors, increases in the rate of correctly performed steps and improvement in the clinical teamwork skills scores, non-technical skills scores, subjective conflict resolution scores and the global assessment of team performance. Cognitive aids had an inconsistent influence on the time to first intervention and time to complete care of the patient's condition. It is possible that this was a reflection of how common or rare the crisis in question was as well as the experience and expertise of the clinicians and team. Sufficient thought should be applied to the development of the content and design of cognitive aids, with consideration of the pre-existing guideline ecosystem. Cognitive aids should be tested before their deployment with adequate clinician and team training.

The Knowledge Profile, Competence and Pending Problems of Chinese Anesthesiologists in Dealing with Malignant Hyperthermia: A Cross-Sectional Survey

Purpose

The National Remote Emergency System for Malignant Hyperthermia (MH-NRES) is an applet in China, designed to help anesthesiologists manage MH crisis. However, there is limited information about encountered difficulties in dealing with MH among Chinese anesthesiologists. The purpose of the study was to explore the current competency and encountered difficulties in the management of MH, as a key first step for assessing the potential user needs to develop the MH-NRES.

Methods

The hospitals of different levels in different provinces across China were invited to participate in an online survey from November to December 2021. Anesthesiologists completed the online questionnaire containing four sections including demographic information, knowledge, competency, and continuing education about MH.

Results

A total of 1357 valid questionnaires were completed from anesthesiologists, most respondents (66.7%, n = 905) correctly answered the MH trigger drugs included volatile anesthetics and succinylcholine. However, most respondents (77.0%, n = 1045) did not know that the recommended initial dose of domestic dantrolene. Up to 83.9% (n = 1138) stated that their hospitals did not store dantrolene for MH emergency. More than half of respondents thought that it would take more than one hour to obtain dantrolene in emergency. Less work experiences, lower levels of hospital and educations and professional titles were associated with lower competency scores in managing MH. Only 31.0% (n = 936) reported that their hospital had ever conducted MH continuing education curricula. Scenario simulation is the training method that most interests the participants (79.0%, n = 1072) but a whopping 46.9% (n = 637) never received simulation.

Conclusion

The study indicated that difficulty in obtaining dantrolene, lack of competency in management of MH, difficulty in obtaining professional help, and poor teamwork were the main problems of most anesthesiologists in face of MH.

Pharmacogenomic profile of actionable molecular variants related to drugs commonly used in anesthesia: WES analysis reveals new mutations

Background: Genetic interindividual variability is associated with adverse drug reactions (ADRs) and affects the response to common drugs used in anesthesia. Despite their importance, these variants remain largely underexplored in Latin-American countries. This study describes rare and common variants found in genes related to metabolism of analgesic and anaesthetic drug in the Colombian population. Methods: We conducted a study that included 625 Colombian healthy individuals. We generated a subset of 14 genes implicated in metabolic pathways of common medications used in anesthesia and assessed them by whole-exome sequencing (WES). Variants were filtered using two pipelines: A) novel or rare (minor allele frequency-MAF <1%) variants including missense, loss-of-function (LoF, e.g., frameshift, nonsense), and splice site variants with potential deleterious effect and B) clinically validated variants described in the PharmGKB (categories 1, 2 and 3) and/or ClinVar databases. For rare and novel missense variants, we applied an optimized prediction framework (OPF) to assess the functional impact of pharmacogenetic variants. Allelic, genotypic frequencies and Hardy-Weinberg equilibrium were calculated. We compare our allelic frequencies with these from populations described in the gnomAD database. Results: Our study identified 148 molecular variants potentially related to variability in the therapeutic response to 14 drugs commonly used in anesthesiology. 83.1% of them correspond to rare and novel missense variants classified as pathogenic according to the pharmacogenetic optimized prediction framework, 5.4% were loss-of-function (LoF), 2.7% led to potential splicing alterations and 8.8% were assigned as actionable or informative pharmacogenetic variants. Novel variants were confirmed by Sanger sequencing. Allelic frequency comparison showed that the Colombian population has a unique pharmacogenomic profile for anesthesia drugs with some allele frequencies different from other populations. Conclusion: Our results demonstrated high allelic heterogeneity among the analyzed sampled, enriched by rare (91.2%) variants in pharmacogenes related to common drugs used in anesthesia. The clinical implications of these results highlight the importance of implementation of next-generation sequencing data into pharmacogenomic approaches and personalized medicine.

Rapid Dantrolene Administration with Body Temperature Monitoring Is Associated with Decreased Mortality in Japanese Malignant Hyperthermia Events

Purpose

Malignant hyperthermia (MH) is a rare genetic disorder but one of the most severe complications of general anesthesia. The mortality rate of MH has dropped from 70% in the 1960s to 15% because of dantrolene, the only currently accepted specific treatment for MH. In this study, we retrospectively identified the optimal dantrolene administration conditions to reduce MH mortality further.

Methods

Our database performed a retrospective analysis of patients with MH clinical grading scale (CGS) grade 5 (very likely) or 6 (almost certain) between 1995 and 2020. We examined whether dantrolene administration affected mortality and compared the clinical variables associated with improved prognosis. Furthermore, a multivariable logistic regression analysis was used to identify specific variables associated with improved prognosis.

Results

128 patients met the inclusion criteria. 115 patients were administered dantrolene; 104 survived, and 11 died. The mortality rate of patients who were not administered dantrolene was 30.8%, which was significantly higher than those of patients who were administered dantrolene (P = 0.047). Among patients administered dantrolene, the interval from the first sign of MH to the start of dantrolene administration was significantly longer in the deceased than in the survivors (100 min vs. 45.0 min, P < 0.001), and the temperature at the start of dantrolene administration was also significantly higher in the deceased (41.6°C vs. 39.1°C, P < 0.001). There was no significant difference in the rate of increase in temperature between the two, but there was a substantial difference in the maximum temperature (P < 0.001). The multivariable analysis also showed that the patient's temperature at dantrolene administration and interval from the first MH sign to dantrolene administration was significantly associated with improved prognosis.

Conclusions

Dantrolene should be given as rapidly as possible once MH has been diagnosed. Beginning treatment at a more normal body temperature can prevent critical elevations associated with a worse prognosis.

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 .

Malignant Hyperthermia in PICU—From Diagnosis to Treatment in the Light of Up-to-Date Knowledge

Malignant Hyperthermia (MH) is a rare, hereditary, life-threatening disease triggered by volatile anesthetics and succinylcholine. Rarely, MH can occur after non-pharmacological triggers too. MH was detected more often in children and young adults, which makes this topic very important for every pediatric specialist, both anesthesiologists and intensivists. MH crisis is a life-threatening severe hypermetabolic whole-body reaction. Triggers of MH are used in pediatric intensive care unit (PICU) as well, volatile anesthetics in difficult sedation, status asthmaticus or epilepticus, and succinylcholine still sometimes in airway management. Recrudescence or delayed onset of MH crisis hours after anesthesia was previously described. MH can also be a cause of rhabdomyolysis and hyperpyrexia in the PICU. In addition, patients with neuromuscular diseases are often admitted to PICU and they might be at risk for MH. The most typical symptoms of MH are hypercapnia, tachycardia, hyperthermia, and muscle rigidity. Thinking of the MH as the possible cause of deterioration of a patient’s clinical condition is the key to early diagnosis and treatment. The sooner the correct treatment is commenced, the better patient´s outcome. This narrative review article aims to summarize current knowledge and guidelines about recognition, treatment, and further management of MH in PICU.

Complications From Operator Modification of the Esophageal Temperature Probe

Intraoperative temperature monitoring of surgical patients is an important aspect of perioperative care. Central core temperature monitoring is often accomplished using an 18 French esophageal device inserted through the mouth into the esophagus, while patients are undergoing general anesthesia. Placement of a modified esophageal temperature probe (i.e. with the protective plastic covering removed) into the nasopharynx of a patient may cause significant patient harm by injuring the nasal mucosa and/or turbinates. An internal survey of current practice at our academic institution reveals that 78% of anesthesia providers modify the esophageal temperature probes, leading to an 11% injury incidence. A practical solution to avoid complications is to place a pediatric size 9 French esophageal temperature probe into the nasopharynx to monitor the central core temperature.

Perioperative management of malignant hyperthermia during general anesthesia: A report of two cases

Malignant hyperthermia (MH) is a lethal complication associated with general anesthesia characterized by sudden onset, rapid progression, and high mortality. We present two seemingly typical cases of intraoperative MH development, with details on perioperative assessment and rescue. Postoperative genetic test showed mutations in the ryanodine receptor type 1 gene.

Gene Panel Sequencing Identifies a Novel RYR1 p.Ser2300Pro Variant as Candidate for Malignant Hyperthermia with Multi-Minicore Myopathy

Malignant hyperthermia (MH), a rare autosomal dominant pharmacogenetic disorder of skeletal muscle calcium regulation, is triggered by sevoflurane in susceptible individuals. We report a Korean having MH with multi-minicore myopathy functionally supported by RYR1-mediated intracellular Ca2+ release testing in B lymphocytes. A 14-year-old boy was admitted for the evaluation of progressive torticollis accompanied by cervicothoracic scoliosis. During the preoperative drape of the patient for the release of the sternocleidomastoid muscle under general anesthesia, his wrist and ankle were observed to have severe flexion contracture. The body temperature was 37.1 °C. To treat MH, the patient was administered a bolus of dantrolene intravenously (1.5 mg/kg) and sodium bicarbonate. After a few minutes, muscle rigidity, tachycardia, and EtCO2 all resolved. Next-generation panel sequencing for hereditary myopathy identified a novel RYR1 heterozygous missense variant (NM_000540.2: c.6898T > C; p.Ser2300Pro), which mapped to the MH2 domain of the protein, a hot spot for MH mutations. Ex vivo RYR1-mediated intracellular Ca2+ release testing in B lymphocytes showed hypersensitive Ca2+ responses to isoflurane and caffeine, resulting in an abnormal Ca2+ release only in the proband, not in his family members. Our findings expand the clinical and pathological spectra of information associated with MH with multi-minicore myopathy.

A case of giant dental calculus in a patient with centronuclear myopathy

INTRODUCTION

Centronuclear myopathy is a hereditary congenital muscle disease. It is characterized by generalized muscle hypotonia from early childhood, elongated cacial appearance, mandibular undergroth, and dental malposition. In this report, we discuss the clinical course and management of a patient with centronuclearmyopathy, who developed a giant dental calculus in the floor of the mouth and underwent surgical excision.

CASE REPORT

A 37-year-old Japanese man was referred to our hospital, and reported a swelling in the floor of the mouth. The patient affects centronuclear myopathy and has generalized muscle weakness. CT images showed a high-density area in the floor of the mouth measuring 35 × 28 × 20 mm. The lesion was clinically diagnosed as giant dental calculus, and surgically removed.

CONCLUSION

We have experienced a case of giant dental calculus in a patient with centronuclear myopathy. In dental treatment, we must consider generalized muscle weakness.

Pharmacokinetics of Dantrolene in the Plasma Exchange Treatment of Malignant Hyperthermia in a 14-Year-Old Chinese Boy: A Case Report and Literature Review

Malignant hyperthermia (MH) is a rare life-threatening response that is triggered by exposure to specific anesthetics commonly used during surgical interventions. Dantrolene is a well-known drug used as the first-line therapy for MH. A 14-year-old Chinese boy with a mutation in type 1 Ryanodine receptor (RyR1) whose muscle biopsy diagnosis was central core disease (CCD) had an occurrence of MH after a cervical spine surgery, during which he was placed under general anesthesia without volatile anesthetics or succinylcholine. The MH crisis treatment workflow was started and intravenous dantrolene was used, which was soon combined with sequent continuous veno-venous hemofiltration (CVVH) and plasma exchange (PE) therapy. We explored the pharmacokinetic profile of dantrolene during PE treatment. It showed that a one-compartment model with first-order kinetics was sufficient to characterize dantrolene pharmacokinetics (PK). The renal clearance estimate for dantrolene was 0.33 mL/(min*kg) and the volume of distribution was 0.51 L/kg. Though a 4-h PE elevated about 27% off-clearance for dantrolene, it eliminated extra dantrolene by a mere 4% of the area under the curve (AUC). We made no recommendation with respect to adjusting dantrolene dosing for MH adolescents with a 4-h PE.

Management of patients susceptible to malignant hyperthermia: A surgeon's perspective

OBJECTIVES

Malignant hyperthermia (MH) susceptibility caries broad implications for the care of pediatric surgical patients. While precautions must often be taken for only a vague family history, two options exist to assess MH-susceptibility. We evaluate the use of MH precautions and susceptibility testing at a freestanding children's hospital.

METHODS

This single institution retrospective cohort study identified patients of any age who received general anesthetics utilizing MH precautions over a five-year period. The electronic medical record was further queried for patients diagnosed with MH. The indication for MH precautions and uses of susceptibility testing are assessed. Secondary outcomes included a diagnosis of bona fide MH.

RESULTS

A total of 125 patients received 174 anesthetics with MH precautions at a mean age of 114 months (0-363 months). Otolaryngology was the procedural service most frequently involved in the care of the cohort (n = 45; 26%). A reported personal or family history of MH (n = 102; 59%) was the most common indication for precautions, followed by muscular dystrophy (n = 29; 17%). No MH events occurred in the cohort and further review of ICD-9 and -10 diagnosis codes found no MH diagnoses. No study subjects received muscle biopsy and contracture testing and only 5 (4%) underwent genetic testing for genomic variants known to cause MH susceptibility. A case example is given to highlight the implications of a reported MH history.

CONCLUSION

Otolaryngologists should maintain a familiarity with the precautions necessary to manage patients at risk for MH and MH-like reactions. Without an accessible test to rule out susceptibility, surgeons must rely on a careful history to appropriately utilize precautions. An inappropriate label of "MH-susceptible" may result in decreased access to care and treatment delays.

Functionalized SPION immobilized on graphene-oxide: Anticancer and antiviral study

The progressive and fatal outbreak of some diseases such as cancer and coronavirus necessitates using advanced materials to bring such devastating illnesses under control. In this study, graphene oxide (GO) is decorated by superparamagnetic iron oxide nanoparticles (SPION) (GO/SPION) as well as polyethylene glycol functionalized SPION (GO/SPION@PEG), and chitosan functionalized SPION (GO/SPION@CS). Field emission scanning electron microscopic (FESEM) images show the formation of high density uniformly distributed SPION nanoparticles on the surface of GO sheets. The structural and chemical composition of nanostructures is confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The saturation magnetization of GO/SPION, GO/SPION@PEG and GO- SPION@CS are found to be 20, 19 and 8 emu/g using vibrating sample magnetometer. Specific absorption rate (SAR) values of 305, 283, and 199 W/g and corresponding intrinsic loss power (ILP) values of 9.4, 8.7, and 6.2 nHm²kg^-1 are achieved for GO/SPION, GO/SPION@PEG and GO/SPION@CS, respectively. The In vitro cytotoxicity assay indicates higher than 70% cell viability for all nanostructures at 100, 300, and 500 ppm after 24 and 72 h. Additionally, cancerous cell (EJ138 human bladder carcinoma) ablation is observed using functionalized GO/SPION under applied magnetic field. More than 50% cancerous cell death has been achieved for GO/SPION@PEG at 300 ppm concentration. Furthermore, Surrogate virus neutralization test is applied to investigate neutralizing property of the synthesized nanostructures through analysis of SARS-CoV-2 receptor-binding domain and human angiotensin-converting enzyme 2 binding. The highest level of SARS-CoV-2 virus inhibition is related to GO/SPION@CS (86%) due to the synergistic exploitation of GO and chitosan. Thus, GO/SPION and GO/SPION@PEG with higher SAR and ILP values could be beneficial for cancer treatment, while GO/SPION@CS with higher virus suppression has potential to use against coronaviruses. Thus, the developed nanocomposites have a potential in the efficient treatment of cancer and coronavirus.

Malignant hyperthermia-like syndrome in acute chlorfenapyr poisoning- a case report

Background

Chlorfenapyr is a pesticide that interferes with mitochondrial oxidative phosphorylation, resulting in the disruption of ATP production and cellular death. We present a fatal case of chlorfenapyr poisoning presented with malignant hyperthermia- like syndrome after intubation.

Case presentation

A 49-year-old male presented with fatigue and diaphoresis four days after ingesting emamectin chlorfenapyr. IV hydration was given, and two sessions of hemoperfusion were performed. He was intubated for airway protection on Day 3 because of drowsiness. Immediately after intubation, he developed tachycardia and hyperthermia (temperature 41 °C), followed by cardiac arrest. During resuscitation, we noted he had severe diaphoresis and generalized muscle rigidity. Peri-arrest ABG showed abrupt onset of severe type 2 respiratory failure, lactate acidosis, and hyperkalemia. The clinical manifestation and ABG result lead to the possible diagnosis of malignant hyperthermia. The resuscitation was unsuccessful, and the patient eventually passed away. Propofol might be the culprit drug in this case as it is known to affect mitochondrial metabolism via uncoupling oxidative phosphorylation.

Conclusion

We suggest monitoring for signs and symptoms of malignant hyperthermia in chlorfenapyr poisoning, especially after intubation. Propofol should be avoided or used with caution during induction for intubation. Further research on the possible antidote and usage of early RRT in ED is needed.

Variants in ASPH cause exertional heat illness and are associated with malignant hyperthermia susceptibility

Exertional heat illness (EHI) and malignant hyperthermia (MH) are life threatening conditions associated with muscle breakdown in the setting of triggering factors including volatile anesthetics, exercise, and high environmental temperature. To identify new genetic variants that predispose to EHI and/or MH, we performed genomic sequencing on a cohort with EHI/MH and/or abnormal caffeine-halothane contracture test. In five individuals, we identified rare, pathogenic heterozygous variants in ASPH, a gene encoding junctin, a regulator of excitation-contraction coupling. We validated the pathogenicity of these variants using orthogonal pre-clinical models, CRISPR-edited C2C12 myotubes and transgenic zebrafish. In total, we demonstrate that ASPH variants represent a new cause of EHI and MH susceptibility.

First National Remote Emergency System for Malignant Hyperthermia (MH-NRES) in China: Protocol for a WeChat applet Design, Development, and Evaluation (Preprint)

Background

Malignant hyperthermia (MH) is a rare life-threatening anesthetic emergency. With respect to the high fatality rate, difficulty in early recognition, and the lack of disease-specific drug (ie, dantrolene) in China, more effort is needed to strengthen early diagnosis and effective treatment of MH emergencies. Nowadays, mobile health (mHealth) apps are changing the way of medical practice; they can serve as an accessible tool to help anesthesiologists deal with MH crises. However, no related mHealth-based emergency system is available currently.

Objective

The aim of this study is to outline the protocol for the development of a WeChat applet used to design a National Remote Emergency System for Malignant Hyperthermia (MH-NRES) in China, as well as the protocol for the evaluation of the user experience and perception of the system.

Methods

The system adopts the client-server architecture, with a custom user interface operating as clients and the back-end system operating as the server. The client-side software was developed using uni-app technology with Vue.js-based framework, which consists of 6 modules: Quick Diagnosis, Dantrolene Mobilization, Instruction on Dantrolene Use, MH Treatment, Recovery Period Treatment, and DNA Test and Biopsy. The back-end system was developed based on the Spring framework. The system will be evaluated by administrating a modified user version of the Mobile App Rating Scale. Pilot testing will be conducted in Sichuan Province, China, and a subsequent evaluation on a national scale is planned.

Results

The theoretical framework design of this system was completed in August 2021. The development of the system was completed in February 2022, and the refinement is currently ongoing. Pilot testing after the implementation of the system in Sichuan Province is planned to take 2 months, and the subsequent evaluation on a national scale is planned to take 2 months.

Conclusions

We have described a novel approach using the WeChat applet to develop the MH-NRES. Findings from the usability testing process in the current study may lead to refinements and is expected to suggest that this system is both feasible and welcomed by anesthesiologists. Depending on the availability of research funding, this system will be extended nationally across China.

International Registered Report Identifier (IRRID)

PRR1-10.2196/37084

Simultaneous malignant hyperthermia reactions in two siblings during living donor liver transplantation

We report a case of simultaneous malignant hyperthermia reactions occurring in two siblings during living donor liver transplantation. This report highlights the conflicting goals in the clinical management of liver transplantation and malignant hyperthermia, including the use of total intravenous anaesthesia and dantrolene in the face of the potential for drug-induced hepatotoxicity in the remnant liver or transplanted liver graft, as well as cautious fluid management needed for liver transplantation balanced against the liberal fluid therapy required to prevent acute kidney injury associated with malignant hyperthermia. The logistical challenges of managing this emergency in two closely related patients are discussed, including rapid preparation of two vapour-free anaesthesia machines, the need for availability of additional dantrolene and the requirement for additional personnel. Prompt recognition, immediate removal of the triggering agents and conversion to total intravenous anaesthesia helped to curtail the malignant hyperthermic reactions in our patients, both of whom made a full recovery.

Awake Plastic Surgery Procedures: The Use of a Sufentanil Sublingual Tablet to Improve Patient Experience

Background

Awake plastic surgery performed under minimal sedation has advantages including patient preference, affordability, and easier recovery compared to when performed under deeper sedation. Commonly used oral analgesics may not be adequate for awake procedures resulting in moderate to severe pain. Sufentanil sublingual tablet (SST) 30 mcg has been shown to provide timely analgesia with a safety profile appropriate for minimal-sedation settings.

Objectives

To examine perioperative outcomes in patients who underwent awake plastic surgery with local anesthesia and SST 30 mcg for pain control.

Methods

This study was a prospective single-group cohort study conducted at a single plastic surgery center. SST 30 mcg was administered approximately 30 minutes prior to the procedure. Outcome measures included the number of patients with adverse events, the number of patients requiring medications in the post-anesthesia care unit (PACU), and recovery time.

Results

Among the 31 patients, the most common procedures were liposuction (71%), facelift (10%), and blepharoplasty (6%). The mean (± standard error [SE]) procedural duration was 81 ± 9 minutes. No vital sign instability or oxygen desaturation was observed. Three patients (10%) experienced nausea, only one of which required treatment with oral ondansetron 4 mg in the PACU. One patient (3%) experienced dizziness that did not require treatment. No patients required opioids or other analgesics in the PACU for pain. The mean (±SE) recovery time was 15 ± 4 minutes.

Conclusions

Awake plastic surgery can be performed using SST 30 mcg with minimal side effects and a rapid recovery time.

Level of Evidence: 4