This study examined the effect of ligation on the load-deflection characteristics of nickel-titanium (NiTi) orthodontic wire. A modified three-point bending system was used for bending the NiTi round wire, which was inserted and ligated in the slots of three brackets, one of which was bonded to each of the three bender rods. Three different ligation methods, stainless steel ligature (SSL), slot lid (SL), and elastomeric ligature (EL), were employed, as well as a control with neither bracket nor ligation (NBL). The tests were repeated five times under each condition. Comparisons were made of load-deflection curve, load at maximum deflection of 2,000 microm, and load at a deflection of 1,500 microm during unloading. Analysis of Variance (ANOVA) and Dunnett's test were conducted to determine method difference (alpha = 0.05). The interaction between deflection and ligation was tested, using repeated-measures ANOVA (alpha = 0.05). The load values of the ligation groups were two to three times greater than the NBL group at a deflection of 1,500 microm during unloading: 4.37 N for EL, 3.90 N for SSL, 3.02 N for SL, and 1.49 N for NBL (P < 0.01). For the EL, a plateau region disappeared in the unloading curve. SL showed the smallest load. The ligation of the bracket wire may make NiTi wire exhibit a significantly heavier load than that traditionally expected. NiTi wire exhibited the majority of its true superelasticity with SL, whereas EL may act as a restraint on its superelasticity.

Methymalonic acidemia (MMA) is a hereditary metabolic disorder characterized by a defect of the methylmalonyl-CoA mutase that breaks down propionate. The efficacy of liver transplantation for MMA was recently reported. However, the anesthetic management of liver transplant for MMA is not clear. The aim of this article is to describe an anesthetic management algorithm of liver transplant for MMA by reviewing our cases of liver transplant for MMA. Fourteen patients received a liver transplant; three cases showed metabolic decompensation during the transplant and two of the patients died. In the two patients who expired, propofol was used for maintenance anesthesia and preoperative continuous hemodiafiltration was used to reduce plasma methylmalonic acid level in one case, and to control severe metabolic decompensation before transplant for the other case. Their renal function was also worse than others and they were already experiencing metabolic decompensation before induction of anesthesia. Based on our experience of these 14 cases, we have established an anesthetic algorithm for patients with MMA undergoing liver transplant or other procedures. There are three important points in our experience: propofol should be avoided, dextrose infusion therapy should be continued to prevent metabolic decompensation, and liver transplant or other procedures should be avoided during metabolic decompensation.

Introduction Failure to secure an airway during general anesthesia is a major cause of adverse events (AEs) in children. The safety of peddiatric anesthesia may be improved by identifying the incidence of AEs and their attributed risk factors. However, previous large cohort studies have not been appropriately designed to explore such aspects. Thus, this study aims to deternine the incidence of AEs and the risk factors attributed to airway management under general anesthesia in children. Methods and design This prospective, multi-center, registry-based, observational study will be conducted in four tertiary care hospitals in Japan from June 2022 to May 2025. Children younger than 18 years of age undergoing surgical and/or diagnostic test procedures under general anesthesia or sedation by anesthesiologists will be enrolled in this study. Data on patient characteristics, discipline of anesthesia providers, and methodology of airway management will be collected through a standardized verification system under monitoring by institutional research leaders among the recruited institutions to minimize the loss of collected data. The primary outcome and exposure are AEs and presence of difficult airway features with potential confounders, which are related to the failure to secure the airway, and the variability in the anesthesia providers’ levels, adjusted using hierarchical multivariable regression models with mixed effects. Discussion This study will determine the incidence of AEs and the risk factors related to airway management under general anesthesia in children. Trial registration This study is registered as a prospective observational study in the University hospital Medical Information Network (UMIN) (registration number UMIN000047351, April 1, 2022).

Oral midazolam 1.5 mg x kg(-1) is excellent for preanaesthetic medication for infants and children undergoing cardiovascular surgery.

ObjectivesEmergence delirium (ED) occurs in approximately 25% of paediatric general anaesthetics and has significant adverse effects. The goal of the current systematic review was to identify the existing literature investigating performance of predictive models for the development of paediatric ED following general anaesthesia and to determine their usability.DesignSystematic review using the Prediction model study Risk Of Bias Assessment Tool (PROBAST) framework.Data sourcesMedline (Ovid), PubMed, Embase (Ovid), Cochrane Database of Systematic Reviews (Ovid), Cochrane CENTRAL (Ovid), PsycINFO (Ovid), Scopus (Elsevier) and Web of Science (Clarivate Analytics), ClinicalTrials.gov, International Clinical Trials Registry Platform and ProQuest Digital Dissertations and Theses International through 17 November 2020.Eligibility criteria for selecting studiesAll randomised controlled trials and cohort studies investigating predictive models for the development of ED in children undergoing general anaesthesia.Data extraction and synthesisFollowing title, abstract and full-text screening by two reviewers, data were extracted from all eligible studies, including demographic parameters, details of anaesthetics and performance characteristics of the predictive scores for ED. Evidence quality and predictive score usability were assessed according to the PROBAST framework.ResultsThe current systematic review yielded 9242 abstracts, of which only one study detailing the development and validation of the Emergence Agitation Risk Scale (EARS) met the inclusion criteria. EARS had good discrimination with c-index of 0.81 (95% CI 0.72 to 0.89). Calibration showed a non-significant Homer-Lemeshow goodness-of-fit test (p=0.97). Although the EARS demonstrated low concern of applicability, the high risk of bias compromised the overall usability of this model.ConclusionsThe current systematic review concluded that EARS has good discrimination performance but low usability to predict ED in a paediatric population. Further research is warranted to develop novel models for the prediction of ED in paediatric anaesthesia.PROSPERO registration numberCRD42019141950.