Simulation training for medical emergencies: Evaluation of dentists' long-term learning skills and confidence.

INTRODUCTION: As the population ages and more patients experience medical emergencies during dental treatments, dentists must competently and confidently manage these situations. We developed a simulation training course for medical emergencies in the dental setting using an inexpensive vital sign simulation app for smartphones/tablets without the need for an expensive simulator. However, the duration for which this effect is maintained is unclear. This study was performed to evaluate the long-term educational effect at 3, 6, and 12 months after taking the course. MATERIALS AND METHODS: Thirty-nine dental residents participated in this course. Scenarios included vasovagal syncope, anaphylaxis, hyperventilation syndrome, and acute coronary syndrome, each of which the participants had to diagnose and treat. The participants were evaluated using a checklist for anaphylaxis diagnosis and treatment skills immediately after and 3, 6, and 12 months after the course. The participants were also surveyed about their confidence in diagnosing and treating these conditions by questionnaire before, immediately after, and 3, 6, and 12 months after the course. RESULTS: The checklist scores for anaphylaxis were significantly lower at 3, 6, and 12 months after the course than immediately after the course. The percentage of participants who provided a correct diagnosis and appropriate treatment for vasovagal syncope, hyperventilation syndrome, and acute coronary syndrome was lower at all reassessments than immediately after the course. CONCLUSION: Because medical emergency management skills and confidence declined within 3 months, it would be useful to introduce a refresher course approximately 3 months after the initial course to maintain skills and confidence.

A survey on the safety of anesthesia management provided by dental anesthesiologists in Japan: a 5-year survey by the Japanese Dental Society of Anesthesiology.

OBJECTIVES: The Japanese Dental Society of Anesthesiology (JDSA) has conducted a survey on the safety of anesthetic practice provided by dental anesthesiologists. This report includes information on the incidence of life-threating events, which is necessary for evaluating the safety of dental anesthesia. MATERIAL AND METHODS: This study was designed as a retrospective observational questionnaire-based survey. All 32 JDSA accredited training facilities participated in this study. The accredited facilities were requested to provide annual data on basic demographic information concerning anesthetic management during the 5-year period from 2014 to 2018, inclusive. Details regarding life-threatening events were also requested. RESULTS: During the survey period between 2014 and 2018, a total of 219,343 cases of anesthetic management (80,138 cases of general anesthesia, 127,819 cases of sedation, and 11,386 cases of monitoring) were reported by the 32 JDSA accredited training facilities. The overall incidence of life-threatening events occurring during clinical dental anesthesia was 2.14/10,000, while the incidence of anesthesia-related events was 0.96/10,000. No deaths arising from anesthesia-related events occurred. CONCLUSIONS: This is the first survey on clinical outcomes of dental anesthesia to be conducted. The survey results provide evidence supporting the safety of anesthetic management as performed by dental anesthesiologists. CLINICAL RELEVANCE: The results of this study will provide a basis for benchmarking the safety of dental anesthesia not only in Japan, but also around the world.

Impact of Stellate Ganglion Block on Tissue Blood Flow/Oxygenation and Postoperative Mandibular Nerve Hypoesthesia: A Cohort Study.

PURPOSE: Although a stellate ganglion block (SGB) increases tissue blood flow in the mandibular region, the change in tissue oxygenation after SGB and therapeutic effect of SGB for postoperative mandibular nerve hypoesthesia remain to be established. The study aim was to measure the change in tissue oxygenation in the mandibular region after SGB. METHODS: To determine the variation in tissue oxygenation in the mandibular region, the tissue oxygen index (TOI; percentage of oxygenated hemoglobin in the total hemoglobin) was measured at the skin near the mental foramen bilaterally, at the primary site of unilateral SGB, achieved using 6 mL of 1% lidocaine hydrochloride, for the treatment of bilateral postoperative mandibular nerve injury. The primary outcome of this study is the temporal variation in TOI after SGB (0.5, 1, 5, 10, 15, 20, and 25 minutes after SGB), and the control group in this study is the TOI at the end of SGB injection (0 minute). All data are expressed as the mean ± standard deviation and 95% confidence interval (CI). Repeated-measures analysis of variance with Dunnett's test was used to determine parametric statistical significance. A P-value <.05 was considered statistically significant. RESULTS: Thirteen patients were enrolled in this study. On both the blocked and contralateral side, the TOI was significantly increased compared to that before SGB (ΔTOI at 15 minute after SGB, 5.87 ± 2.89%, P < .001, 95% CI: 4.122 to 7.617% in the blocked side, 1.88 ± 2.73%, P = .005, 95% CI: 1.877 to 2.725% in the contralateral side). CONCLUSIONS: Unilateral SGB using 6 mL of 1% lidocaine hydrochloride results in an increase in tissue oxygenation in the mandibular region. Based on these findings, we hypothesize that a series of SGBs may contribute to a more rapid recovery of postoperative trigeminal nerve injury.

Effects of magnesium sulfate administration in attenuating chronic postsurgical pain in rats.

Chronic postsurgical pain (CPSP) is a serious issue for many postoperative patients. Though there are numerous treatment options for the prevention of CPSP, none of them is optimal as the mechanisms of the transition from acute to chronic postoperative pain have not been elucidated. Ketamine and opioids have been administered for chronic postoperative pain treatment but induce severe adverse reactions and/or physical dependency. Here, we examined whether pre-administration of the nonselective N-methyl-d-aspartate (NMDA) receptor antagonist magnesium sulfate attenuates CPSP behavior and alters the expression of glutamate ionotropic receptor NMDA type subunit 1a (Grin1 mRNA) in a rat skin/muscle incision and retraction (SMIR) model. We assessed the effects of a single subcutaneous magnesium sulfate injection on nociceptive behaviors including guarding pain, mechanical hyperalgesia, and heat hypersensitivity in rats after SMIR surgery. We used reverse transcription-quantitative PCR (RT-qPCR) to evaluate Grin1 mRNA expression in the dorsal horn of the spinal cord on postoperative day 14. Compared with the vehicle, magnesium sulfate administration before SMIR surgery reduced mechanical hyperalgesia for 17 d Grin1 gene expression was significantly higher on the ipsilateral side than the contralateral side (P = 0.001) on postoperative day 14. The magnesium sulfate injection prevented Grin1 mRNA upregulation in the spinal cord dorsal horn. A single magnesium sulfate injection mitigated SMIR-induced mechanical hyperalgesia possibly by modulating Grin1 expression. Preoperative magnesium sulfate administration could prove to be a simple and safe CPSP treatment.

Effect of nasal high-flow oxygen therapy on the swallowing reflex: an in vivo volunteer study.

OBJECTIVE: The advantages of nasal high-flow oxygen therapy (NHF) include not only allowing talking, but also eating and drinking, during the therapy. However, the effect of NHF on the swallowing reflex remains unclear. In the present study, we aimed to assess the effects of NHF on the swallowing reflex. METHODS: Nine healthy adult Japanese male volunteers with no history of dysphagia or diseases that may cause dysphagia, such as stroke or Parkinson's disease, were evaluated. Participants received one of four levels of NHF intervention (0 (control), 15, 30 and 45 L/min of oxygen) with the NHF system through the nasal cannula. Swallowing was induced by the administration of a bolus injection of 5 mL of distilled water over 3 s through a polyethylene catheter at each level of oxygen flow. The primary end-point was the latency period of the swallowing reflex after bolus injection, which was defined as the time from the start of the bolus injection to the onset of the electromyogram (EMG) burst of the first swallow. RESULTS: Mean latency times of the swallowing reflex with 15 (9.8 ± 2.9 s), 30 (9.0 ± 2.7 s) and 45 (8.5 ± 3.0 s) L/min of NHF were significantly shorter than those under control conditions (11.9 ± 3.7 s; P < 0.05). CONCLUSIONS: Our study demonstrates that NHF may enhance swallowing function with increasing levels of NHF by reducing the latency of the reflex. CLINICAL RELEVANCE: NHF may allow continuation of oral intake without aspiration during oxygen therapy.

Nitrous Oxide Inhalation Sedation Through a Nasal High-Flow System: The Possibility of a New Technique in Dental Sedation.

High-flow nasal cannula (HFNC) systems are increasingly used for patients with both acute and chronic respiratory failure because of the clinical effectiveness and patient comfort associated with their use. Recently, HFNC has been used not only as a respiratory support device, but also as a drug delivery system. HFNC is designed to administer heated and humidified inspiratory oxygen flows (100% relative humidity at 37°C). Therefore, HFNC can provide high flows (up to 60 L/min) without discomfort. Moreover, HFNC improves oxygenation by exerting physiologic effects such as (a) dead-space washout and (b) moderate positive airway pressure. These characteristics and physiologic effects of HFNC may permit administration of high-flow nitrous oxide sedation while ensuring patient comfort and adequate sedative effect.

Perioperative management of tooth extractions for a patient with hereditary angioedema.

Hereditary angioedema (HAE) is a rare genetic disorder that causes a deficiency in or dysfunction of C1 esterase inhibitor (C1-INH) and is clinically characterized by sudden and recurrent attacks of angioedema. Although almost any part of the body can be affected, HAE is of greatest concern and can be life-threatening when the upper airway is involved, particularly the larynx (laryngeal attack). HAE attacks can be triggered by physical or psychological stress or can arise spontaneously without any apparent trigger. Dental treatments and routine oral surgical procedures, such as tooth extraction, abound with factors that can trigger an attack of HAE. Indeed, several cases of death resulting from HAE attacks have been reported after such procedures. Therefore, patients with HAE are of special concern in dentistry and require precautionary preparations before treatment. This report describes the successful management of tooth extractions in a patient with HAE who was at high risk of an HAE-induced laryngeal attack.

Comparison of insertion of the modified i-gel airway for oral surgery with the LMA Flexible: a manikin study.

We previously modified the i-gel airway to enable its use in the field of oral and maxillofacial surgery and reported its fabrication methods. In general, the standard i-gel airway is quick to insert and has a high success rate, but the modified i-gel airway has yet to be assessed for these attributes. We, therefore, set out to compare the ease of insertion of the modified i-gel airway with the LMA Flexible to investigate the usefulness of the modified i-gel airway. The study participants, who included 20 new interns with no experience using either the LMA Flexible or the modified i-gel airway, inserted each device 3 times into an intubation practice manikin. The variables measured in this study were insertion time and rate of successful insertions. Mean insertion time over 3 attempts was significantly shorter for the modified i-gel™ airway (18.9 ± 4.7 seconds) than the LMA Flexible (24.9 ± 5.1 seconds, P < .001). The rate of successful insertions as a total of all 3 attempts was significantly higher for the modified i-gel airway (56/60 times, 93.3%) than the LMA Flexible (45/60 times, 75%; P = .012). When used by an inexperienced operator, the modified i-gel™ airway is faster and has a higher success rate than the LMA Flexible, suggesting that it can be easily manipulated during insertion.

Upside-down mask ventilation technique for a patient with a long and narrow mandible.

Mask ventilation, along with tracheal intubation, is one of the most basic skills for managing an airway during anesthesia. Facial anomalies are a common cause of difficult mask ventilation, although numerous other factors have been reported. The long and narrow mandible is a commonly encountered mandibular anomaly. In patients with a long and narrow mandible, the gaps between the corners of the mouth and the lower corners of the mask are likely to prevent an adequate seal and a gas leak may occur. When we administer general anesthesia for these patients, we sometimes try to seal the airway using several sizes and shapes of commercially available face masks. We have found that the management of the airway for patients with certain facial anomalies may be accomplished by attaching a mask upside down.

Effectiveness of tranexamic acid on intra- and postoperative bleeding in Bimaxillary osteotomies: a retrospective study.

PURPOSE: Perioperative bleeding is a serious concern during orthognathic surgery. Tranexamic acid (TXA), a synthetic lysine analog with antifibrinolytic properties, reduces blood loss across various surgical fields. This study aimed to investigate the effectiveness of preoperative TXA administration in reducing intraoperative and postoperative blood loss following combined Le Fort I and sagittal split ramus osteotomies at our hospital. METHODS: This single-center, retrospective cohort study included patients who underwent combined Le Fort I and sagittal split ramus osteotomies between November 2017 and October 2022. The primary outcome was the volume of intraoperative blood loss. RESULTS: Among 1,329 eligible patients, 87 were included in the analysis (32 in the TXA group and 55 in the control group, where no TXA was administered). The median (interquartile range) intraoperative blood loss was 200.0 (157.5-237.5) mL in the TXA group and 260.0 (180.0-350.0) mL in the control group, showing a significant difference between the groups (p = 0.0365). However, postoperative blood drainage within 24 h and 24-48 h did not differ significantly between the two groups. CONCLUSION: A single intravenous administration of TXA was associated with a decrease in intraoperative bleeding without severe adverse events during combined Le Fort I and sagittal split ramus osteotomies. However, postoperative blood loss, nausea, vomiting, and autologous blood transfusion were not significantly associated with this administration.

Analysis of Sedation Accident Records Available in the Japan Council for Quality Health Care Public Database.

OBJECTIVE: Medical accidents occur frequently. However, only a few studies have been conducted on sedation-related medical accidents. This study aimed to classify sedation accidents and analyze their causes using the (Patient-management Software Hardware Environment Livewear (P-mSHELL) model. METHODS: The Japan Council for Quality Health Care database on medical accidents was used. Sedation accidents that occurred during procedures between January 2010 and June 2022 were included. After examining the accident details for several variables, the accident factors were classified by factors in the P-mSHELL model, and statistical analyses, including multivariate analysis of each factor and outcome (presence or absence of residual disability), were conducted. RESULTS: Regarding the influence of the P-mSHELL factors on outcome, P factor (odds ratio = 6.347, 95% confidence interval = 2.000, 20.144) was a factor for having disability. There was a significant association between outcome and accident timing (that is, preoperative, intraoperative, or postoperative; p =0.01). No significant association was found between the outcomes and types of drugs used (p =1, 0.722, 0.594); however, there was a significant association between the incidence of respiratory depression and multiple drug use (p <0.001). CONCLUSIONS: To prevent sedation accidents, it is important to monitor patients throughout the perioperative period. However, it is especially important to know the patient's condition in advance, and strict postoperative management is essential, especially for high-risk patients, to prevent serious accidents.

The impact of preoperative psychiatric intervention for postoperative delirium after major oral and maxillofacial surgery with free flap reconstruction.

BACKGROUND: Postoperative delirium (POD) is a severe complication associated with various adverse outcomes, especially in older patients. Although the incidence and risk factors for POD have been explored in general surgery, they have not been fully elucidated. Early identification of high-risk patients and active preoperative intervention are considered essential for the prevention of POD. Recently, psychiatric consultation intervention have been shown to prevent delirium. This study investigated the effect of preoperative psychiatric interventions on preventing POD in our specific surgical context. MATERIALS AND METHODS: This retrospective, single-center observational study included 86 patients who underwent major oral and maxillofacial surgery with free flap reconstruction between 2016 and 2023. The effect of psychiatric intervention were compared between patients with and without delirium. RESULTS: Preoperative psychiatric intervention did not reduce the incidence of POD. The incidence of POD was 29.1 %. Univariate analyses showed no significant associations between POD and any clinical variables. CONCLUSION: There was no difference in the incidence of POD between patients who received preoperative psychiatric intervention and those who did not, and further investigation is needed to determine the efficacy of preoperative psychiatric intervention in the prevention of POD.

Comparative Analysis of the Hemodynamic Effects of Remimazolam and Propofol During General Anesthesia: A Retrospective Study.

PURPOSE: Hypotension is common during anesthesia induction. However, minimal hemodynamic effects of remimazolam anesthesia have been reported. We hypothesized that remimazolam would have weaker hemodynamic effects than would propofol. To test this, we simultaneously evaluated the hemodynamics using the estimated continuous cardiac output (esCCO) system and heart rate variability (HRV) during anesthesia induction. METHODS: This was a single-center, observational, retrospective study of patients undergoing dental surgery under general anesthesia between 2020 and 2022. Seventy patients were divided into two groups: remimazolam (R group; n=34) and propofol (P group; n=36). The information obtained from the anesthesia records, patient information, esCCO system parameters, and HRV were integrated and analyzed. The percentages of various parameters were set to 100% for the pre-induction phase as the baseline. RESULTS: The %MAP (noninvasive mean arterial blood pressure) decreased over a narrower range in the R compared to the P group (-17.8% (-26.3%, -11.9%) vs. -22.6% (-32.9%, -17.0%); P=0.039). The %HR (heart rate) increased significantly in the R group and decreased in the P group (+10.7% (+6.5%, +18.6%) vs. -6.5% (-14.5%, +8.4%); P<0.01). The %SVesCCO (stroke volume calculated using the esCCO system) decreased significantly in both groups, but the R group showed a smaller difference compared to the P group (- 5.1% (-7.7%, -2.1%) vs. -10.0% (-13.8%, -5.6%); P<0.01). The rates of change in %LF nu (normalized unit of low frequency) and %HF nu (normalized unit of high frequency) were lower for the R than for the P group, although the difference was not significant (+6.8% (-14.5%, 32.4%) vs. +9.2% (-7.2%, +59.7%), P=0.30; +7.9% (-51.0%, +66.9%) vs. +22.8% (-26.1%, +61.6%), P=0.57). CONCLUSION: Remimazolam demonstrated a lower MAP reduction rate than propofol. A compensatory increase in HR occurred with a decrease in stroke volume. However, the HR increase was not attributable to the autonomic nervous system.

Effect of Dental Local Anesthetics on Reactive Oxygen Species: An In Vitro Study.

Introduction Oxidative stress, an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, plays an important role in various dental diseases. Local anesthetics are frequently used in dentistry. The potential antioxidant activity of dental local anesthetics can contribute to dental practice. Therefore, this study aimed to investigate the ROS-scavenging activities of three commonly used dental local anesthetics, lidocaine, prilocaine, and articaine, focusing on their effects on hydroxyl radicals (HO•) and superoxide anions (O2 •-). Materials and methods The electron spin resonance (ESR) spin-trapping technique was employed to specifically measure the ROS-scavenging activities of these local anesthetics at varying concentrations. Results Lidocaine, prilocaine, and articaine exhibited concentration-dependent HO•-scavenging activities, with IC50 values of 0.029%, 0.019%, and 0.014%, respectively. Lidocaine and prilocaine showed concentration-dependent O2 •--scavenging activity, with IC50 values of 0.033% and 0.057%, respectively. However, articaine did not scavenge O2 •-. Conclusions The proactive use of dental local anesthetics may mitigate oxidative injury and inflammatory damage through direct ROS scavenging. However, further research is needed to elucidate the specific mechanisms underlying the antioxidant effects of these dental local anesthetics and their potential impact on the dental diseases associated with oxidative stress.

Survey on the Awareness of the Use of Oropharyngeal Throat Packs in Dental Anesthesia: An International Online Survey.

INTRODUCTION: Oropharyngeal throat packs (OPTPs) are frequently used to administer general anesthesia during oral surgery and dental procedures. However, the use of OPTPs has remained controversial, with concerns about their effectiveness, the potential for falling short of expectations, and the inherent risk of serious oversight in removing them. This study aimed to assess the awareness of dental anesthesiologists in the United States of America (USA) and Japan regarding the use of OPTPs. METHODS: An online questionnaire was distributed to 41 dental anesthesia education facilities in May 2023 and responses were obtained from 32 facilities. RESULTS: The responses to the questionnaire indicated that dental anesthesiologists in both the USA and Japan believe that using OPTPs during general anesthesia with airway securement is of significant importance, albeit with varying primary purposes for their application. In contrast, notable disparities were observed between the USA and Japan regarding the perceived importance and routine use of OPTPs during open-airway general anesthesia. In both countries, there is a common understanding that the residual risks of OPTPs are severe and that multiple preventive procedures are required. CONCLUSIONS:  The present study showed that dental anesthesiologists in the USA and Japan believed that the use of OPTPs was generally necessary for dental anesthesia. However, there was a difference in awareness between Japan and the USA regarding the importance of OPTPs for open-airway general anesthesia. Therefore, there should be a consensus among dental anesthesiologists in Japan and the USA on using OPTPs during open-airway general anesthesia in the near future.

Anti-inflammatory potential of remimazolam: A laboratory and clinical investigation.

BACKGROUND: Anesthetic agents, particularly intravenous anesthetics, may affect immune function and tumorigenic factors. We herein investigated whether the anti-inflammatory effects of anesthetic agents are attributed to their antioxidant properties. The antioxidant and anti-inflammatory effects of remimazolam, a new anesthetic, remain unclear. We hypothesized that remimazolam exerts anti-inflammatory effects due to its antioxidant properties, which may affect the postoperative inflammatory response. This retrospective clinical study examined this hypothesis using laboratory and clinical approaches. METHODS: The antioxidant effects of remimazolam and dexmedetomidine were assessed by electron spin resonance (ESR) spectroscopy, and postoperative inflammatory responses were compared in 143 patients who underwent transcatheter aortic valve replacement at Kindai University Hospital between April 2021 and December 2022. The primary endpoint was the presence or absence of the antioxidant effects of the anesthetics themselves using ESR. RESULTS: Remimazolam at clinical concentrations exerted antioxidant effects, whereas dexmedetomidine did not. Increases in C-reactive protein (CRP) levels on POD3 from preoperative values were significantly smaller in the remimazolam group than in the dexmedetomidine group (1.33 ± 1.29 vs. 2.17 ± 1.84, p = .014). CONCLUSIONS: Remimazolam exerted stronger anti-inflammatory effects than dexmedetomidine, and these effects were enhanced by its antioxidant properties, which may have affected postoperative CRP production.

General Anesthesia for Patients With Cyclic Vomiting Syndrome and Obesity: A Case Report.

Cyclic vomiting syndrome (CVS) is a chronic digestive disorder characterized by recurrent episodes of severe nausea and vomiting. The perioperative management of patients with CVS undergoing general anesthesia is challenging, especially when combined with obesity. This case report describes the successful management of a patient with CVS and obesity who underwent dental surgery under general anesthesia. A 21-year-old woman with CVS, obesity (body mass index, 35), and intellectual disability was scheduled for tooth extraction and composite resin restoration under general anesthesia. The patient was diagnosed with CVS at the age of 20 years with frequent vomiting attacks requiring hospitalization. Surgery was scheduled during the CVS remission to reduce the risk of perioperative vomiting. Preoperative laboratory test results were normal, including serum adrenocorticotropic hormone (ACTH), anti-diuretic hormone (ADH), and cortisol levels. General anesthesia was induced using remifentanil and propofol. Nasal endotracheal intubation was performed after rocuronium administration. Local anesthesia (2% lidocaine with 1:80,000 epinephrine) was used for all dental procedures. Postoperatively, midazolam was administered to control agitation. No postoperative vomiting occurred. Serum ACTH, ADH, and cortisol levels showed no significant changes before and after anesthesia, suggesting that hypothalamic-pituitary-adrenal (HPA) axis activation due to surgical stress did not occur. This case highlights the importance of careful perioperative planning and monitoring stress-related hormone levels in patients with CVS or obesity. An anesthetic approach using midazolam may effectively suppress HPA axis activation and prevent postoperative vomiting.

Thermosoftening of the Parker Flex-Tip(TM) tracheal tube in preparation for nasotracheal intubation.

The Parker Flex-Tip tracheal tube (PFTT, Parker Medical, Highlands Ranch, Colo) has a soft, flexible, curved tip with double Murphy eyes. Previous studies have shown that the PFTT reduces the incidence of epistaxis during nasotracheal intubation and the incidence of postintubation nasal pain, as compared to conventional tracheal tubes. Although thermosoftening is a well-known and effective technique for reducing epistaxis during nasotracheal intubation with conventional tracheal tubes, we occasionally encounter difficulties with advancing the tube through the nasal passage when the PFTT is thermosoftened prior to nasotracheal intubation. Consequently, when using the PFTT for nasotracheal intubation, the procedure of thermosoftening should be avoided.

Treatment of unexplained facial numbness with stellate ganglion blockade: A case report.

To date, there is no established treatment for facial numbness or dysesthesia of unspecified causes. Herein, we report a case of unexplained facial numbness and confirmed hypesthesia that achieved clinical response to stellate ganglion blockade (SGB). SGB might be an effective treatment of psychological stress-related facial numbness of unknown origin.