Surgical Video Projection onto a Mannequin: An Educational Tool for Simulation Practice of Perioperative Anesthetic Management.

Simulation practice is known to be effective in anesthesiology education. In our simulation practice of general anesthesia for open cholecystectomy at the Tohoku University simulation center, we projected a surgical video onto a mannequin's abdomen. In this observational study, we investigated whether video-linked simulation practice improved students' performance. We retrospectively compared the general anesthesia simulation practice scores of fifth-year medical students in a video-linked or conventional group. In the simulation practice, we evaluated the performance of each group in three sections: perioperative analgesia, intraoperative bleeding, and arrhythmia caused by abdominal irrigation. The primary endpoint was the total score of the simulation practice. The secondary endpoints were their scores on each section. We also investigated the amount of bleeding that caused an initial action and the amount of bleeding when they began to transfuse. The video group had significantly higher total scores than the conventional group (7.5 [5-10] vs. 5.5 [4-8], p = 0.00956). For the perioperative analgesia and arrhythmia sections, students in the video group responded appropriately to surgical pain. In the intraoperative bleeding section, students in both groups scored similarly. The amount of bleeding that caused initial action was significantly lower in the video group (200 mL [200-300]) than in the conventional group (400 mL [200-500]) (p = 0.00056).Simulation practice with surgical video projection improved student performance. By projecting surgical videos, students could practice in a more realistic environment similar to an actual case.

Multilevel and general linear modeling of weather and time effects on the emotional and behavioral states of children with profound intellectual and multiple disabilities.

Introduction: Eliciting the emotional and behavioral states of children with severe or profound intellectual disabilities (IDs) and profound intellectual and multiple disabilities (PIMD) due to their complex and atypical developmental trajectories has become increasingly elusive. It is evident that the environment, influenced by weather conditions and time of the day, plays a pivotal role in molding children's behaviors, emotions, and interactions. This underscores the significance of the environment as a critical factor in exploring the communication dynamics of children with PIMD/IDs. Methods: Over five months during fall and winter seasons, we conducted 105 video-recorded sessions with 20 children aged 8 to 16 with PIMD/IDs. These sessions aimed to capture the emotional and behavioral states interpreted by caregivers while simultaneously collecting indoor and outdoor weather indices, location, and time data. Using cross-classified multilevel and general linear models adjusted for individual characteristics and location variability with subsequent simple slope analyses, we examined the main and seasonal interaction effects of indoor and outdoor weather indices and time of the day on the emotional and behavioral states of children with PIMD/IDs. Results: The models revealed that higher atmospheric pressure (atm), indicative of pleasant and favorable weather conditions, was associated with increased engagement (indoor: p < 0.01; outdoor: p < 0.01) and interest (outdoor: p < 0.01) behaviors. In contrast, engagement levels decreased before lunchtime (p < 0.01; p < 0.001), and inclement or unstable weather conditions characterized by low-pressure systems (p < 0.05) and stronger wind speed (p < 0.05) led to more refusal or disagreement. During winter, children displayed significantly more agreement with their caregivers (p < 0.001). Interestingly, they also engaged more on cloudy days (p < 0.05). Furthermore, simple slope analyses revealed that high atm conditions in fall were linked to more engagement (p < 0.05) while humid conditions predicted more assent behaviors (p < 0.001). However, cloudy weather predicted less attentional focusing (p < 0.05) and interest (p < 0.01) behaviors in winter. Conclusion: This study confirms that fluctuations in weather indices, including seasonal changes and time of the day, can provide potential pathway indicators and supplement behavioral observations to elicit the behavioral states of children with PIMD/IDs. These findings highlight the importance of considering these factors when designing meaningful interactions and communication interventions for this population.

Machine learning-based classification of the movements of children with profound or severe intellectual or multiple disabilities using environment data features.

Communication interventions have broadened from dialogical meaning-making, assessment approaches, to remote-controlled interactive objects. Yet, interpretation of the mostly pre-or protosymbolic, distinctive, and idiosyncratic movements of children with intellectual disabilities (IDs) or profound intellectual and multiple disabilities (PIMD) using computer-based assistive technology (AT), machine learning (ML), and environment data (ED: location, weather indices and time) remain insufficiently unexplored. We introduce a novel behavior inference computer-based communication-aid AT system structured on machine learning (ML) framework to interpret the movements of children with PIMD/IDs using ED. To establish a stable system, our study aimed to train, cross-validate (10-fold), test and compare the classification accuracy performance of ML classifiers (eXtreme gradient boosting [XGB], support vector machine [SVM], random forest [RF], and neural network [NN]) on classifying the 676 movements to 2, 3, or 7 behavior outcome classes using our proposed dataset recalibration (adding ED to movement datasets) with or without Boruta feature selection (53 child characteristics and movements, and ED-related features). Natural-child-caregiver-dyadic interactions observed in 105 single-dyad video-recorded (30-hour) sessions targeted caregiver-interpreted facial, body, and limb movements of 20 8-to 16-year-old children with PIMD/IDs and simultaneously app-and-sensor-collected ED. Classification accuracy variances and the influences of and the interaction among recalibrated dataset, feature selection, classifiers, and classes on the pooled classification accuracy rates were evaluated using three-way ANOVA. Results revealed that Boruta and NN-trained dataset in class 2 and the non-Boruta SVM-trained dataset in class 3 had >76% accuracy rates. Statistically significant effects indicating high classification rates (>60%) were found among movement datasets: with ED, non-Boruta, class 3, SVM, RF, and NN. Similar trends (>69%) were found in class 2, NN, Boruta-trained movement dataset with ED, and SVM and RF, and non-Boruta-trained movement dataset with ED in class 3. These results support our hypotheses that adding environment data to movement datasets, selecting important features using Boruta, using NN, SVM and RF classifiers, and classifying movements to 2 and 3 behavior outcomes can provide >73.3% accuracy rates, a promising performance for a stable ML-based behavior inference communication-aid AT system for children with PIMD/IDs.

Evaluation of contrast-enhanced ultrasonography with Sonazoid® in visualization of local anesthetic distribution in rectus sheath block: a prospective, clinical study.

PURPOSE: Clear visualization of ultrasound (US) images is crucial for successful US-guided nerve block. However, accurate determination of local anesthetic (LA) distribution from US images remains difficult. Sonazoid®, which comprises perflubutane microbubbles, is used to diagnose hepatic and breast tumors. This study aimed to investigate the visibility of Sonazoid® in perioperative US-guided nerve block. METHODS: We performed rectus sheath block (RSB) in patients scheduled for laparoscopic abdominal surgery (n = 10). 10 mL of a mixture containing equal amounts of 0.75% ropivacaine and iohexol with the addition of Sonazoid® diluted 100-fold was administered. We investigated the correlation and agreement between Sonazoid® and iohexol distributions. The brightness of the solution and tissues was calculated: a grayscale value between 0 (dark) and 255 (bright) was measured in all pixels of the region of interest. Adverse events were also investigated. RESULTS: Sonazoid® was clearly visualized and distinguished from the surrounding tissues both during and after RSB. The spread of Sonazoid® and iohexol was significantly correlated (spearman's ρ = 0.53, p = 0.0004). Bland-Altman analyses revealed significant mean difference between two methods (15.6 mm; 95% confidence interval [CI]: 10.6, 20.6; standard deviation (SD) 15.65; p < 0.0001). Limits of agreement were - 14.94 to 46.24 mm. Sonazoid® significantly increased the mean grayscale values at the posterior rectus sheath (93.7 vs. 201.9, p < 0.0001). There were no complications. CONCLUSION: Sonazoid diluted 100-fold® was clearly visualized real-time, and the enhancement was sustained and measurable after RSB. Sonazoid® could potentially be used for the contrast agent of US-guided nerve block.

Integrating Behavior of Children with Profound Intellectual, Multiple, or Severe Motor Disabilities With Location and Environment Data Sensors for Independent Communication and Mobility: App Development and Pilot Testing.

BACKGROUND: Children with profound intellectual and multiple disabilities (PIMD) or severe motor and intellectual disabilities (SMID) only communicate through movements, vocalizations, body postures, muscle tensions, or facial expressions on a pre- or protosymbolic level. Yet, to the best of our knowledge, there are few systems developed to specifically aid in categorizing and interpreting behaviors of children with PIMD or SMID to facilitate independent communication and mobility. Further, environmental data such as weather variables were found to have associations with human affects and behaviors among typically developing children; however, studies involving children with neurological functioning impairments that affect communication or those who have physical and/or motor disabilities are unexpectedly scarce. OBJECTIVE: This paper describes the design and development of the ChildSIDE app, which collects and transmits data associated with children's behaviors, and linked location and environment information collected from data sources (GPS, iBeacon device, ALPS Sensor, and OpenWeatherMap application programming interface [API]) to the database. The aims of this study were to measure and compare the server/API performance of the app in detecting and transmitting environment data from the data sources to the database, and to categorize the movements associated with each behavior data as the basis for future development and analyses. METHODS: This study utilized a cross-sectional observational design by performing multiple single-subject face-to-face and video-recorded sessions among purposively sampled child-caregiver dyads (children diagnosed with PIMD/SMID, or severe or profound intellectual disability and their primary caregivers) from September 2019 to February 2020. To measure the server/API performance of the app in detecting and transmitting data from data sources to the database, frequency distribution and percentages of 31 location and environment data parameters were computed and compared. To categorize which body parts or movements were involved in each behavior, the interrater agreement κ statistic was used. RESULTS: The study comprised 150 sessions involving 20 child-caregiver dyads. The app collected 371 individual behavior data, 327 of which had associated location and environment data from data collection sources. The analyses revealed that ChildSIDE had a server/API performance >93% in detecting and transmitting outdoor location (GPS) and environment data (ALPS sensors, OpenWeatherMap API), whereas the performance with iBeacon data was lower (82.3%). Behaviors were manifested mainly through hand (22.8%) and body movements (27.7%), and vocalizations (21.6%). CONCLUSIONS: The ChildSIDE app is an effective tool in collecting the behavior data of children with PIMD/SMID. The app showed high server/API performance in detecting outdoor location and environment data from sensors and an online API to the database with a performance rate above 93%. The results of the analysis and categorization of behaviors suggest a need for a system that uses motion capture and trajectory analyses for developing machine- or deep-learning algorithms to predict the needs of children with PIMD/SMID in the future.

Discrimination of thoracic spine from muscle based on their difference in ultrasound reflection and scattering characteristics.

PURPOSE: Medical ultrasound is often used to specify the puncture position during epidural anesthesia. However, visualization of the thoracic spine is difficult because of the complex structure, i.e., it is difficult to determine whether the thoracic spine or muscle is depicted. Therefore, this study aims to distinguish bone from muscle tissue using the differences in reflection and scattering characteristics of ultrasound. METHODS: We experimentally investigated the difference in signals received from bone and muscle. We proposed a new parameter utilizing the ratio of the amplitude of the received signals averaged in a wide range around the ideal delay line and that only along the ideal delay line, to emphasize the bone. RESULTS: First, we confirmed the difference in signals received from bone and muscle tissue by basic experiments. We also investigated the difference by in vitro experiments using chicken thigh and in vivo experiments in humans. In both experiments, the proposed method succeeded to clearly depict bone, suppressing the depiction of muscle, compared with conventional B-mode imaging. CONCLUSION: Using the difference in the characteristics of reflection from bone and scattering from muscle tissue, we could distinguish bone from muscle tissue with the proposed method.

Comparison of Clinical Efficacy and Anatomical Investigation between Retrolaminar Block and Erector Spinae Plane Block.

Retrolaminar block (RLB) and erector spinae plane block (ESPB) are alternative approaches to paravertebral block (PVB) and are advantageous in that they are easier and safer techniques compared with the traditional PVB. Many clinical reports of these blocks have described their efficacy for ipsilateral thoracic analgesia. The local anesthetic injection points of RLB and ESPB are the lamina and transverse process, respectively. Despite the similarity of the puncture sites, there have been no clinical studies comparing RLB and ESPB. In addition, the underlying mechanism of these blocks has not been clarified. Recent anatomical investigations indicated that the injectate was distributed in the paravertebral space and spread laterally into the intercostal spaces. The limited distribution into the paravertebral space indicated that compared to PVB, RLB and ESPB exert their effects via a different mechanism. In this review, we describe the features of and differences between RLB and ESPB based on current clinical and anatomical reports. We also propose the clinical indication and discuss the differences, clinical outcomes, and anatomical mechanisms of the techniques.

The human central nervous system discharges carbon dioxide and lactic acid into the cerebrospinal fluid.

BACKGROUND: The central nervous system was previously thought to draw oxygen and nutrition from the arteries and discharge carbon dioxide and other metabolic wastes into the venous system. At present, the functional role of cerebrospinal fluid in brain metabolism is not fully known. METHODS: In this prospective observational study, we performed gas analysis on venous blood and cerebrospinal fluid simultaneously acquired from 16 consecutive preoperative patients without any known neurological disorders. RESULTS: The carbon dioxide partial pressure (pCO2) (p < 0.0001) and lactic acid level (p < 0.001) in the cerebrospinal fluid were significantly higher than those in the peripheral venous blood, suggesting that a considerable proportion of metabolic carbon dioxide and lactic acid is discharged from the central nervous system into the cerebrospinal fluid. The oxygen partial pressure (pO2) was much higher in the cerebrospinal fluid than in the venous blood, corroborating the conventional theory of cerebrospinal fluid circulatory dynamics. The pCO2 of the cerebrospinal fluid showed a strong negative correlation with age (R = - 0.65, p = 0.0065), but the other studied variables did not show significant correlation with age. CONCLUSION: Carbon dioxide and lactic acid are discharged into the circulating cerebrospinal fluid, as well as into the venules. The level of carbon dioxide in the cerebrospinal fluid significantly decreased with age.

Perioperative anesthetic management for cesarean delivery of severe Wilson's disease with liver failure: a case report.

BACKGROUND: Wilson's disease is a rare autosomal recessive disorder affecting copper metabolism, which presents liver and brain dysfunction caused by abnormal copper accumulation. We report a patient who showed exacerbation of liver failure during pregnancy. CASE PRESENTATION: A 24-year-old woman with Wilson's disease was scheduled for emergency cesarean delivery at 30 weeks of gestation. The patient exhibited severe coagulopathy and prominent body weight gain (+ 30 kg) caused by systemic edema and ascites. We decided to perform emergency cesarean delivery under general anesthesia. We used platelet concentrates, cryoprecipitate, and fibrinogen concentrate. Intraoperative hemorrhage was well controlled. On the 15th postpartum day, weight was reduced by 20 kg and liver function had improved. She and her baby were discharged without complications. CONCLUSIONS: The appropriate continued treatment of Wilson's disease and supplementation of coagulation factors and/or platelets when indicated greatly increase the likelihood of a successful pregnancy, even in patients with liver failure exacerbation.

Analgesic Effect of Double-Level Retrolaminar Paravertebral Block for Breast Cancer Surgery in the Early Postoperative Period: A Placebo-Controlled, Randomized Clinical Trial.

Thoracic epidural anesthesia (TEA) and paravertebral block (PVB) have been performed for perioperative regional anesthesia in the trunk. However, TEA and PVB are associated with a risk of serious complications, such as pneumothorax, hypotension, or nerve damage. Retrolaminar paravertebral block (RLB) was introduced as a new alternative to PVB. This new approach might lower the risk of serious complications, but its use has not been well established yet. Therefore, we conducted a double-masked, placebo-controlled, randomized clinical trial to evaluate the efficacy of a double-level RLB for postoperative analgesia after breast cancer surgery. A total of 122 women who underwent breast cancer surgery with axillary lymph node dissection under general anesthesia were allocated into RLB group (60 patients) and Control group (62 patients). RLB was performed upon surgery completion with 15 ml ropivacaine (0.5%) for each lamina of the T2 and T4 vertebrae. In Control group, the same volume of normal saline was injected at each level. The time to first postoperative analgesic administration was significantly longer in RLB group than that in Control group (161.5 min vs. 64.0 min). The pain score in RLB group was significantly lower immediately after surgery. However, the number of patients requiring analgesics during the 12-hour post-surgical period was similar between RLB group (20 patients) and Control group (22 patients). In conclusion, the double-level RLB could delay the time to initial administration of analgesics, but this technique may be insufficient to reduce the analgesic requirement within the 12-hour postoperative period following breast cancer surgery.

Optimal intrathecal hyperbaric bupivacaine dose with opioids for cesarean delivery: a prospective double-blinded randomized trial.

BACKGROUND: Single-shot spinal anesthesia is commonly used for cesarean delivery. Achieving adequate anesthesia throughout surgery needs to be balanced with associated complications. We investigated the optimal dose of intrathecal hyperbaric bupivacaine, co-administered with opioids, for anesthesia for cesarean delivery. METHODS: This prospective, randomized, double-blinded, dose-ranging trial included parturients scheduled to undergo cesarean delivery under spinal anesthesia. An epidural catheter was first inserted at the T11-12 vertebral interspace, followed by spinal anesthesia at the L2-3 or L3-4 vertebral interspace. Subjects were randomly assigned to one of seven doses of intrathecal hyperbaric bupivacaine 0.5% (6, 7, 8, 9, 10, 11 or 12mg), with added 15µg fentanyl and 75µg morphine. Successful induction of anesthesia (successind) was defined as achievement of bilateral sensory loss to cold at the T6 dermatome or higher, within 10 minutes. Successful maintenance of anesthesia (successmain) was defined by no epidural supplementation within 60 minutes of intrathecal injection. The effective doses for 50% (ED50) and 95% (ED95) of patients were estimated using logistic regression analysis. RESULTS: The ED50 and ED95 for successmain were 6.0mg (95% CI: 4.5 to 7.5mg) and 12.6mg (95% CI: 7.9 to 17.2mg), respectively. The incidence of respiratory discomfort and maternal satisfaction scores did not differ significantly between dose groups. Phenylephrine dose and nausea/vomiting incidence increased with increasing doses of bupivacaine. CONCLUSION: Under study conditions, our results suggest that 12.6mg of intrathecal bupivacaine, administered with fentanyl and morphine, is required to achieve adequate intraoperative analgesia without the need for epidural supplemention.

[The trends of ultrasound-guided neuraxial block].

Ultrasound-guided neuraxial block has provided safe and accurate analgesia. Although the classic anatomical landmark technique is still standard for completing epidural or subarachnoid puncture, it is difficult to identify the anatomical structure in some cases such as pregnant women, obese patients and patients with spinal deformity. Preparatory ultrasound scanning enables to identify the midline and determine the point of insertion, which reduces the number of puncture attempts and failure rate of procedure. Moreover, there are reports about the efficacy of ultrasound guidance in children. Usually, neuraxial block for children is performed under general anesthesia which has some risk for nerve injury and inadequate catheterization. Visualization of epidural and subarachnoid space facilitates an appropriate insertion. Additionally, the utility of ultrasound-guided lumbar puncture has also been reported in emergency department. Cerebrospinal puncture is an important procedure for diagnosis of some critical conditions such as subarachnoid hemorrhage and central nervous system infections. Ultrasound imaging contributes to smooth procedure and fewer complications. This review summarizes the basic ultrasound-guided technique for expected difficult neuraxial block patients, presenting recent findings.

Remifentanil use for cesarean section in a patient with intracranial re-ruptured arteriovenous malformation.

We describe the successful administration of remifentanil as part of the anesthetic technique used for cesarean section performed under general anesthesia in a 24-year-old woman with intracranial re-hemorrhage caused by re-ruptured arteriovenous malformation. A low dose of remifentanil was useful to obtund the hypertensive response during induction and maintenance of anesthesia without neonatal respiratory depression.