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Postoperative delirium incidences are increasing in older adults. A Cochrane Review found no significant difference in the incidence of postoperative delirium between total intravenous anesthesia (TIVA) and inhalational anesthesia (IA). This study evaluated the differences in postoperative delirium and morbidity between patients who underwent either TIVA or IA.A nationwide Japanese inpatient database was used to retrospectively compare differences in postoperative delirium and composite morbidity between patients older than 65 years, who underwent general anesthesia (TIVA or IA). The primary outcome was postoperative delirium. The secondary outcomes were: morbidity incidence, length of hospital stay, and mortality. A 1:3 propensity score analysis of patients who underwent all surgical procedures was conducted according to covariates, to calculate odds ratios and their 95% confidence intervals (CIs). Sensitivity analyses were conducted using an instrumental variable analysis of the proportion of TIVA by hospital scale, stabilized inverse probability of treatment weighting analyses, limiting the definitions of postoperative delirium, and subgroup analysis.Of 738,600 patients, 149,540 received TIVA and 589,060 received IA. After 1:3 propensity score matching, the adjusted odds ratios for postoperative delirium and composite morbidity were 0.93 (95% CI 0.91-0.95) and 0.94 (95% CI 0.90-0.97), respectively, for TIVA concerning IA. There were no differences in the length of the intensive care unit and hospital stay, or hospital mortality. The findings were consistent with the sensitivity analyses.This study demonstrated that TIVA was related to a slightly decreased postoperative delirium and incidence of morbidity compared to IA.

Background Conventional myoelectric prosthesis (myo-prosthesis) training involves repetitive grasping and manipulation training, which requires considerable training time. It is necessary to develop a short and efficient myo-prosthesis training. The purpose of this study was to verify the immediate and sustained effects of action observation (AO) using virtual reality (VR) on myo-prosthesis control and clarify the effect of visual feedback of electromyogram (EMG) signals during AO using VR. Methods We evaluated 24 healthy right-handed individuals wearing a myo-prosthesis simulator in their dominant hands. We divided participants into three groups: VR video observation with EMG presentation during manipulation (VR+), VR video observation without EMG presentation (VR), and control group. We evaluated prosthetic control skills using the Gripping force adjustment test (GFAT) and Bowknot task immediately before and after AO and one week later. Additionally, we evaluated level of immersion, motivation, and enjoyment during AO. Results The rate of change in the GFAT one week after the intervention was significantly greater in the VR+ (p

Smart Pilot View (SPV) (Drager Medical) provide information about the estimated drug effect of anesthetic drugs. We conducted a prospective randomized trial to evaluated the recovery time in SPV-guided general anesthesia compared with usual practice in patients with desflurane general anesthesia. Thirty-four American Society of Anesthesiologist’s physical status I–II patients scheduled for elective surgery under general anesthesia were enrolled in the study. The patients were allocated to one of the following two groups: the Smart Pilot View group (group SPV) or the control group (group C). General anesthesia was induced by propofol and maintained by desflurane end-tidal concentration of 4.2%. During the procedure, desflurane concentration was adjusted to maintain BIS values between 40 and 60 and above MAC 90. In group SPV, desflurane concentration and infusion rate of remifentanil were decreased to achieve MAC 90 about 10 min before the end of the procedure. In group C, the desflurane concentration and infusion rate of remifentanil were maintained unchanged until the end of the procedure. Fifteen patients were enrolled in group C, and seventeen of these were enrolled in group SPV. The time taken for the opening of the patient's eyes was 292 ± 53 s in group C and 218 ± 44 s in group SPV. The time taken for recovery of orientation was 451 ± 100 s in group C and 316 ± 57 s in group SPV. Both times were significantly faster in the group SPV. Smart Pilot View guided anesthesia enabled faster recovery from desflurane general anesthesia.

This study investigates the relationship between void size and insulation lifetime due to partial discharges (PDs) in internal voids. Experimental results clearly show that the larger the void size, the shorter the insulation lifetime, which decreases the lifetime n-value index of the voltage-time characteristics. The results also show a clear relationship between the insulation lifetime of a solid insulator having void defects and the PD energy generated in the void, which is related to the cumulative PD energy density per cycle. Therefore, we propose estimating the insulation lifetime of an insulator with voids by calculating the cumulative PD energy density per cycle.

Objectives In an ageing society, community-based medical education in a home care setting needs to be developed. Drawing on Kolb's experiential learning theory, this study aimed to explore the learning processes in overnight home care by medical trainees in terms of their understanding of terminally ill patients and their conceptualization of themselves as future physicians. Methods An overnight home care program in which a trainee had to take care of terminally ill patients on his/her own under the supervision of a healthcare team was conducted. Nineteen trainees, including eight medical students and 11 residents, participated in this study. Text data of reflective reports written after the overnight care were collected and thematically analyzed. Results The trainees' learning experiences in the program were categorized into four stages: predeparture, concrete experience, reflective observation and abstract conceptualization. Although they had mixed feelings, including anxiety, fear and expectations, at the predeparture stage, they could be actively involved in providing medical care and daily life support and in taking care of dying patients at the patients' homes overnight. By reflecting on their experiences, they gained a sense of achievement and identified the aspects upon which they should improve as future physicians. Subsequently, based on their reflective observation, they conceptualized their approaches to home care and the roles/responsibilities of physicians as healers, which led to professional identity formation. Conclusions Overnight home care by medical trainees has the potential as an educational strategy to promote their realistic understanding of home care and facilitate professional identity formation.

Silicon carbide particle-loaded semi-conductive materials with electric field-dependent conductivity have been used for end-turn stress grading (SG) systems of high voltage rotating electrical machines for decades. Particularly, high voltage class turbogenerators use double-layer SG systems, at which two SG materials with different conductivities are applied, to reduce power dissipations within the SG materials. To prevent the excessive local heating of the SG material and resulting flashover, the field-dependent conductivities of the two SG materials, as well as length of the SG layer in the longitudinal direction along a coil, were optimized, by a nonlinear transient electrical field and thermal coupled analysis. The field-dependent conductivities of the SG materials were adjusted to the suitable ones by changing the average diameter of silicon carbide particles. Then, the appropriate length of the SG layer was selected to minimize the temperature rise in the system. As a result, the newly optimized double-layer SG system showed a 20% lower temperature rise, and more than 15% higher flashover voltage than the conventional ones. Therefore, the effectiveness of the optimized double-layer SG system is successfully confirmed.

LMA® ProSeal™ (pLMA) has been used as an alternative to tracheal tubes. It is unclear how many cases are required to achieve proficiency in performing pLMA insertion among novice residents. Therefore, we analyzed the learning curve of pLMA insertion using a cumulative sum (CUSUM) chart and assessed the effects of learning. In this single-center, prospective, observational study, we included 15 novice residents. Staff anesthesiologists recorded success or failure; insertion time; and incidences of bleeding or reflex including cough, hiccups, and limb movement. A successful pLMA insertion was defined as effective ventilation within two attempts with an insertion time of ≤ 120 s. Regarding CUSUM, we set acceptable and unacceptable failure rates as 20% and 40%, respectively. Further, α and β errors were designated as 0.1. We stratified the number of cases encountered by each resident into four groups of 10 cases each (1–10, 11–20, 21–30, and ≥ 31 cases) and evaluated the effects of learning. Each resident encountered 44 ± 5 (mean ± SD) cases of pLMA insertion, and 14/15 achieved proficiency in performing pLMA insertion after 20 ± 8 cases. Success rate (76%, 86%, 91%, and 93%; P

Background Pain catastrophizing and self-efficacy are useful for predicting pain; these are associated with pain intensity and facilitate evaluation of psychological factors. However, it remains unclear whether the effects are direct or indirect in patients with frozen shoulder; the impact on each variable has also not been clarified. Thus, this study aimed to examine the structural relationship between pain catastrophizing, self-efficacy, and pain intensity in patients with frozen shoulder. Methods Participants who were diagnosed with frozen shoulder between January 2016 and March 2017 were recruited from a single orthopedic clinic. Patients aged 18 years or older, who had been symptomatic for < 1 year and reported localized pain in one shoulder, experienced night pain, and had restricted active and passive shoulder motions were included. Pain intensity (Numerical Rating Scale (NRS)), pain catastrophizing (Pain Catastrophizing Scale (PCS)), and self-efficacy (Pain Self-Efficacy Questionnaire (PSEQ)) were measured at the first examination, and the relationship was examined using the Bayesian estimation method. The model was modified repeatedly based on the posterior prediction p value, deviance information criterion (DIC), and Bayesian information criterion (BIC); the model with the highest explanatory power was adopted as the final model. Results Ninety-three patients diagnosed with frozen shoulder were included in this study. On path analysis, the model in which pain intensity affected psychological factors had the most explanation. The convergence index potential scale reduction was below 1.1, and the convergence of the estimate was confirmed. The posterior prediction p value was 0.25, DIC = 1328.705, and BIC = 1356.872; the validity of the fit of the model was confirmed. The path coefficients from the NRS to the PSEQ, from the NRS to the PCS, and from the PSEQ to the PCS scores were − 0.232 (95% confidence interval (CI), − 0.406 to − 0.033), 0.259 (95% CI, 0.083–0.419), and − 0.504 (95% CI, − 0.646 to − 0.334), respectively; these values were statistically significant (p < 0.05). Conclusion Our results show that pain intensity increases the risk of chronic pain including pain catastrophizing and self-efficacy and that pain catastrophizing increases by decreasing self-efficacy in patients with frozen shoulder.

Background During laparoscopic gynecological surgery, increased peak airway pressure (PAWP) can cause airway leak upon ventilation with the LMA® ProSeal™. We hypothesized that compared with the use of volume-controlled ventilation (VCV), the use of the AutoFlow® mode would decrease PAWP and airway leak during laparoscopic gynecological surgery with LMA ProSeal. Methods This single-center, randomized, controlled trial allocated 80 adult women undergoing elective laparoscopic gynecological surgery to one of two groups, namely, the AutoFlow group or the VCV group. Ventilation settings for both groups were 8 ml/kg of tidal volume and 5 cmH2O of positive end-expiratory pressure, and respiratory rate was adjusted to maintain end-tidal carbon dioxide at 35–40 mmHg. Airway leak, PAWP, and other ventilatory parameters and vital signs were recorded at four timepoints (1, 1 min after insertion of the gastric tube; 2, 2 min after intravenous administration of rocuronium 0.6–0.8 mg/kg; 3, 1 min after initiation of pneumoperitoneum; and 4, 1 min after changing to the Trendelenburg position). The primary outcome was PAWP during pneumoperitoneum and in the Trendelenburg position, whereas the secondary outcomes included PAWP at other timepoints and airway leak development. We used the Mann–Whitney U test for PAWP and Fisher’s exact test for comparing airway leak among the groups. Results Data from 40 patients in the AutoFlow group and 39 in the VCV group were used for analysis. PAWP at pneumoperitoneum pressure and in the Trendelenburg position was significantly lower in the AutoFlow group than in the VCV group [median (interquartile range), 16 (15–18) cmH2O vs. 18 (17–19) cmH2O; P P = 0.68). Conclusions Even though AutoFlow ventilation decreased PAWP, it did not reduce the incidence of airway leak compared with VCV during laparoscopic gynecological surgery with the LMA ProSeal. Trial registration UMIN Clinical Trials Registry, identifier UMIN000023173.

Previous studies have reported qualitative characteristics of myelopathy hand, but few studies have reported quantitative kinematic parameters of this condition. Our purpose of this study was to quantitatively evaluate the abnormal finger movements in patients with cervical compressive myelopathy (CCM) (termed myelopathy hand) and to understand the characteristics of myelopathy hand during the grip and release test (GRT) using gyro sensors. Sixty patients with CCM (severe: n = 30; mild-to-moderate: n = 30) and sixty healthy adults (age-matched control: n = 30; young control: n = 30) were included in this study. All participants performed the GRT. The index and little fingers’ and the wrist’s movements during the GRT were recorded using three gyro sensors. The number of cycles, switching time-delay, time per cycle, and peak angular velocity were calculated and compared between groups. Patients with severe CCM had the lowest number of cycles and longest switching time-delays, followed by patients with mild-to-moderate CCM, the age-matched control group, and the young control group. The time per cycle and the peak angular velocities of fingers in participants with severe CCM were significantly lower than those in participants with mild-to-moderate CCM; however, there were no significant differences between the control groups. The peak angular velocities of fingers were significantly lower during extension motions than during flexion motions in participants with CCM. Participants with CCM have lower peak angular velocities during finger movement. Finger extension also is impaired in participants with CCM. Abnormal finger movements and the severity of myelopathy in participants with CCM can be assessed using gyro sensors.

The purpose of this study was to examine motor imagery ability in patients with peripheral nerve disorder using the hand mental rotation task. Five patients with left total avulsion brachial plexus palsy (BPP) and 16 healthy age-matched adults participated in this study. The mean±SD time from the injury was 103.6±49.7 months. Participants performed a hand mental rotation task as the motor imagery task; outcome measures included the reaction time from cognizing hand stimuli to the judgment of hand laterality (right or left) and the error rate. Patients also completed the Hand 20 questionnaire to assess the use of their affected limb. Log-transformed reaction times of the affected limb in patients with BPP were significantly higher than those of the unaffected limb and the left-sided limb of the healthy participants. Log-transformed reaction times of the unaffected limb in patients were significantly higher than those of the right-sided limb in healthy participants. Log-transformed error rate did not differ between patients and healthy participants. According to the results of the Hand 20 questionnaire, patients with BPP hardly used their affected limb because of severe sensory-motor dysfunction. Motor imagery ability of the affected and unaffected limbs in patients with complete BPP may be decreased owing to long-term disuse. These findings suggest that long-term disuse in those with severe peripheral nerve disorders could affect motor imagery ability of both the affected and unaffected limbs.

Phantom limb pain (PLP) is a frequent painful sensation in amputees, and motor imagery (MI) is a useful approach for the treatment of this type of pain. However, it is not clear regarding the best MI modality for PLP.The purpose of this study was to investigate the relationship between the PLP and MI modality in upper limb amputees.Observational study.Eleven patients who underwent unilateral upper limb amputation participated in this study. The MI modality (kinesthetic and visual) and PLP intensity were evaluated using the Kinesthetic and Visual Imagery Questionnaire (KVIQ)-20 and a visual analog scale. MI ability was also assessed during the hand mental rotation task. We examined the correlation between MI modalities, ability, and pain intensity.The total KVIQ kinesthetic score was negatively correlated with pain intensity (r = -0.71, P0.01): the more vivid the kinesthetic imagery, the weaker the pain. In particular, the reduction in pain intensity was associated with strong kinesthetic imagery of opposing movements of the deficient thumb (r = -0.81, P0.01). The KVIQ visual score and MI ability were not associated with pain intensity.Our data showed that the reduction of PLP could be associated with the kinesthetic modality of MI but not with visual modality or MI ability. In other words, it was suggested that the more vivid the sensation of moving muscles and joints in the defect area, the lower the PLP intensity. To reduce PLP, clinicians may prefer interventions using the kinesthetic modality.

Purpose Ultrasound-guided supra-inguinal fascia iliaca block (SFIB) is widely used as regional anesthesia of the hip and thigh. It is difficult to judge the blocking effect and the spreading local anesthesia. We hypothesize that the effect and spread of the block could be proven objectively by a rise in the temperature. In this prospective observational study, the broad regional rise in skin temperature of twenty patients who were scheduled for hip surgery was measured using an infrared thermographic camera at multiple intervals following ultrasound-guided SFIB. Methods Infrared thermographic imaging of skin temperature at the femoral, obturator, and lateral femoral cutaneous nerve sites was performed before and at 5-min intervals after ultrasound-guided SFIB for up to 15-min post-injection. The primary outcomes are skin surface temperature. Sensory block was assessed immediately after the final infrared thermographic image acquisition using the cold test. Results Compared to pre-injection baseline, temperature increased by 1.2 °C [95% confidence interval (CI) 0.4–2.0 °C] after 5 min, 1.2 °C (95% CI 0.4–2.0 °C) after 10 min, and 0.9 °C (95% CI 0.4–2.1°C) after 15 min. The cold test response was reduced in all cases at the femoral and lateral femoral cutaneous nerve sites and in 13 cases at the obturator nerve site. The sensitivity and specificity of the temperature increase to cold loss were 96% and 63%, respectively when we defined >0°C as the clinical threshold. Conclusions Successful SFIB significantly enhanced skin temperature at the hip and thigh in all cases, suggesting that infrared surface thermography can be used as an objective assessment tool for adequate analgesia. Trial registration University Hospital Medical Information Network Clinical Trials Registry (UMIN 000037866). Registered 31 August 2019.

Background: The evaluation of pain catastrophizing and self-efficacy is useful for predicting pain and is also associated with shoulder pain. The purposes of our study were to examine the relationship between pain catastrophizing, self-efficacy, and pain intensity in patients with a frozen shoulder.Methods: Ninety-three patients who were diagnosed with frozen shoulder were included in this study. Pain intensity (Numerical Rating Scale: NRS), pain catastrophizing (Pain Catastrophizing Scale: PCS), and self-efficacy (Pain Self-Efficacy Questionnaire: PSEQ) were measured at the first examination, and the relationship was examined using Bayesian estimation method. We developed a hypothesis model in which self-efficacy affects pain catastrophizing and pain catastrophizing affects pain intensity.Results: The path coefficients from the PSEQ score to the PCS score and from the PCS score to the NRS score were significant. The convergence of the hypothesized model was confirmed and validated (posterior prediction p-value 0.35). Conclusion: Our results suggest that self-efficacy affects pain catastrophizing, and pain catastrophizing affects pain intensity.

Interprofessional collaboration (IPC) is vital to primary care. Improving IPC requires cooperation between medical and other healthcare professionals. Transprofessional role plays can enhance the quality of IPC; thus, in this study, we conducted transprofessional role plays, based on existing theories regarding IPC and medical education, with healthcare professionals in primary care. As a study design, the realist approach was used to clarify the effectiveness of transprofessional role plays. Five Likert-scale questionnaires regarding the competency of IPC were used to assess the change in perception of medical and care professionals through educational intervention. The realist approach was employed for the clarification of contexts, mechanisms and outcomes of transprofessional role play using one-on-one interview data. Sixty-two medical care professionals participated in the transprofessional role plays, and 31 participants were interviewed. The difference in the score of the competency scale of IPC was statistically significant in all six competencies (p-value

Background Patients with myotonic dystrophy may have increased sensitivity to drugs used for anesthesia. We successfully managed general anesthesia in a patient with myotonic dystrophy using a novel intravenous anesthetic, remimazolam. Case presentation The patient was a 46-year-old man, 169 cm in height, and weighing 60 kg. He was diagnosed with myotonic dystrophy 5 years previously. Phacoemulsification for both eyes was scheduled under general anesthesia. Anesthesia was induced with remimazolam 6 mg/kg/h for 1 min and maintained by continuous infusion at 0.25 mg/kg/h during surgery, a 1/4 dose of the standard infusion rate, as indexed by a bispectral index (BIS). Six minutes after remimazolam discontinuation, the patient opened his eyes on verbal command with sufficient spontaneous respiration. Flumazenil (0.2 mg) was administered to boost the patient’s recovery. Conclusion In addition to the short-acting anesthetic remimazolam, the presence of the antagonist flumazenil enabled complete recovery from anesthesia, without postoperative complications.

Background Regular body-powered prosthesis (bp-prosthesis) training often facilitates acquisition of skills through repeated practice but requires adequate time and motivation. Therefore, if there are auxiliary tools, such as indirect training, skill acquisition may be easy. In this study, we examined the effects of action observation (AO) using virtual reality (VR) as an auxiliary tool. We examined two different modalities during AO, VR and tablet device (Tab), and two perspectives, first- and third-person perspectives. This study aimed to examine whether AO training using VR is effective in acquiring bp-prosthetic control skills in the short term. Methods Forty healthy right-handed participants simulated bp-prosthesis with the non-dominant hand. They were divided into five groups with different interventions and displays for AO: first-person perspective on VR (VR1st), third-person perspective on VR (VR3rd), first-person perspective on Tab (Tab1st), third-person perspective on Tab (Tab3rd), and control group (Con) without AO. Participants of VR1st, VR3rd, Tab1st, and Tab3rd observed the video image of experts operating prosthesis twice, 10 min each time. We evaluated the immersion during the video observation using the Visual Analog Scale. Prosthetic control skills were evaluated using the box and block test (BBT) and bowknot task (BKT). Results In BBT, no significant enhancements of prosthetic control skills between groups were found. In contrast, the BKT change rates of prosthetic control skills in VR1st and VR3rd were significantly higher than those in Con (p < 0.001). Additionally, immersion scores of VR1st and VR3rd were higher than those of Tab3rd (p < 0.05), and there was a significant negative correlation between immersion and BKT change rate (Spearman’s rs = -0.47, p < 0.01). Conclusions In BKT (bilateral manual dexterity), VR video viewing led to significantly better short-term prosthetic control acqusition than Con. Additionally, it was suggested that the higher the immersion, the shorter the BKT task execution time. Our findings suggest that VR-based AO training is effective in acquiring bp-prosthetic control in the short term. Especially, it is effective for bilateral prosthetic control, which is necessary in the daily life of upper limb amputees.

Background Regular body-powered (BP) prosthesis training facilitates the acquisition of skills through repeated practice but requires adequate time and motivation. Therefore, auxiliary tools such as indirect training may improve the training experience and speed of skill acquisition. In this study, we examined the effects of action observation (AO) using virtual reality (VR) as an auxiliary tool. We used two modalities during AO: three-dimensional (3D) VR and two-dimensional (2D) computer tablet devices (Tablet). Each modality was tested from first- and third-person perspectives. Methods We studied 40 healthy right-handed participants wearing a BP prosthesis simulator on their non-dominant hands. The participants were divided into five groups based on combinations of the different modalities and perspectives: first-person perspective on VR (VR1), third-person perspective on VR (VR3), first-person perspective on a tablet (Tablet1), third-person perspective on a tablet (Tablet3), and a control group (Control). The intervention groups observed and imitated the video image of prosthesis operation for 10 min in each of two sessions. We evaluated the level of immersion during AO using the visual analogue scale. Prosthetic control skills were evaluated using the Box and Block Test (BBT) and a bowknot task (BKT). Results In the BBT, there were no significant differences in the amount of change in the skills between the five groups. In contrast, the relative changes in the BKT prosthetic control skills in VR1 (p p p p s = − 0.47, p Conclusions Using the BKT of bilateral manual dexterity, VR-based AO significantly improved short-term prosthetic control acquisition. Additionally, it appeared that the higher the immersion score was, the shorter the execution time of the BKT task. Our findings suggest that VR-based AO training may be effective in acquiring bilateral BP prosthetic control, which requires more 3D-based operation.

Precise identification of the femoral nerve (FN) is essential for an ultrasound-guided femoral nerve block. We hypothesized that the distance between the FN and the femoral artery (FA) is correlated with patient age. In this prospective observational study, we evaluated the FN–FA (from the lateral edge of the FA to the medial edge of the FN) distance [0.42 ± 0.42 (mean ± standard deviation) cm] in 102 patients using ultrasound. In addition, we calculated the cross-sectional area of the iliopsoas muscle using computed tomography or magnetic resonance imaging. Multiple regression analyses revealed that age was significantly and positively correlated with the FN–FA distance (R2 = 0.72, p

LMAIn this single-center, prospective, observational study, we included 15 novice residents. Staff anesthesiologists recorded success or failure; insertion time; and incidences of bleeding or reflex including cough, hiccups, and limb movement. A successful pLMA insertion was defined as effective ventilation within two attempts with an insertion time of ≤ 120 s. Regarding CUSUM, we set acceptable and unacceptable failure rates as 20% and 40%, respectively. Further, α and β errors were designated as 0.1. We stratified the number of cases encountered by each resident into four groups of 10 cases each (1-10, 11-20, 21-30, and ≥ 31 cases) and evaluated the effects of learning.Each resident encountered 44 ± 5 (mean ± SD) cases of pLMA insertion, and 14/15 achieved proficiency in performing pLMA insertion after 20 ± 8 cases. Success rate (76%, 86%, 91%, and 93%; P 0.001) and insertion time (45 s, 35 s, 31 s, and 26 s; P 0.001) significantly improved with increased experience; however, incidences of bleeding (16%, 10%, 8%, and 10%; P = 0.124) and reflex (5%, 3%, 3%, and 3%; P = 0.54) remained unchanged.Experience with 20 ± 8 cases is needed to achieve proficiency in performing pLMA insertion for novice residents in a tertiary teaching hospital.

Tracheal intubation without neuromuscular blockade may be associated with worse intubating conditions and increased laryngeal morbidity. We hypothesised that tracheal intubation using the McGRATH™ MAC videolaryngoscope would not increase postoperative hoarseness, even without neuromuscular blockade. In this prospective, randomised, parallel-group, double-blind, non-inferiority trial, 248 patients were randomly assigned to tracheal intubation with or without neuromuscular blockade using rocuronium. Hoarseness and sore throat were evaluated at 24 h and 48 h postoperatively. The primary outcome was the incidence of hoarseness at 48 h postoperatively with a pre-defined non-inferiority margin of 10%. Hoarseness at 48 h did not differ between the non-paralysed group and the paralysed group (8.1% vs. 13.6%; absolute difference: -5.4%; 95%CI: -13.3 to 2.4). Also, no significant differences were found between the two groups for hoarseness at 24 h (22.8% vs. 27.1%) or for sore throat at 24 h (12.2% vs. 9.3%) and 48 h postoperatively (1.6% vs. 0.8%). Although more patients in the non-paralysed group showed an adducted position of the vocal cords (29.3% vs. 0%), there were no significant group differences in the ease of laryngoscopy (96.7% vs. 98.3%), Cormack grade laryngeal view 1 (97.6% vs. 96.6%) or first-pass success rate (100% vs. 100%). We conclude that when using the McGRATH MAC videolaryngoscope for tracheal intubation, the incidence of postoperative hoarseness was not inferior if neuromuscular blockade was avoided.

Study objective Several authors have reported rare, but severe, complications associated with the length of the intravascular guidewire during central venous catheter placement, as the wire tip can cause cardiac arrhythmia or perforation or become trapped within the vessel. Although one report investigated the optimal guidewire length using fluoroscopy, few reports have precisely measured guidewire position using transesophageal echocardiography (TEE). Here, we investigated the appropriate intravascular length of a guidewire for right internal jugular vein approach using TEE during cardiac surgery. Design A prospective observational study. Setting Operating room. Patients Fifty-two patients undergoing elective cardiac surgery. Measurements The intravascular guidewire distance from the insertion site to the superior vena cava–right atrium (SVC-RA) junction was measured by TEE. Demographic factors (height, weight, age, etc) were recorded. Results The mean distance from the access site to the SVC-RA junction was 17.8 ± 1.3 cm (maximum/minimum =20.0/15.0 cm). There was a greater correlation with height than with weight or age. Conclusion We confirmed the wire tips at all cases by ultrasonography. The distance using TEE was similar to that by fluoroscopy, but TEE was more precise. Guidewire length was weakly correlated to height. About 15 cm as minimum length should be considered the limit for guidewire length in an adult, in consideration of height, to ensure patient safety during central catheter placement for right internal jugular vein approach.

Partial discharge characteristics as well as breakdown phenomena in a power transformer insulation, i.e. oil and paper insulation, has to be clarified for miniaturization of the apparatus. In recent years, environmental-friendly transformers using ester oil, which shows excellent biodegradability, receive much attention due to the worldwide growing environmental awareness. Considering this, researches on fundamental characteristics of discharge phenomena within the ester oil are required. Although various papers on discharge characteristics in the ester oil have been published by many researchers, there are still few reports on these researches using ester oil and pressboard (PB) composite insulation system. In this paper, the discharge inception field and starting point in the ester oil and PB composite insulation configuration are investigated and the results are compared with those in the mineral oil to discuss the detailed discharge mechanisms.

Development of direct current (DC) power equipment is necessary for spreading DC power transmission systems in order to increase the amount of renewable energy. The insulation performance of power equipment deteriorates by various defects. In particular, when a metallic particle is present inside the power equipment, such as oil immersed transformer, the partial discharge inception voltage (PDIV) decreases greatly. For AC transformers, many investigations have been made on partial discharge (PD) caused by metallic particles. On the other hand, there are few reports on PD under DC voltage. In this paper, we have investigated PD characteristics caused by metallic particles under DC voltage in the oil / pressboard (PB) composite insulation system. Three results were obtained from our experiments. First, PDIV under positive DC voltage was lower than under negative DC voltage due to the difference of the discharge formations, etc. On the other hand, PDIV under positive DC voltage was the same as PDIV under AC voltage in the oil insulation setup. Secondly, PDIV was almost constant if the curvature radius was 10 $\mu$m or less due to the electric field relaxation effect caused by space charges in the vicinity of the needle tip. Finally, the electric field in the vicinity of the needle tip at the PDIV in oil was in the range of 200~400 kV/mm, regardless of the gap distance, the type of the applied voltage: AC or positive DC voltage, and the insulation system: only oil system or oil / PB composite system. That is, the condition for starting PD in the presence of metallic particle is determined by the electric field in the vicinity of the tip of the metallic particle regardless of the gap distance, the type of the applied voltage, and the insulation system.

Fetoscopic laser coagulation is an ef- fective treatment for the vascular anastomoses present in twin to twin transfusion syndrome (TTTS); how- ever, anesthetic management during the procedure has not yet been standardized. We hypothesized that dex- medetomidine could produce excellent maternal seda- tion during fetoscopic surgery. Therefore, we per- formed a prospective study to compare dexmedetomi- dine with fentanyl infusion, which had been previously used for sedation.Patients scheduled for fetoscopic laser coagulation for TTTS were randomized into 2 groups. In the first group (n =19), fentanyl (2 μg · kg-1) was intravenously infused, followed by a maintenance dose of 1-2,μg · kg⁻¹ · hr⁻¹. The second group (n=18) received a loading dose of dexmedetomidine (1 μg · kg⁻¹) for 10 min, followed by a maintenance dose of 0.7 μg · kg⁻¹ · hr⁻¹. Both groups received 1% lidocaine administered locally. Adverse event incidence, hemo- dynamic parameters, and face scale were evaluated.One patient in the dexmedetomidine group required conversion to general anesthesia. Vomiting, nausea, and respiratory depression were significantly more frequent with fentanyl than with dexmedetomi- dine. Face scale scores were significantly better with dexmedetomidine than with fentanyl.Continuous dexmedetomidine infusion provides acceptable maternal analgesia and sedation during endoscopic treatment of TTTS.

Mirror syndrome is a rare obstetric condition where a mother "mirrors" the edema of her hydropic fetus and placenta. We present the successful resolution of mirror syndrome following fetoscopic laser photocoag- ulation for twin to twin transfusion syndrome (TTTS). A 36-year-old woman was pregnant with monocho- rionic twins. She was diagnosed with TTTS at the 23rd week of pregnancy and transported to our hospi- tal by ambulance for treatment Her human chorionic gonadotropin serum concentration was 144,437 IU - ml'. Fetoscopic laser photocoagulation was performed under local anesthesia with dexmedetomidine. How- ever, her restlessness disturbed the procedure and conversion to general anesthesia was required, which facilitated successful completion of the surgical proce- dure. Postoperatively, her vital signs were stable, and after 30 min, the saturation decreased to 80%. She was intubated, sedated with propofol, and transported to the intensive care unit A transthoracic ultrasound examination showed no cardiomyopathy. A chest X-ray suggested pulmonary edema. Pulmonary edema disap- peared immediately, and she was extubated after 36 hr. Postoperatively, the twins had a good prognosis. There are several reports of mirror syndrome after fetoscopic laser photocoagulation for TTTS. Recovery from mirror syndrome can improve following the reso- lution of fetal hydrops in TTTS using fetoscopic laser photocoagulation.