Development and Evaluation of a Virtual Reality Simulator for Spinal Cord Stimulation: A Randomized Controlled Trial.

Purpose: The aim of this prospective study was to develop a virtual reality simulator (VRS) for spinal cord stimulation (SCS) trials and establish its effectiveness. Methods: We developed a VRS for SCS training by integrating patient imaging data analytics, creating artificial X-ray images, and using spatial alignment techniques and virtual reality technologies. The simulator was created by a physician with considerable experience in performing SCS, and can simulate the feeling of the procedure in a virtual environment. The efficacy of the simulator for SCS trials was assessed using a cohort of 20 novice trainees. The primary outcomes were duration of the procedure, checklist score, number of C-arm images captured, and overall trainee satisfaction. Results: The cohort that utilized the VRS had better Zwisch scale scores (P <0.001), completed the procedure in a shorter time (P <0.001), took fewer C-arm images (P <0.001), and reported better overall satisfaction (P = 0.011) than the cohort that did not. Conclusion: We developed a realistic and efficient VRS for educating novice trainees on SCS trials, thereby eliminating the risk of radiation exposure associated with cadaver training. The results of this study indicate that our VRS has potential as an instrumental resource that can be integrated into the educational framework for SCS trials.

Iliopsoas plane block does not improve pain after primary total hip arthroplasty in the presence of multimodal analgesia: a single institution randomized controlled trial.

BACKGROUND: The clinical analgesic efficacy of iliopsoas plane block remains a subject of discussion. This study aimed to assess the analgesic efficacy of iliopsoas plane block under general anesthesia using multimodal analgesia. METHODS: Fifty-six adult patients who underwent elective primary hip arthroplasty were enrolled. Patients were randomized to receive either a single-shot iliopsoas plane block (10 mL 0.75% ropivacaine with 1:200 000 epinephrine) or a sham block (10 mL normal saline). All patients received general anesthesia, multimodal analgesia (preoperative buprenorphine patch, 5 µg/h), intraoperative intravenous dexamethasone (8 mg) and nefopam (20 mg), and round-the-clock acetaminophen and celecoxib. The primary outcome was the numeric rating scale pain score at rest 6 hour after surgery. RESULTS: Iliopsoas plane block did not have a notable advantage over the sham block in terms of pain relief at rest, as assessed by the numeric rating scale score, 6 hour after total hip arthroplasty (iliopsoas plane block: median, 4.0; IQR, 2.0-5.8; sham: median, 5.5; IQR, 2.3-6.8; median difference, -1.0; 95% CI -2.0 to 0.0; p≥0.999). Linear mixed model analysis showed no differences in pain scores, opioid consumption, quadriceps strength, or quality of recovery between the groups. CONCLUSIONS: Iliopsoas plane block did not improve postoperative analgesia following total hip arthroplasty under general anesthesia with a multimodal analgesic regimen. The blockade of sensory femoral branches supplying the anterior hip capsule using iliopsoas plane block may not yield additional benefits concerning patient outcomes in the aforementioned clinical context. TRIAL REGISTRATION NUMBER: NCT05212038, https://clinicaltrials.gov/ct2/show/NCT05212038.

Identification for antitumor effects of tramadol in a xenograft mouse model using orthotopic breast cancer cells.

In our previous research showed that tramadol having potential anti-tumor effect was associated with enhancement of oncological prognosis in patients with breast cancer surgery. As these effects have not been confirmed by clinical dose-regulated animal or prospective human studies, we investigated the anti-tumor effect of tramadol in vivo. Female nude mice orthotopically inoculated with luciferase-expressing MCF-7 cells, were randomly divided into the control (saline), tramadol group 1 (1.5 mg kg-1 day-1), tramadol group 2 (3 mg kg-1 day-1), and morphine (0.5 mg kg-1 day-1) (n = 5/group). Bioluminescence signals after D-luciferin injection, tumor size, and tumor weight were compared among groups after 4 weeks. Estrogen receptor (ER), progesterone receptor (PR), and transient receptor potential vanilloid (TRPV)-1 expression, natural killer (NK) cell activity, and serum interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-6 were then examined. Tumour growth was attenuated in tramadol-treated groups (P < 0.05). NK cell activity was significantly decreased only in the morphine treated group not in sham, control, and tramadol groups. The expression levels of ERα, PRα and ß, and TRPV1 were decreased in tramadol group 2 compared with those in the morphine group, but not compared to the control group. Serum levels of IL-6 and TNFα were reduced in both tramadol-treated group 1 and 2 compared to the control group. Overall, clinical dose of tramadol has anti-tumour effects on MCF-7 cell-derived breast cancer in a xenograft mouse model.

Anterior neck soft tissue measurements on computed tomography to predict difficult laryngoscopy: a retrospective study.

Predicting difficult laryngoscopy is an essential component of the airway management. We aimed to evaluate the use of anterior neck soft tissue measurements on computed tomography for predicting difficult laryngoscopy and to present a clear measurement protocol. In this retrospective study, 281 adult patients whose tracheas were intubated using a direct laryngoscope for thyroidectomy were enrolled. On computed tomography, the distances from the midpoint of the thyrohyoid membrane to the closest concave point of the vallecular (membrane-to-vallecula distance; dMV), and to the most distant point of the epiglottis (membrane-to-epiglottis distance; dME) were measured, respectively. The extended distances straight to the skin anterior from the dMV and dME were called the skin-to-vallecula distance (dSV) and skin-to-epiglottis distance (dSE), respectively. Difficult laryngoscopy was defined by a Cormack-Lehane grade of > 2. Difficult laryngoscopy occurred in 40 (14%) cases. Among four indices, the dMV showed the highest prediction ability for difficult laryngoscopy with an area under the receiver operating characteristic curve of 0.884 (95% confidence interval 0.841-0.919, P < 0.001). The optimal dMV cut-off value for predicting difficult laryngoscopy was 2.33 cm (sensitivity 75.0%; specificity 93.8%). The current study provides novel evidence that increased dMV is a potential predictive indicator of difficult laryngoscopy.

The Effect of Intraoperative Fluid Management According to Stroke Volume Variation on Postoperative Bowel Function Recovery in Colorectal Cancer Surgery.

Stroke volume variation (SVV) has been used to predict fluid responsiveness; however, it remains unclear whether goal-directed fluid therapy using SVV contributes to bowel function recovery in abdominal surgery. This prospective randomized controlled trial aimed to compare bowel movement recovery in patients undergoing colon resection surgery between groups using traditional or SVV-based methods for intravenous fluid management. We collected data between March 2015 and July 2017. Bowel function recovery was analyzed based on the gas-passing time, sips of water time, and soft diet (SD) time. Finally, we analyzed data from 60 patients. There was no significant between-group difference in the patients' characteristics. Compared with the control group (n = 30), the SVV group (n = 30) had a significantly higher colloid volume and lower crystalloid volume. Moreover, the gas-passing time (77.8 vs. 85.3 h, p = 0.034) and SD time (67.6 vs. 85.1 h, p < 0.001) were significantly faster in the SVV group than in the control group. Compared with the control group, the SVV group showed significantly lower scores of pain on a numeric rating scale and morphine equivalent doses during post-anesthetic care, at 24 postoperative hours, and at 48 postoperative hours. Our findings suggested that, compared with the control group, the SVV group showed a faster postoperative SD time, reduced acute postoperative pain intensity, and lower rescue analgesics. Therefore, SVV-based optimal fluid management is expected to potentially contribute to postoperative bowel function recovery in patients undergoing colon resection surgery.

Predictability of preoperative carotid artery-corrected flow time for hypotension after spinal anaesthesia in patients undergoing caesarean section: A prospective observational study.

BACKGROUND: Spinal anaesthesia-induced hypotension is frequently reported in patients undergoing caesarean section. Mechanistically, sympathetic blockade reduces the systemic vascular resistance and the left ventricular preload, causing hypotension, which is augmented by aortocaval compression. The corrected blood flow time (FTc) is affected by the preload and is inversely related to the afterload. OBJECTIVE: We hypothesised that the preanaesthetic carotid artery FTc could predict hypotension after induction in patients undergoing a caesarean section with spinal anaesthesia. DESIGN: A prospective observational study. SETTING: A tertiary referral centre in South Korea from September 2018 to November 2019. PARTICIPANTS: Thirty-eight parturients scheduled for elective caesarean section under spinal anaesthesia. INTERVENTIONS: Using carotid ultrasonography, FTc was measured twice prior to inducing spinal anaesthesia. FTc was calculated using both Bazett's (B) and Wodey's (W) formulae. Hypotension was defined as an SBP decrease to less than 80 mmHg, or less than 75% of baseline, or if symptoms consistent with hypotension occurred from the time of injection of the spinal anaesthetic until delivery. MAIN OUTCOME MEASURES: The primary endpoint was to determine the predictive value of preanaesthetic FTc for postspinal hypotension during caesarean delivery. RESULTS: Among the 35 patients who completed this study, hypotension occurred in 21 (60%). The areas under the receiver-operating characteristic curves for FTc (B) and FTc (W) were 0.905 [95% confidence interval (CI), 0.757 to 0.978, P < 0.001] and 0.922 (95% CI, 0.779 to 0.985, P < 0.001), respectively. The optimal cut-off values for predicting hypotension were 346.4 and 326.9 ms, respectively. The grey zone for FTc (B) and FTc (W) included 40 and 14% of the patients, respectively. CONCLUSION: Preanaesthetic carotid artery FTc was a reliable indicator of postspinal hypotension in parturients. Considering the grey zone, Wodey's formula is better than Bazett's formula. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03631329.

Relationships between Body Image, Body Mass Index, and Smoking in Korean Adolescents: Results of a Nationwide Korea Youth Risk Behavior Web-based Survey.

OBJECTIVE: This study assessed the association between subjective body image or objective body mass index (BMI) and the risk of daily smoking in Korean adolescents, with a purpose of identifying the most suitable models. MATERIALS AND METHODS: Using the 2013 9th Korea Youth Risk Behavior Web-based Survey data for 72,435 students, odds ratios were calculated for daily smoking in the past month, according to the subjective body image and calculated BMI using a respective multiple logistic regression model. The combined effect of these two factors was also analyzed by pairing a BMI category with a subjective body image category, using odds ratios for the same event within each sex group. RESULTS: Among the surveyed students, 7.2% of boys and 1.8% of girls were classified as daily smokers. Students who perceived themselves as being very obese tended to be at lower risk of daily smoking (OR=0.61 in boys with 95% CI=0.47 to 0.79; OR=0.66 in women with 95% CI=0.47 to 0.93). In addition, boys within the obese or overweight BMI category showed a lower risk of daily smoking (OR=0.86, 95% CI: 0.77-0.96). Lean BMI was significantly associated with higher odds ratios for daily smoking only in female students (OR=1.24, 95% CI: 1.02-1.52). When pairing these two objective and subjective factors, results suggested that subjective body image has a greater effect on daily smoking than BMI in both boys and girls. CONCLUSIONS: In both male and female students, subjective body image had a greater effect on daily smoking than body mass index. A model using the combination of BMI and subjective body image was the best fit in girls, in contrast to the model using subjective body image only best suitable in boys, for the prediction of daily smoking. These results including several factors associated with daily smoking in Korean students, provide useful data for the development and implementation of smoking intervention and cessation programs for adolescents.

Stress shielding and fatigue limits of poly-ether-ether-ketone dental implants.

The poly-ether-ether-ketone (PEEK) polymer is of great interest as an alternative to titanium in orthopedics because of its biocompatibility and low elastic modulus. This study evaluated the fatigue limits of PEEK and the effects of the low elastic modulus PEEK in relation to existing dental implants. Compressive loading tests were performed with glass fiber-reinforced PEEK (GFR-PEEK), carbon fiber-reinforced PEEK (CFR-PEEK), and titanium rods. Among these tests, GFR-PEEK fatigue tests were performed according to ISO 14801. For the finite element analysis, three-dimensional models of dental implants and bone were constructed. The implants in the test groups were coated with a 0.5-mm thick and 5-mm long PEEK layer on the upper intrabony area. The strain energy densities (SED) were calculated, and the bone resorption was predicted. The fatigue limits of GFR-PEEK were 310 N and were higher than the static compressive strength of GFR-PEEK. The bone around PEEK-coated implants showed higher levels of SED than the bone in direct contact with the implants, and the wider diameter and stiffer implants showed lower levels of SED. The compressive strength of the GFR-PEEK and CFR-PEEK implants ranged within the bite force of the anterior and posterior dentitions, respectively, and the PEEK implants showed adequate fatigue limits for replacing the anterior teeth. Dental implants with PEEK coatings and PEEK implants may reduce stress shielding effects. Dental implant application of PEEK polymer-fatigue limit and stress shielding.