The Use of the Perfusion Index to Predict Post-Induction Hypotension in Patients Undergoing General Anesthesia: A Systematic Review and Meta-Analysis.

Post-induction hypotension (PIH) is a common and potentially serious complication of general anesthesia. This meta-analysis (Prospero registration number: CRD42024566321) aimed to evaluate the predictive efficacy of the perfusion index (PI) for PIH in patients undergoing general anesthesia. A comprehensive literature search was performed using multiple electronic databases (Google Scholar, EMBASE, Cochrane Library, and MEDLINE). Studies involving adult patients undergoing general anesthesia, with the PI measured before anesthesia induction and reporting PIH incidence, were included. The primary outcome was the diagnostic accuracy of the PI in predicting the probability of PIH. The secondary outcome was the pooled PIH incidence. Eight studies with 678 patients were included. The pooled incidence of PIH was 44.8% (95% confidence interval [CI]: 29.9%-60.8%). The combined sensitivity and specificity of the PI for predicting PIH were 0.84 (95% CI: 0.65-0.94) and 0.82 (95% CI: 0.70-0.90), respectively. The summary receiver operating characteristic (sROC) analysis revealed an area under curve of 0.89 (95% CI: 0.86-0.92). The Deek's funnel plot asymmetry test indicated no significant publication bias. The PI demonstrates high predictive efficacy for PIH in patients undergoing general anesthesia, indicating that it can be a valuable tool for identifying those at risk of PIH.

Effects of perioperative magnesium on postoperative analgesia following thoracic surgery: a meta-analysis of randomised controlled trials.

To evaluate the analgesic effects of intravenous magnesium in patients undergoing thoracic surgery. Randomised clinical trials (RCTs) were systematically identified from MEDLINE, EMBASE, Google Scholar and the Cochrane Library from inception to May 1st, 2023. The primary outcome was the effect of intravenous magnesium on the severity of postoperative pain at 24 hours following surgery, while the secondary outcomes included association between intravenous magnesium and pain severity at other time points, morphine consumption, and haemodynamic changes. Meta-analysis of seven RCTs published between 2007 and 2019, involving 549 adults, showed no correlation between magnesium and pain scores at 1-4 (standardized mean difference [SMD]=-0.06; p=0.58), 8-12 (SMD=-0.09; p=0.58), 24 (SMD=-0.16; p=0.42), and 48 (SMD=-0.27; p=0.09) hours post-surgery. Perioperative magnesium resulted in lower equivalent morphine consumption at 24 hours post-surgery (mean difference [MD]=-25.22 mg; p=0.04) and no effect at 48 hours (MD=-4.46 mg; p=0.19). Magnesium decreased heart rate (MD = -5.31 beats/min; p=0.0002) after tracheal intubation or after surgery, but had no effect on postoperative blood pressure (MD=-6.25 mmHg; p=0.11). There was a significantly higher concentration of magnesium in the magnesium group compared with that in the placebo group (MD = 0.91 mg/dL; p<0.00001). This meta-analysis provides evidence supporting perioperative magnesium as an analgesic adjuvant at 24 hours following thoracic surgery, but no opioid-sparing effect at 48 hours post-surgery. The severity of postoperative pain did not significantly differ between any of the postoperative time points, irrespective of magnesium. Further research on perioperative magnesium in various surgical settings is needed.

The impact of perioperative ketamine or esketamine on the subjective quality of recovery after surgery: a meta-analysis of randomised controlled trials.

BACKGROUND: This meta-analysis aimed to evaluate the impact of ketamine/esketamine on postoperative subjective quality of recovery (QoR). METHODS: MEDLINE, Embase, Cochrane library, and Google Scholar were searched for randomised controlled trials (RCTs) that examined the impacts of perioperative ketamine/esketamine use and postoperative QoR. The primary outcome was subjective QoR (QoR-9, QoR-15, QoR-40) on postoperative day (POD) 1-3, whereas the secondary outcomes included pain severity, anxiety scores, depression scores, risk of adverse events (i.e. nausea, vomiting, dizziness, drowsiness), and length of stay. RESULTS: The analysis included 18 RCTs (1554 participants; ketamine: seven trials, esketamine: 11 trials), of which 15 were conducted in China. Ketamine/esketamine improved the QoR scores on PODs 1 and 2 compared with the control (standardised mean difference [SMD]: 0.63, P<0.0001 for POD 1; SMD: 0.56, P=0.04 for POD 2), without beneficial effect on POD 3. Subgroup analyses revealed significant differences in QoR scores on POD 1 by regimen (SMD: esketamine 1.14, ketamine 0.01) and country (SMD: China 0.82, other countries -0.21). The emotional domain of QoR was improved from PODs 1 to 3, whereas the other domains were only improved on POD 1. Lower postoperative anxiety (SMD: -0.48, P=0.003) and depression (SMD: -0.72, P=0.001) scores were also observed with ketamine/esketamine use. Furthermore, pain severity was reduced on PODs 1 and 2, with no difference in the risk of adverse events or length of stay. CONCLUSIONS: This meta-analysis demonstrated that ketamine/esketamine use in the perioperative period is associated with improved early subjective QoR, pain severity, and psychological symptoms without an increase in the likelihood of adverse events. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023477580).

Impact of the geriatric nutritional risk index on long-term outcomes in patients undergoing hemodialysis: a meta-analysis of observational studies.

Background: This meta-analysis aimed to synthesize current evidence on the association between the Geriatric Nutritional Risk Index (GNRI) and long-term outcomes in patients undergoing hemodialysis. Methods: Electronic databases were systematically searched for relevant studies that investigated the association between GNRI and long-term outcomes in hemodialysis patients until November 2023. The primary outcome was the association between the GNRI (i.e., low versus high) and overall mortality risk, while the secondary outcome was the relationship between the GNRI and cardiovascular mortality risk. Results: Thirty cohort studies involving 55,864 patients were included. A low GNRI was found to be significantly associated with increased overall mortality (hazard ratio [HR]: 2.42, 95% confidence interval [CIs]: 2.10-2.79, p < 0.00001, I2 = 65%). Each unit increase in GNRI corresponded to a 5% reduction in mortality risk (HR: 0.95, 95% CI: 0.93-0.96, p < 0.00001, I2 = 79%). The association remained consistent across Asian (HR = 2.45, 95% CI: 2.08-2.88, p < 0.00001, I2 = 70%) and non-Asian subgroups (HR = 2.3, 95% CI: 1.72-3.06, p < 0.00001, I2 = 23%). Meta-regression analysis of patient age (coefficient: -0.002; p = 0.896), male proportion (coefficient: 0.002; p = 0.875), percentage of diabetes mellitus (coefficient: -0.003; p = 0.605), and follow-up duration (coefficient: -0.003; p = 0.431) revealed that these moderator variables did not significantly influence the association between GNRI and overall mortality risk. Cardiovascular mortality risk also increased with low GNRI (HR, 1.93; 95%CI: 1.51-2.45, p < 0.00001; I2 = 2%). Similarly, an inverse association was observed between the GNRI values and cardiovascular mortality risk (HR, 0.94; 95% CI: 0.91-0.97; p < 0.0001; I2 = 65%) (per unit increase). Conclusion: The GNRI is a simple nutritional screening tool that can be used to effectively stratify patients undergoing hemodialysis globally. Further studies are warranted to determine whether nutrition optimization based on the GNRI improves long-term outcomes. Systematic review registration: https://www.crd.york.ac.uk/prospero/, CRD42023483729.

Virtual Dental Articulation Using Computed Tomography Data and Motion Tracking.

Dental articulation holds crucial and fundamental importance in the design of dental restorations and analysis of prosthetic or orthodontic occlusions. However, common traditional and digital articulators are difficult and cumbersome in use to effectively translate the dental cast model to the articulator workspace when using traditional facebows. In this study, we have developed a personalized virtual dental articulator that directly utilizes computed tomography (CT) data to mathematically model the complex jaw movement, providing a more efficient and accurate way of analyzing and designing dental restorations. By utilizing CT data, Frankfurt's horizontal plane was established for the mathematical modeling of virtual articulation, eliminating tedious facebow transfers. After capturing the patients' CT images and tracking their jaw movements prior to dental treatment, the jaw-tracking information was incorporated into the articulation mathematical model. The validation and analysis of the personalized articulation approach were conducted by comparing the jaw movement between simulation data (virtual articulator) and real measurement data. As a result, the proposed virtual articulator achieves two important functions. Firstly, it replaces the traditional facebow transfer process by transferring the digital dental model to the virtual articulator through the anatomical relationship derived from the cranial CT data. Secondly, the jaw movement trajectory provided by optical tracking was incorporated into the mathematical articulation model to create a personalized virtual articulation with a small Fréchet distance of 1.7 mm. This virtual articulator provides a valuable tool that enables dentists to obtain diagnostic information about the temporomandibular joint (TMJ) and configure personalized settings of occlusal analysis for patients.

Lidocaine induces epithelial­mesenchymal transition and aggravates cancer behaviors in non­small cell lung cancer A549 cells.

The effects of clinically relevant concentrations of lidocaine on epithelial-mesenchymal transition (EMT) and associated lung cancer behaviors have rarely been investigated. The aim of the present study was to assess the impact of lidocaine on EMT and its related phenomena, including chemoresistance. Lung cancer cell lines (A549 and LLC.LG) were incubated with various concentrations of lidocaine, 5-fluorouracil (5-FU) or both to test their effects on cell viability. Subsequently, the effects of lidocaine on various cell behaviors were assessed in vitro and in vivo using Transwell migration, colony-formation and anoikis-resistant cell aggregation assays, and human tumor cell metastasis in a chorioallantoic membrane (CAM) model quantitated by PCR analysis. Prototypical EMT markers and their molecular switch were analyzed using western blotting. In addition, a conditioned metastasis pathway was generated through Ingenuity Pathway Analysis. Based on these measured proteins (slug, vimentin and E-cadherin), the molecules involved and the alteration of genes associated with metastasis were predicted. Of note, clinically relevant concentrations of lidocaine did not affect lung cancer cell viability or alter the effects of 5-FU on cell survival; however, at this dose range, lidocaine attenuated the 5-FU-induced inhibitory effect on cell migration and promoted EMT. The expression levels of vimentin and Slug were upregulated, whereas the expression of E-cadherin was downregulated. EMT-associated anoikis resistance was also induced by lidocaine administration. In addition, portions of the lower CAM with a dense distribution of blood vessels exhibited markedly increased Alu expression 24 h following the inoculation of lidocaine-treated A549 cells on the upper CAM. Thus, at clinically relevant concentrations, lidocaine has the potential to aggravate cancer behaviors in non-small cell lung cancer cells. The phenomena accompanying lidocaine-aggravated migration and metastasis included altered prototypical EMT markers, anoikis-resistant cell aggregation and attenuation of the 5-FU-induced inhibitory effect on cell migration.

Association of a low vitamin D status with risk of post-stroke depression: A meta-analysis and systematic review.

Background: Although post-stroke depression (PSD) affects one-third of patients following an acute stroke, pooled evidence addressing the correlation between a low vitamin D status and the risk of PSD remains inconclusive. Methods: Comprehensive database search of Medline, EMBASE, Cochrane library, and Google Scholar was performed from inception to December 2022. The primary outcome was the association of PSD risk with a low vitamin D status, while the secondary outcomes included the relationship between PSD and other risk factors. Results: Analysis of seven observational studies published between 2014 and 2022 with 1,580 patients showed pooled incidences of vitamin D deficiency (defined as 25[OH] D levels < 50 nmol/L) and PSD of 60.1 and 26.1%, respectively. Patients with PSD had a lower circulating vitamin D concentration compared to those without [mean difference (MD) =-13.94 nmol/L, 95% CI: -21.83 to -6.05, p = 0.0005, I 2 = 91%, six studies, 1,414 patients]. Meta-analysis also demonstrated a correlation between a low vitamin D level and an increased PSD risk [odd ratio (OR) = 3.25, 95% CI: 1.57-6.69, p = 0.001, I 2 = 78.7%, 1,108 patients], the heterogeneity of which was found to be associated with the incidence of vitamin D deficiency but not female proportion on meta-regression. Besides, female gender (OR = 1.78, 95% CI: 1.3-2.44, p = 0.003, I 2 = 31%, five studies, 1,220 patients), hyperlipidemia (OR = 1.55, 95% CI: 1.01-2.36, p = 0.04, I 2 = 0%, four studies, 976 patients), and high National Institutes of Health Stroke Scale (NIHSS) scores (MD = 1.45, 95% CI: 0.58-2.32, p = 0.001, I 2 = 82%, five studies, 1,220 patients) were potential risk factors for PSD. For the primary outcome, the certainty of evidence was very low. Regarding secondary outcomes, the certainty of evidence was low for BMI, female gender, hypertension, diabetes, and stroke history, and very low for age, level of education, hyperlipidemia, cardiovascular disease, and NIHSS scores. Conclusion: The results suggested an association of a low circulating vitamin D level with an increased risk of PSD. Besides, female gender, hyperlipidemia, high NIHSS score were related to an increased risk or occurrence of PSD. The current study may imply the necessity of routine circulating vitamin D screening in this population. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022381580.

Usefulness of Analgesia Nociception Index for guiding intraoperative opioid administration: a systematic review and meta-analysis.

INTRODUCTION: This study primarily aimed at investigating the efficacy of Analgesia Nociception Index (ANI) for guiding intraoperative opioid administration in patients receiving surgery under general anesthesia. EVIDENCE ACQUISITION: The Medline, Embase, Google scholar, and the Cochrane Library databases were searched from inception to April 2022 for randomized controlled trials. The primary outcome was intraoperative opioid administration, while the secondary outcomes included postoperative opioid consumption, pain score, emergency time, risk of nausea/vomiting (PONV), and Postanesthesia Care Unit (PACU) stay. EVIDENCE SYNTHESIS: Six studies including 399 participants (published from 2015 to 2022) focused on non-cardiac surgery, including spine surgery (two trials), breast surgery (two trials), gynecologic surgery (one trial), and laparoscopic cholecystectomy (one trial) were included. Meta-analysis revealed no difference in intraoperative opioid administration with the use of ANI-guided analgesia compared to the control group that used conventional clinical measurements (e.g., heart rate) to guide opioid use [standardized mean difference (SMD)=-0.17, 95% CI: -0.56 to 0.22, P=0.39, I2=72%, six trials, 399 participants]. Gender-based subgroup analysis showed effectiveness of ANI for reducing opioid administration in female patients (SMD=-0.53, P=0.02). There were no differences in postoperative recovery characteristics including pain score [Mean difference (MD): -0.03, P=0.79], opioid consumption (SMD: -0.34, P=0.08), emergence time (MD=1.12, P=0.47), length of stay in the PACU (MD: -0.56, P=0.83), and risk of PONV [risk ratio(RR): 0.75, P=0.46] between the two groups. CONCLUSIONS: Analgesia nociception index-guided analgesia was unable to reduce intraoperative opioid administration compared to monitoring using conventional clinical parameters. Further studies are required to support our findings.

Impact of Opioid-Free Anesthesia on Analgesia and Recovery Following Bariatric Surgery: a Meta-Analysis of Randomized Controlled Studies.

This meta-analysis aimed at exploring the impact of opioid-free anesthesia (OFA) on pain score and opioid consumption in patients undergoing bariatric surgery (BS). Literature search identified eight eligible trials. Forest plot revealed a significantly lower pain score (mean difference (MD) = - 0.96, p = 0.0002; 318 patients), but not morphine consumption (MD = - 5.85 mg, p = 0.1; 318 patients) at postoperative 24 h in patients with OFA than in those without. Pooled analysis also showed a lower pain score (p = 0.002), morphine consumption (p = 0.0003) in the postanesthetic care unit, and risk of postoperative nausea/vomiting (p = 0.0003) in the OFA group compared to the controls. In conclusion, this meta-analysis demonstrated that opioid-free anesthesia improved pain outcomes immediately and at 24 h after surgery without a beneficial impact on opioid consumption at postoperative 24 h. KEY POINTS: • Roles of opioid-free anesthesia (OFA) in bariatric surgery (BS) were investigated. • Outcomes included postoperative pain score, opioid use, and nausea/vomiting risk. • OFA was associated with lower 24-h pain score but not opioid consumption. • Lower pain score and opioid consumption were noted in the postanesthetic care unit. • OFA correlated with a lower risk of postoperative nausea/vomiting.

Fire safety study on high-flow nasal oxygen in shared-airway surgeries with diathermy and laser: simulation based on a physical model.

High-flow nasal oxygen (HFNO) has been used in "tubeless" shared-airway surgeries but whether HFNO increased the fire hazard is yet to be examined. We used a physical model for simulation to explore fire safety through a series of ignition trials. An HFNO device was attached to a 3D-printed nose with nostrils connected to a degutted raw chicken. The HFNO device was set at twenty combinations of different oxygen concentration and gas flow rate. An electrocautery and diode laser were applied separately to a fat cube in the cavity of the chicken. Ten 30 s trials of continuous energy source application were conducted. An additional trial of continuous energy application was conducted if no ignition was observed for all the ten trials. A total of eight short flashes were observed in one hundred electrocautery tests; however, no continuous fire was observed among them. There were thirty-six events of ignition in one hundred trials with laser, twelve of which turned into violent self-sustained fires. The factors found to be related to a significantly increased chance of ignition included laser application, lower gas flow, and higher FiO2. The native tissue and smoke can ignite and turn into violent self-sustained fires under HFNO and continuous laser strikes, even in the absence of combustible materials. The results suggest that airway surgeries must be performed safely with HFNO if only a short intermittent laser is used in low FiO2.

Efficacy of greater occipital nerve block for pain relief in patients with postdural puncture headache: A meta-analysis.

BACKGROUND: This study aimed at assessing the therapeutic effectiveness of greater occipital nerve block (GONB) against postdural puncture headache (PDPH). METHODS: Studies investigating analgesic effects of GONB against PDPH in adults were retrieved from the MEDLINE, EMBASE, Google scholar, and Cochrane central databases from their inception dates to May, 2021. Pain score at postprocedural 24 hours was the primary endpoint, while secondary endpoints were pain score at postprocedural 1 hour and 12 hours as well as the risk of intervention failure. RESULTS: Of the 7 studies (randomized controlled trials [RCTs], n = 4; non-RCTs, n = 3) that recruited 275 patients, 2 investigated female patients undergoing cesarean section and the other 5 were conducted in both obstetric and nonobstetric settings. Pooled results showed a lower mean pain score at 24 hours (i.e., primary outcome) (mean difference [MD] = -2.66, 95%: CI: -3.98 to -1.33, P < .001; I2 = 97%, 6 studies), 1 hour (MD = -4.23, 95% confidence interval [CI]: -5.08 to -3.37, P < .00001; I2 = 86%, 5 studies), and 6 hours (MD = -2.78, 95% CI: -4.99 to -0.57, P = .01; I2 = 98%, 4 studies) in patients with GONB compared to those without. Trial sequential analysis supported the robustness of evidence at postprocedural 24 hours. The use of GONB also decreased the risk of intervention failure (relative ratio [RR] = 0.4, 95% CI: 0.19 to 0.82, P = .01; I2 = 96%, 6 studies, 277 patients). CONCLUSION: Our results suggested a therapeutic effect of greater occipital nerve block against postdural puncture headache up to postprocedural 24 hours. Further large-scale studies are warranted to evaluate its therapeutic benefit beyond the acute stage.

Comparison of video-stylet and video-laryngoscope for endotracheal intubation in adults with cervical neck immobilisation: A meta-analysis of randomised controlled trials.

BACKGROUND: The efficacy of video-stylet versus video-laryngoscope for tracheal intubation in patients with cervical spine immobilisation, which is known to impede the intubation process, remains unclear. METHODS: We searched electronic databases including EMBASE, MEDLINE, Google Scholar, and Cochrane Library for randomised controlled trials comparing video-stylets with video-laryngoscopes in human subjects with cervical spine immobilisation from inception to the 25th of January 2021. The primary outcome was the rate of successful first-attempt intubation, while secondary outcomes included overall intubation success rate, time for successful intubation, and risk of tissue damage. RESULTS: Five trials (709 patients) published between 2009 and 2020 met the inclusion criteria. There were four types of video-stylets and three types of video-laryngoscopes examined. Hard cervical collar was applied in four studies, while manual inline stabilisation was used in one study for cervical immobilisation. There was no difference in successful first-attempt intubation rate between the video-stylet and the video-laryngoscope groups [risk ratio (RR) = 0.96, 95% CI: 0.90-1.03, p = 0.3; I2 = 47%] (5 trials, 709 patients). The overall success rate (RR = 0.98, 95% CI: 0.96-1.0, p = 0.05; I2 = 0%), intubation time [mean difference (MD) = 5.24, 95% CI: -8.95 to 19.43, p = 0.47; I2 = 92%], and risk of tissue damage (RR = 0.87, 95% CI: 0.26-2.85, p = 0.81; I2 = 39%) were also comparable between the two groups. CONCLUSIONS: This study validates the efficacy of both video-stylets and video-laryngoscopes for tracheal intubation in the situation of cervical spine immobilisation. Further large-scale trials are warranted to support our findings in this clinical setting.

Intercostal Nerve Block Using an Innovative Intraneedle Ultrasound Transducer: A Proof-of-Concept study.

Intercostal nerve block is a widely used and effective approach to providing regional anesthesia in the thoracic region for pain relief. However, during ultrasound-guided intercostal nerve block, inaccurate identification of the anatomic structures or suboptimal positioning of the needle tip may result in complications and blockade failure. In this study, we designed an intraneedle ultrasound (INUS) system and validated its efficacy in identifying anatomic structures relevant to thoracic region anesthesia. The 20-MHz INUS transducer comprised a single lead magnesium niobate-lead titanate crystal, and gain was set to 20 dB. It fit into a regular 18G needle and emitted radiofrequency-mode ultrasound signals at 1 mm from the needle tip. One hundred intercostal punctures were performed in 10 piglets. Intercostal spaces were identified by surface ultrasound or palpation and located by inserting and advancing the INUS transducer needle until the appropriate anatomy was identified. Blockade success was defined by ideal saline and dye spreading and confirmed by dissection. The pleura had a distinctive ultrasound signal, and successful detection of the intercostal muscles, endothoracic fascia and double-layered parietal and visceral pleura was achieved in all 100 puncture attempts. INUS allows real-time identification of intercostal structures and facilitates successful intercostal nerve blocks.

The Use of Propofol versus Dexmedetomidine for Patients Receiving Drug-Induced Sleep Endoscopy: A Meta-Analysis of Randomized Controlled Trials.

The sedation outcomes associated with dexmedetomidine compared with those of propofol during drug-induced sleep endoscopy (DISE) remains unclear. Electronic databases (i.e., the Cochrane controlled trials register, Embase, Medline, and Scopus) were searched from inception to 25 December 2020 for randomized controlled trials (RCTs) that evaluated the sedation outcomes with dexmedetomidine or propofol in adult patients diagnosed with obstructive sleep apnea (OSA) receiving DISE. The primary outcome was the difference in minimum oxygen saturation (mSaO2). Five RCTs (270 participants) published between 2015 and 2020 were included for analysis. Compared with dexmedetomidine, propofol was associated with lower levels of mSaO2 (mean difference (MD) = -7.24, 95% confidence interval (CI) -12.04 to -2.44; 230 participants) and satisfaction among endoscopic performers (standardized MD = -2.43, 95% CI -3.61 to -1.26; 128 participants) as well as a higher risk of hypoxemia (relative ratios = 1.82, 95% CI 1.2 to 2.76; 82 participants). However, propofol provided a shorter time to fall asleep and a lower risk of failed sedation compared with dexmedetomidine. No significant difference was found in other outcomes. Compared with propofol, dexmedetomidine exhibited fewer adverse effects on respiratory function and provided a higher level of satisfaction among endoscopic performers but was associated with an elevated risk of failed sedation.

Modeling of digital dental articulator and its accuracy verification using optical measurement.

BACKGROUND AND OBJECTIVES: Temporomandibular joint has been considered one of the most complex joints in human body. Dental articulation hinged upon temporomandibular joint is essential and fundamentally important for dental restoration design and prosthetic/orthodontic occlusion analysis. As digital dentistry rapidly grows, a complete digital work flow requires the use of a digital articulator for occlusion analysis. However, commercial CAD/CAM systems do not provide any method to verify the modeling accuracy of a digital articulator. There is also a lack of detail and generalized mathematical modeling of the digital articulator for simulating the jaw movement. METHODS: This paper presents the development of a digital articulator by mathematically modeling a general dental articulator which simulates the relative jaw motion between the maxilla and mandible. As the digital articulator moves, the digital upper teeth move relatively to the digital lower teeth, thus simulating the occlusal path with teeth collision detection function. To verify the accuracy of our modeled digital articulator, an improved optical tracking method is proposed to measure the pose of a mechanical articulator with 6 degrees of freedom and compare that with the digital articulator. RESULTS: The digital articulator system proposed in this paper achieves the following functions: 1. Digitalize the dental articulator with verified precision. Combined with dental design software, restorations can be designed with more efficiency and accuracy. 2. Provide an improved optical tracking method which can compare the movement error between the mechanical articulator and digital articulator. Thus the accuracy of the digital articulation can be verified. The result shows the error of our system is controlled under sub-millimeter which provides sufficient accuracy for the design of restoration under static and dynamic occlusion conditions. CONCLUSIONS: We develop a general digital articulator which can simulate jaw movement between opposing teeth and an improved optical tracking method to verify the accuracy of the digital articulator. The modeling and accuracy verification of the digital articulator shows that there is a systematic and reliable way to replace traditional mechanical articulator and can close the gap for digital restoration fabrication.

Myasthenic crisis and late deep vein thrombosis following thymectomy in a patient with myasthenia gravis: A case report.

INTRODUCTION: Surgical stress and pain are potential provoking factors for postoperative myasthenic crisis (POMC). We report the occurrence of early POMC and late deep vein thrombosis (DVT) in a man with myasthenia gravis (MG) undergoing thymectomy, addressing possible link between reversal of opioid overdose with naloxone and the triggering of POMC. PATIENT CONCERNS: A 71-year-old man with impaired renal function (ie, estimated glomerular filtration rate [egfr]: 49.1 mL/min/1.73 m) with diagnosis of MG made 2 months ago was scheduled for thymectomy. After uncomplicated surgery, he experienced opioid overdose that was treated with naloxone. Hyperlactatemia then developed with a concomitant episode of hypertension. Three hours after reversal, he suffered from myasthenic crisis presenting with respiratory failure and difficult weaning from mechanical ventilation. DIAGNOSIS: Stress-induced hyperlactatemia and subsequent myasthenic crisis INTERVENTIONS:: Pyridostigmine and immunosuppressive therapy with prednisolone were initiated. Hyperlactatemia subsided on postoperative day (POD) 5. Tracheal extubation was performed successfully on POD 6. OUTCOMES: During the course of hospitalization, his eGFR (ie, 88.9 mL/min/1.73 m) was found to improve postoperatively. After discharge from hospital, he developed DVT in the left femoral and popliteal veins on POD 24 when he was readmitted for immediate treatment with low-molecular-weight heparin. He was discharged without sequelae on POD 31. There was no recurrence of myasthenic crisis or DVT at 3-month follow-up. CONCLUSIONS: Following naloxone administration, hyperlactatemia may be an indicator of pain-related stress response, which is a potential provoking factor for myasthenic crisis. Additionally, patients with MG may have an increased risk of DVT possibly attributable to immune-mediated inflammation. These findings highlight the importance of perioperative avoidance of provoking factors including monitoring of stress-induced elevations in serum lactate concentration, close postoperative surveying for myasthenic crisis, and early recognition of possible thromboembolic complications in this patient population.

Intravenous loading of nitroglycerin during rewarming of cardiopulmonary bypass improves metabolic homeostasis in cardiac surgery: a retrospective analysis.

PURPOSE: The aim of the study was to evaluate the effects of high-dose nitroglycerine (NTG) on glucose metabolism, tissue oxygenation and postoperative recovery in cardiac surgical patients. METHODS: Cardiac surgical patients in the retrospective survey were classified into two groups based on the NTG regimen. NTG group had intravenous loading of NTG (infusion rate 10-20 mg/h with total dose of ≥0.5 mg/kg) starting at rewarming of cardiopulmonary bypass (CPB) (n = 101), and control group had no intravenous loading of NTG (n = 151). Data for intraoperative plasma glucose and lactate levels, and regular insulin consumption were collected. Propensity score methodology was utilized to adjust for potential confounders. RESULTS: After adjustment for propensity score, the plasma glucose was significantly lower in the NTG group during (161 ± 39 versus 179 ± 45 mg/dl, p = 0.005) and after CPB (167 ± 41 versus 184 ± 48 mg/dl, p = 0.012). Total consumption of regular insulin was significantly lower in the NTG group, median 8 (range 0-50) versus 13 (0-90) international units, p = 0.005. There was a trend towards statistical significance in a lower incidence of hyperlactatemia (>2.2 mmol/l) in the NTG group during CPB, 21/100 (21 %) versus 40/132 (30.3 %), p = 0.065. The mixed venous oxygen saturation in the intensive care unit was higher in the NTG group, 65 ± 9 versus 62 ± 11 %, p = 0.056. CONCLUSIONS: Intravenous loading of NTG during and after CPB is safe and effective for attenuating the hyperglycemic response and reduce the incidence of hyperlactatemia during cardiac surgery with CPB.

Optimized Spiral Metal-Gallium-Nitride Nanowire Cavity for Ultra-High Circular Dichroism Ultraviolet Lasing at Room Temperature.

Circularly polarized laser sources with small footprints and high efficiencies can possess advanced functionalities in optical communication and biophotonic integrated systems. However, the conventional lasers with additional circular-polarization converters are bulky and hardly compatible with nanophotonic circuits, and most active chiral plasmonic nanostructures nowadays exhibit broadband emission and low circular dichroism. In this work, with spirals of gallium nitride (GaN) nanowires (NWRs) covered by a metal layer, we demonstrated an ultrasmall semiconductor laser capable of emitting circularly-polarized photons. The left- and right-hand spiral metal nanowire cavities with varied periods were designed at ultraviolet wavelengths to achieve the high quality factor circular dichroism metastructures. The dissymmetry factors characterizing the degrees of circular polarizations of the left- and right-hand chiral lasers were 1.4 and -1.6 (±2 if perfectly circular polarized), respectively. The results show that the chiral cavities with only 5 spiral periods can achieve lasing signals with the high degrees of circular polarizations.