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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.

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.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.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.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.

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.

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.

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 to 1.03, p = 0.3; I2 = 47%] (5 trials, 709 patients). The overall success rate (RR = 0.98, 95% CI: 0.96 to 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 to 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 immobiliz-sation. Further large-scale trials are warranted to support our findings in this clinical setting.

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 FiO

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 m2) 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 m2) 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.

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.

This study demonstrated a metal-coated GaN laser from a defect cavity with shallow grating structure. With a structure optimization for surface plasmon waves, the shallow grating can support a high quality factor (Q) resonant mode, which leads to a lasing action in the metal-coated GaN cavity. The defect lasing mode was observed at a wavelength of approximately 365 nm at room temperature. The defect grating structure was 840 nm in period, 220 nm in width, and 200 nm in height, and the cavity length of the defect region was 300 nm. The quality factor was 480 and the threshold power density was 4.6 W/cm 2 . Lasing modes were also characterized with FEM simulation. Furthermore, the optical image and far-field angle of the metal-coated defect mode GaN grating structure were analyzed, and the lasing behavior of the defect grating structure was attributed to the defect mode.

Room temperature highly circular polarized laser was demonstrated with a compact metal/GaN double-spiral nanowire cavity. The lasing action was observed with a UV wavelength of 363 nm and a high dissymmetry factor of +1.05.

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.

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. 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. 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. 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.

The compact and energy-efficient planar metal-GaN spiral nanowire cavity lasing device has been demonstrated with high circularly polarized UV laser light at 364 nm and the circular dichroism performance enhanced to dissymmetry factor of +1.4.

The left ventricular assist device (LVAD) is a battery-operated, mechanical pump-type device that helps in maintaining the pumping ability of a failing heart. Thromboembolism poses a significant risk during and after LVAD implantation. It occurs in up to 35% of patients with adverse sequelae. We present the case of a 75-year-old man who underwent coronary artery bypass graft surgery and LVAD implantation for acute myocardial ischemia and severe left ventricular dysfunction. However, subsequent transthoracic echocardiographic examination revealed an LVAD thrombus, and LVAD removal was suggested following the failure of thrombolytic therapy. After the LVAD cannula was removed, transesophageal echocardiography (TEE) revealed a residual thrombus in the left atrium. Thrombectomy was successfully performed by opening the left atrium with cardiopulmonary bypass. We believe that TEE monitoring aided the implantation and removal of the LVAD device. In this case, we found that TEE not only helped in monitoring the ventricular function but also in detecting other problems such as the residual thrombus. We strongly recommend TEE monitoring during the entire LVAD-removal procedure, particularly for patients who need to undergo LVAD removal because of thrombosis formation.

We demonstrated a metal-cavity GaN spiral structure lasing at room temperature with the threshold power density about 17 W/cm2 under circularly polarized pumping condition. The emission wavelength is approximately 363 nm.

We had investigated a metal-coated GaN spiral structure laser at room temperature. The lasing action was observed around 363 nm wavelength with a low threshold power density. We also compare the lasing characteristics from metal-coated GaN spiral and grating structures. The experiment results ensure the circular-polarized emission from the metal-coated GaN spiral laser.

Background: Examinations are necessary for assessment of student proficiency in medical education, but comparison of achievement across different cohorts in different tests is challenging. We applied psychometric test equating methods to compare student proficiency in two different examinations for a clinical anesthesiology course. Methods: Each examination contained 50 multiple choice items and nine common items were identified from the two examinations (administered in 2011 and 2012). The common item design was used for test equating. Two psychometric test-equating approaches, chained linear equating and item response theory, were used to compare student proficiency in anesthesiology across distinct medical student cohorts. Raw scores from the 2012 test were linearly transformed to the 2011 scale using the chained method, and then Rasch analysis was applied to calibrate examinee ability and item difficulty in the two examinations on a common scale. Results: Both the linear equating method and Rasch analysis indicated that students in the 2011 examination performed better than those who took the 2012 examination (both p

The study proposes an improved Gabor order tracking (GOT) technique to cope with crossing orders that cannot be effectively separated by using the original GOT scheme. The improvement aids both the reconstruction and interpretation of two crossing orders such as a transmission-element- related order component and a structural resonance. The dual function of the Gabor elementary function can affect the precision of tracked order components. Its influence on the computed Gabor expansion coefficients is investigated in the study. For applying the improved GOT in practical works, the separation and extraction of close-order components of vibration signals measured from a transmission-element test bench is illustrated by using both the GOT and Vold-Kalman filtering OT schemes. Additionally, the ranking of noise components from a riding electric scooter is demonstrated.Copyright © 2005 by ASME