Raspberry Pi-Based Data Archival System for Electroencephalogram Signals From the SedLine Root Device.

BACKGROUND: The retrospective analysis of electroencephalogram (EEG) signals acquired from patients under general anesthesia is crucial in understanding the patient's unconscious brain's state. However, the creation of such database is often tedious and cumbersome and involves human labor. Hence, we developed a Raspberry Pi-based system for archiving EEG signals recorded from patients under anesthesia in operating rooms (ORs) with minimal human involvement. METHODS: Using this system, we archived patient EEG signals from over 500 unique surgeries at the Emory University Orthopaedics and Spine Hospital, Atlanta, for about 18 months. For this, we developed a software package that runs on a Raspberry Pi and archives patient EEG signals from a SedLine Root EEG Monitor (Masimo) to a secure Health Insurance Portability and Accountability Act (HIPAA) compliant cloud storage. The OR number corresponding to each surgery was archived along with the EEG signal to facilitate retrospective EEG analysis. We retrospectively processed the archived EEG signals and performed signal quality checks. We also proposed a formula to compute the proportion of true EEG signal and calculated the corresponding statistics. Further, we curated and interleaved patient medical record information with the corresponding EEG signals. RESULTS: We retrospectively processed the EEG signals to demonstrate a statistically significant negative correlation between the relative alpha power (8-12 Hz) of the EEG signal captured under anesthesia and the patient's age. CONCLUSIONS: Our system is a standalone EEG archiver developed using low cost and readily available hardware. We demonstrated that one could create a large-scale EEG database with minimal human involvement. Moreover, we showed that the captured EEG signal is of good quality for retrospective analysis and combined the EEG signal with the patient medical records. This project's software has been released under an open-source license to enable others to use and contribute.

Comparison of a Handheld Device vs Endotracheal Tube-Based Neuromonitoring for Recurrent Laryngeal Nerve Stimulation.

OBJECTIVE: To measure the effect of thyroidectomy difficulty on intraoperative neuromonitoring false loss of signal (LOS) and to compare intraoperative endotracheal tube-based neuromonitoring (ETNM) and Checkpoint palpation-based direct stimulation (pDS) signals with postoperative laryngoscopy. We hypothesized that pDS has higher a positive predictive value for postdissection confirmation of recurrent laryngeal nerve function than ETNM and that this difference is accentuated with increasing thyroidectomy difficulty. STUDY DESIGN: Prospective single-arm cross-sectional study comparing ETNM and pDS for patients undergoing hemi-, total, or completion thyroidectomy from July 2018 to March 2020. SETTING: Single-surgeon series at a tertiary care hospital. METHODS: Percentage concordance and positive and negative predictive values were measured. Each thyroidectomy was assigned a validated thyroidectomy difficulty score, and recorded recurrent laryngeal nerve signals were compared with postoperative vocal fold mobility. RESULTS: Percentage concordance was 90.09%. Positive and negative predictive values were 0.19 (95% CI, 0.09-0.31) and 1.0 for ETNM and 0.59 (95% CI, 0.35-0.82) and 1.0 for pDS. The difference in positive predictive value was significant (0.40 [95% CI, 0.33-0.47], P < .001). False LOS rates for ETNM and pDS were 13.19% versus 3.30% (9.89% [95% CI, 1.80%-18.62%], P = .0155), 44.11% versus 0% (44.11% [95% CI, 25.80%-60.54%], P < .001), and 73.33% versus 13.33% (60% [95% CI, 24.76%-78.46%], P = .001) for the second through fourth thyroidectomy difficulty score quartiles, respectively. False LOS with ETNM was linearly correlated with increasing difficulty (R2 = 0.97). CONCLUSION: ETNM was subject to high rates of postdissection false LOS that increased with thyroidectomy difficulty score. pDS is a reliable alternative that has higher positive predictive value than ETNM, particularly in more challenging cases such as those with posteriorly fixed thyroid cancers and fibrotic glands. EVIDENCE LEVEL: 2.

Comparison of the resonance sonorheometry based Quantra® system with rotational thromboelastometry ROTEM® sigma in cardiac surgery - a prospective observational study.

BACKGROUND: Measures of the sonorheometry based Quantra® viscoelastic hemostatic analyzer (HemoSonics, LCC, Charlottesville, VA, USA) were compared with corresponding results of the ROTEM® sigma device (Instrumentation Laboratory, Bedford, MA, USA). METHODS: In thirty-eight patients scheduled for elective cardiac surgery between December 2018 and October 2019, blood samples were taken after induction of anesthesia (sample 1) and after heparin neutralization (sample 2) and measured on Quantra (QPlus® Cartridge) and ROTEM sigma (ROTEM® sigma complete + hep Cartridge). Clot times and clot stiffness values were recorded. Clot stiffness values of ROTEM amplitudes (A in mm) were converted to shear modulus (G) in hectoPascal (hPa): G (hPa) = (5 x A)/(100-A). Additionally, time-to-results was recorded. Spearman rank test correlation and Bland Altman analysis were performed. RESULTS: Clot stiffness parameters of the Quantra correlated strongly with corresponding measurements of the ROTEM with r = 0.93 and 0.94 for EXTEM A10 vs CS and r = 0.94 and 0.96 for FIBTEM A10 vs FCS for sample 1 and 2, respectively. Quantra clot time correlated strongly with ROTEM INTEM CT with r = 0.71 for sample 1 and r = 0.75 for sample 2. However, Bland Altman analysis showed no agreement in all compared assays of both methods. The median time to delivery of first and complete results was significantly shorter for Quantra (412 and 658 s) compared to ROTEM sigma (839 and 1290 s). CONCLUSIONS: The Quantra showed a strong correlation with the ROTEM sigma for determining clot times and clot stiffness and the parameters assess similar aspects of clot development. However, these parameters are not directly interchangeable and implicate that separate cut-off values need to be established for users of the Quantra device. Word count: 278. TRIAL REGISTRATION: The study was retrospectively registered with ClinicalTrials.gov (ID: NCT04210830 ) at December 20th 2019.

Comparison of Monopolar and Bipolar Stimulator Probes for Intraoperative Nerve Mapping During Thyroidectomy: A Prospective Study.

OBJECTIVES/HYPOTHESIS: During intraoperative neuromonitoring in thyroid surgery, two different kinds of stimulator probes, monopolar and bipolar, are commonly used to stimulate the laryngeal nerves. We explore the unique characteristics of both of these probes as they relate to intraoperative laryngeal nerve mapping. METHODS: Twenty-one patients undergoing neuromonitored thyroidectomy by a single surgeon were enrolled. Electromyography (EMG) amplitude and latency measurements were prospectively recorded concurrently from 1 mA stimulation of vagus nerve (VN) and inferior/superior recurrent laryngeal nerve before (with and without fascia) and after thyroid resection using bipolar and monopolar stimulator probes. RESULTS: Significantly higher amplitudes were obtained with monopolar stimulator probes as compared to bipolar probes, in several stimulation scenarios such as at right VN pre-resection (carotid sheath intact), right VN pre-resection (carotid sheath dissected), right VN post-resection and left VN (carotid sheath dissected). No significant differences were found between amplitudes and latency values in all other stimulation scenarios. CONCLUSIONS: According to this study, both probes are reliable and safe for neural mapping. The kind of probe used during neural monitoring is based on surgical situations and surgeon preference. LEVEL OF EVIDENCE: 3 (According to Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence) Laryngoscope, 131:E2718-E2726, 2021.

Comparison of accuracy of two uncalibrated pulse contour cardiac output monitors in off-pump coronary artery bypass surgery patients using pulmonary artery catheter-thermodilution as a reference.

BACKGROUND: Cardiac output (CO) is a key measure of adequacy of organ and tissue perfusion, especially in critically ill or complex surgical patients. CO monitoring technology continues to evolve. Recently developed CO monitors rely on unique algorithms based on pulse contour analysis of an arterial blood pressure (ABP) waveform. The objective of this investigation was to compare the accuracy of two monitors using different methods of pulse contour analysis - the Retia Argos device and the Edwards Vigileo-FloTrac device - with pulmonary artery catheter (PAC)-thermodilution as a reference. METHODS: Fifty-eight patients undergoing off-pump coronary artery bypass surgery formed the study cohort. A total of 572 triplets of CO measurements from each device - Argos, Vigileo-FloTrac (third generation), and thermodilution - were available before and after interventions (e.g., vasopressors, fluids, and inotropes). Bland-Altman analysis accounting for repeated measurements per subject and concordance analysis were applied to assess the accuracy of the CO values and intervention-induced CO changes of each pulse contour device against thermodilution. Cluster bootstrapping was employed to statistically compare the root-mean-squared-errors (RMSE = √(µ2 + σ2), where µ and σ are the Bland-Altman bias and precision errors) and concordance rates of the two devices. RESULTS: The RMSE (mean (95% confidence intervals)) for CO values was 1.16 (1.00-1.32) L/min for the Argos device and 1.54 (1.33-1.77) L/min for the Vigileo-FloTrac device; the concordance rate for intervention-induced CO changes was 87 (82-92)% for the Argos device and 72 (65-78)% for the Vigileo-FloTrac device; and the RMSE for the CO changes was 17 (15-19)% for the Argos device and 21 (19-23)% for the Vigileo-FloTrac device (p < 0.0167 for all comparisons). CONCLUSIONS: In comparison with CO measured by the PAC, the Argos device proved to be more accurate than the Vigileo-FloTrac device in CO trending and absolute CO measurement in patients undergoing off-pump coronary artery bypass surgery.

ClearSight™ finger cuff versus invasive arterial pressure measurement in patients with body mass index above 45 kg/m2.

BACKGROUND: Measuring blood pressure in patients with obesity is challenging. The ClearSight™ finger cuff (FC) uses the vascular unloading technique to provide continuous non-invasive blood pressure measurements. We aimed to test the agreement of the FC with invasive radial arterial monitoring (INV) in patients with obesity. METHODS: Participants had a body mass index (BMI) ≥45 kg/m2 and underwent laparoscopic bariatric surgery. FC and INV measurements were obtained simultaneously every 5 min on each patient, following induction of anesthesia. Agreement over time was assessed using modified Bland-Altman plots and error grid analysis permitted clinical interpretation of the results. Four-quadrant plots allowed assessment of concordance in blood pressure changes. RESULTS: The 30 participants had a median (IQR) BMI of 50.2 kg/m2 (IQR 48.3-55.3). The observed bias (SD, 95% limits of agreement) for systolic blood pressure (SBP) was 14.3 mmHg (14.1, -13.4 - 42.0), 5.2 mmHg (10.9, -16.0 - 26.5) for mean arterial pressure (MAP) and 2.6 mmHg (10.8, -18.6 - 23.8) for diastolic blood pressure (DBP). Error grid analysis showed that the proportion of readings in risk zones A-E were 90.8, 6.5, 2.7, 0 and 0% for SBP and 91.4, 4.3, 4.3, 0 and 0% for MAP, respectively. Discordance occurred in ≤8% of pairs for consecutive change in SBP, MAP and DBP. CONCLUSIONS: The vascular unloading technique was not adequately in agreement with radial arterial monitoring. Evaluation in a larger sample is required before recommending this technique for intraoperative monitoring of patients with BMI ≥45 kg/m2.

Fast and robust localization of surgical array using Kalman filter.

PROBLEM: Intraoperative tracking of surgical instruments is an inevitable task of computer-assisted surgery. An optical tracking system often fails to precisely reconstruct the dynamic location and pose of a surgical tool due to the acquisition noise and measurement variance. Embedding a Kalman filter (KF) or any of its extensions such as extended and unscented Kalman filters (EKF and UKF) with the optical tracker resolves this issue by reducing the estimation variance and regularizing the temporal behavior. However, the current KF implementations are computationally burdensome and hence takes long execution time which hinders real-time surgical tracking. AIM: This paper introduces a fast and computationally efficient implementation of linear KF to improve the measurement accuracy of an optical tracking system with high temporal resolution. METHODS: Instead of the surgical tool as a whole, our KF framework tracks each individual fiducial mounted on it using a Newtonian model. In addition to simulated dataset, we validate our technique against real data obtained from a high frame-rate commercial optical tracking system. We also perform experiments wherein a diffusive material (such as a drop of blood) blocks one of the fiducials and show that KF can substantially reduce the tracking error. RESULTS: The proposed KF framework substantially stabilizes the tracking behavior in all of our experiments and reduces the mean-squared error (MSE) by a factor of 26.84, from the order of [Formula: see text] to [Formula: see text] mm[Formula: see text]. In addition, it exhibits a similar performance to UKF, but with a much smaller computational complexity.

Accuracy of noninvasive continuous arterial pressure monitoring using ClearSight during one-lung ventilation.

ABSTRACT: Noninvasive continuous arterial pressure monitoring may be clinically useful in patients who require continuous blood pressure monitoring in situations where arterial catheter placement is limited. Many previous studies on the accuracy of the noninvasive continuous blood pressure monitoring method reported various results. However, there is no research on the effectiveness of noninvasive arterial pressure monitoring during one-lung ventilation. The purpose of this study was to compare arterial blood pressure obtained through invasive method and noninvasive method by using ClearSight during one-lung ventilation.In this retrospective observational study, a total of 26 patients undergoing one-lung ventilation for thoracic surgery at a single institution between March and July 2019 were recruited. All patients in this study were cannulated on their radial artery to measure continuously invasive blood pressures and applied ClearSight on the ipsilateral side of the cannulated arm. We compared and analyzed the agreement and trendability of blood pressure recorded with invasive and noninvasive methods during one-lung ventilation.Blood pressure and pulse rate showed a narrower limit of agreement with a percentage error value of around 30%. In addition, the tracking ability of each measurement could be determined by the concordance rate, all of which were below acceptable limits (92%).In noninvasive arterial blood pressure monitoring using ClearSight, mean blood pressure and pulse rate show acceptable agreement with the invasive method.

Comparison of Sugammadex Dose for Intraoperative Neuromonitoring in Thyroid Surgery: A Randomized Controlled Trial.

OBJECTIVES/HYPOTHESIS: To compare effect of 1 and 2 mg/kg of sugammadex on the incidence of intraoperative bucking and intraoperative neuromonitoring (IONM) quality in thyroid surgery. STUDY DESIGN: Randomized controlled trial. METHODS: Patients qualified for thyroid surgery with IONM were eligible for this double-blind, randomized, controlled trial. After tracheal intubation with 0.6 mg/kg rocuronium, 1 or 2 mg/kg of sugammadex was administered to patients in group I or II, respectively. The quality of the IONM for the external branch of the superior laryngeal nerve (EBSLN) was evaluated (strong/intermediate/weak). The initial amplitude of electromyography for the vagus nerve (V1) and the recurrent laryngeal nerve (R1) were recorded. Intraoperative bucking movements was recorded. RESULTS: A total of 102 patients (51 in each group) completed the study. Time from sugammadex administration to initial checking for the EBSLN was not different between group I and II (25.0 ± 7.9 vs. 25.5 ± 9.0 minutes, P = .788). There was no difference in the neuromonitoring quality for the EBSLN between group I and II (strong/intermediate/weak: 46/5/0 vs. 50/1/0, P = .205). The amplitudes of V1 (1,086.3 ± 673.3 µV vs. 1,161.8 ± 727.5 µV, P = .588) and R1 (1,328.2 ± 934.1 µV vs. 1,410.5 ± 919.6 µV, P = .655) were comparable between the groups. Patients who experienced bucking were significantly fewer in the group I than the group II (13.7% vs. 35.3%, P = .020). CONCLUSION: A dose of 1 mg/kg sugammadex induced less bucking than 2 m/kg while providing comparable IONM quality during thyroid surgery. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:2154-2159, 2021.

A Prospective Validation Study of the First 3D Digital Exoscope for Visualization of 5-ALA-Induced Fluorescence in High-Grade Gliomas.

BACKGROUND: We report on the first use of a digital 3-dimensional (3D) exoscope equipped with a 5-aminolevulinic acid (5-ALA) fluorescence visual system. METHODS: We conducted a prospective clinical trial to evaluate the utility and sensitivity/specificity of the Olympus Orbeye 3D digital exoscope when used to visualize 5-ALA-induced fluorescence in patients with high-grade glioma undergoing a clinically indicated craniotomy. At least 2 tissue samples were each obtained from regions of strong, weak. and no fluorescence and evaluated in a blinded manner by a neuropathologist. RESULTS: Twenty patients were enrolled. Intraoperative fluorescence was observed in 100% of subjects. One hundred twenty-one surgical specimens were collected for histopathological analysis; 40 with strong, 40 weak, and 41 with no visible fluorescence. Histopathology demonstrated 62.8% of samples (n = 76) contained abundant, 20.7% (n = 25) scarce, and 16.5% (n = 20) no tumor cells. Thirty-three of the 40 specimens (82.5%) in the strong fluorescence group correlated with abundant tumor cells and 7 (17.5%) with scarce. Twenty-nine of the 40 specimens (72.5%) in the weak fluorescence group correlated with abundant tumor cells, 7 (17.5%) with scarce, and 4 (10%) with none. Fourteen of the 41 (34.2%) specimens in the no fluorescence group had abundant tumor cells, 11 (26.8%) had scarce, and 16 (39%) had none. The sensitivity was 75% and specificity was 80%. The positive predictive value was 95% and negative predictive value was 39%. CONCLUSIONS: Visualization of 5-ALA-induced tumor fluorescence with use of the Orbeye 3D digital exoscope was feasible and associated with a high positive predictive value.

Laryngeal Force Sensor for Suspension Microlaryngoscopy: A Prospective Controlled Trial.

OBJECTIVES: The laryngeal force sensor (LFS) provides real-time force data for suspension microlaryngoscopy. This study investigates whether active use of the LFS can prevent the development of complications. STUDY DESIGN: Prospective controlled trial. SETTING: Academic tertiary center. METHODS: The LFS and custom software were developed to track intraoperative force metrics. A consecutive series of 100 patients had force data collected with operating surgeons blinded to intraoperative readings. The subsequent 100 patients had surgeons actively use the LFS monitoring system. Patients were prospectively enrolled, completing pre- and postoperative surveys to assess the development of tongue pain, paresthesia, paresis, dysgeusia, or dysphagia. RESULTS: On univariate analysis, the active monitoring group had lower total impulse (P < .001) and fewer extralaryngeal complications (P < .01). On multiple logistic regression, maximum force (odds ratio [OR], 1.08; 95% CI, 1.01-1.16; P = .02) was a significant predictive variable for the development of postoperative complications. Similarly, active LFS monitoring showed a 29.1% (95% CI, 15.7%-42.4%; P < .001) decrease in the likelihood of developing postoperative complications. These effects persisted at the first postoperative visit for maximum force (P = .04) and active LFS monitoring (P = .01). Maximum force (OR, 1.11; 95% CI, 1.04-1.18; P < .01) and active LFS monitoring (16.6%; 95% CI, 2.7%-30.5%; P = .02) were also predictive for the development of an abnormal 10-item Eating Assessment Tool score. These effects also persisted at the first postoperative visit for maximum force (P = .01) and active LFS monitoring (P = .01). CONCLUSION: Maximum force is predictive of the development postoperative complications. Active monitoring with the LFS is able to mitigate these forces and prevent postoperative complications. LEVEL OF EVIDENCE: 2.

Performance-aware programming for intraoperative intensity-based image registration on graphics processing units.

PURPOSE: Intensity-based image registration has been proven essential in many applications accredited to its unparalleled ability to resolve image misalignments. However, long registration time for image realignment prohibits its use in intra-operative navigation systems. There has been much work on accelerating the registration process by improving the algorithm's robustness, but the innate computation required by the registration algorithm has been unresolved. METHODS: Intensity-based registration methods involve operations with high arithmetic load and memory access demand, which supposes to be reduced by graphics processing units (GPUs). Although GPUs are widespread and affordable, there is a lack of open-source GPU implementations optimized for non-rigid image registration. This paper demonstrates performance-aware programming techniques, which involves systematic exploitation of GPU features, by implementing the diffeomorphic log-demons algorithm. RESULTS: By resolving the pinpointed computation bottlenecks on GPU, our implementation of diffeomorphic log-demons on Nvidia GTX Titan X GPU has achieved ~ 95 times speed-up compared to the CPU and registered a 1.3-M voxel image in 286 ms. Even for large 37-M voxel images, our implementation is able to register in 8.56 s, which attained ~ 258 times speed-up. Our solution involves effective employment of GPU computation units, memory, and data bandwidth to resolve computation bottlenecks. CONCLUSION: The computation bottlenecks in diffeomorphic log-demons are pinpointed, analyzed, and resolved using various GPU performance-aware programming techniques. The proposed fast computation on basic image operations not only enhances the computation of diffeomorphic log-demons, but is also potentially extended to speed up many other intensity-based approaches. Our implementation is open-source on GitHub at https://bit.ly/2PYZxQz .

Educational application of intraoperative records from an energy device in laparoscopic gastrectomy: a preliminary report.

PURPOSE: Video review is a reliable method for surgical education in laparoscopic gastrectomy (LG), but more objective methods are still needed. The purpose of this study was to determine whether the energy device records reflected surgical competency, and thereby may improve surgical education. METHODS: A total of 16 patients who underwent LG for gastric cancer using the Thunderbeat® device were preliminarily retrospectively analyzed. This device has the function of 'intelligent tissue monitoring' (ITM), a safety assist system stopping energy output, and can record ITM detections and firing time during surgery. The number of ITM detections and firings, and the total firing time during gastrocolic ligament dissection and infrapyloric dissection were compared between trainees (n = 9 by 5 surgeons) and experts (n = 7 by 5 surgeons). The non-edited videos (n = 16) were scored, and the correlations between the scores and the records were then analyzed. RESULTS: Significantly more ITM detections, firings, and a longer total firing time were observed in trainees than in experts. The number of ITM detections and firing had negative correlations with the scores of the operation speed, the use of the non-dominant hand, and the use of an energy device. CONCLUSIONS: Our preliminary study suggested that the above described energy device records reflected surgical competency, and thereby may improve surgical education.

Continuous monitoring of intrapelvic pressure during flexible ureteroscopy using a sensor wire: a pilot study.

PURPOSE: To evaluate the feasibility of measuring the intrapelvic pressure (IPP) during f-URS with a wire including a pressure sensor and to assess IPP profiles during the procedure. METHODS: Patients undergoing f-URS for stone disease were recruited. A wire with pressure sensor was placed in the renal cavities to measure IPP. For these cases, either no ureteral access sheath (UAS) or 10/12 or 12/14-Fr UASs were used according to surgeon discretion. Irrigation was ensured by a combination of a continuous pressure generator set at 80 cmH2O and a hand-assisted irrigation system providing on-demand forced irrigation to provide proper visibility. Pressures were monitored in real time and recorded for analysis. RESULTS: Four patients undergoing five f-URS were included. IPP monitoring was successful in all patients. Mean baseline IPP was 6 cmH2O. During f-URS with only the endoscope in the renal cavities and irrigation pressure set at 80 cmH2O without any forced irrigation, the mean IPP was 63 cmH2O. Mean IPP during laser lithotripsy with the use of on-demand forced irrigation was 115.3 cmH2O. The maximum pressure peaks recorded during this therapeutic period using forced irrigation ranged from 289.3 to 436.9 cmH2O. CONCLUSION: High IPP levels may be achieved during f-URS with on-demand irrigation systems. The impact of these high pressures on the risk of complications and long-term consequences still need to be evaluated adequately. But, in this preliminary pilot study, IPP could be reliably and conveniently monitored and recorded using a wire with a digital pressure sensor.

Intraoperative parathyroid hormone (IOPTH) assay might be better than the second-generation assay in parathyroidectomy for primary hyperparathyroidism.

BACKGROUND: It is unclear whether the third-generation intraoperative parathyroid hormone assay can improve surgical outcomes over second-generation assay in primary hyperparathyroidism. We aimed to compare the rate of decrease and diagnostic accuracy between the two assays after parathyroid adenoma excision. METHODS: Consecutive patients undergoing parathyroidectomy with intraoperative parathyroid hormone were analyzed. Blood was drawn before and 10 minutes and 20 minutes after excision of the adenoma. The same blood sample was run simultaneously in the second-generation assays (Elecsys PTH STAT) and third-generation assays (Elecsys 1-84 PTH). Biochemical cure meant >50% intraoperative parathyroid hormone decrease at 10 minutes. Cure meant normocalcemia 6 months after operation. RESULTS: Relative to the second-generation assay, the value of the intraoperative parathyroid hormone level was less in the third-generation assay before excision (P < .001), at 10 minutes (P < .001), and at 20 minutes (P < .001). The intraoperative parathyroid hormone rate of decrease and the proportion of normalized post-excision intraoperative parathyroid hormone were greater in the third-generation assay (P < .001), but the prediction accuracy appeared similar between the 2 (91.5% vs 91.0%). Patients with worse renal function (estimated glomerular filtration rate <80mL/min/1.73m2) had a slower intraoperative parathyroid hormone decrease in the second-generation but not in the third-generation assay. CONCLUSION: Despite comparable accuracy between the two generations of assay, the third-generation assay might be better than the second-generation assay because of the more rapid decrease in the intraoperative parathyroid hormone and a greater percentage of normalized intraoperative parathyroid hormone, regardless of baseline renal function.

Real-Time, Intraoperative, Ultrasound-Assisted Transoral Robotic Surgery for Obstructive Sleep Apnea.

OBJECTIVES/HYPOTHESIS: To investigate the lingual artery (LA) position in the tongue base through intraoperative ultrasound (IOU) imaging during transoral robotic surgery (TORS) and evaluate bleeding complications with or without the assistance of IOU. STUDY DESIGN: Cohort study with historical control. METHODS: Patients with obstructive sleep apnea (OSA) who underwent TORS for tongue base resection were recruited since 2016. During surgery, ultrasound imaging was employed to identify anatomic parameters of the LA in the tongue base, including distance to the midline and arterial depth and diameter. RESULTS: Ninety-three OSA patients (82 men, 88.2%) were analyzed. Mean age was 42.2 ± 10.0 years and body mass index was 29.2 ± 4.5 kg/m2 . Average apnea-hypopnea index (AHI) was 58.1 ± 21.4 events/hour. Overall, 70 patients who underwent TORS with IOU had a shorter operation time (191.7 ± 3.8 vs. 220.1 ± 6.6 minutes), lower total blood loss (11.3 ± 10.8 vs. 19.6 ± 26.7 mL), and higher tongue base reduction volume (7.1 ± 2.5 vs. 3.9 ± 1.6 mL) than 23 patients who underwent TORS without IOU. Significant predictors of arterial depth included higher AHI level during the rapid eye movement sleep (P = .038), larger tonsil size (P = .034), and more elevated Friedman tongue position (P = .012). Postoperative complications associated with LA injury were not found in patients subjected to IOU. CONCLUSIONS: With the assistance of IOU, surgeons can confidently determine LA position. The use of IOU can maximize efficiency and minimize catastrophic bleeding complications when OSA patients undergo TORS for tongue base resection. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1383-E1390, 2021.

Establish pre-clinical diagnostic efficacy for parathyroid hormone as a point-of-surgery-testing-device (POST).

Measuring the Parathyroid hormone (PTH) levels assists in the investigation and management of patients with parathyroid disorders. Rapid PTH monitoring is a valid tool for accurate assessment intraoperatively. Rapid Electro-Analytical Device (READ) is a point-of-care device that uses impedance change between target and capture probe to assess the PTH concentration in undiluted patient plasma samples. The aim of this work focuses on evaluating the analytical performance of READ platform to Roche analyzer as a prospective clinical validation method. The coefficient of variation (CV) for intra-assay imprecision was < 5% and inter-assay imprecision CV was < 10% for high (942 pg/mL) and low (38.2 pg/mL) PTH concentration. Functional sensitivity defined at 15% CV was 1.9 pg/mL. Results obtained from READ platform correlated well (r = 0.99) with commercially available clinical laboratory method (Roche Diagnostics) to measure PTH concentrations with a turn-around time of less than 15 min. Furthermore, the mean bias of 7.6 pg/mL determined by Bland-Altman analysis, showed good agreement between the two methods. We envision such a sensing system would allow medical practitioners to facilitate targeted interventions, thereby, offering an immediate prognostic approach as the cornerstone to delivering successful treatment for patients suffering from primary hyperparathyroidism.

Clinical Evaluation of a High-fidelity Upper Arm Cuff to Measure Arterial Blood Pressure during Noncardiac Surgery.

BACKGROUND: In most patients having noncardiac surgery, blood pressure is measured with the oscillometric upper arm cuff method. Although the method is noninvasive and practical, it is known to overestimate intraarterial pressure in hypotension and to underestimate it in hypertension. A high-fidelity upper arm cuff incorporating a hydraulic sensor pad was recently developed. The aim of the present study was to investigate whether noninvasive blood pressure measurements with the new high-fidelity cuff correspond to invasive measurements with a femoral artery catheter, especially at low blood pressure. METHODS: Simultaneous measurements of blood pressure recorded from a femoral arterial catheter and from the high-fidelity upper arm cuff were compared in 110 patients having major abdominal surgery or neurosurgery. RESULTS: 550 pairs of blood pressure measurements (5 pairs per patient) were considered for analysis. For mean arterial pressure measurements, the average bias was 0 mmHg, and the precision was 3 mmHg. The Pearson correlation coefficient was 0.96 (P < 0.0001; 95% CI, 0.96 to 0.97), and the percentage error was 9%. Error grid analysis showed that the proportions of mean arterial pressure measurements done with the high-fidelity cuff method were 98.4% in zone A (no risk), 1.6% in zone B (low risk) and 0% in zones C, D, and E (moderate, significant, and dangerous risk, respectively). The high-fidelity cuff method detected mean arterial pressure values less than 65 mmHg with a sensitivity of 84% (95% CI, 74 to 92%) and a specificity of 97% (95% CI, 95% to 98%). To detect changes in mean arterial pressure of more than 5 mmHg, the concordance rate between the two methods was 99.7%. Comparable accuracy and precision were observed for systolic and diastolic blood pressure measurements. CONCLUSIONS: The new high-fidelity upper arm cuff method met the current international standards in terms of accuracy and precision. It was also very accurate to track changes in blood pressure and reliably detect severe hypotension during noncardiac surgery.