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Background: This survey aimed to explore the availability and accessibility of echocardiography during noncardiac surgery worldwide., Methods: An internet-based 45-item survey was sent, followed by reminders from August 30, 2021, to August 20, 2022., Results: 1189 responses were received from 62 countries. Nearly seventy-one percent of respondents had intraoperatively used transesophageal or transthoracic echocardiography (TEE and TTE, respectively) for monitoring or examination. The unavailability of echocardiography machines (30.3%), lack of trained personnel (30.2%), and absence of clinical indications (22.6%) were the top 3 reasons for not using intraoperative echocardiography in noncardiac surgery. About 61.5% of participants had access to at least one echocardiography machine. About 41% had access to at least 1 TEE probe, and 62.2% had access to at least 1 TTE probe. Seventy-four percent of centers had a procedure to request intraoperative echocardiography if needed for noncardiac cases. Intraoperative echocardiography service was immediately available in 58% of centers., Conclusions: Echocardiography machines and skilled echocardiographers are still unavailable at many centers worldwide. National societies should aim to train a critical mass of certified TEE/TTE anesthesiologists and provide all anesthesiologists access to perioperative TEE/TTE machines in anesthesiology departments, considering the increasing number of older and sicker surgical patients scheduled for noncardiac surgery., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Anesthesiologists frequently use intraoperative transesophageal echocardiography (TEE) to aid in the diagnosis and management of hemodynamic problems during liver transplantation (LT). Although the use of TEE in US centers continues to increase, data regarding international use are lacking., Methods: This prospective, global, survey-based study evaluates international experience with TEE for LT. Responses from 252 LT (105 US and 147 non-US) centers representing 1789 anesthesiologists were analyzed., Results: Routine use of TEE in the United States has increased in the last 5 y (from 37% to 47%), but only 21% of non-US LT anesthesiologists use TEE routinely. Lack of training (44% US versus 70% non-US) and equipment (9% non-US versus 34% US) were cited as obstacles. Most survey participants preferred not to perform a complete cardiac examination but rather use only 6 of 11 basic views. Although non-US LT anesthesiologists more frequently had additional clinical training than their US counterparts, they had less TEE experience (13% versus 44%) and less frequently, TEE certification (22% versus 35%). Most LT anesthesiologists agreed that TEE certification is essential for proficiency. Of all respondents, 89% agreed or strongly agreed that TEE provides valuable information needed for immediate clinical decision-making, and >86% agreed or strongly agreed that that information could not be derived from other sources., Conclusions: The use of TEE for LT surgery in the US LT centers is currently higher compared with non-US LT centers. This may become a standard monitoring modality during LT in the near future., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: In this study, we aimed to analyse survey data to explore two different hypotheses; and for this purpose, we distributed an online survey to Chinese anaesthesiologists. The hypothetical questions in this survey include: (1) Chinese anaesthesiologists mainly use the depth of anaesthesia (DoA) monitors to prevent intraoperative awareness and (2) the accuracy of these monitors is the most crucial performance factor during the clinical daily practice of Chinese anaesthesiologists., Methods: We collected and statistically analysed the response of a total of 12,750 anesthesiologists who were invited to participate in an anonymous online survey. The Chinese Society of Anaesthesiologists (CSA) trial group provided the email address of each anaesthesiologist, and the selection of respondents was random from the computerized system., Results: The overall response rate was 32.0% (4037 respondents). Only 9.1% (95% confidence interval, 8.2-10.0%) of the respondents routinely used DoA monitors. Academic respondents (91.5, 90.3-92.7%) most frequently used DoA monitoring to prevent awareness, whereas nonacademic respondents (88.8, 87.4-90.2%) most frequently used DoA monitoring to guide the delivery of anaesthetic agents. In total, the number of respondents who did not use a DoA monitor and whose patients experienced awareness (61.7, 57.8-65.6%) was significantly greater than those who used one or several DoA monitors (51.5, 49.8-53.2%). Overall, the crucial performance factor during DoA monitoring was considered by 61.9% (60.4-63.4%) of the respondents to be accuracy. However, most respondents (95.7, 95.1-96.3%) demanded improvements in the accuracy of the monitors for DoA monitoring. In addition, broad application in patients of all ages (86.3, 85.2-87.4%), analgesia monitoring (80.4, 79.2-81.6%), and all types of anaesthetic agents (75.6, 74.3-76.9%) was reported. In total, 65.0% (63.6-66.5%) of the respondents believed that DoA monitors should be combined with EEG and vital sign monitoring, and 53.7% (52.1-55.2%) believed that advanced DoA monitors should include artificial intelligence., Conclusions: Academic anaesthesiologists primarily use DoA monitoring to prevent awareness, whereas nonacademic anaesthesiologists use DoA monitoring to guide the delivery of anaesthetics. Anaesthesiologists demand high-accuracy DoA monitors incorporating EEG signals, multiple vital signs, and antinociceptive indicators. DoA monitors with artificial intelligence may represent a new direction for future research on DoA monitoring., (© 2021. The Author(s).)

Background: Functional preservation of cranial nerves remains an issue in surgical treatment of vestibular schwannoma., Aims: To explore the functional outcomes of vestibular schwannoma removed by microsurgery via a retrosigmoid transmeatal approach with intraoperative monitoring techniques., Study Design: A retrospective cross-sectional study was conducted on a group of patients with vestibular schwannoma operated by microsurgery., Methods: The outcomes, including the extent of tumor removal, the anatomic positions of the facial nerve, and postoperative Karnofsky performance status score, facial nerve function, and hearing function were reviewed and were statistically compared among tumor sizes (small, medium, and giant) and intraoperative monitoring types [electrophysiological monitoring only (E), electrophysiological monitoring + intraoperative imaging examination (E+I), and electrophysiological monitoring + neuronavigation (E+N)]., Results: A total of 436 patients with VS received microsurgery. The position of the facial nerve was anterior in 85.5% of cases with small vestibular schwannoma. Other position patterns, especially anterior- superior and anterior-inferior, increased in tumors > 2.0 cm. Total resections were performed in all patients with small vestibular schwannoma. A total of 98.1% and 84.8% of patients with medium and giant vestibular schwannoma, respectively, had total resections. More than 90% of patients in all of the 3 monitoring groups had total resections. More than 80% of patients had excellent Karnofsky performance status score regardless of tumor size and monitoring type. After surgery, 100%, 84.4%, and 59.8% of patients with small-, medium-, and giant-sized vestibular schwannoma, respectively, had good facial nerve function. More than 70% of patients in all of the 3 monitoring groups had good facial nerve function postoperatively. The hearing preservation rate was 26.7% and 7.7% in small- and medium-sized vestibular schwannoma, respectively, and was 21.6% and 27.3% in the E group and the E+N group, respectively. The statistical analyses showed that tumor size was significantly associated with the extent of tumor resection, facial nerve localization, complications, postoperative Karnofsky performance status score, facial nerve function, and hearing function (all P ≤ .001). Monitoring type was significantly associated with the extent of resection (P ≤ .001). Additionally, patients in the E+N group had higher total resection rates than those in the E group (P ≤ .001). No cerebrospinal fluid leakage and surgery-related death occurred., Conclusion: In vestibular schwannoma microsurgery, tumor size is an important parameter that affects the localization of the facial nerve, the extent of resection, postoperative outcomes and complications. Intraoperative electrophysiological techniques combined with neuronavigation may be helpful to improve the extent of resection.

Background: Intraoperative nerve monitoring (IONM) is used increasingly in thyroid surgery to prevent recurrent laryngeal nerve (RLN) injury, despite lack of definitive evidence. This study analysed the United Kingdom Registry of Endocrine and Thyroid Surgery (UKRETS) to investigate whether IONM reduced the incidence of RLN injury., Methods: UKRETS data were extracted on 28 July 2018. Factors related to risk of RLN palsy, such as age, sex, retrosternal goitre, reoperation, use of energy devices, extent of surgery, nodal dissection and IONM, were analysed. Data with missing entries for these risk factors were excluded. Outcomes of patients who had preoperative and postoperative laryngoscopy were analysed., Results: RLN palsy occurred in 4.9 per cent of thyroidectomies. The palsy was temporary in 64.6 per cent and persistent in 35.4 per cent of patients. In multivariable analysis, IONM reduced the risk of RLN palsy (odds ratio (OR) 0.63, 95 per cent confidence interval (CI) 0.54 to 0.74, P < 0.001) and persistent nerve palsy (OR 0.47, 0.37 to 0.61, P < 0.001). Outpatient laryngoscopy was also associated with a reduced incidence of RLN palsy (OR 0.50, 0.37 to 0.67, P < 0.001). Bilateral RLN palsy occurred in 0.3 per cent. Reoperation (OR 12.30, 2.90 to 52.10, P = 0.001) and total thyroidectomy (OR 6.52, 1.50 to 27.80; P = 0.010) were significantly associated with bilateral RLN palsy., Conclusion: The use of IONM is associated with a decreased risk of RLN injury in thyroidectomy. These results based on analysis of UKRETS data support the routine use of RLN monitoring in thyroid surgery., (© The Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background/aim: The aim of this study is to evaluate the effects of preemptive oral pregabalin on hemodynamic response, anxiety, sedation, and recovery in patients who underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) under sedation with intravenous ketamine-propofol combination., Materials and Methods: Sixty patients were included in this study, and patients were randomly divided into two equal groups to receive the placebo (Group 1) versus pregabalin 150 mg (Group 2) one hour prior to EBUS- TBNA procedure. Patients received 0.25 mg kg-1 ketamine and 0.25 mg kg-1 propofol mixture (ketofol) for sedation. Timing of the parameters was defined as follows; T0: in hospital ward before pregabalin or placebo administration, T1: premedication, T2: in operating room, T3: before the procedure, T4: initiation, T5: 3 min after induction, T6: 6 min after induction, T7: 9 min after induction, and T8: 12 min after induction. Hemodynamic parameters, severity of coughing, sedation and anxiety scores, and complications were recorded. The level of satisfaction of the bronchoscopist and the patients were evaluated at the end of the procedure., Results: The heart rate and mean arterial pressure were significantly higher in Group 1 (P = 0.008, P = 0.04). Total doses of anesthetics, recovery time, and desaturation rate were significantly higher in Group 1 (P = 0.014, P = 0.001, P = 0.045). In Group 2, SpO2 level was significantly higher at various time periods (T1; P = 0.025, T4; P =0.043, T6; P = 0.001, T7; P = 0.003, T8; P < 0.001). The severity of coughing was found significantly lower in Group 2 (T4; P = 0.011, T5; P = 0.01, T6; P = 0.02, T7; P = 0.03, T8; P < 0.01). Anxiety scores were significantly lower in Group 2 (P < 0.001)., Conclusion: Preemptive oral pregabalin, in addition to sedation with ketamine-propofol combination, was effective in providing limited hemodynamic response, restricted coughing reflex, and lower anxiety during EBUS-TBNA. Besides, with pregabalin usage, decreased anesthetics consumption, lower complication rate, and shorter recovery time might have contributed to safety of the procedure and comfort of the bronchoscopist., Competing Interests: All authors declare that they have no conflict of interest., (This work is licensed under a Creative Commons Attribution 4.0 International License.)

Background: Early graft failure can affect the short- and long-term outcomes of patients undergoing coronary bypass grafting surgery (CABG). The aim of our study was to explore the predictive value of transit-time flow measurement (TTFM) parameters for early graft failure (before discharge) after CABG in different coronary territories and calculate the TTFM cut-off values., Methods: We analyzed a total of 761 grafts (360 patients) that were evaluated by intraoperative TTFM and computed tomography angiography prior to discharge. Logistic model was established to detect the parameters of TTFM to predict early graft failure and receiver operating characteristic curve analysis was used to calculate the cut-off values., Results: The overall early graft failure was 3.5%. The results demonstrated that compared with off-pump CABG, mean graft flow volume was higher (28.0 vs 21.0 mL/min, p = 0.000), but pulse index (PI) (2.3 vs 2.5, p = 0.049) and diastolic flow fraction (DF) (68.0% vs 71.0%, p = 0.001) were lower in on-pump CABGs. DF (73.0% vs 65.5%, p = 0.000) of arterial grafts was higher than that of venous grafts. DF (72.0% vs 62.0%, p = 0.000) in left was higher than that in the right coronary artery territories. The results of multivariate logistic analysis showed that not only in the overall (OR 1.18, 95% CI 1.07-1.30, p = 0.001), but also the left (OR 1.21, 95% CI 1.03-1.41, p = 0.017) and right (OR 1.15, 95% CI 1.03-1.29, p = 0.017) coronary artery target territories, PI was a risk factor for early graft failure and the cut-off value was 3.4, 3.4, and 3.6, respectively. For grafts in left target territories, the results showed that DF (OR 0.94, 95% CI 0.91-0.97, p = 0.000) just in the univariate analysis was a risk factor that affected graft failure., Conclusions: The overall early graft failure was about 3.5%. High PI value is a risk factor for early graft failure in not only overall grafts but in grafts of different target territories. DF might be more useful for the quality evaluation of grafts in left than in right target territories., (Copyright © 2020. Published by Elsevier Ltd.)

Abstract: Postoperative delirium (PODE) can be associated with severe clinical complications; therefore, preventive measures are important. The objective of this trial was to elucidate whether haemodynamic or electroencephalographic (EEG) monitoring parameters during general anaesthesia or sevoflurane dosage correlate with the incidence of PODE. In addition, sevoflurane dosages and EEG stages during the steady state of anaesthesia were analyzed in patients of different ages.Eighty adult patients undergoing elective abdominal surgery received anaesthesia with sevoflurane and sufentanil according to the clinical routine. Anaesthesiologists were blinded to the EEG. Haemodynamic parameters, EEG parameters, sevoflurane dosage, and occurrence of PODE were analyzed.Thirteen patients (4 out of 33 women, 9 out of 47 men) developed PODE. Patients with PODE had a greater mean arterial pressure (MAP) variance (267.26 (139.40) vs 192.56 (99.64) mmHg2, P = .04), had a longer duration of EEG burst suppression or suppression (27.09 (45.32) vs 5.23 (10.80) minutes, P = .03), and received higher minimum alveolar sevoflurane concentrations (MAC) (1.22 (0.22) vs 1.09 (0.17), P = .03) than patients without PODE. MAC values were associated with wide ranges of EEG index values representing different levels of hypnosis.The results suggest that, in order to prevent PODE, a great variance of MAP, higher doses of sevoflurane, and deep levels of anaesthesia should be avoided. Titrating sevoflurane according to end-tidal gas monitoring and vital signs can lead to unnecessarily deep or light hypnosis. Intraoperative EEG monitoring may help to prevent PODE., Competing Interests: The authors have no funding and conflicts of interests to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Continuous intraoperative neuromonitoring may facilitate reversal of intraoperative injurious operative maneuvers in comparison with intermittent intraoperative neuromonitoring. The aim of this study was to evaluate the impact of the routine use of continuous intraoperative neuromonitoring on intraoperative injuries to the recurrent laryngeal nerve., Method: This study was a prospective case series with retrospective analysis of consecutive patients undergoing total thyroidectomy from August 2013 to August 2019. During this period, intermittent intraoperative neuromonitoring (before Mar 2016) and continuous intraoperative neuromonitoring (after Mar 2016) were used in all patients., Results: We reviewed the outcomes of 603 patients (466 female patients) comprising 236 who underwent intermittent intraoperative neuromonitoring and 367 who underwent continuous intraoperative neuromonitoring. Intraoperative adverse electromyography events (>50% decrease in amplitude between VN1 and VN2) were observed in 87 patients (14.5%) and were less frequent in the continuous intraoperative neuromonitoring group (10.6 vs 20.3%, P = .001). Intraoperative loss of signal (electromyography events with VN2 ≤100μV) were observed in 35 patients (5.8%) without any difference between the 2 groups of patients (5.2 vs 6.8%, P = .415). Postoperative recurrent laryngeal nerve palsies were observed in 36 patients (5.9%) without any difference between the 2 groups of patients (4.9 vs 7.6%, P = .168)., Conclusion: The routine use of continuous intraoperative neuromonitoring improves the rate of intraoperative adverse electromyography events but does not impact significantly the rates of loss of signal and recurrent laryngeal nerve palsy., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Recurrent laryngeal nerve (RLN) injury is a well-known, potentially serious complication of thyroid surgery. We investigated factors associated with RLN injury during thyroid surgery using a multi-institutional data set., Materials and Methods: Patients who underwent either lobectomy or total thyroidectomy were abstracted from the American College of Surgeons National Surgical Quality Improvement Program thyroidectomy-specific database (2016-2017). Baseline and operative factors associated with RLN injury ≤30 d of surgery were analyzed using bivariate and multivariate methods. Secondary complications of interest included unplanned reintubation and hypocalcemia., Results: RLN injury occurred in 6.0% (n = 677) of the 11,370 patients included in the study. The RLN injury rate varied significantly based on the primary indication for surgery, from 4.3% in patients undergoing surgery for a single nodule to 9.0% in patients undergoing surgery for differentiated cancer (P < 0.01). RLN injury occurred more often in thyroidectomies than lobectomies (6.9% versus 4.3%, P < 0.01) and in surgeries without intraoperative nerve monitoring (6.5% versus 5.6%, P = 0.01). After multivariate adjustment, RLN injury was independently associated with age ≥65 y [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.3-2.0], total thyroidectomy (OR = 1.4, 95% CI 1.1-1.6), and diagnosis of thyroid malignancy (OR = 2.1, 95% CI = 1.6-2.7) (all P < 0.001) but not intraoperative RLN monitoring (OR = 0.9, 95% CI = 0.7-1.0, P = 0.06)., Conclusions: In this large multi-institutional study, RLN injury ≤30 d of surgery occurred in nearly 6% of thyroid surgeries. This comprehensive analysis of RLN injury can be used to guide informed consent discussions and aid surgeons in identifying candidates who may be at higher risk for injury., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Intraoperative monitoring of parathyroid hormone (IOPTH) is a reliable method of predicting the cure of primary hyperparathyroidism (PHPT). The aim of this study is to assess whether common clinical variables (CCV) frequently encountered in patients with PHPT may affect the magnitude of PTH drop or the likelihood of patients meeting the intraoperative cure criterion., Design: Patients who were surgically cured from PHPT caused by single gland disease (SGD) and had full IOPTH protocol (4 measurements) were stratified according to age, gland weight, renal function, vitamin D status and severity of hypercalcemia. The percentage of IOPTH drop and the frequency of patients who had true positive IOPTH test results were compared among groups., Results: 762 patients had surgery for PHPT, of whom 746 were (98%) cured. Of these 746 patients, 511 who had SGD and a full IOPTH protocol were included in this study. The median IOPTH drop was significantly higher among younger patients, those with severe hypercalcaemia at 5, 10, 15 min after gland excision, giant glands (at 5-min only), patients with vitamin D deficiency (at 10, 15 min), and those with normal renal function (at 15 min only). The likelihood of the patients meeting the intraoperative cure criterion was not significantly affected among the groups except in patients with mild hypercalcaemia, who were significantly less likely to have 50% IOPTH drop than those with severe hypercalcaemia at all time points. The frequency of mildly hypercalcaemic patients who met cure criterion was significantly improved by extending measurement to 15 min., Conclusions: IOPTH monitoring has the ability to mitigate the variability of IOPTH kinetics associated with most clinical variables. Mildly hypercalcemic patients in particular may benefit from waiting for 15-min measurement before any surgical decision is made.

Background: The delayed graft function (DGF) in kidney transplantation (KT) is a risk factor for long-term poor graft survival. The pathogenesis is multifactorial but mainly related to an ischemia-reperfusion injury. However, the graft hemodynamics have been recently identified as a key aspect for early DGF risk assessment and potential therapeutic intervention., Methods: A pilot study on 20 single kidney grafts from donor after brain death with intraoperative measurement of graft arterial flowmetry, 30 minutes after reperfusion. Exclusion criteria were grafts with multiple arteries or severe atherosclerosis of the recipient's external iliac artery., Results: KT recipients with DGF (n = 4, 20%) were homogenous with controls (n = 16) in terms of cold ischemia time, donor age, recipients' hemodynamic parameters, renal artery, and recipients' external iliac artery diameters. Nonetheless, at transplant, the kidney grafts that developed DGF were characterized by a significantly higher renal artery resistive index (DGF vs no-DGF 0.96 ± 0.04 vs 0.77 ± 0.13, P = .02), as well as lower flow extraction rate (24.8% ± 11.8 vs 59.2% ± 21.1, P < .01)., Conclusions: Intraoperative arterial graft flowmetry seems to be an effective tool to identify grafts at high risk of DGF., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: To determine whether image guidance improves dissection quality among residents in the temporal bone lab and to gauge their reactions to its use., Methods: Prospective cohort study of nine otolaryngology residents who dissected cadaveric temporal bones with and without image guidance in the temporal bone laboratory. Quality of dissection was measured with the Welling scale. A survey was administered assessing their interactions with the navigation system., Results: There was no significant difference in quality of dissection for the majority of structures or number of major errors with use of image guidance. Dissection quality of the tegmen (4.67 vs. 5.67, P = .034) and sinodural angle (0.83 vs. 1.56, P = .005) was superior in the non-navigation specimens. The majority of residents reported increased confidence with locating several critical anatomic structures and found the system intuitive to use. Nearly all thought it would be helpful in revision cases or for aural atresia., Conclusion: Image guidance did not improve quality of temporal bone dissection or number of major errors in this cohort of residents, but the majority found it intuitive and increased confidence in finding several structures. Navigation systems may play an important adjunctive role in resident education and further work is required to determine its optimal use., Level of Evidence: NA Laryngoscope, 130:E368-E371, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Arterial hypotension during the early phase of anesthesia can lead to adverse outcomes such as a prolonged postoperative stay or even death. Predicting hypotension during anesthesia induction is complicated by its diverse causes. We investigated the feasibility of developing a machine-learning model to predict postinduction hypotension. Naïve Bayes, logistic regression, random forest, and artificial neural network models were trained to predict postinduction hypotension, occurring between tracheal intubation and incision, using data for the period from between the start of anesthesia induction and immediately before tracheal intubation obtained from an anesthesia monitor, a drug administration infusion pump, an anesthesia machine, and from patients' demographics, together with preexisting disease information from electronic health records. Among 222 patients, 126 developed postinduction hypotension. The random-forest model showed the best performance, with an area under the receiver operating characteristic curve of 0.842 (95% confidence interval [CI]: 0.736-0.948). This was higher than that for the Naïve Bayes (0.778; 95% CI: 0.65-0.898), logistic regression (0.756; 95% CI: 0.630-0.881), and artificial-neural-network (0.760; 95% CI: 0.640-0.880) models. The most important features affecting the accuracy of machine-learning prediction were a patient's lowest systolic blood pressure, lowest mean blood pressure, and mean systolic blood pressure before tracheal intubation. We found that machine-learning models using data obtained from various anesthesia machines between the start of anesthesia induction and immediately before tracheal intubation can predict hypotension occurring during the period between tracheal intubation and incision., Competing Interests: The authors have declared that no competing interests exist.

Major hemodynamic changes are frequently noted during liver transplantation (LT). We evaluated the performance of electrical velocimetry (EV) as compared to that of TEE in SV optimization during liver transplantation. This was an observational study in 32 patients undergoing LT. We compared SV values measured simultaneously by EV (SV EV ) and TEE (SV TEE ) at baseline 30 min after induction, at the end of dissection phase, 30 min after anhepatic phase, 30 min after reperfusion. We also evaluated the reliability of EV to track changes In SV before and after 49 fluid challenges. Finally, the SV variation (SVV) and pulse pressure variation (PPV) were tested as predictors for volume responsiveness, defined as an increase in SV ≥ 10% after 250 ml of colloid. For 112 paired SV data, the overall correlation was 0.76 and bias (limits of agreement) 0.3 (- 29 to 29) ml percentage error 62%. The EV was able to track changes in SV with a concordance rate of 97%, and a sensitivity and specificity of 93% to detect a positive fluid challenge. The AUC values (with 95% confidence intervals) for SVV and PPV were 0.68 (0.52-0.83) and 0.72 (0.57-0.86), respectively, indicating low predictive capacity in these setting. The absolute values of SV derived from EV did not agree with SV derived from TEE. However, EV was able to track the direction of changes in SV during hemodynamic management of patients undergoing liver transplantation.Clinical trial registration: Clinicaltrials.gov Identifier: NCT03228329 prospectively Registered on 13-July-2017.

Objective: To investigate intraoperative nerve monitoring (IONM) use among thyroid surgeons., Methods: A 25-question survey was used to assess attitudes regarding IONM use. Surveys were sent to surgeons registered to the American Academy of Otolaryngology-Head and Neck Surgery, International Association of Endocrine Surgeons, and American Head and Neck Society., Results: Among 1,015 respondents, 83% reported using IONM (65.1% always using IONM and 18.1% reporting selective use). For selective users, a majority reported using IONM for reoperative cases (95.1%) and in cases with preoperative vocal cord paralysis (59.8%). When comparing location, there was a significant difference in IONM implementation (P < 0.001), with 70.4% of North American responders using it ubiquitously compared to 27.4% of non-North American responders. Preoperative laryngeal exam was performed more universally by North American surgeons and more selectively by non-North American surgeons (P < 0.001). Other attitudes toward their implementation and the postoperative laryngeal exam were similar. Surgeons ≤45 years of age and those with ≤15 years of practice used IONM more than their peers (P < 0.001). Thyroid surgery volume, fellowship training, and type of practice had no bearing on IONM use., Conclusion: The prevalence of IONM in thyroid and parathyroid surgeries has increased significantly over the past decade, with 83% of surgeons using IONM in some or all cases. Although IONM use may be more ubiquitous in North America, attitudes toward its implementation and pre- and postoperative laryngeal exams are fairly uniform. IONM use is more prevalent among younger surgeons, whereas its use has no correlation with thyroid surgery volume or type of practice., Level of Evidence: 4 Laryngoscope, 130:1097-1104, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Ex vivo aspiration of parathyroid glands for the measurement of intraoperative parathyroid hormone (IOPTH) levels is a rapid point-of-care method to confirm parathyroid tissue during parathyroidectomy and an alternative to frozen section (FS). This study sought to determine the awareness and utilization of this technique among endocrine surgeons., Materials and Methods: A de-identified 12-question survey regarding techniques for intraoperative identification/confirmation of parathyroid tissue and the use of IOPTH monitoring was distributed to all 608 members of the American Association of Endocrine Surgeons., Results: Among the 182 (30%) respondents, FS was the most common primary technique utilized by 115 (63%) respondents to confirm parathyroid tissue; only 12 (7%) utilized ex vivo aspiration, although 78 (42%) were familiar with the technique. Availability and familiarity were the principal reasons for use of the primary technique; the most common barrier was time. Serum IOPTH monitoring was routinely used by 124 (74%). Of respondents who utilized FS, serum IOPTH monitoring was routinely used by 75% (86/115), including 71% (45/63) who reported time as a barrier to FS. Of these 45, only 15 (33%) were familiar with ex vivo parathyroid aspiration. Only 48% of surgeons knew how PTH samples were charged., Conclusions: FS was the most common method of identification/confirmation of parathyroid tissue. Although most respondents routinely performed IOPTH monitoring, relatively few utilized ex vivo aspiration as a technique for parathyroid identification and less than 50% were familiar with this technique. Broader dissemination about novel techniques such as ex vivo aspiration and cost awareness are recommended., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: This study aims to present the diagnostic characteristics of multimodal intraoperative monitoring (IOM) in spinal deformity surgery and to define and categorise the neuromonitoring events, as well as propose an algorithm of action., Materials and Methods: We reviewed 1,155 consecutive patients (807 female, 348 male) who underwent deformity correction using standardised perioperative care, cortical/cervical somatosensory evoked potentials (SSEPs), and upper/lower limb transcranial electrical motor evoked potential (MEPs) by a single surgeon. The mean age at surgery was 13.8 years (range 10-23.3). We categorised IOM events as true, transient true, and false positive or negative. Diagnostic performance criteria were calculated., Results: The most common diagnosis was adolescent idiopathic scoliosis in 717 (62%) patients. We identified 3 true positive monitoring events occurring in 2 patients (0.17%), 8 transient true positive (0.69%), and 8 transient false positive events (0.69%). There were no false negative events and no patient had postoperative neurological complications. The multimodal IOM technique had a sensitivity of 100%, specificity of 99.3%, positive predictive value of 55.6%, and negative predictive value of 100%. Sensitivity was 100% for MEPs and multimodal monitoring compared to 20% for cortical or cervical SSEPs. The frequency of true or transient true positive events was higher (p = 0.07) in Scheuermann's kyphosis (3/91 patients, 3.3%) compared to adolescent idiopathic scoliosis (6/717 patients, 0.84%)., Conclusion: Multimodal IOM is highly sensitive and specific for spinal cord injury. This technique is reliable for the assessment of the condition of the spinal cord during major deformity surgery. We propose an algorithm of intraoperative action to allow close cooperation between the surgical, anaesthetic, and neurophysiology teams and to prevent neurological deficits., (© 2019 The Author(s) Published by S. Karger AG, Basel.)

Importance: Acute kidney injury (AKI) is one of the most common complications after noncardiac surgery. Yet current postoperative AKI risk stratification models have substantial limitations, such as limited use of perioperative data., Objective: To examine whether adding preoperative and intraoperative data is associated with improved prediction of noncardiac postoperative AKI., Design, Setting, and Participants: A prognostic study using logistic regression with elastic net selection, gradient boosting machine (GBM), and random forest approaches was conducted at 4 tertiary academic hospitals in the United States. A total of 42 615 hospitalized adults with serum creatinine measurements who underwent major noncardiac surgery between January 1, 2014, and April 30, 2018, were included in the study. Serum creatinine measurements from 365 days before and 7 days after surgery were used in this study., Main Outcomes and Measures: Postoperative AKI (defined by the Kidney Disease Improving Global Outcomes within 7 days after surgery) was the primary outcome. The area under the receiver operating characteristic curve (AUC) was used to assess discrimination., Results: Among 42 615 patients who underwent noncardiac surgery, the mean (SD) age was 57.9 (15.7) years, 23 943 (56.2%) were women, 27 857 (65.4%) were white, and the most frequent surgery types were orthopedic (15 718 [36.9%]), general (8808 [20.7%]), and neurologic (6564 [15.4%]). The rate of postoperative AKI was 10.1% (n = 4318). The progressive addition of clinical data improved model performance across all modeling approaches, with GBM providing the highest discrimination by AUC. In GBM models, the AUC increased from 0.712 (95% CI, 0.694-0.731) using prehospitalization variables to 0.804 (95% CI, 0.788-0.819) using preoperative variables (inclusive of prehospitalization variables) (P < .001 for AUC comparison). The AUC further increased to 0.817 (95% CI, 0.802-0.832) when adding intraoperative variables (P < .001 for comparison vs model using preoperative variables). However, the statistically significant improvements in discrimination did not appear to be clinically significant. In particular, the AKI rate among patients classified as high risk improved from 29.1% to 30.0%, a net of 15 patients were appropriately reclassified as high risk, and an additional 15 patients were appropriately reclassified as low risk., Conclusions and Relevance: The findings of the study suggest that electronic health record data may be used to accurately stratify patients at risk of perioperative AKI, but the modest improvements from adding intraoperative data should be weighed against challenges in using intraoperative data.

Background: Elderly patients with hip fractures are at high risk for perioperative anemia as a result of fracture- and surgery-related blood loss. The detection of anemia is dependent on intermittent blood samples and therefore might be delayed, potentially leading to a significant delay in transfusion. This study aimed to investigate the possible delay in perioperative anemia detection, accumulated perioperative anemia-associated burden, peripheral perfusion, and their association with patient outcomes in elderly patients with hip fracture., Methods: Elderly patients with acute hip fracture scheduled for surgery were enrolled in this prospective study from August 2016 to December 2016. All patients were monitored continuously for hemoglobin concentration (SpHb) and perfusion index (PI) with the Radical-7® Pulse CO-Oximeter® and Rainbow® R1 Adhesive Multi-parameter Sensors (Masimo Corp., Irvine, CA, US) from 12 h presurgery to 24 h postsurgery., Results: Fifty-one patients were enrolled, and 41 were included in the final analyses. Mean delay in the detection of low Hb (<10 g/dL) using intermittent blood samples, when compared with SpHb, was 1.07 h (standard deviation, ±2.84 h). Median perioperative cumulated time with low SpHb (<10 g/dL for at least one min) was 25 min (interquartile range [IQR]: 21-690). There was a significant association between perioperative time with low SpHb and the occurrence of postoperative delirium (median cumulated time with low SpHb: 162 min in patients with delirium vs 22 min in patients without delirium, P = 0.034) and a nonsignificant trend for an association between perioperative time with low SpHb and 90-day mortality or medical complications (median cumulated time with low SpHb: 119 min for patients with mortality or severe complication vs 22 min for patients without mortality or severe complication, P = 0.104). PI values during the perioperative period were not significantly associated with patient outcomes. Cumulated time with low PI (<0.5) preoperatively (but not perioperatively) was significantly associated with the occurrence of postoperative delirium (P = 0.047)., Conclusions: This study showed a delay in transfusion threshold detection, and the presence of significant associations between low SpHb or time with low SpHb and postoperative outcomes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Visual estimation and gravimetric methods are commonly used to quantify the volume of blood loss during cesarean delivery (CD). However, the correlation between blood loss and post-CD hemoglobin (Hb) is poorly studied, and it is unclear whether the correlation varies according to how blood loss is measured., Methods: After obtaining Institutional Review Board approval, we performed a prospective study of 61 women undergoing CD to assess the relations between post-CD Hb and blood loss measured using 4 modalities: gravimetric blood loss measurement (gBL), visual blood loss estimation by a blinded obstetrician (oBL) and anesthesiologist (aBL), and the Triton System (tBL). Hb was measured preoperatively and within 10 minutes after CD. gBL was quantified as blood volume in a suction canister in addition to the weight of blood-soaked sponges. tBL was measured with the Triton System by photographing blood-soaked sponges and suction canister contents. To assess the relation between blood loss and post-CD Hb, we performed correlation analyses and compared the magnitude of the correlations across the 4 measurement modalities using William t test. A Bonferroni correction was set to identify a statistically significant correlation (P < .0125) and statistically significant differences between correlation coefficients (P < .008)., Results: The mean (standard deviation) preoperative Hb was 12 (1.1) g/dL and post-CD Hb was 11.3 (1.0) g/dL. Median (interquartile range) values for gBL, oBL, aBL, and tBL were 672 mL (266-970), 700 mL (600-800), 750 mL (600-1000), and 496 mL (374-729), respectively. A statistically significant but weak correlation was observed between tBL and post-CD Hb (r = -0.33; P = .01). No statistically significant correlations were observed among aBL (r = -0.25; P = .06), oBL (r = -0.2; P = .13), and gBL (r = -0.3; P = .03) with post-CD Hb. We did not detect any significant differences between any 2 correlation coefficients across the 4 modalities., Conclusions: Given that we observed only weak correlations between each modality with post-CD Hb and no significant differences in the magnitude of the correlations across the 4 modalities, there may be limited clinical utility in estimating post-CD Hb from blood loss values measured with any of the 4 modalities.

An intraoperative automated closed-loop system for goal-directed fluid therapy has been successfully tested in silico, in vivo and in a clinical case-control matching. This trial compared intraoperative cardiac output (CO) in patients managed with this closed-loop system versus usual practice in an academic medical center. The closed-loop system was connected to a CO monitoring system and delivered automated colloid fluid boluses. Moderate to high-risk abdominal surgical patients were randomized either to the closed-loop or the manual group. Intraoperative final CO was the primary endpoint. Secondary endpoints were intraoperative overall mean cardiac index (CI), increase from initial to final CI, intraoperative fluid volume and postoperative outcomes. From January 2014 to November 2015, 46 patients were randomized. There was a lower initial CI (2.06 vs. 2.51 l min -1 m -2 , p = 0.042) in the closed-loop compared to the control group. No difference in final CO and in overall mean intraoperative CI was observed between groups. A significant relative increase from initial to final CI values was observed in the closed-loop but not the control group (+ 28.6%, p = 0.006 vs. + 1.2%, p = 0.843). No difference was found for intraoperative fluid management and postoperative outcomes between groups. There was no significant impact on the primary study endpoint, but this was found in a context of unexpected lower initial CI in the closed-loop group.Trial registry number ID-RCB/EudraCT: 2013-A00770-45. ClinicalTrials.gov Identifier NCT01950845, date of registration: 17 September 2013.

This study assessed the ability of a continuous non-invasive blood pressure (BP) monitoring system to reduce intra-anesthetic hemodynamic fluctuation compared with intermittent BP cuff measurement. Forty patients undergoing total knee arthroplasty under general anesthesia were enrolled and randomly divided into two groups (Control and CS group). BP management was performed using the same protocol with BP measured by intermittent BP cuff in the Control and that by continuous non-invasive BP monitoring in the CS group. We assessed the accuracy and precision of the continuous non-invasive BP monitoring compared with BP cuff measurement using Bland-Altman, four-quadrant plot, and polar-plot analyses. Additionally, the occurrence of hypotension and hypertention during general anesthesia was compared between the two groups. The continuous non-invasive BP monitoring showed excellent accuracy of - 1.1 ± 8.1 mmHg during surgery and an acceptable trending ability with a concordance rate of 95.1% according to the four-quadrant plot analysis and an angular concordance rate of 86.7% by polar-plot analysis. Hypotension was less common in the CS group during induction of anesthesia (p = 0.002) and surgery (p = 0.008). Hypertension occurred more frequently in the Control group during emergence from anesthesia (p = 0.037). The duration of hemodynamic stability (systolic BP 80-110% of baseline) intraoperatively was longer in the CS group than in the Control group (87.7 vs. 61.9%; p < 0.001). Accuracy and trending ability of the continuous non-invasive BP monitoring was clinically acceptable, and lead to hemodynamic stability and reduction of intra-anesthetic hypotension and hypertension intraoperatively.

This study explores the association between postadmission and intraoperative cerebral oxygenation (ScO 2 ), reflecting systemic perfusion, and postoperative mortality and delirium. Forty elderly (age > 65 years) patients with hip fractures were included in this prospective observational study. The ScO 2 was determined using near-infrared spectroscopy at initial resuscitation after patients were admitted to the hospital and during surgery. Postoperative delirium was assessed up to seven days after surgery using the memorial delirium assessment scale and the confusion assessment method. Ten patients (25%) developed postoperative delirium within the first seven postoperative days. At initial resuscitation ScO 2 was lower in patients that later developed delirium, but the difference was not significant (p = 0.331). Intraoperative ScO 2 values remained similar in the two groups. Mortality regardless of cause was 10% (4 out of 40 patients) after 30 days. At initial resuscitation ScO 2 was significant lower in the mortality group than in the surviving group (p = 0.042), and the ScO 2 nadir values were also significant lower (p = 0.047). Low ScO 2 during initial resuscitation (defined as ScO 2  < 55 for a minimum of two consecutive minutes) was also significantly associated with 30-day mortality (p = 0.015). There were no associations between low blood pressure and postoperative delirium or 30-day mortality. We found that low preoperative ScO 2 was better associated with 30-day all-cause mortality in elderly patients undergoing surgery for hip fracture than blood pressure measurements. Future studies in preoperative resuscitation of hip fracture patients should focus on perfusion measures as opposed to conventional haemodynamic.

The evolution of non-invasive hemoglobin measuring technology would save time and improve transfusion practice. The validity of pulse co-oximetry hemoglobin (SpHb) measurement in the perioperative setting was previously evaluated; however, the accuracy of SpHb in different volume statuses as well as in different perfusion states was not well investigated. The aim of this work is to evaluate the accuracy and trending of SpHb in comparison to laboratory hemoglobin (Lab-Hb) during acute bleeding and after resuscitation. Seventy patients scheduled for major orthopedic procedures with anticipated major blood loss were included. Radical-7 device was used for continuous assessment of SpHb, volume status [via pleth variability index (PVI)] and perfusion status [via perfusion index (PI)]. Lab-Hb and SpHb were measured at three time-points, a baseline reading, after major bleeding, and after resuscitation. Samples were divided into fluid-responsive and fluid non-responsive samples, and were also divided into high-PI and low-PI samples. Accuracy of SpHb was determined using Bland-Altman analysis. Trending of SpHb was evaluated using polar plot analysis. We obtained 210 time-matched readings. Fluid non-responsive samples were 106 (50.5%) whereas fluid responsive samples were 104 (49.5%). Excellent correlation was reported between Lab-Hb and SpHb (r = 0.938). Excellent accuracy with moderate levels of agreement was also reported between both measures among all samples, fluid non-responsive samples, fluid-responsive samples, high-PI samples, and low-PI samples [Mean bias (limits of agreement): 0.01 (- 1.33 and 1.34) g/dL, - 0.08 (- 1.27 and 1.11) g/dL, 0.09 (- 1.36 and 1.54) g/dL, 0.01 (- 1.34 to 1.31) g/dL, and 0.04 (- 1.31 to 1.39) g/dL respectively]. Polar plot analysis showed good trending ability for SpHb as a follow up monitor. In conclusion, SpHb showed excellent correlation with Lab-Hb in fluid responders, fluid non-responders, low-PI, and high PI states. Despite a favorable mean bias of 0.01 g/dL for SpHb, the relatively wide levels of agreement (- 1.3 to 1.3 g/dL) might limit its accuracy. SpHb showed good performance as a trend monitor.

Blood glucose and its variability of is a major prognostic factor associated with morbidity. We hypothesized that intravenous microdialysis incorporated in a central venous catheter (CVC) would be interchangeable with changes in blood glucose measured by the reference method using a blood gas analyzer. Microdialysis and central venous blood glucose measurements were simultaneously recorded in high-risk cardiac surgical patients. The correlation between absolute values was determined by linear regression and the Bland-Altman test for repeated measurements was used to compare bias, precision, and limits of agreement. Changes in blood glucose measurement were evaluated by four-quadrant plot and trend interchangeability methods (TIM). In the 23 patients analyzed, the CVC was used as part of standard care with no complications. The correlation coefficient for absolute values (N = 99) was R = 0.91 (P < 0.001). The bias, precision and limits of agreement were - 9.1, 17.4 and - 43.2 to 24.9 mg/dL, respectively. The concordance rate for changes in blood glucose measurements (N = 77) was 85% with the four-quadrant plot. The TIM showed that 14 (18%) changes of blood glucose measurements were uninterpretable. Among the remaining 63 (82%) interpretable changes, 23 (37%) were interchangeable, 13 (20%) were in the gray zone, and 27 (43%) were not interchangeable. Microdialysis using a CVC appears to provide imprecise absolute blood glucose values with risk of insulin misuse. Moreover, only one third of changes in blood glucose measurements were interchangeable with the reference method using the TIM.

Objective: Cricothyroid (CT) muscle twitch inspection with neurostimulation is a widely accepted method to identify the external branch of the superior laryngeal nerve (EBSLN) and its integrity in thyroid surgery. However, there has been no large-scale research to evaluate the diagnostic values of CT muscle twitch inspection based on postoperative electromyography (EMG) results, which are considered the gold standard. In this study, we aimed to demonstrate the diagnostic value of CT muscle twitch inspection based on postoperative EMG., Study Design: Prospective cohort study., Methods: A total of 454 patients underwent primary thyroid surgery. Among them, 55 patients were excluded because of preoperative vocal fold palsy, problems with the stimulator, or refusal to participate in the EMG study. Finally, 399 patients were prospectively enrolled in this study. Intraoperatively, CT muscle twitch was inspected with neurostimulation. Bilateral EMG examination of the CT muscle was performed 2 to 3 months postoperatively in all patients., Results: A total of 712 EBSLNs at risk were analyzed in this study. Of these, 21 (2.9%) nerves were visually identified, and positive CT muscle twitch by neurostimulation was observed in 694 (97.5%). Normal results on postoperative EMG of the CT muscle were reported in 657 (92.3%). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 97.7%, 5.5%, 92.5%, and 16.7%, respectively., Conclusion: CT muscle twitch inspection could be a useful intraoperative tool to determine EBSLN integrity considering its high sensitivity and PPV. However, the test may not completely replace EMG for evaluating EBSLN integrity due to its low specificity and NPV., Level of Evidence: 2b. Laryngoscope, 2654-2661, 2018., (© 2018 The American Laryngological, Rhinological and Otological Society, Inc.)

VPloop, the graphical representation of pressure versus velocity, and its characteristic angles, GALA and β, can be used to monitor cardiac afterload during anesthesia. Ideally VPloop should be measured from pressure and velocity obtained at the same arterial location but standard of care usually provide either radial or femoral pressure waveforms. The purpose of this study was to look at the influence of arterial sites and the use of a transfer function (TF) on VPloop and its related angles. Invasive pressure signals were recorded in 25 patients undergoing neuroradiology intervention under general anesthesia with transesophageal flow velocity monitoring. Pressures were recorded in the descending thoracic aorta, abdominal aorta, femoral and radial arteries. We compared GALA and β from VPloops generated from each location and in high and low risk patients. GALA was similar in the central locations (55°[49-63], 52°[47-61] and 54°[45-62] from descending thoracic to femoral artery, median[interquartile], p = 0.10), while there was a difference in β angle (16°[4-27] to 8°[3-15], p < 0.0001). GALA and β obtained from radial waveforms were different (39°[31-47] compared to 46°[36-54] and 6°[2-14] compared to 16°[4-27] for GALA and β angles respectively, p < 0.001) which was corrected by the use of a TF (45°[32-55] and 17°[5-28], p = ns). GALA and β are underestimated when measured with a radial catheter. Using pressure waveforms from femoral locations alters VPloops, GALA and β in a smaller extend. The use of a TF on radial pressure allows to correctly plot VPloops and their characteristic angles for routine clinical use.

Background: UK national anaesthetic activity was studied in 2013 but weekend working was not examined. Understanding changes since 2013 in workload and manpower distribution, including weekends, would be of value in workforce planning., Methods: We performed an observational survey of NHS hospitals' anaesthetic practice in October 2016 as part of the 6th National Audit Project of the Royal College of Anaesthetists (NAP6). All cases cared for by an anaesthetist during the study period were included. Patient characteristics and details of anaesthetic conduct were collected by local anaesthetists., Results: Responses were received from 342/356 (96%) hospitals. In total, 15 942 cases were reported, equating to an annual anaesthetic workload of ≈3.13 million cases. Approximately 95% (9888/10 452) of elective and 72% (3184/4392) of emergency work was performed on weekdays and 89% (14 145/15 942) of activity was led by senior (consultant or career grade) anaesthetists and 1.1% (180/15942) by those with <2 yr anaesthetic experience. During weekends case urgency increased, the proportion of healthy patients reduced and case mix changed. Cases led by senior anaesthetists fell to 80% (947/1177) on Saturday and 66% (342/791) on Sunday. Senior involvement in obstetric anaesthetic activity was 69% (628/911) during the week and 45% (182/402) at weekends, compared with 93% (791/847) in emergency orthopaedic procedures during the week and 89% (285/321) at weekends. Since 2013, the proportion of obese patients, elective weekend working, and depth of anaesthesia monitoring has increased [12% (1464/12 213) vs 2.8%], but neuromuscular monitoring has not [37% (2032/5532) vs 38% of paralysed cases]., Conclusions: Senior clinicians deliver most UK anaesthesia care, including at weekends. Our findings are important for any planned workforce reorganisation to rationalise 7-day working., (Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: The aim of this study was to evaluate the analgesic potency dose of remifentanil to maintain Surgical Pleth Index (SPI) values at less than 50 after intubation in patients undergoing general anesthesia with target-controlled infusion of propofol and remifentanil., Methods: We randomly allocated 120 patients to receive one of three remifentanil target effect-site concentrations (5, 7, or 9 ng×mL-1) during intubation. The target effect-site concentrations of propofol were adjusted within a range of 2.5-3 μg×mL-1 to maintain bispectral index values at less than 60 during anesthesia induction. A reusable SPI sensor was placed on the index finger of the arm, and the SPI values were continuously recorded. The predicted probability for maintaining the SPI values at less than 50 after intubation against the cumulative amount of remifentanil was analyzed using logistic regression. The measurands were the baseline SPI value in patients without pain scheduled for surgery, and the maximal SPI value after intubation in patients receiving remifentanil with a target effect-site concentration of 7 ng×mL-1., Results: The estimated cumulative amount of remifentanil associated with a 50% and 95% probability of maintaining the SPI values at less than 50 after intubation were 135.0 µg and 330.4 µg, respectively. The estimated expanded uncertainty for the baseline and maximal SPI values after intubation in patients scheduled for surgery were 54.9±44.4 and 54.1±37.9, respectively, which corresponded to a confidence level of approximately 95%., Conclusions: The analgesic potency dose of remifentanil to maintain SPI values at less than 50 after intubation was 135.0 µg.

Background: To assess the thoughts of practicing anaesthesiologists about the use of depth of hypnosis monitors in children., Methods: Members of the European Society for Paediatric Anaesthesiology were invited to participate in an online survey about their thoughts regarding the use, applicability and reliability of hypnosis monitoring in children., Results: The survey achieved a response rate of 30% (N = 168). A total of 138 completed surveys were included for further analysis. Sixty-eight respondents used hypnosis monitoring in children (Users) and 70 did not (Non-users). Sixty-five percent of the Users reported prevention of intra-operative awareness as their main reason to apply hypnosis monitoring. Among the Non-users, the most frequently given reason (43%) not to use hypnosis monitoring in children was the perceived lack or reliability of the devices in children. Hypnosis monitoring is used with a higher frequency during propofol anaesthesia than during inhalation anaesthesia. Hypnosis monitoring is furthermore used more frequently in children > 4 years than in younger children. An ideal hypnosis monitor should be reliable for all age groups and any (combination of) anaesthetic drug. We found no agreement in the interpretation of monitor index values and subsequent anaesthetic interventions following from it., Conclusions: Prevention of intraoperative awareness appears to be the most important reason to use hypnosis monitoring in children. The perceived lack of reliability of hypnosis monitoring in children is the most important reasons not to use it. No consensus currently exists on how to adjust anaesthesia according to hypnosis monitor index values in children.

Objective: Patients undergoing pulmonary endarterectomy (PEA) have impaired right ventricular function. The authors sought to assess the clinical utility of commonly used perioperative echocardiographic and right heart catheter measurements in patients undergoing PEA., Design: A single-center prospective observational study., Setting: The study was conducted in a quaternary care cardiac surgical center in the United Kingdom., Participants: Patients undergoing PEA between April 2015 and January 2016., Interventions: Thermodilution cardiac index and echocardiography variables were measured at 3 time points: before sternotomy (T1), after pericardial incision (T2), and after sternal closure (T3). Six-month follow-up echocardiography and 6-minute walk (6-MWT) test were performed., Measurements and Main Results: Fifty patients were recruited and complete data sets were available for 41 patients. Tricuspid annular plane systolic excursion declined after pericardial incision and cardiopulmonary bypass (T1: 15 ± 4 mm, T2: 13 ± 4 mm, T3: 7 ± 2 mm; p < 0.0001), returning to baseline 6 months postoperatively. Cardiac index (T1: 2.5 ± 0.7 L/min/m 2 , T2: 2.6 ± 0.6 L/min/m 2 , T3: 2.3 ± 0.5 L/min/m 2 ; p = 0.07) and right ventricular fractional area change (T1: 36 ± 11%, T2: 40 ± 12%, T3: 40 ± 9%; p = 0.12) were preserved perioperatively. 6-MWT improved from baseline (294 ± 111 m) to follow-up (357 ± 107 m) (p < 0.001). Pulmonary vascular resistance at T3 correlated moderately with follow-up 6-MWT (R = -0.60)., Conclusions: In patients undergoing PEA, invasive measurements and echocardiography assessment of right ventricular function are not interchangeable. Tricuspid annular plane systolic excursion is not a reliable measure of right ventricular function perioperatively. Pulmonary vascular resistance shows moderate correlation with postoperative functional capacity., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Evidence to date suggests that capnography monitoring during gastrointestinal endoscopic procedures (GEP) reduces the incidence of hypoxemia, but the association of capnography monitoring with the incidence of other adverse outcomes surrounding these procedures has not been well studied. Our aims were to estimate the incidence of pharmacological rescue events and death at discharge from an inpatient or outpatient hospitalization where GEP was performed with sedation, and to determine if capnography monitoring was associated with reduced incidence of these adverse outcomes., Methods: This retrospective Premier Database analysis included medical inpatients and all outpatients undergoing GEP with sedation. Patients were grouped as follows: (1) pulse oximetry (SpO 2 ) only, (2) capnography only, (3) SpO 2 with capnography, and (4) neither SpO 2 nor capnography. Multivariable logistic regression and propensity-score matching were used to compare patients with capnography sensor use to patients with only SpO 2 sensor use. Outcome measures included the incidence of pharmacological rescue events, as defined by administration of naloxone and/or flumazenil, and death., Results: Two hundred fifty eight thousand and two hundred sixty two inpatients and 3,807,151 outpatients were analyzed. For inpatients, capnography monitoring was associated with a 47% estimated reduction in the odds of death at discharge (OR: 0.53 [95% CI: 0.40-0.70]; P < 0.0001) and a non-significant 10% estimated reduction in the odds of pharmacological rescue event at discharge (0.91 [0.65-1.3]; P = 0.5661). For outpatients, capnography monitoring was associated with a 61% estimated reduction in the odds of pharmacological rescue event at discharge (0.39 [0.29, 0.52]; P < 0.0001) and a non-significant 82% estimated reduction in the odds of death at discharge (0.18 [0.02, 1.99]; P = 0.16)., Conclusions: In hospital medical inpatients and all outpatients undergoing GEP performed with sedation, capnography monitoring was associated with a reduced likelihood of pharmacological rescue events in outpatients and death in inpatients when assessed at discharge. Despite the limitations of the retrospective data analysis methodology, the use of capnography during these procedures is recommended.

Phase-rectified signal averaging (PRSA) has been known to be a useful method to detect periodicities in non-stationary biological signals. Determination of quasi-periodicities in electroencephalogram (EEG) is a candidate for quantifying the changes in the depth of anesthesia (DOA). In this paper, DOA monitoring capacity of periodicities detected using PRSA was quantified by assessing EEG signals collected from 56 patients during surgery. The method is compared with sample entropy (SampEn), detrended fluctuation analysis (DFA), and permutation entropy (PE). The performance of quasi-periodicities defined by deceleration capacity and acceleration capacity was tested using the area under the receiver operating characteristic curve (AUC) and Pearson correlation coefficient. During the surgery, a significant difference ( ) in the quasi-periodicities was observed among three different stages under general anesthesia. There is a larger mean AUC and correlation coefficient of quasi-periodicities compared with SampEn, DFA, and PE using expert assessment of conscious level and bispectral index as the gold standard, respectively. Quasi-periodicities detected using PRSA in EEG signals are a powerful monitor of DOA and perform more accurate and robust results compared with SampEn, DFA, and PE. The results do provide a valuable reference to researchers in the field of clinical applications.

Background: Spatial positioning is the key function of a surgical navigation robot system, and accuracy is the most important performance index of such a system., Methods: The kinematic parameters of a six degrees of freedom (DOF) robot arm were used to form the transformation from intraoperative fluoroscopy images to a robot's coordinate system without C-arm calibration and to solve the redundant DOF problem. The influences of three typical error sources and their combination on the final navigation error were investigated through Monte Carlo simulation., Results: The navigation error of the proposed method is less than 0.6 mm, and the feasibility was verified through cadaver experiments. Error analysis suggests that the robot kinematic error has a linear relationship with final navigation error, while the image error and gauge error have nonlinear influences., Conclusions: This kinematic parameters based method can provide accurate and convenient navigation for orthopedic surgeries. The result of error analysis will help error design and assignment for surgical robots., (Copyright © 2016 John Wiley & Sons, Ltd.)

Background: Machine-generated indices based on quantitative electroencephalography (EEG), such as the patient state index (PSI™) and burst-suppression ratio (BSR), are increasingly being used to monitor intraoperative depth of anaesthesia in the endeavour to improve postoperative neurological outcomes, such as postoperative delirium (POD). However, the accuracy of the BSR compared with direct visualization of the EEG trace with regard to the prediction of POD has not been evaluated previously., Methods: Forty-one consecutive patients undergoing non-cardiac, non-intracranial surgery with general anaesthesia wore a SedLine ® monitor during surgery and were assessed after surgery for the presence of delirium with the Confusion Assessment Method. The intraoperative EEG was scanned for absolute minutes of EEG suppression and correlated with the incidence of POD. The BSR and PSI™ were compared between patients with and without POD., Results: Visual analysis of the EEG by neurologists and the SedLine ® -generated BSR provided a significantly different distribution of estimated minutes of EEG suppression ( P =0.037). The Sedline ® system markedly underestimated the amount of EEG suppression. The number of minutes of suppression assessed by visual analysis of the EEG was significantly associated with POD ( P =0.039), whereas the minutes based on the BSR generated by SedLine ® were not associated with POD ( P =0.275)., Conclusions: Our findings suggest that SedLine ® (machine)-generated indices might underestimate the minutes of EEG suppression, thereby reducing the sensitivity for detecting patients at risk for POD. Thus, the monitoring of machine-generated BSR and PSI™ might benefit from the addition of a visual tracing of the EEG to achieve a more accurate and real-time guidance of anaesthesia depth monitoring and the ultimate goal, to reduce the risk of POD., (© The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

Background and Purpose: In Germany, all surgical and endovascular procedures on the carotid bifurcation must be documented in a statutory nationwide quality assurance database. We aimed to analyze the association between procedural and perioperative variables and in-hospital stroke or death rates after carotid endarterectomy., Methods: Between 2009 and 2014, overall 142 074 elective carotid endarterectomy procedures for asymptomatic or symptomatic carotid artery stenosis were documented in the database. The primary outcome of this secondary data analysis was in-hospital stroke or death. Major stroke or death, stroke, and death, each until discharge were secondary outcomes. Adjusted relative risks (RRs) were assessed by multivariable multilevel regression analyses., Results: The primary outcome occurred in 1.8% of patients, with a rate of 1.4% in asymptomatic and 2.5% in symptomatic patients, respectively. In the multivariable analysis, lower risks of stroke or death were independently associated with local anesthesia (versus general anesthesia: RR, 0.85; 95% confidence interval [CI], 0.75-0.95), carotid endarterectomy with patch plasty compared with primary closure (RR, 0.71; 95% CI, 0.52-0.97), intraoperative completion studies by duplex ultrasound (RR, 0.74; 95% CI, 0.63-0.88) or angiography (RR, 0.80; 95% CI, 0.71-0.90), and perioperative antiplatelet medication (RR, 0.83; 95% CI, 0.71-0.97). No shunting and a short cross-clamp time were also associated with lower risks; however, these are suspected to be confounded., Conclusions: Local anesthesia, patch plasty compared with primary closure, intraoperative completion studies by duplex ultrasound or angiography, and perioperative antiplatelet medication were independently associated with lower in-hospital stroke or death rates after carotid endarterectomy., (© 2017 American Heart Association, Inc.)

Objective: To determine efficacy of intraoperative microvascular Doppler ultrasound in assisting subinguinal microsurgical varicocelectomy for pain relief in the treatment of painful varicoceles, compared to the microsurgery without Doppler ultrasound., Methods: Total 153 patients underwent microsurgical varicocelectomy were randomly allocated to two groups: Groups 1 and 2 included 82 and 71 patients monitored with and without using intraoperative microvascular Doppler ultrasound, respectively. The assessments were compared between two groups, including intraoperative parameters (vessel numbers and operative time) and postoperative outcomes (pain resolution, complications and recurrence)., Results: The average numbers of internal spermatic veins ligated (13.87±6.43 vs 11.72±5.66) and arteries preserved (1.96±0.87 vs 1.73±0.86) were significantly greater in Group 1 with Doppler ultrasound. Precisely, the smaller size of the internal spermatic veins was ligated and the more encircled arteries were also preserved in Group 1. In two groups with and without using Doppler ultrasound, 56 (68.3%) and 36 (50.7%) patients experienced a complete resolution of pain, 21 (25.6%) and 29 (40.9%) patients experienced partial resolution, whereas 5 (6.1%) and 6 (8.5%) patients experienced no change in the chronic pain, respectively. Thus, patients in Group 1 had a better outcome in chronic pain resolution (P = 0.033). The operative time, complications and recurrence rate were not different between the two groups., Conclusions: Subinguinal microsurgical varicocelectomy is an effective method to treat painful varicoceles. With the assistance of Doppler Ultrasound monitoring, greater numbers of vessels were identified and a better outcome of pain resolution was achieved.

Background: During parathyroidectomy with intraoperative parathyroid hormone monitoring, the successful removal of a hypersecreting gland(s) resulting in normocalcemia is indicated by a >50% decrease in intraoperative parathyroid hormone level, typically into the normal range. Some patients, however, will have baseline parathyroid hormone levels within the normal range. We sought to determine the utility of intraoperative parathyroid hormone testing in these patients., Methods: We retrospectively studied all patients who underwent parathyroidectomy for primary hyperparathyroidism at our institution over a 10-year period., Results: Overall, 317 (17%) patients had parathyroid hormone within the normal range at the onset of operation (baseline intraoperative parathyroid hormone), and 1,544 (83%) had classic primary hyperparathyroidism. The intraoperative parathyroid hormone degradation was slower in normal baseline intraoperative parathyroid hormone patients than classic primary hyperparathyroidism patients, though this did not reach statistical significance (P < .254). A >50% intraoperative parathyroid hormone decrease predicted cure in 98.7% of normal baseline patients and 98.8% of classic primary hyperparathyroidism patients (P = .810). Normal baseline patients had a lesser cure rate the longer it took to achieve a 50% decrease intraoperatively; however, the cure rate was constant at any time point the 50% decrease occurred in patients with classic primary hyperparathyroidism (P < .05)., Conclusion: The 50% rule delineating operative cure can be applied with equal confidence to patients with normal range, baseline intraoperative parathyroid hormone. Moreover, the time at which the 50% drop is achieved impacts operative success rates in these patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Intraoperative hypotension may be associated with adverse outcomes in children undergoing surgery. Infants and neonates under 6 months of age have less autoregulatory cerebral reserve than older infants, yet little information exists regarding when and how often intraoperative hypotension occurs in infants., Aims: To better understand the epidemiology of intraoperative hypotension in infants, we aimed to determine the prevalence of intraoperative hypotension in a generally uniform population of infants undergoing laparoscopic pyloromyotomy., Methods: Vital sign data from electronic records of infants who underwent laparoscopic pyloromyotomy with general anesthesia at a children's hospital between January 1, 1998 and October 4, 2013 were analyzed. Baseline blood pressure (BP) values and intraoperative BPs were identified during eight perioperative stages based on anesthesia event timestamps. We determined the occurrence of relative (systolic BP <20% below baseline) and absolute (mean arterial BP <35 mmHg) intraoperative hypotension within each stage., Results: A total of 735 full-term infants and 82 preterm infants met the study criteria. Relative intraoperative hypotension occurred in 77%, 72%, and 58% of infants in the 1-30, 31-60, and 61-90 days age groups, respectively. Absolute intraoperative hypotension was seen in 21%, 12%, and 4% of infants in the 1-30, 31-60, and 61-90 days age groups, respectively. Intraoperative hypotension occurred primarily during surgical prep and throughout the surgical procedure. Preterm infants had higher rates of absolute intraoperative hypotension than full-term infants., Conclusions: Relative intraoperative hypotension was routine and absolute intraoperative hypotension was common in neonates and infants under 91 days of age. Preterm infants and infants under 61 days of age experienced the highest rates of absolute and relative intraoperative hypotension, particularly during surgical prep and throughout surgery., (© 2016 John Wiley & Sons Ltd.)

Background: Delayed graft function (DGF) is an early postoperative complication of kidney transplantation (KT) predisposing to acute rejection and lower graft survival. Intraoperative arterial hypotension and hypovolemia are associated with DGF. Central venous pressure (CVP) is used to estimate volemia but its reliability has been criticized. Pleth variability index (PVI) is a hemodynamic parameter predicting fluid responsiveness. The aim of this study was to examine the relationship between intraoperative PVI and CVP values and the occurrence of DGF., Methods: This was a prospective, noninterventional, observational, single-center study. All consecutive patients with KT from deceased donors were included. Recipients received standard, CVP, and PVI monitoring. Intraoperative hemodynamic parameters were recorded from recipients at 5 time points during KT., Results: Forty patients were enrolled. There was a poor correlation between PVI and CVP values (r 2  = 0.003; P = .44). Immediate graft function and DGF patients had similar hemodynamic values during KT, with the exception of PVI values, which were significantly higher in the DGF group. In particular, a PVI >9% before unclamping of the renal artery was the only predictive parameter of DGF in our multivariate analysis (P = .02)., Conclusions: This study suggests that PVI values >9% during KT are associated with the occurrence of DGF., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: Lesion formation is a critical determinant of technical and clinical success of pulmonary vein isolation. Different catheter designs aim to enhance tissue contact during ablation to enable optimized lesion formation. We analyzed procedural characteristics and predictors of clinical success in patients ablated with three different contemporary ablation catheters., Methods: Two hundred sixty-eight sequentially included patients receiving pulmonary vein isolation (PVI) with conventional (n = 122), contact-force (n = 96) and flexible-tip (n = 60) catheters were followed for a median of 14.1 months with 7d-Holter-monitoring and TTE at 3, 6, 12, and 24 months. Baseline characteristics and follow-up times were homogeneous across all groups., Results: Multivariable Cox proportional hazard regression for arrhythmia recurrence demonstrated a favorable hazard ratio for contact-force and flexible-tip catheters vs. conventional open irrigation catheters. Procedure time and fluoroscopy time were shorter for contact-force and flexible-tip catheters versus conventional catheters, but equal between. Linear lesions were applied in 58 % of contact-force and 66 % of flexible-tip cases, and CFAEs were targeted in 26 % of either., Conclusions: Our non-randomized prospectively collected data do not show a difference in observed procedure characteristics and in clinical outcome for flexible-tip versus contact-force catheter designs, while both display improved performance against conventional open irrigated-tip catheters. Linear lesions and CFAEs ablation were not associated with improved arrhythmia-free survival.

Background: A blood pressure (BP) waveform contains various pieces of information related to respiratory variation. Systolic time interval (STI) reflects myocardial performance, and diastolic time interval (DTI) represents diastolic filling. This study examined whether respiratory variations of STI and DTI within radial arterial waveform are comparable to dynamic indices., Methods: During liver transplantation, digitally recorded BP waveform and stroke volume variation (SVV) were retrospectively analyzed. Beat-to-beat STI and DTI were extracted within each BP waveform, which were separated by dicrotic notch. Systolic time variation (STV) was calculated by the average of 3 consecutive respiratory cycles: [(STImax- STImin)/STImean]. Similar formula was used for diastolic time variation (DTV) and pulse pressure variation (PPV). Receiver operating characteristic analysis with area under the curve (AUC) was used to assess thresholds predictive of SVV ≥12% and PPV ≥12%., Results: STV and DTV showed significant correlations with SVV (r= 0.78 and r= 0.67, respectively) and PPV (r= 0.69 and r= 0.69, respectively). Receiver operating characteristic curves demonstrated that STV ≥11% identified to predict SVV ≥12% with 85.7% sensitivity and 89.3% specificity (AUC = 0.935; P< .001). DTV ≥11% identified to predict SVV ≥12% with 71.4% sensitivity and 85.7% specificity (AUC = 0.829; P< .001). STV ≥12% and DTV ≥11% identified to predict PPV ≥12% with an AUC of 0.881 and 0.885, respectively., Conclusion: Respiratory variations of STI and DTI derived from radial arterial contour have a potential to predict hemodynamic response as a surrogate for SVV or PPV., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The aim of this study was to compare a continuous non-calibrated left heart cardiac index (CI) measurement by arterial waveform analysis (FloTrac(®)/Vigileo(®)) with a continuous calibrated right heart CI measurement by pulmonary artery thermodilution (CCOmbo-PAC(®)/Vigilance II(®)) for hemodynamic monitoring during lung transplantation. CI was measured simultaneously by both techniques in 13 consecutive lung transplants (n = 4 single-lung transplants, n = 9 sequential double-lung transplants) at distinct time points perioperatively. Linear regression analysis and Bland-Altman analysis with percentage error calculation were used for statistical comparison of CI measurements by both techniques. In this study the FloTrac(®) system underestimated the CI in comparison with the continuous pulmonary arterial thermodilution (p < 0.000). For all measurement pairs we calculated a bias of -0.55 l/min/m(2) with limits of agreement between -2.31 and 1.21 l/min/m(2) and a percentage error of 55 %. The overall correlations before clamping a branch oft the pulmonary artery (percentage error 41 %) and during the clamping periods of a branch oft the pulmonary artery (percentage error 66 %) failed to reached the required percentage error of less than 30 %. We found good agreement of both CI measurements techniques only during the measurement point "15 min after starting the second one-lung ventilation period" (percentage error 30 %). No agreement was found during all other measurement points. This pilot study shows for the first time that the CI of the FloTrac(®) system is not comparable with the continuous pulmonary-artery thermodilution during lung transplantation including the time periods without clamping a branch of the pulmonary artery. Arterial waveform and continuous pulmonary artery thermodilution are, therefore, not interchangeable during these complex operations.

Prior studies have examined the static effect of intravenous ketamine on the BIS Index for sedation but it remains unknown if the BIS Index is a reliable method to track sedation levels in the presence of ketamine. The major objective of the current investigation was to compare the BIS Vista Index ability to track varying depths of sedation as determined by OASS scores in a standardized anesthetic regimen with and without ketamine. The study was a randomized, double blinded clinical trial. Patients undergoing breast surgery under sedation with propofol were randomized to receive ketamine (1.5 μg kg min(-1)) or saline. Infusion data was used to estimate propofol plasma concentrations (Cp). The main outcome of interest was the correlation between the BIS Vista Index with the OASS score. Twenty subjects were recruited and fifteen completed the study. Four hundred fifty-five paired data points were included in the analysis. Model performance (Nagelkerke R(2)) of the multinomial logistic regression model was 0.57 with the c-statistic of 0.87 (95 % CI 0.82-0.91). Compared to awake the odds ratio for BIS values predicting moderate sedation in the saline/propofol group 1.19 (95 % CI 1.12-1.25) but only 1.06 (95 % CI 1.02-1.1) in the ketamine/propofol group (P = 0.001). There was no difference in the odds for BIS values to predict deep sedation between groups (P = 0.14). The BIS monitor can be used to monitor sedation level even when ketamine is used with propofol as part of the sedation regimen. However, ketamine reduces the value of the BIS in predicting moderate sedation levels.