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We aimed to compare the effect of sugammadex to that of neostigmine with respect to the occurrence of postoperative nausea and vomiting (PONV) during the first 24 h following general anesthesia. This retrospective cohort study included patients who underwent elective surgery under general anesthesia in 2020 at an academic medical center in Seoul, South Korea. The exposure groups were determined according to whether the patient received sugammadex or neostigmine as a reversal agent. The primary outcome was PONV occurrence during the first 24 h postoperatively (overall). The association between the type of reversal agent and primary outcome was investigated using logistic regression while adjusting for confounding variables using stabilized inverse probability of treatment weighting (sIPTW). Of the 10,912 patients included in this study, 5,918 (54.2%) received sugammadex. Sugammadex was associated with a significantly lower incidence of overall PONV (15.8% vs. 17.7%; odds ratio, 0.87; 95% confidence interval [CI], 0.79–0.97; P = 0.010) after sIPTW. In conclusion, compared with neostigmine/glycopyrrolate, sugammadex use has a lower risk of PONV during the first 24 h following general anesthesia.

Pediatric acute liver failure (PALF) is a common cause of liver transplantation (LT) but showed poor post-LT outcomes. We reviewed 36 PALF patients and 120 BA patients who underwent LT in our institution. The cause of PALF was unknown in 66.7%. PALF patients were older (6.2 vs. 2.9 years) with higher PELD scores (31.5 vs. 24.4) and shorter waitlist time (15.7 vs. 256.1 days) (p < 0.01). PALF patients showed higher rates of post-transplant renal replacement therapy (RRT) (13.9% vs. 4.2%) and hepatic artery complications (13.9% vs. 0.8%), while portal vein complications rates were lower (0% vs. 10.8%), (p < 0.05). Although PALF patients showed lower 5-year survival rates (77.8% vs. 95.0 %, p < 0.01), the 5-year survival rates of patients who lived beyond the first year were comparable (96.6% vs. 98.3%, p = 0.516). The most common cause of deaths within one year was graft failure (75.0%) in PALF patients, but infection (67.7%) in BA patients. In multivariate analysis, lower body weight, hepatic artery complications and post-transplant RRT were associated with worse survival outcomes (p < 0.05). In conclusion, physicians should be alert to monitor the immediate postoperative graft dysfunction and hepatic artery complications and patients on post-transplant RRT in order to improve survival outcomes in PALF patients.

Emergency abdominal surgery has high rates of mortality and morbidity. However, perioperative strategies to mitigate adverse outcomes are not well established yet. Given the frequent comorbidities and pathophysiology of these patients, the incidence of acute kidney injury (AKI) could be high. Therefore, we aimed to investigate the incidence and prognosis of AKI and potentially modifiable risk factors of AKI after emergency abdominal surgery. We retrospectively reviewed consecutive patients who underwent emergency open abdominal surgery at a single tertiary care university hospital. The overall incidence of AKI was 20.3% (n = 96). Postoperative AKI is significantly associated with clinical outcomes including admission to ICU, length of hospital and ICU stay, and in-hospital mortality. Multivariable logistic regression analysis for postoperative AKI revealed that age, body-mass index and ASA classification class 3 or 4 versus 2 were significant predictors. Furthermore, intraoperative vasopressin infusion (odds ratio 4.06, 95% confidence interval [CI] 1.19–13.9), preoperative platelet count (odds ratio 0.72, 95% CI 0.57–0.90, p = 0.003) and maximal serum lactate level (and odds ratio 1.14, 95% CI 1.04–1.26, p = 0.006) were identified as potentially modifiable risk factors. Further prospective clinical trials are required to investigate whether modification of these risk factors could mitigate the risk of AKI.

In modern anesthesia, multiple medical devices are used simultaneously to comprehensively monitor real-time vital signs to optimize patient care and improve surgical outcomes. However, interpreting the dynamic changes of time-series biosignals and their correlations is a difficult task even for experienced anesthesiologists. Recent advanced machine learning technologies have shown promising results in biosignal analysis, however, research and development in this area is relatively slow due to the lack of biosignal datasets for machine learning. The VitalDB (Vital Signs DataBase) is an open dataset created specifically to facilitate machine learning studies related to monitoring vital signs in surgical patients. This dataset contains high-resolution multi-parameter data from 6,388 cases, including 486,451 waveform and numeric data tracks of 196 intraoperative monitoring parameters, 73 perioperative clinical parameters, and 34 time-series laboratory result parameters. All data is stored in the public cloud after anonymization. The dataset can be freely accessed and analysed using application programming interfaces and Python library. The VitalDB public dataset is expected to be a valuable resource for biosignal research and development.

We investigated whether two needle insertion techniques for ultrasound-guided internal jugular vein (IJV) catheterization differ in the number of needling attempts and complication rate between inexperienced and experienced practitioners. A total of 308 patients requiring IJV catheterization were randomly assigned into one of four groups: IJV catheterization performed by inexperienced practitioners using either Seldinger (IE-S; n = 78) or modified Seldinger technique (IE-MS; n = 76) or IJV catheterization performed by experienced practitioners using either Seldinger (E-S; n = 78) or modified Seldinger technique (E-MS; n = 76). All catheterizations were performed under the real-time ultrasound guidance. The number of needling attempts was not significantly different between the two techniques within each experience group (between IE-S vs. IE-MS P = 0.550, between E-S and E-MS P = 0.834). Time to successful catheterization was significantly shorter in the E-S group compared to E-MS group (P P = 0.226). Complication rate was not significantly different between the two techniques within each experience group. Practitioner’s experience did not significantly affect the clinical performance of needle insertion techniques during ultrasound-guided IJV catheterization except the time to successful catheterization. Regarding the number of needling attempts and complication rate, both techniques could be equally recommended regardless of practitioner’s experience.Trial registration: clinicaltrials.gov (https://clinicaltrials.gov/ct2/show/NCT03077802).

Background: We aimed to compare the use of sugammadex to that of neostigmine in association with the occurrence of postoperative nausea and vomiting (PONV) during the first 24 h following general anesthesia.Methods: This retrospective cohort study included 10,912 patients who underwent elective surgery under general anesthesia in 2020 at an academic medical center in Seoul, South Korea. The exposure groups were determined according to whether the patient received sugammadex or neostigmine as a reversal agent. Demographic and perioperative variables, including PONV occurrence, were collected from the electronic medical records. The primary outcome was PONV occurrence during the first 24 h postoperatively (overall). Secondary outcomes were PONV occurrence during 0–2 h (early) and 2–24 h (delayed) postoperatively, and antiemetic use during the first 24 h postoperatively. The associations between the type of reversal agent and primary and secondary outcomes were investigated using logistic regression, while adjusting for confounding variables using stabilized inverse probability of treatment weighting (sIPTW). An interaction analysis was also performed to investigate whether the type of general anesthesia influenced the association between sugammadex use and PONV occurrence.Results: Of the 10,912 patients included in this study, 5,918 (54.2%) received sugammadex. Sugammadex (vs. neostigmine) was found to be significantly associated with the occurrence of overall PONV (15.8 vs. 17.7%; odds ratio [OR], 0.87; 95% confidence interval [CI], 0.79–0.97; P = 0.010), the occurrence of early PONV (7.6 vs. 9.7%; OR, 0.77; 98.7% CI, 0.65–0.91; P < 0.001), and antiemetic use within 24 h postoperatively (11.8 vs. 14.3%, OR, 0.80; 98.3% CI, 0.70–0.92; P < 0.001) after sIPTW. There was no evidence of interactions between sugammadex use and type of anesthesia for the primary and secondary outcomes.Conclusions: Compared with neostigmine/glycopyrrolate, sugammadex use was associated with a lower occurrence of PONV during the first 24 h following general anesthesia. Additionally, there was no significant interaction between the type of reversal agent and type of general anesthesia related to overall PONV occurrence. However, our retrospective study design precludes a firm conclusion regarding the effect of sugammadex on PONV after general anesthesia.Trial registration: not applicable

Background Postoperative delirium after liver transplantation (LT) is associated with increased hospital length of stay and higher morbidity and mortality. Dexmedetomidine is a recommended and widely used sedative in critically ill patients with reports of potential for delirium prevention. Methods A randomized controlled clinical trial was performed to investigate whether perioperative low-dose dexmedetomidine infusion would decrease delirium after living-donor LT. Dexmedetomidine (0.1 mcg/kg/hour) was administered during anesthesia and through postoperative day 2 for patients in the dexmedetomidine group, whereas 0.9% saline was administered at the same rate for the same duration for patients in the control group. The incidence of delirium after LT was compared between the 2 groups. Delirium duration, mechanical ventilation duration, intensive care unit (ICU) and hospital length of stay, and in-hospital and 3-month mortality were also compared. Results There was no significant difference in delirium incidence in the dexmedetomidine group compared to the control group (9% vs 5.9%; P = .44). Duration of delirium and mechanical ventilation, ICU and hospital length of stay, and in-hospital and 3-month mortality were comparable between the 2 groups. Conclusions Perioperative low-dose dexmedetomidine infusion did not reduce the incidence of delirium in living-donor LT.

Background: Post-reperfusion syndrome (PRS) results in sudden hemodynamic instability following graft reperfusion. Although PRS is known to influence outcomes following liver transplantation, little is known regarding the effects of anesthetics on PRS. This study investigated the association between the type of anesthetic agent and PRS in liver transplantation. Methods: This single-center retrospective cohort study included patients who underwent liver transplantation between June 2016 and December 2019. Patients were divided into sevoflurane and propofol groups according to the anesthetic agent used. Stabilized inverse probability of treatment weighting (IPTW) analysis was performed to investigate the association between PRS identified based on blood pressure recordings and the type of anesthesia. Associations between the anesthetic agent and the duration of hypotension as well as early postoperative outcomes were also investigated.Results: Data were analyzed for 398 patients, 304 (76.4%) and 94 (23.6%) of whom were anesthetized with propofol and sevoflurane, respectively. PRS developed in 40.7% of the 398 patients. Following stabilized IPTW analysis, the association with PRS was lower in the sevoflurane group than in the propofol group (odds ratio, 0.47; P = 0.018). However, there was no association between the type of anesthetic used and early postoperative outcomes. Conclusions: The association of PRS was lower in the sevoflurane group than in the propofol group. However, there was no association between the type of anesthetic and the early postoperative outcomes. Further studies are required to determine the optimal anesthetic for liver transplantation.

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan–Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12–1.36, p &lt, 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15–1.37, p &lt, 0.001). Kaplan–Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

This report describes a purely laparoscopic/robotic technique for successful living donor liver transplantation (LDLT). Purely laparoscopic explant hepatectomy followed by purely laparoscopic and robotic graft implantation can be performed in LDLT.

Background Arterial pressure-based cardiac output (APCO) is a less invasive method for estimating cardiac output without concerns about complications from the pulmonary artery catheter (PAC). However, inaccuracies of currently available APCO devices have been reported. Improvements to the algorithm by researchers are impossible, as only a subset of the algorithm has been released. Objective In this study, an open-source algorithm was developed and validated using a convolutional neural network and a transfer learning technique. Methods A retrospective study was performed using data from a prospective cohort registry of intraoperative bio-signal data from a university hospital. The convolutional neural network model was trained using the arterial pressure waveform as input and the stroke volume (SV) value as the output. The model parameters were pretrained using the SV values from a commercial APCO device (Vigileo or EV1000 with the FloTrac algorithm) and adjusted with a transfer learning technique using SV values from the PAC. The performance of the model was evaluated using absolute error for the PAC on the testing dataset from separate periods. Finally, we compared the performance of the deep learning model and the FloTrac with the SV values from the PAC. Results A total of 2057 surgical cases (1958 training and 99 testing cases) were used in the registry. In the deep learning model, the absolute errors of SV were 14.5 (SD 13.4) mL (10.2 [SD 8.4] mL in cardiac surgery and 17.4 [SD 15.3] mL in liver transplantation). Compared with FloTrac, the absolute errors of the deep learning model were significantly smaller (16.5 [SD 15.4] and 18.3 [SD 15.1], P Conclusions The deep learning–based APCO algorithm showed better performance than the commercial APCO device. Further improvement of the algorithm developed in this study may be helpful for estimating cardiac output accurately in clinical practice and optimizing high-risk patient care.

Minimally invasive approaches are increasingly being applied in surgeries and have recently been used in living donor hepatectomy. We have developed a safe and reproducible method for minimally invasive living donor liver transplantation, which consists of pure laparoscopic explant hepatectomy and pure laparoscopic implantation of the graft, which was inserted through a suprapubic incision. Pure laparoscopic explant hepatectomy without liver fragmentation was performed in a 60-year-old man with alcoholic liver cirrhosis and hepatocellular carcinoma. The explanted liver was retrieved through a suprapubic incision. A modified right liver graft, procured from his 24-year-old son using the pure laparoscopic method, was inserted through a suprapubic incision, and implantation was performed intracorporeally throughout the procedure. The time required to remove the liver was 369 minutes, and the total operative time was 960 min. No complications occurred during or after the surgery. The patient recovered well, and his hospital stay was of 11 days. Pure laparoscopic living donor liver transplantation from explant hepatectomy to implantation was performed successfully. It is a feasible procedure when performed by a highly experienced surgeon and transplantation team. Further studies with larger sample sizes are needed to confirm its safety and feasibility.

We aimed to investigate the incidence of sugammadex-induced anaphylaxis in a large Korean population. We retrospectively investigated the incidence of sugammadex-induced anaphylaxis between 2013 and 2019 from the database of the Korea Institute of Drug Safety-Risk Management-Korea Adverse Event Reporting System (KIDS-KAERS). We estimated the incidence of sugammadex-induced anaphylaxis from the KIDS-KAERS database, assuming that the reporting efficiency was 10%, 50%, and 100%, respectively. We also investigated its annual sales volume in Korea and assumed that the exposure to sugammadex was 95% of the estimated sales volume. During the study period, 1,401,630 sugammadex vials were sold, and 19 cases of sugammadex-induced anaphylaxis were identified in the KIDS-KAERS database. The estimated incidence of sugammadex-induced anaphylaxis was 0.0143%, 0.00279%, and 0.0014%, assuming a reporting efficiency of 10%, 50%, and 100%, respectively. All patients, except for one with a missing record, fully recovered after anaphylaxis. The incidence of sugammadex-induced anaphylaxis identified in the national pharmacovigilance database was lower than previously reported rates in other countries. Therefore, its use in general anesthesia should not be hindered by concerns about the resulting risk of anaphylaxis in Korea.

Acute kidney injury (AKI) after living donor liver transplantation (LDLT) is associated with increased mortality. We sought to identify associations between intraoperative hemodynamic variables and postoperative AKI.We retrospectively reviewed 734 cases of LDLT. Intraoperative hemodynamic variables of systemic and pulmonary arterial pressure, central venous pressure (CVP), and pulmonary artery catheter-derived parameters including mixed venous oxygen saturation (SvO2), right ventricular end-diastolic volume (RVEDV), stroke volume, systemic vascular resistance, right ventricular ejection fraction, and stroke work index were collected. Propensity score matching analysis was performed between patients with (n = 265) and without (n = 265) postoperative AKI. Hemodynamic variables were compared between patients with AKI, defined by Kidney Disease Improving Global Outcomes criteria, and those without AKI in the matched sample.The incidence of AKI was 36.1% (265/734). Baseline CVP, baseline RVEDV, and SvO2 at 5 minutes before reperfusion were significantly different between patients with and without AKI in the matched sample of 265 pairs. Multivariable logistic regression analysis revealed that baseline CVP, baseline RVEDV, and SvO2 at 5 minutes before reperfusion were independent predictors of AKI (CVP per 5 cm H2O increase: odds ratio [OR], 1.20; 95% confidence interval [CI], 1.09-1.32; SvO2: OR, 1.45; 95% CI, 1.27-1.71; RVEDV: OR, 1.48; 95% CI, 1.24-1.78).The elevated baseline CVP, elevated baseline RVEDV after anesthesia induction, and decreased SvO2 during anhepatic phase were associated with postoperative AKI. Prospective trials are required to evaluate whether the optimization of these variables may decrease the risk of AKI after LDLT.

Bispectral index (BIS), a useful marker of anaesthetic depth, is calculated by a statistical multivariate model using nonlinear functions of electroencephalography-based subparameters. However, only a portion of the proprietary algorithm has been identified. We investigated the BIS algorithm using clinical big data and machine learning techniques. Retrospective data from 5,427 patients who underwent BIS monitoring during general anaesthesia were used, of which 80% and 20% were used as training datasets and test datasets, respectively. A histogram of data points was plotted to define five BIS ranges representing the depth of anaesthesia. Decision tree analysis was performed to determine the electroencephalography subparameters and their thresholds for classifying five BIS ranges. Random sample consensus regression analyses were performed using the subparameters to derive multiple linear regression models of BIS calculation in five BIS ranges. The performance of the decision tree and regression models was externally validated with positive predictive value and median absolute error, respectively. A four-level depth decision tree was built with four subparameters such as burst suppression ratio, power of electromyogram, 95% spectral edge frequency, and relative beta ratio. Positive predictive values were 100%, 80%, 80%, 85% and 89% in the order of increasing BIS in the five BIS ranges. The average of median absolute errors of regression models was 4.1 as BIS value. A data driven BIS calculation algorithm using multiple electroencephalography subparameters with different weights depending on BIS ranges has been proposed. The results may help the anaesthesiologists interpret the erroneous BIS values observed during clinical practice.

BACKGROUND Arterial pressure-based cardiac output (APCO) is a less invasive method for estimating cardiac output without concerns about complications from the pulmonary artery catheter (PAC). However, inaccuracies of currently available APCO devices have been reported. Improvements to the algorithm by researchers are impossible, as only a subset of the algorithm has been released. OBJECTIVE In this study, an open-source algorithm was developed and validated using a convolutional neural network and a transfer learning technique. METHODS A retrospective study was performed using data from a prospective cohort registry of intraoperative bio-signal data from a university hospital. The convolutional neural network model was trained using the arterial pressure waveform as input and the stroke volume (SV) value as the output. The model parameters were pretrained using the SV values from a commercial APCO device (Vigileo or EV1000 with the FloTrac algorithm) and adjusted with a transfer learning technique using SV values from the PAC. The performance of the model was evaluated using absolute error for the PAC on the testing dataset from separate periods. Finally, we compared the performance of the deep learning model and the FloTrac with the SV values from the PAC. RESULTS A total of 2057 surgical cases (1958 training and 99 testing cases) were used in the registry. In the deep learning model, the absolute errors of SV were 14.5 (SD 13.4) mL (10.2 [SD 8.4] mL in cardiac surgery and 17.4 [SD 15.3] mL in liver transplantation). Compared with FloTrac, the absolute errors of the deep learning model were significantly smaller (16.5 [SD 15.4] and 18.3 [SD 15.1], P CONCLUSIONS The deep learning–based APCO algorithm showed better performance than the commercial APCO device. Further improvement of the algorithm developed in this study may be helpful for estimating cardiac output accurately in clinical practice and optimizing high-risk patient care.

The position of the left side liver graft is important, and it could lead to complications of the hepatic vein (HV) and portal vein (PV), especially in a small child using a variant left lateral section (vLLS) graft. The purpose of this study was to evaluate the outcome of a novel technique for the implantation of a vLLS graft to the right side (dextroplantation) in infants. For 3 years, 10 consecutive infants underwent dextroplantation using a vLLS graft (group D). The graft was implanted to the right side of the recipient after 90° counterclockwise rotation; the left HV graft was anastomosed to inferior vena cava using the extended right and middle HV stump, and PV was reconstructed using oblique anastomosis without angulation. Surgical outcomes were compared with the historical control group (n = 17, group C) who underwent conventional liver transplantation using a vLLS during infancy. Group D recipients were smaller than group C (body weight6 kg: 50.0% versus 11.8%; P = 0.03). The rate of graft-to-recipient weight ratio4% was higher in group D (60.0%) than C (11.8%; P = 0.01). Surgical drains were removed earlier in group D than in group C (15 versus 18 postoperative days [PODs]; P = 0.048). Each group had 1 PV complication (10.0% versus 5.9%); no HV complication occurred in group D, but 3 HV complications (17.6%) occurred in group C (P 0.05). Hospital stay was shorter in group D than in group C (20 versus 31 PODs; P = 0.02). Dextroplantation of a vLLS graft, even a large-for-size one, was successful in small infants without compromising venous outcomes, compared with conventional vLLS transplantation. We could remove the surgical drains earlier and reduce hospital stays in cases of dextroplantation.

Anesthesia with desflurane and remifentanil can be maintained with either fixed or titrated desflurane concentration. We hypothesized that the fixed-gas concentration (FG) method would reduce the number of anesthetic titrations without hypnotic and hemodynamic instability compared to the bispectral index (BIS)-guided (BG) method. Forty-eight patients were randomly allocated to the FG or BG groups. In the FG group, desflurane vaporizer setting was fixed at 1 age-corrected minimum alveolar concentration (MAC). In the BG group, desflurane was titrated to target a BIS level at 50. Remifentanil was titrated to maintain a systolic arterial pressure (SAP) of 120 mmHg in both groups. Our primary endpoint was the hypnotic stability measured by the wobble of BIS in performance analysis, and the secondary endpoints included the wobble of SAP, mean BIS value during surgery, and the number of anesthetic titrations. The BIS in the FG group showed significantly less wobble (3.9 ± 1.1% vs 5.5 ± 1.5%, P vs 46 ± 7, P vs 5.2 (4.2–8.3)%, P = 0.557]. The numbers of anesthetic titrations in the FG group were significantly lower than the BG group (0 ± 0 vs 8 ± 5, Pvs 22 ± 17, P = 0.047 for remifentanil). Less wobble in BIS and reduced anesthetic titration without hemodynamic instability during the FG technique may be practical in balanced anesthesia using desflurane and remifentanil anesthesia. Clinical trial: This study was registered at ClinicalTrials.gov (NCT02283866).

Preoperative hyponatremia is associated with an increased risk of mortality on the liver transplantation (LT) waiting list. We sought to investigate the impact of pre- and intraoperative serum sodium levels on the one-year mortality after LT. We identified 1,164 patients for whom preoperative and intraoperative serum sodium levels were available. Cox regression analysis with multivariable adjustment was performed for one-year mortality. A propensity score matching analysis was performed for preoperative and intraoperative serum sodium groups to compare one-year survival. The cutoff of sodium level with minimal p-value was 130 mEq/L for both preoperative and intraoperative sodium. Intraoperative hyponatremia was an independent predictor of one-year mortality in the multivariable Cox regression analysis, while preoperative hyponatremia was not. Kaplan-Meier curve showed that there was a significant difference in the one-year mortality between preoperative and intraoperative serum sodium groups. However, after propensity score matching, there was no difference in the one-year mortality among the preoperative sodium groups, while there was a significant difference among the intraoperative sodium groups. Intraoperative hyponatremia defined by mean sodium

For ABO-incompatible liver transplantation (ABO-i LT), therapeutic plasma exchange (TPE) is performed preoperatively to reduce the isoagglutinin titer of anti-ABO blood type antibodies. We evaluated whether perioperative high isoagglutinin titer is associated with postoperative risk of acute kidney injury (AKI). In 130 cases of ABO-i LT, we collected immunoglobulin (Ig) G and Ig M isoagglutinin titers of baseline, pre-LT, and postoperative peak values. These values were compared between the patients with and without postoperative AKI. Multivariable logistic regression analysis was used to evaluate the association between perioperative isoagglutinin titers and postoperative AKI. Clinical and graft-related outcomes were compared between high and low baseline and postoperative peak isoagglutinin groups. The incidence of AKI was 42.3%. Preoperative baseline and postoperative peak isoagglutinin titers of both Ig M and Ig G were significantly higher in the patients with AKI than those without AKI. Multivariable logistic regression analysis showed that preoperative baseline and postoperative peak Ig M isoagglutinin titers were significantly associated with the risk of AKI (baseline: odds ratio 1.06, 95% confidence interval 1.02 to 1.09, postoperative peak: odds ratio 1.08, 95% confidence interval 1.04 to 1.13). Cubic spline function curves show a positive relationship between the baseline and postoperative peak isoagglutinin titers and the risk of AKI. Clinical outcomes other than AKI were not significantly different according to the baseline and postoperative peak isoagglutinin titers. Preoperative high initial and postoperative peak Ig M isoagglutinin titers were significantly associated with the development of AKI. As the causal relationship between high isoagglutinin titers and risk of AKI is unclear, the high baseline and postoperative isoagglutinin titers could be used simply as a warning sign for the risk of AKI after liver transplantation.

Acute kidney injury (AKI) after liver transplantation has been reported to be associated with increased mortality. Recently, machine learning approaches were reported to have better predictive ability than the classic statistical analysis. We compared the performance of machine learning approaches with that of logistic regression analysis to predict AKI after liver transplantation. We reviewed 1211 patients and preoperative and intraoperative anesthesia and surgery-related variables were obtained. The primary outcome was postoperative AKI defined by acute kidney injury network criteria. The following machine learning techniques were used: decision tree, random forest, gradient boosting machine, support vector machine, na&iuml, ve Bayes, multilayer perceptron, and deep belief networks. These techniques were compared with logistic regression analysis regarding the area under the receiver-operating characteristic curve (AUROC). AKI developed in 365 patients (30.1%). The performance in terms of AUROC was best in gradient boosting machine among all analyses to predict AKI of all stages (0.90, 95% confidence interval [CI] 0.86&ndash, 0.93) or stage 2 or 3 AKI. The AUROC of logistic regression analysis was 0.61 (95% CI 0.56&ndash, 0.66). Decision tree and random forest techniques showed moderate performance (AUROC 0.86 and 0.85, respectively). The AUROC of support the vector machine, na&iuml, ve Bayes, neural network, and deep belief network was smaller than that of the other models. In our comparison of seven machine learning approaches with logistic regression analysis, the gradient boosting machine showed the best performance with the highest AUROC. An internet-based risk estimator was developed based on our model of gradient boosting. However, prospective studies are required to validate our results.

We previously demonstrated the usefulness of milrinone for living donor hepatectomy. However, a less-invasive alternative to central venous catheterization and perioperative contributors to good surgical outcomes remain undetermined. The current study evaluated whether the stroke volume variation (SVV)-guided method can substitute central venous catheterization during milrinone-induced profound vasodilation.We randomly assigned 42 living liver donors to receive either SVV guidance or central venous pressure (CVP) guidance to obtain milrinone-induced low CVP. Target SVV of 9% was used as a substitute for CVP of 5 mm Hg. The surgical field grade evaluated by 2 attending surgeons on a 4-point scale was compared between the CVP- and SVV-guided groups (n = 19, total number of scores = 38 per group) as a primary outcome variable. Multivariable analysis was performed to identify independent factors associated with the best surgical field as a post hoc analysis.Surgical field grades, which were either 1 or 2, were not found to be different between the 2 groups via Mann-Whitney U test (P = .358). There was a very weak correlation between SVV and CVP during profound vasodilation such as CVP ≤ 5 mm Hg (R = -0.06; 95% confidence interval, -0.09 to -0.04; P.001). Additional post hoc analysis suggested that younger age, lower baseline CVP, and longer duration of milrinone infusion might be helpful in providing the best surgical field.Milrinone-induced vasodilation resulted in favorable surgical environment regardless of guidance methods of low CVP during living donor hepatectomy. However, SVV was not a useful indicator of low CVP because of very weak correlation between SVV and CVP during profound vasodilation. In addition, factors contributing to the best surgical field such as donor age, proactive fasting, and proper dosing of milrinone need to be investigated further, ideally through prospective studies.

ABO-incompatible liver transplantation (ABO-i LT) is associated with a higher risk of acute kidney injury (AKI) compared to ABO-compatible liver transplantation (ABO-c LT). We compared the risk of AKI associated with transfusion between ABO-c and ABO-i living donor liver transplantation (LDLT). In 885 cases of LDLT, we used a propensity score analysis to match patients who underwent ABO-c (n = 766) and ABO-i (n = 119) LDLT. Baseline medical status, laboratory findings, and surgical- and anesthesia-related parameters were used as contributors for propensity score matching. AKI was defined according to the &ldquo, Kidney Disease Improving Global Outcomes&rdquo, criteria. After 1:2 propensity score matching, a conditional logistic regression analysis was performed to evaluate the relationship between the intraoperative transfusion of packed red blood cells (pRBCs) and fresh frozen plasma (FFP) on the risk of AKI. The incidence of AKI was higher in ABO-i LT than in ABO-c LT before and after matching (after matching, 65.8% in ABO-i vs 39.7% in ABO-c, p &lt, 0.001). The incidence of AKI increased in direct proportion to the amount of transfusion, and this increase was more pronounced in ABO-i LT. The risk of pRBC transfusion for AKI was greater in ABO-i LT (multivariable adjusted odds ratio (OR) 1.32 per unit) than in ABO-c LT (OR 1.11 per unit). The risk of FFP transfusion was even greater in ABO-i LT (OR 1.44 per unit) than in ABO-c LT (OR 1.07 per unit). In conclusion, the association between transfusion and risk of AKI was stronger in patients with ABO-i LT than with ABO-c LT. Interventions to reduce perioperative transfusions may attenuate the risk of AKI in patients with ABO-i LT.

The widespread use of remifentanil during total intravenous anesthesia (TIVA) has raised concerns about the risk of postoperative remifentanil-associated pain. Although a recent meta-analysis suggests that remifentanil-associated pain is unlikely to occur in patients with TIVA because of the protective effect of co-administered propofol, the evidence is not conclusive. We retrospectively assessed 635 patients who received robotic thyroid surgery under TIVA to evaluate the risk of remifentanil-associated pain. Postoperative pain was evaluated using 11-point numeric rating scale (NRS). Time dependent Cox proportional hazards regression analysis was used to determine the risk factors of treatment-requiring pain (NRS > 4) during the first 48 postoperative hours. Postoperative pain rapidly decreased, and treatment-requiring pain remained in 12.8% (81 out of 635) of patients at 48 hours postoperatively. After adjusting for the time-dependent analgesic consumption, intraoperative use of remifentanil > 0.2 mcg/kg/min was a positive predictor of postoperative pain with a hazard ratio of 1.296 (95% C.I., 1.014–1.656, P = 0.039) during 48 hours after surgery. In conclusion, excessive use of remifentanil during TIVA was associated with increased risk of pain after robotic thyroid surgery. Prospective trials are required to confirm these results and determine whether decreasing remifentanil consumption below the threshold can reduce postoperative pain.

This study aimed to evaluate the effect of riluzole on the activity of excitatory amino acid transporter type 3 (EAAT3), a neuronal glutamate transporter, and to investigate the role of protein kinase C (PKC) in this effect. EAAT3 expression was induced in Xenopus oocytes by injecting EAAT3 mRNA. Using the two-electrode voltage clamping method, membrane currents were recorded before, during, and after applying l-glutamate (30 μM) in the absence and presence of prior incubation with riluzole (0.3-100 μM). To study the effect of PKC on the riluzole-induced change in EAAT3 activity, oocytes were preincubated with 100 μM phorbol-12-myristate-13-acetate (PMA), a PKC activator, or PKC inhibitors (2 µM staurosporine and 100 µM chelerythrine) before the recording. Responses were quantified by integrating current traces and are reported in microCoulombs (μC). Riluzole reduced EAAT3 activity in a concentration-dependent manner (0.3-100 μM). Treatment of oocytes with PMA significantly increased the baseline and riluzole-reduced EAAT activity (P0.05). In addition, treatment of oocytes with PKC inhibitors reduced basal transporter currents, but did not show a further significant decrease in the riluzole-reduced EAAT3 activity. These results suggest that riluzole reduces EAAT3 activity through PKC inhibition.

Background Water is known to have lubricating properties, thus it is used for lubrication of tracheal tubes to reduce airway injuries caused by intubation. However, there is no definite evidence to substantiate the beneficial effects of lubricating tracheal tubes using water for attenuating airway injuries. Moreover, the lubrication pretreatment may cause contamination of the tube, leading to respiratory infections. Therefore, this trial aims to assess whether no pretreatment of tracheal tubes does not increase post-intubation airway complications as compared with water lubrication of tubes. Methods/design This is a prospective, double-blind, single-center, parallel-arm, noninferiority, randomized controlled trial to be conducted in participants aged 20–80 years who are undergoing elective surgery under general anesthesia with orotracheal intubation. Participants are randomly assigned into one of two groups depending on whether intubation is performed using a tracheal tube lubricated with water (n = 150) or without any pretreatment (n = 150). The primary outcome is the incidence of sore throat at 0, 2, 4, and 24 h after surgery, which is analyzed with a noninferiority test. The secondary outcomes are the incidence and severity of postoperative hoarseness, oropharyngeal injuries, and respiratory infections. Discussion Because we hypothesized that lubricating tracheal tubes using water has no advantage in reducing airway injuries associated with intubation, we will compare the incidence of sore throat, which is the most common complaint after intubation, in a noninferiority manner. This is the first randomized controlled trial to investigate the possibly beneficial or harmful effects of lubricating tracheal tubes using water before intubation. We expect that this trial will provide useful evidence to formulate a protocol for preparing tracheal tubes before intubation. Trial registration This trial is registered at ClinicalTrials.gov on 1 July 2015 (NCT02492646) Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1699-0) contains supplementary material, which is available to authorized users.

In the present study, we evaluated the effects of single-handed chin lift and two-handed jaw thrust on lightwand-guided intubation and postoperative sore throat. Sixty adult patients were included in the study. After induction of anesthesia, intubation was performed using a lightwand under single-handed chin lift or two-handed jaw thrust. In the single-handed chin lift group, the lightwand was inserted with the right hand after the mandible was lifted by placing the thumb of the left hand into the mouth. In the two-handed jaw thrust group, the lightwand was inserted while jaw thrust was achieved by an assistant using two hands. Lightwand search time, number of intubation attempts, and time to achieve intubation were assessed. Heart rate and mean arterial pressure were measured before and after intubation. Postoperative sore throat was evaluated at 1 and 24 h after surgery. Lightwand search time was significantly shorter in the two-handed jaw thrust group compared to the single-handed chin lift group (7.2 ± 4.6 vs. 12.1 ± 9.1 s, respectively; p = 0.016). The two-handed jaw thrust group had shorter intubation time than the single-handed chin lift group (21.0 ± 6.6 vs. 27.9 ± 9.9 s, respectively; p = 0.004). The number of intubation attempts and hemodynamic changes during intubation were similar between the two groups. The incidence and severity of postoperative sore throat were lower at 24 h after surgery in the two-handed jaw thrust group compared with the single-handed chin lift group (p = 0.011). The two-handed jaw thrust facilitated lightwand-guided intubation, and reduced the incidence and severity of postoperative sore throat compared to the single-handed chin lift.

Background Sore throat is common after tracheal intubation. Water can be used to lubricate tracheal tubes, but its benefit has not been validated. We thus did a randomised non-inferiority trial to test the hypothesis that a tube lubricated with water does not reduce sore throat after tracheal intubation. Methods We randomized female or male patients (n = 296) undergoing surgery in the ears or eyes to receive either a tube lubricated with water or a tube without lubrication for intubation. We assessed sore throat at 0, 2, 4, and 24 h after surgery; pharyngeal injury at 2 and 24 h after surgery; and respiratory infections within 7 days after surgery. For the incidence of sore throat within 24 h after surgery (primary outcome), the two-sided 90% confidence interval of the risk difference was compared with the prespecified non-inferiority margin of 15%. Other outcomes were analyzed with two-sided superiority tests. Results The incidence of sore throat within 24 h after surgery was 80/147 (54.4%) in the non-lubricated tube group and 83/149 (55.7%) in the water-lubricated tube group (risk difference -1.3%, 90% confidence interval -10.9% to 8.3%). Because the confidence interval was below the non-inferiority margin, the incidence of sore throat was not higher in the non-lubricated tube group than in the water-lubricated tube group. There was no significant association between groups in the sore throat, pharyngeal injury, and respiratory infection at each assessment time. Conclusions The tube lubricated with water did not reduce sore throat and pharyngeal injury after tracheal intubation compared to the tube without lubrication.

We report a case of bilateral vocal cord paralysis (VCP) that occurred after coronary artery bypass surgery and we review the mechanisms of VCP and the preventable factors. We emphasize to consider VCP if respiratory insufficiency occurs following extubation in cardiac surgery, and an early diagnosis is sure to prevent life-threatening problems such as airway compromise and aspiration pneumonia. A 66-year-old female patient (153.4 cm, 46.8 kg) was scheduled for a coronary artery bypass surgery. She had a medical history of hypertension, coronary artery disease, and diabetes mellitus. Recent coronary angiography showed progressed lesions at the left anterior descending and left circumflex arteries. After the patient was transferred to the operating room and an arterial cannulation was done, anesthesia was induced. Tracheal intubation was performed with a 7.0 mm-internal diameter endotracheal tube (SoftVent® Pro, HVLP-Cuff, Murphy, Unomedical, Malaysia) using a direct curved laryngoscope. The balloon was inflated until the cuff pressure was measured as 25 cmH2O by a handheld aneroid manometer (VBM, Germany). The cuff was palpated at the suprasternal notch and the endotracheal tube was fixed at 20 cm from the incisors. An ultrasound guided insertion of a central venous cannula was performed in the right internal jugular vein and a transesophageal echocardiographic (TEE) probe (diameter: 10.5 mm, width of tip: 14.5 mm; TEV5Ms, Siemens Medical Solutions, Mountain View, USA) was inserted without difficulty. After median sternotomy, the left internal mammary artery was harvested and off-pump coronary artery bypass surgery was performed. The cuff pressure of the endotracheal tube was intermittently measured maintaining the intracuff pressure at 25 cmH2O during the operation and the post operation period, and the fraction of inspired oxygen was maintained below 0.5 using medical air and oxygen. A planned extubation was performed after ventilator care for 2 days. Immediately after extubation, the patient complained of respiratory difficulties and an inspiratory stridor was detected. Dexamethasone 5 mg was given and respiration was assisted with a bag-valve-mask for several minutes. The respiratory difficulties were relieved and the stridor disappeared. Chest X-ray findings and arterial blood gas analysis were within normal range. Methylprednisolone 25 mg/day was administered due to the suspicion of laryngeal edema and spontaneous breathing was maintained without events under oxygen 10 L/min via a facial mask. One day after extubation the patient complained of hoarseness. The otorhinolaryngeal department was consulted for a vocal cord examination and a gap was shown between the vocal cords and both vocal folds were shown to be immobile. Feeding through a nasogastric tube was started and the patient was kept under close observation. The patient had no respiratory difficulties even though a minimal stridor was detected intermittently. On the 18th post-operative day, the videofluoroscopic swallowing study showed an aspiration at the pharyngeal stage and the patient was put on rehabilitation for dysphagia. On the 20th post-operative day, the fiberoptic endoscopic evaluation of swallowing (FESS) showed improved movement of both vocal cords and no aspiration signs. The patient was discharged one week later and after three months, her voice was normalized and the FESS showed no abnormal findings. VCP results from a direct vocal cord injury or a recurrent laryngeal nerve (RLN) paralysis following cardiac surgery. Direct manipulation and retraction of the heart, median sternotomy, as well as an excessive sternal traction for harvesting of the internal mammary artery may be a cause of RLN paralysis related to the anatomy of RLN [1]. The right RLN crosses the subclavian artery, winds the artery backward, and ascends in the tracheoesophageal groove. The left RLN crosses the aortic arch and reaches the tracheoesophageal groove [1]. Hypothermic injury with ice/slush collecting in the pleural cavity in close proximity to the left RLN has been also reported to contribute to RLN paralysis [2]. The repeated and unsuccessful attempts of inserting TEE probe can compress the nerve at its entry into the larynx, resulting in RLN paralysis [3]. During central venous catheterization, direct RLN injury is possible because the catheterized vessels are close to the RLN. In addition, traumatic endotracheal intubation can cause a direct mechanical injury such as a cricoarytenoid dislocation, and an excessively inflated endotracheal tube cuff can compress the RLN or its anterior branch at the tracheoesophageal groove [4]. In this case, the chest x-ray and manometer findings checked during the intubation period show that endotracheal tube location and cuff pressure were within a normal range. The central line, TEE, and the endotracheal tube also were all inserted without any difficulty and events. Therefore, controllable or intubation related factors can be excluded. We suppose that the causes of VCP in this case were the factors associated with the heart operation such as excessive sternal traction and direct manipulation of the heart. The clinical manifestations of a bilateral VCP are respiratory insufficiency, stridor, and hoarseness. In this case, the patient had respiratory difficulties and stridor immediately after extubation and the symptoms subsided after steroid injection. The day after extubation, the patient complained of hoarseness and was diagnosed with bilateral VCP. This shows that laryngeal spasm or edema that causes respiratory difficulties and stridor immediately after extubation [5] could be accompanied by bilateral VCP in this case. Generally, bilateral VCP is clinically fatal and prompt management such as re-intubation and mechanical ventilation can be required because the vocal cords can be immobile while being closed. In our case, a gap existed between the vocal folds. Therefore adequate ventilation and oxygenation was possible via the gap. However, re-intubation and mechanical ventilation under the suspicion of bilateral VCP should have taken place if the stridor or respiratory symptoms had still existed after the use of steroid or the assistance of ventilation. It is not easy to prevent a VCP in cardiac surgery, because there are several contributing factors for the occurrence. We should take effort to avoid any controllable risk factors, including abnormal tube size and location, high intra-cuff pressure, and traumatic insertion of TEE probe or central venous catheter. Also, a VCP must be suspected if patients have hoarseness, stridor, and respiratory difficulties after extubation.