Use of hydroxocobalamin to treat intraoperative vasoplegic syndrome refractory to vasopressors and methylene blue during liver transplantation.

INTRODUCTION: For patients with catecholamine-resistant vasoplegic syndrome (VS) during liver transplantation (LT), treatment with methylene blue (MB) and/or hydroxocobalamin (B12) has been an acceptable therapy. However, data on the effectiveness of B12 is limited to case reports and case series. METHODS: We retrospectively reviewed records of patients undergoing LT from January 2016 through March 2022. We identified patients with VS treated with vasopressors and MB, and abstracted hemodynamic parameters, vasopressor requirements, and B12 administration from the records. The primary aim was to describe the treatment efficacy of B12 for VS refractory to vasopressors and MB, measured as no vasopressor requirement at the conclusion of the surgery. RESULTS: One hundred one patients received intraoperative VS treatment. For the 35 (34.7%) patients with successful VS treatment, 14 received MB only and 21 received both MB and B12. Of the 21 patients with VS resolution after receiving both MB and B12, 17 (89.5%) showed immediate, but transient, hemodynamic improvements at the time of MB administration and later showed sustained response to B12. CONCLUSION: Immediate but transient hemodynamic response to MB in VS patients during LT supports the diagnosis of VS and should prompt B12 administration for sustained treatment response.

Asystolic donor warm ischemia time is associated with development of postreperfusion syndrome in donation after circulatory death liver transplant.

BACKGROUND: Individual events during donation after circulatory death (DCD) procurement, such as hypotensive or hypoxic warm ischemia, or circulatory arrest are all a part of donor warm ischemia time (dWIT), and may have differing effects on the outcome of the liver graft. This study aimed to identify risk factors for postreperfusion syndrome (PRS), a state of severe hemodynamic derangement following graft reperfusion, and its impact on DCD liver transplantation (LT) outcomes. METHODS: This was a retrospective analysis using 106 DCD LT. Detailed information for events during procurement (withdrawal of life support; systolic blood pressure < 80 mmHg; oxygen saturation < 80%; circulatory arrest; aortic cold perfusion) and their association with the development of PRS were examined using logistic regression. RESULTS: The overall incidence of PRS was 26.4%, occurring in 28 patients. Independent risk factors for PRS were asystolic dWIT (odds ratio (OR) 3.65, 95% confidence interval (CI) 1.38-9.66) and MELD score (OR 1.06, 95% CI 1.01-1.10). Total bilirubin was significantly higher in the PRS group at postoperative day (POD) 1 (p = .02; 5.2 mg/dL vs. 3.4 mg/dL), POD 3 (p = .049; 4.5 mg/dL vs. 2.8 mg/dL), and POD 7 (p = .04; 3.1 mg/dL vs. 1.9 mg/dL). Renal replacement therapy after LT was more likely to be required in the PRS group (p = .01; 48.2% vs. 23.1%). CONCLUSION: Asystolic dWIT is a risk factor for the development of PRS in DCD LT. Our results suggest that asystolic dWIT should be considered when selecting DCD liver donors.

Remote Monitoring and Artificial Intelligence: Outlook for 2050.

Remote monitoring and artificial intelligence will become common and intertwined in anesthesiology by 2050. In the intraoperative period, technology will lead to the development of integrated monitoring systems that will integrate multiple data streams and allow anesthesiologists to track patients more effectively. This will free up anesthesiologists to focus on more complex tasks, such as managing risk and making value-based decisions. This will also enable the continued integration of remote monitoring and control towers having profound effects on coverage and practice models. In the PACU and ICU, the technology will lead to the development of early warning systems that can identify patients who are at risk of complications, enabling early interventions and more proactive care. The integration of augmented reality will allow for better integration of diverse types of data and better decision-making. Postoperatively, the proliferation of wearable devices that can monitor patient vital signs and track their progress will allow patients to be discharged from the hospital sooner and receive care at home. This will require increased use of telemedicine, which will allow patients to consult with doctors remotely. All of these advances will require changes to legal and regulatory frameworks that will enable new workflows that are different from those familiar to today's providers.

Novel inhaled pulmonary vasodilators in adult cardiac surgery: a scoping review.

PURPOSE: Pulmonary hypertension (PH) is a common cause of postoperative mortality in cardiac surgery that is commonly treated with conventional inhaled therapies, specifically nitric oxide and prostacyclin. Alternative therapies include inhaled milrinone and levosimendan, which are receiving more research interest and are increasing in clinical use as they may cut costs while allowing for easier administration. We sought to conduct a scoping review to appraise the evidence base for the use of these two novel inhaled vasodilators as an intervention for PH in cardiac surgery. SOURCE: We searched Embase and MEDLINE for relevant articles from 1947 to 2022. PRINCIPAL FINDINGS: We identified 17 studies including 969 patients. The included studies show that inhaled milrinone and levosimendan are selective pulmonary vasodilators with potential benefits ranging from ease of weaning from cardiopulmonary bypass to reduction in ventricular dysfunction. Nevertheless, high-quality data are limited, and study design and comparators are extremely heterogeneous, limiting the potential validity and generalizability of findings. CONCLUSION: The findings of this scoping review suggest that milrinone and levosimendan may be effective alternatives to current inhaled therapies for cardiac dysfunction in the setting of PH. Nevertheless, randomized trials have focused on specific agents and consistent outcome measures are needed to better validate the early-stage promise of these agents. STUDY REGISTRATION: Open Science Framework ( https://osf.io/z3k6f/ ); first posted 21 July 2022.

RéSUMé: OBJECTIF: L'hypertension pulmonaire (HTP) est une cause fréquente de mortalité postopératoire en chirurgie cardiaque généralement traitée par des thérapies inhalées conventionnelles, en particulier le monoxyde d'azote et la prostacycline. Les thérapies alternatives comprennent la milrinone et le lévosimendan inhalés, qui suscitent de plus en plus d'intérêt dans la recherche et sont de plus en plus utilisés en clinique car ils peuvent réduire les coûts tout en permettant une administration plus facile. Nous avons cherché à réaliser une étude de portée afin d'évaluer la base de données probantes concernant l'utilisation de ces deux nouveaux vasodilatateurs inhalés comme intervention pour l'HTP en chirurgie cardiaque. SOURCES: Nous avons cherché des articles pertinents dans Embase et MEDLINE de 1947 à 2022. CONSTATATIONS PRINCIPALES: Nous avons identifié 17 études incluant 969 patient·es. Les études incluses montrent que la milrinone et le lévosimendan inhalés sont des vasodilatateurs pulmonaires sélectifs possédant des avantages potentiels allant de la facilité de sevrage de la circulation extracorporelle à la réduction de la dysfonction ventriculaire. Néanmoins, les données de haute qualité sont limitées, et la conception des études et les comparateurs sont extrêmement hétérogènes, ce qui limite la validité potentielle et la généralisabilité des résultats. CONCLUSION: Les résultats de cette étude de portée suggèrent que la milrinone et le lévosimendan pourraient être des solutions de rechange efficaces aux traitements inhalés actuels pour le dysfonctionnement cardiaque dans un contexte d'HTP. Néanmoins, les études randomisées se sont concentrées sur des agents spécifiques et des mesures cohérentes des résultats sont nécessaires pour mieux valider les promesses de ces agents à un stade précoce. ENREGISTREMENT DE L'éTUDE: Open Science Framework ( https://osf.io/z3k6f/ ); première publication le 21 juillet 2022.

Prediction, prevention, and treatment of post reperfusion syndrome in adult orthotopic liver transplant patients.

IMPORTANCE: This review explores proposed predictors, preventative measures, and treatment options for post-reperfusion syndrome (PRS) in liver transplantation and provides updated data for clinicians. OBJECTIVES: The review aims to understand the status and progress made regarding PRS during orthotopic liver transplantation. Moreover, the predictors of PRS will be analyzed to highlight risk factors. Mediators of PRS and the modes of action of the currently available preventative and management agents that target particular PRS factors will be investigated. DATA SOURCES: Data is drawn from secondary sources from databases of peer-reviewed journals. The bibliographies of select sources were also used to obtain additional data studies using the 'snowball' method. STUDY SELECTION: The initial data search provided 1394 studies analyzed using PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. After applying the eligibility criteria, 18 studies were fit for inclusion. RESULTS: The study identified that in addition to the severity of underlying medical conditions, other significant PRS predictors included patient age, sex, duration of cold ischemia, and the surgical technique. While the use of epinephrine and norepinephrine is well-established, further preventative measures commonly involve specifically targeting known mediators of the syndrome, such as antioxidants, vasodilators, free radical scavengers, and anticoagulants. Current management strategies involve supportive therapy. Machine Perfusion may ultimately decrease the risk of PRS. CONCLUSION: PRS still holds unknowns, including the underlying pathophysiology, controllable factors, and ideal management practices. There is a need for further study, particularly prospective trials since liver transplantation is the gold standard for treating end-stage liver disease and the incidence of PRS remains high.

Influence of semaglutide use on the presence of residual gastric solids on gastric ultrasound: a prospective observational study in volunteers without obesity recently started on semaglutide.

PURPOSE: Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) have become increasingly popular as both diabetic and weight loss therapies. One effect of this class of medication is delayed gastric emptying, which may impact the risk of aspiration during anesthesia delivery. METHODS: In this prospective study, we used gastric ultrasound to evaluate the presence of solid gastric contents in both supine and lateral positions after an eight-hour fast in those taking GLP-1RA compared with controls. Participants underwent a second ultrasound evaluation two hours later after drinking 12 fluid ounces of water (approximately 350 mL). RESULTS: Twenty adults voluntarily enrolled, giving a total of ten participants in each group. In the supine position, 70% of semaglutide participants and 10% of control participants had solids present on gastric ultrasound (risk ratio [RR], 3.50; 95% confidence interval [CI], 1.26 to 9.65; P = 0.02.) In the lateral position, 90% of semaglutide participants and 20% of control participants had solids identified on gastric ultrasound (RR, 7.36; 95% CI, 1.13 to 47.7; P = 0.005). Two hours after drinking clear liquids, the two groups did not differ in the lateral position, but in the supine position, 90% of control group participants were rated as empty compared with only 30% of semaglutide group participants (P = 0.02). CONCLUSIONS: This study provides preliminary evidence that GLP-1RAs may affect gastric emptying and residual gastric contents following an overnight fast and two hours after clear liquids, which may have implications for aspiration risk during anesthetic care.

RéSUMé: OBJECTIF: Les agonistes des récepteurs du peptide-1 de type glucagon (GLP-1) (AR-GLP-1) sont de plus en plus populaires comme traitements du diabète et pour la perte de poids. L'un des effets de cette classe de médicaments est le retard de la vidange gastrique, ce qui peut avoir un impact sur le risque d'aspiration pendant l'administration de l'anesthésie. MéTHODE: Dans cette étude prospective, nous avons utilisé l'échographie gastrique pour évaluer la présence de contenu gastrique solide en décubitus dorsal et latéral après un jeûne de huit heures chez les personnes prenant des AR-GLP-1 par rapport à un groupe témoin. Les participant·es ont passé une deuxième échographie deux heures plus tard, après avoir bu 12 onces liquides d'eau (environ 350 mL). RéSULTATS: Vingt personnes adultes se sont inscrites volontairement, soit un total de dix participant·es dans chaque groupe. En décubitus dorsal, 70 % des personnes du groupe sémaglutide et 10 % des personnes du groupe témoin présentaient des solides à l'échographie gastrique (risque relatif [RR], 3,50; intervalle de confiance [IC] à 95 %, 1,26 à 9,65; P = 0,02). En décubitus latéral, 90 % des personnes du groupe sémaglutide et 20 % des personnes du groupe témoin présentaient des solides à l'échographie gastrique (RR, 7,36; IC 95 %, 1,13 à 47,7; P = 0,005). Deux heures après avoir bu des liquides clairs, le contenu gastrique évalué ne différait pas entre les deux groupes en position latérale, mais en décubitus dorsal, l'estomac de 90 % des participant·es du groupe témoin a été jugé vide, comparativement à seulement 30 % chez les participant·es du groupe sémaglutide (P = 0,02). CONCLUSION: Cette étude procure des données préliminaires selon lesquelles les AR-GLP-1 pourraient affecter la vidange gastrique et le contenu gastrique résiduel après un jeûne d'une nuit et deux heures après l'ingestion de liquides clairs, ce qui pourrait avoir des implications quant au risque d'aspiration pendant les soins anesthésiques.

Intraoperative intracardiac thrombus in liver transplantation: A 9-year retrospective review focusing on treatment and outcomes.

This study characterizes incidence and outcomes surrounding intracardiac thrombosis (ICT) during liver transplantation over 9 years at a single center before and after the routine use of transesophageal echocardiography (TEE). Adult liver transplantation patients from 2011 to 2020 were divided into eras based on routine TEE use. ICTs were identified by querying anesthetic records for search terms. Descriptive statistics included counts and proportions for baseline recipient, donor, intraoperative, and postoperative characteristics. Outcome data were based on date of hospital discharge and date of death. The incidence of ICT increased in the TEE era (2016-2020) compared with the pre-TEE era (2011-2015; 3.7% [25/685] vs. 1.9% [9/491]; p < 0.001). Patients with ICT had significantly higher Model for End-Stage Liver Disease-sodium (MELD-Na) scores, pretransplant hospitalization, malignancy, drug-induced liver injury, hypertension, deep vein thrombosis, reperfusion syndrome, transfused platelets and cryoprecipitate, and use of hemostatic medications. A higher proportion of patients in the ICT group underwent simultaneous liver-kidney transplantation. The patients with ICT were similar, except patients in the pre-TEE era had higher MELD-Na scores and incidences of hepatitis C virus and lower incidences of encephalopathy. In the pre-TEE era, all ICTs presented as intraoperative cardiac arrest, and the 30-day mortality in the setting of ICT was 66.7% (6/9). During the TEE era, 80% of ICTs were diagnosed incidentally or attributed to hemodynamic instability (p = 0.002). The 30-day mortality rate was 36% (9/25) in the TEE era (p = 0.25). ICT incidence increased in the TEE era, yet the mortality rate was lower, suggesting that routine intraoperative TEE may lead to the early detection of ICT prior to hemodynamic collapse.

Self-reported Race/Ethnicity and Intraoperative Occult Hypoxemia: A Retrospective Cohort Study.

BACKGROUND: Pulse oximetry is ubiquitous in anesthesia and is generally a reliable noninvasive measure of arterial oxygen saturation. Concerns regarding the impact of skin pigmentation and race/ethnicity on the accuracy of pulse oximeter accuracy exist. The authors hypothesized a greater prevalence of occult hypoxemia (arterial oxygen saturation [Sao2] less than 88% despite oxygen saturation measured by pulse oximetry [Spo2] greater than 92%) in patients undergoing anesthesia who self-reported a race/ethnicity other than White. METHODS: Demographic and physiologic data, including self-reported race/ethnicity, were extracted from a departmental data warehouse for patients receiving an anesthetic that included at least one arterial blood gas between January 2008 and December 2019. Calculated Sao2 values were paired with concurrent Spo2 values for each patient. Analysis to determine whether Black, Hispanic, Asian, or Other race/ethnicities were associated with occult hypoxemia relative to White race/ethnicity within the Spo2 range of 92 to 100% was completed. RESULTS: In total, 151,070 paired Sao2-Spo2 readings (70,722 White; 16,011 Black; 21,223 Hispanic; 8,121 Asian; 34,993 Other) from 46,253 unique patients were analyzed. The prevalence of occult hypoxemia was significantly higher in Black (339 of 16,011 [2.1%]) and Hispanic (383 of 21,223 [1.8%]) versus White (791 of 70,722 [1.1%]) paired Sao2-Spo2 readings (P < 0.001 for both). In the multivariable analysis, Black (odds ratio, 1.44 [95% CI, 1.11 to 1.87]; P = 0.006) and Hispanic (odds ratio, 1.31 [95% CI, 1.03 to 1.68]; P = 0.031) race/ethnicity were associated with occult hypoxemia. Asian and Other race/ethnicity were not associated with occult hypoxemia. CONCLUSIONS: Self-reported Black and Hispanic race/ethnicity are associated with a greater prevalence of intraoperative occult hypoxemia in the Spo2 range of 92 to 100% when compared with self-reported White race/ethnicity.

Research priorities in liver transplant anesthesiology: Results of a survey of liver transplant anesthesiologists.

Optimal perioperative care contributes to improved patient outcomes, as demonstrated in the field of liver transplant (LT). The evolution in perioperative care over the past two decades has been driven by research in areas such as preoperative testing, coagulation management, and intraoperative monitoring. However, much of this research is driven by local institutional pressures and practices with a dearth of studies emanating from research consortia or other groups of experts within the field. To better characterize the top research questions in the field, we queried a group of 128 LT anesthesiologists representing 87 international liver transplant centers with a response from 71 practitioners (59.2%). Three experts then codified the responses into the top 20 questions, which were sent to the survey recipients as a second survey to rank order. Seventy-five respondents (61.5%) provided responses, which were merged into a weighted ranked priority list and analyzed by respondent location and center size. The highest ranked question was, "What intraoperative anesthetic management/interventions affect graft outcome?" Most of the top research questions focused on preoperative risk factor management or optimization and intraoperative management techniques. In general, this priorities list may serve as a guide for transplant anesthesiology researchers to focus future research endeavors on shared interests that improve patient care.

Postreperfusion syndrome in liver transplantation: Outcomes, predictors, and application for recipient selection.

BACKGROUND: This study aimed to identify risk factors for postreperfusion syndrome (PRS) and its impact on LT outcomes. METHODS: Data analysis was performed in 1021 adult patients undergoing donation after brain death (DBD) LT to identify PRS incidence, the risk factors for PRS development, and its impact on LT outcomes. RESULTS: The overall incidence of PRS was 16.1%. Independent risk factors for PRS included donor age (odds ratio (OR) 1.01, P = .02), donor body mass index (BMI) (OR 1.04, P = .003), moderate macrosteatosis (OR 2.48, P = .02), and cold ischemia time (CIT) (OR 1.06, P = .02). On multivariable analysis for 30-day graft failure, PRS (hazard ratio (HR) 3.49; P < .001) and Model for End-stage Liver Disease (MELD) score (HR 1.01; P = .05) were independent risk factors. Patients were categorized into four distinct groups based on PRS risk groups and MELD groups, which showed different 1-year graft survival (P < .001). There were comparable outcomes between low PRS risk - high MELD and high PRS risk - low MELD group (P = .33). CONCLUSIONS: Donor age, donor BMI, moderate macrosteatosis, and CIT were identified as risk factors for the development of PRS in LT using DBD grafts. PRS risk evaluation may improve donor-to-recipient matching based on their MELD scores.

The Optimal Cell Salvage Settings to Maximize Hematocrit and Minimize Potassium Using the Cobe BRAT2 Autologous Blood Recovery Unit.

OBJECTIVE: The objective was to determine the optimal cell saver device settings (infusion rate and wash rate) at which hematocrit is preserved and potassium and lactate are removed from banked red blood cells (RBC). DESIGN: Red cells were washed using the Cobe BRAT 2 Autologous Blood Recovery Unit and sampled for electrolyte composition and hematocrit pre- and postwash. SETTING: This was a single-center study. INTERVENTIONS: Red cells were washed using six infusion rates (100-1,000 mL/min) and six wash rates (100-1,000 mL/min) for a total of 36 combinations. Hematocrit, potassium, glucose, and lactate were evaluated before and after washing. MEASUREMENTS AND MAIN RESULTS: At wash rates ≤400 mL/min, hematocrit increased independent of infusion rate. At wash rates ≥400 mL/min, slower infusion rates were associated with higher hematocrit compared to faster infusion rates (p < 0.0001 for a wash rate 400-800 mL/min, p < 0.0005 for a wash rate 1,000 mL/min). Maximal wash speeds were associated with decreasing hematocrit. Infusion and wash rate were both independent predictors of potassium change; slower rates were associated with a larger decrease in potassium. Glucose decreased proportionally as infusion and wash rate decreased. Lactate did not show an association with either infusion or wash rate. CONCLUSION: Red-cell washing produces higher hematocrit and lower potassium as infusion rate and wash rate decrease. A 340-mL unit of RBC can be processed in 4.26 minutes without loss of hematocrit or an increase in potassium when both infusion and wash rates are set to 400 mL/min.

Multi-domain analysis of non-surgical risk factors amenable to pre-operative optimization in microvascular head and neck surgery.

PURPOSE: The goal of this study was to conduct a multi-domain, organ system-based analysis of non-surgical comorbidities amenable to pre-operative optimization in patients undergoing free tissue transfer, in order to better understand factors that influence patient outcomes. STUDY DESIGN: Retrospective review. SETTINGS: Tertiary academic center. MATERIALS AND METHODS: A retrospective analysis of 546 patients in a prospectively maintained database who underwent free tissue transfer reconstruction between 2007 and 2016 was performed. Analysis of the relationship between binary-coded system-based domains and log-transformed length of stay (LOS), rehabilitation requirement, 30-day readmission, and post-operative complications was conducted with multiple linear regression or logistic regression models. RESULTS: Poor nutritional status and the presence of anxiety/depression independently increased median hospital LOS. Endocrine and metabolic deficits, poor nutrition status, and psychiatric comorbidities were significant predictors for rehabilitation facility requirement upon discharge. CONCLUSION: Interventions targeted to patient psychiatric and nutritional health may yield substantially improved outcomes in the head and neck cancer population receiving free tissue transfer surgery.

Single-stage long-segment tracheal transplantation.

Tracheal transplantation has been envisioned as a viable option for reconstruction of long-segment tracheal defects. We report the first human single-stage long-segment tracheal transplantation. Narrow-band imaging and bronchoscopic biopsies demonstrate allograft vascularization and viable epithelial lining. The recipient was immunosuppressed with Tacrolimus, Mycophenolate mofetil, and corticosteroids. Six months after transplantation, the trachea is both functional and the patient is breathing without the need of a tracheostomy or stent.

Orthotopic liver transplant in the pregnant recipient: A systematic review of preoperative management and maternal and fetal outcomes.

Severe liver dysfunction requiring transplantation is a major event at any stage of life, but for those requiring liver transplantation while pregnant, two lives hang in the balance. Available evidence on this relatively rare event consists solely of case reports and have yet to be reviewed or synthesized. We performed a systematic literature review and analyzed reports of 22 patients who underwent liver transplantation during pregnancy. This review describes the reported etiologies of hepatic failure in pregnant patients requiring transplantation, perioperative anesthetic management techniques, and the maternal and fetal clinical outcomes.

A protocol for the management of hyponatremia peri-liver transplant reduces post-transplant neurological complications.

Rapid changes in serum sodium (ΔSNa) peri-liver transplant (LT) predispose to post-LT neurological complications (NC). We aimed to assess whether implementation of a protocol directed at limiting peri-LT ΔSNa reduced post-LT NC. A retrospective single-center review of adult LT recipients from 1/2016 to 10/2017 was performed. Patients with hyponatremia (SNa < 135 mEq/L) within 7 days of LT were analyzed in two eras: pre-protocol (1/2016-9/2016) and post-protocol (10/2016-10/2017). The primary outcome was the development of NC within 1 month of LT. Perioperative ΔSNa (ΔSNaPost-LT) was assessed as a secondary outcome. Among 85 and 107 patients who underwent LT pre- and post-protocol, 39 (46%) and 42 (39%) were hyponatremic within 7 days of LT, respectively. Significantly fewer patients in the post-protocol era developed NC vs. pre-protocol (7.1% vs. 25.6%, p = .02). Additionally, fewer LT recipients in the post-protocol era developed ΔSNaPost-LT ≥ 10 mEq/L (9.5% vs. 30.7%, p = .02). Intraoperatively, more patients post-protocol received hypotonic saline (33.3% vs. 2.6%, p < .01). Multivariable logistic regression revealed that transplantation in the post-protocol era was associated with significantly reduced odds (odds ratio 0.11, 95% confidence interval 0.01-0.50) of developing NC. In conclusion, the implementation of a multidisciplinary protocol aimed at reducing ΔSNa peri-LT was independently associated with a reduction in post-LT NC.

Intraoperative Cardiac Arrest During Adult Liver Transplantation: Incidence and Risk Factor Analysis From 7 Academic Centers in the United States.

BACKGROUND: Intraoperative cardiac arrest (ICA) has a reported frequency of 1 in 10,000 anesthetics but has a much higher estimated incidence in orthotopic liver transplantation (OLT). Single-center studies of ICA in OLT are limited by small sample size that prohibits multivariable regression analysis of risks. METHODS: Utilizing data from 7 academic medical centers, we performed a retrospective, observational study of 5296 adult liver transplant recipients (18-80 years old) between 2000 and 2017 to identify the rate of ICA, associated risk factors, and outcomes. RESULTS: ICA occurred in 196 cases (3.7% 95% confidence interval [CI], 3.2-4.2) and mortality occurred in 62 patients (1.2%). The intraoperative mortality rate was 31.6% in patients who experienced ICA. In a multivariable generalized linear mixed model, ICA was associated with body mass index (BMI) <20 (odds ratio [OR]: 2.04, 95% CI, 1.05-3.98; P = .0386), BMI ≥40 (2.16 [1.12-4.19]; P = .022), Model for End-Stage Liver Disease (MELD) score: (MELD 30-39: 1.75 [1.09-2.79], P = .02; MELD ≥40: 2.73 [1.53-4.85], P = .001), postreperfusion syndrome (PRS) (3.83 [2.75-5.34], P < .001), living donors (2.13 [1.16-3.89], P = .014), and reoperation (1.87 [1.13-3.11], P = .015). Overall 30-day and 1-year mortality were 4.18% and 11.0%, respectively. After ICA, 30-day and 1-year mortality were 43.9% and 52%, respectively, compared to 2.6% and 9.3% without ICA. CONCLUSIONS: We established a 3.7% incidence of ICA and a 1.2% incidence of intraoperative mortality in liver transplantation and confirmed previously identified risk factors for ICA including BMI, MELD score, PRS, and reoperation and identified new risk factors including living donor and length of surgery in this multicenter retrospective cohort. ICA, while rare, is associated with high intraoperative mortality, and future research must focus on therapy to reduce the incidence of ICA.

Analysis of urgent/emergent conversions from monitored anesthesia care to general anesthesia with airway instrumentation.

BACKGROUND: Monitored Anesthesia Care (MAC) is an anesthetic service involving the titration of sedatives/analgesics to achieve varying levels of sedation while avoiding general anesthesia (GA) and airway instrumentation. The goal of our study was to determine the overall incidence of conversion from MAC to general anesthesia with airway instrumentation and elucidate reasons and risk factors for conversion. METHODS: In this retrospective observational study, all non-obstetric adult patients who received MAC from July 2002 to July 2015 at Mount Sinai Hospital were electronically screened for inclusion via a clinical database. Patient, procedure, anesthetic, and practitioner data were all collected and analyzed to generate descriptive analyses. Subsequent univariate and multivariate analyses were used to identify specific risk factors associated with conversion to GA. RESULTS: Overall, 0.50% (1097/219,061) of MAC cases were converted to GA. Approximately half of conversions were due to the patient's "intolerance" of MAC (with or without failed regional anesthesia), while the other half were due to physiologic derangements. Body mass index, male sex, American Society of Anesthesiologists Physical Status Classification, anesthesia team composition, and surgical specialty were all associated with risk of conversion to GA. CONCLUSIONS: This is one of the first and largest retrospective studies aimed at identifying reasons and risk factors associated with the conversion of MAC to GA. These findings may be used to help better anticipate or prevent these events.

Reliability of simulation-based assessment for practicing physicians: performance is context-specific.

INTRODUCTION: Even physicians who routinely work in complex, dynamic practices may be unprepared to optimally manage challenging critical events. High-fidelity simulation can realistically mimic critical clinically relevant events, however the reliability and validity of simulation-based assessment scores for practicing physicians has not been established. METHODS: Standardised complex simulation scenarios were developed and administered to board-certified, practicing anesthesiologists who volunteered to participate in an assessment study during formative maintenance of certification activities. A subset of the study population agreed to participate as the primary responder in a second scenario for this study. The physicians were assessed independently by trained raters on both teamwork/behavioural and technical performance measures. Analysis using Generalisability and Decision studies were completed for the two scenarios with two raters. RESULTS: The behavioural score was not more reliable than the technical score. With two raters > 20 scenarios would be required to achieve a reliability estimate of 0.7. Increasing the number of raters for a given scenario would have little effect on reliability. CONCLUSIONS: The performance of practicing physicians on simulated critical events may be highly context-specific. Realistic simulation-based assessment for practicing physicians is resource-intensive and may be best-suited for individualized formative feedback. More importantly, aggregate data from a population of participants may have an even higher impact if used to identify skill or knowledge gaps to be addressed by training programs and inform continuing education improvements across the profession.

Olanzapine for the Prevention of Postdischarge Nausea and Vomiting after Ambulatory Surgery: A Randomized Controlled Trial.

BACKGROUND: Postdischarge nausea and vomiting after ambulatory surgery is a common problem that is not adequately addressed in current practice. This prospective, randomized, double-blind, parallel-group, placebo-controlled study was designed to test the hypothesis that oral olanzapine is superior to placebo at preventing postdischarge nausea and vomiting. METHODS: In a single-center, double-blind, randomized, placebo-controlled trial, the authors compared a single preoperative dose of olanzapine 10 mg to placebo, in adult female patients 50 years old or less, undergoing ambulatory gynecologic or plastic surgery with general anesthesia. All patients received standard antiemetic prophylaxis with dexamethasone and ondansetron. The primary composite outcome was nausea and/or vomiting in the 24 h after discharge. Secondary outcomes included severe nausea, vomiting, and side effects. RESULTS: A total of 140 patients were randomized and evaluable. The primary outcome occurred in 26 of 69 patients (38%) in the placebo group and in 10 of 71 patients (14%) in the olanzapine group (relative risk, 0.37; 95% CI, 0.20 to 0.72; P = 0.003). Severe nausea occurred in 14 patients (20%) in the placebo group and 4 patients (6%) in the olanzapine group (relative risk, 0.28; 95% CI, 0.10 to 0.80). Vomiting occurred in eight patients (12%) in the placebo group and two patients (3%) in the olanzapine group (relative risk, 0.24; 95% CI, 0.05 to 1.10). The median score for sedation (scale 0 to 10, with 10 being highest) in the 24 h after discharge was 4 (interquartile range, 2 to 7) in the placebo group and 6 (interquartile range, 3 to 8) in the olanzapine group (P = 0.023). CONCLUSIONS: When combined with ondansetron and dexamethasone, the addition of olanzapine relative to placebo decreased the risk of nausea and/or vomiting in the 24 hafter discharge from ambulatory surgery by about 60% with a slight increase in reported sedation.

Efficiency of microvascular free flap reconstructive surgery: An observational study.

OBJECTIVE: We aimed to assess operative workflow and efficiency in microvascular free flaps via a direct observational study based on Lean principles of quality improvement (QI). METHODS: Observers monitored the workflow of twenty-three free flaps. Pre-operative preparation and surgical duration was recorded with supplemental data provided from our institution's surgical tracking database. Traffic patterns of operating room (OR) staff were documented as "entries" and "exits" from the OR and classified by role and the reason that the entry or exit was required. Patient data was obtained via chart review. RESULTS: The mean surgical time was 9.0 h. Approximately 20% of OR time was dedicated to the pre-incision process, averaging 1.6 h per case. One third of entries and exits occurred during this period. In total, 180.2 surgical hours were observed during which 6215 "entries" and "exits" occurred. The mean number of entries and exits per case was 270; the most common reasons were supplies and communication. No association was observed between elapsed surgical time or total number of entries and exits with post-operative infection rates. CONCLUSION: Comprehensive observational workflow studies of free flaps are challenging to execute due to lengthy procedure times. At our high-volume institution, a significant portion of OR time is devoted to the pre-incision period, largely due to inadequate supply availability and pre-operative communication. These findings will serve as a foundation for QI interventions at our institution, while our observational model provides a broadly applicable framework for assessing surgical efficiency.