Association of Intravenous Neostigmine and Anticholinergics or Sugammadex with Postoperative Delirium: A Retrospective Cohort Study.

BACKGROUND: Administration of cholinesterase inhibitors in combination with anticholinergic drugs for reversal of neuromuscular blocks may precipitate delirium through impairment of central cholinergic transmission, which could be avoided by using sugammadex. Therefore, we tested the primary hypothesis that postoperative delirium is less common when neuromuscular block is reversed with sugammadex than with neostigmine combined with glycopyrrolate or atropine. METHODS: We conducted a single-center retrospective cohort study, analyzing all adult patients having general anesthesia for noncardiac surgery who received neostigmine or sugammadex from January 2016 to March 2022. Inverse propensity score weighting and propensity score calibration were used to adjust for appropriate confounders. Our primary outcome was presence of delirium within the first 4 days after surgery, defined as at least 1 positive brief Confusion Assessment Method (bCAM) screening. The secondary outcome was the presence of early delirium within 24 hours of surgery. RESULTS: Among 49,468 cases in our analysis, 6881 received sugammadex and 42,587 received neostigmine. After propensity weighting, the incidence of delirium was 1.09% in the sugammadex group and 0.82% in the neostigmine group. The odds of postoperative delirium did not differ between the sugammadex and neostigmine groups, with an estimated odds ratio (95% confidence interval) of 1.33 (0.91-1.95), P = .147. A sensitivity analysis restricted to only include cases with at least 6 bCAM measurements over postoperative day (POD) 1 to 4 had consistent results, as sugammadex compared with neostigmine was associated with an estimated odds ratio for postoperative delirium of 1.20 (0.82-1.77), P = .346. Sugammadex was significantly associated with an increased incidence of early postoperative delirium, with an estimated odds ratio of 1.71 (1.07-2.72), P = .025. Further analysis showed no treatment-by-age interaction for either postoperative delirium (P = .637) or postoperative early delirium (P = .904). CONCLUSIONS: Compared to neostigmine, use of sugammadex for reversal of neuromuscular block was not associated with an increased risk of postoperative delirium in this retrospective single-center study. Though sugammadex was associated with a statistically significant increased risk of postoperative early delirium, the difference was small and not clinically relevant, and may reflect the presence of unknown confounders.

Metformin Use in Type 2 Diabetics and Delirium After Noncardiac Surgery: A Retrospective Cohort Analysis.

INTRODUCTION: The cause of postoperative delirium is unknown, but it is thought to result at least in part from inflammation. Metformin, besides its hypoglycemic properties, demonstrates anti-inflammatory effects systemically and in the brain. We tested the primary hypothesis that chronic metformin use in adults with type 2 diabetes is associated with less delirium during the first 5 days after major noncardiac surgery. Secondary outcomes were a composite of serious complications (myocardial infarction, cardiac arrest, stage 2-3 acute kidney injury [AKI], and mortality) and time to discharge alive. METHODS: We considered adults with type 2 diabetes who did or did not routinely use metformin daily and had noncardiac surgery. Delirium was assessed by Confusion Assessment Method for Intensive Care Unit (CAM-ICU) or brief Confusion Assessment Method (bCAM) for 5 postoperative days. Postoperative AKI was defined by Kidney Disease Improving Global Guidelines. Logistic regression and generalized estimating equation models accounted for within-patient correlation across multiple surgeries and explored the association between metformin use and postoperative delirium and complications. Inverse propensity score weighting and propensity score calibration (PSC) adjusted for confounding variables. RESULTS: No significant difference was observed in the incidence of postoperative delirium between the 2 groups, with 260 of 4744 cases (5.5%) among metformin users and 502 of 5918 cases (8.5%) cases in nonmetformin users, for an odds ratio of 0.88 (95% confidence interval [CI], 0.73-1.05; P = .155), number-needed-to-expose = 118 patients. Similarly, there were fewer composite complications in metformin users (3.3%) than in nonusers (11.7%); However, the common-effect odds ratio of 0.67 was not statistically significant (97.5% CI, 0.39-1.17; P = .106). Discharge from the hospital was significantly faster in patients who took metformin (3 [interquartile range, IQR, 1-5] days for metformin users and 3 [IQR, 2-6] days for nonmetformin users), with a hazard ratio of 1.07 for early discharge, and tight CIs (1.01-1.13). CONCLUSIONS: Chronic metformin use was associated with slightly and nonsignificantly less delirium. However, patients who used metformin had clinically meaningfully fewer major complications, mostly stage 2 to 3 kidney injury. While not statistically significant, the reduction was substantial and warrants further investigation because there is currently no effective preventive measure for perioperative renal injury. Benefit would be especially meaningful if it could be produced by acute perioperative treatment. Finally, metformin was associated with faster hospital discharge, although not by a clinically meaningful amount.

Development and validation of delirium prediction models for noncardiac surgery patients.

STUDY OBJECTIVE: Postoperative delirium is associated with morbidity and mortality, and its incidence varies widely. Using known predisposing and precipitating factors, we sought to develop postoperative delirium prediction models for noncardiac surgical patients. DESIGN: Retrospective prediction model study. SETTING: Major quaternary medical center. PATIENTS: Our January 2016 to June 2020 training dataset included 51,677 patients of whom 2795 patients had delirium. Our July 2020 to January 2022 validation dataset included 14,438 patients of whom 912 patients had delirium. INTERVENTIONS: None. MEASUREMENTS: We trained and validated two static prediction models and one dynamic delirium prediction model. For the static models, we used random survival forests and traditional Cox proportional hazard models to predict postoperative delirium from preoperative variables, or from a combination of preoperative and intraoperative variables. We also used landmark modeling to dynamically predict postoperative delirium using preoperative, intraoperative, and postoperative variables before onset of delirium. MAIN RESULTS: In the validation analyses, the static random forest model had a c-statistic of 0.81 (95% CI: 0.79, 0.82) and a Brier score of 0.04 with preoperative variables only, and a c-statistic of 0.86 (95% CI: 0.84, 0.87) and a Brier score of 0.04 when preoperative and intraoperative variables were combined. The corresponding Cox models had similar discrimination metrics with slightly better calibration. The dynamic model - using all available data, i.e., preoperative, intraoperative and postoperative data - had an overall c-index of 0.84 (95% CI: 0.83, 0.85). CONCLUSIONS: Using preoperative and intraoperative variables, simple static models performed as well as a dynamic delirium prediction model that also included postoperative variables. Baseline predisposing factors thus appear to contribute far more to delirium after noncardiac surgery than intraoperative or postoperative variables. Improved postoperative data capture may help improve delirium prediction and should be evaluated in future studies.

Anesthetic management in patients having catheter-based thrombectomy for acute pulmonary embolism: A narrative review.

Pulmonary embolism is the third leading cause of cardiovascular death. Novel percutaneous catheter-based thrombectomy techniques are rapidly becoming popular in high-risk pulmonary embolism - especially in the presence of contraindications to thrombolysis. The interventional nature of these procedures and the risk of sudden cardiorespiratory compromise requires the presence of an anesthesiologist. Facilitating catheter-based thrombectomy can be challenging since qualifying patients are often critically ill. The purpose of this narrative review is to provide guidance to anesthesiologists for the assessment and management of patients having catheter-based thrombectomy for acute pulmonary embolism. First, available techniques for catheter-based thrombectomy are reviewed. Then, we discuss definitions and application of common risk stratification tools for pulmonary embolism, and how to assess patients prior to the procedure. An adjudication of risks and benefits of anesthetic strategies for catheter-based thrombectomy follows. Specifically, we give guidance and rationale for use monitored anesthesia care and general anesthesia for these procedures. For both, we review strategies for assessing and mitigating hemodynamic perturbations and right ventricular dysfunction, ranging from basic monitoring to advanced inodilator therapy. Finally, considerations for management of right ventricular failure with mechanical circulatory support are discussed.

Generalizability of nociception level as a measure of intraoperative nociceptive stimulation: A retrospective analysis.

BACKGROUND: Nociception-guided intraoperative opioid administration might help reduce postoperative pain. A commonly used and validated nociception monitor system is nociception level (NOL), which provides the nociception index, ranging from 0 to 100, with 0 representing no nociception and 100 representing extreme nociception. We tested the hypothesis that NOL responses are similar in men and women given remifentanil and fentanyl, across various types of anesthesia, as a function of American Society of Anesthesiologists physical status designations, and over a range of ages and body morphologies. METHODS: We conducted a retrospective cohort analysis of trial data from eight prospective NOL validation studies. Among 522 noncardiac surgical patients enrolled in these studies, 447 were included in our analysis. We assessed NOL responses to various noxious and non-noxious stimuli. RESULTS: The average NOL in response to 315 noxious stimuli was 47 ± 15 (95% CI = 45-49). The average NOL in response to 361 non-noxious stimuli was 10 ± 12 (95% CI = 9-11). NOL responses were similar in men and women, in patients given remifentanil and fentanyl, across various types of anesthesia, as a function of American Society of Anesthesiologists physical status designations, and over a range of ages and body morphologies. CONCLUSION: Nociception level appears to provide accurate estimates of intraoperative nociception over a broad range of patients and anesthetic conditions.

Postoperative oxygenation assessed by SpO2/FiO2 ratio and respiratory complications after reversal of neuromuscular block with Sugammadex or neostigmine: A retrospective cohort study.

STUDY OBJECTIVE: Residual neuromuscular block may lead to postoperative muscle weakness, inadequate oxygenation, and other pulmonary complications. Sugammadex may provide more rapid and effective restoration of neuromuscular function than neostigmine. We therefore tested the primary hypothesis that noncardiac surgical patients given sugammadex oxygenate better during initial recovery than those given neostigmine. Secondarily, we tested the hypothesis that patients given sugammadex have fewer pulmonary complications during hospitalization. DESIGN: Retrospective cohort analysis. SETTING: Postoperative recovery area of a tertiary care hospital. PATIENTS: Adults who had non-cardiothoracic surgery and were given either neostigmine or sugammadex. INTERVENTIONS: None. MEASUREMENTS: The primary outcome was the lowest SpO2/FiO2 ratio in the post-anesthesia care unit. The secondary outcome was a composite of pulmonary complications. MAIN RESULTS: Among 71,457 cases, 10,708 (15%) were given sugammadex and 60,749 (85%) received neostigmine. After propensity weighting, the mean minimum SpO2/FiO2 ratio was 301 ± 77 (SD) in patients given sugammadex and 303 ± 71 in those given neostigmine, yielding an estimated difference in means of -3.5 (95% confidence interval: -5.3, -1.7; P = 0.0002). 4.4% of patients given sugammadex and 3.6% of patients given neostigmine had postoperative pulmonary complications (P = 0.0005, number-needed-to-be-exposed =136; 95% CI: 83, 330), with the main contributing components being new bronchospasm or exacerbation of obstructive pulmonary disease. CONCLUSIONS: Postoperative minimum SpO2/FiO2 ratio during PACU admission was similar after reversal of neuromuscular block by sugammadex and neostigmine. Reversal with sugammadex was associated with more pulmonary complications, but most were minor and of little consequence.

[Perioperative hyperoxia-More harmful than beneficial?] / Die perioperative Hyperoxie ­ mehr Schaden als Nutzen?

BACKGROUND: The ideal perioperative oxygen concentration is controversial and study results are inconsistent. OBJECTIVE: Current knowledge on the beneficial and adverse effects of perioperative hyperoxia. MATERIAL AND METHODS: Narrative review RESULTS: Perioperative hyperoxia is unlikely to increase the incidence of atelectasis, pulmonary or cardiovascular complications or mortality. Few and small potential beneficial effects, such as reduction of surgical wound infections or postoperative nausea and vomiting have been demonstrated. According to the current state of evidence, it is recommended to avoid perioperative hyperoxia and to aim for normoxia instead.

Perioperative strategies to reduce risk of myocardial injury after non-cardiac surgery (MINS): A narrative review.

Myocardial injury is a frequent complication of surgical patients after having non-cardiac surgery that is strongly associated with perioperative mortality. While intraoperative anesthesia-related deaths are exceedingly rare, about 1% of patients undergoing non-cardiac surgery die within the first 30 postoperative days. Given the number of surgeries performed annually, death following surgery is the second leading cause of death in the United States. Myocardial injury after non-cardiac surgery (MINS) is defined as an elevation in troponin concentrations within 30 days postoperatively. Although typically asymptomatic, patients with MINS suffer myocardial damage and have a 10% risk of death within 30 days after surgery and excess risks of mortality that persist during the first postoperative year. Many factors for the development of MINS are non-modifiable, such as preexistent coronary artery disease. Preventive measures, systematic approaches to surveillance and treatment standards are still lacking, however many factors are modifiable and should be considered in clinical practice: the importance of hemodynamic control, adequate oxygen supply, metabolic homeostasis, the use of perioperative medications such as statins, anti-thrombotic agents, beta-blockers, or anti-inflammatory agents, as well as some evidence regarding the choice of sedative and analgesic for anesthesia are discussed. Also, as age and complexity in comorbidities of the surgical patient population increase, there is an urgent need to identify patients at risk for MINS and develop prevention and treatment strategies. In this review, we provide an overview of current screening standards and promising preventive options in the perioperative setting and address knowledge gaps requiring further investigation.

Nociception Level Index-Guided Intraoperative Analgesia for Improved Postoperative Recovery: A Randomized Trial.

BACKGROUND: Nociception is the physiological response to nociceptive stimuli, normally experienced as pain. During general anesthesia, patients experience and respond to nociceptive stimuli by increasing blood pressure and heart rate if not controlled by preemptive analgesia. The PMD-200 system from Medasense (Ramat Gan, Israel) evaluates the balance between nociceptive stimuli and analgesia during general anesthesia and generates the nociception level (NOL) index from a single finger probe. NOL is a unitless index ranging from 0 to 100, with values exceeding 25 indicating that nociception exceeds analgesia. We aimed to demonstrate that titrating intraoperative opioid administration to keep NOL <25 optimizes intraoperative opioid dosing. Specifically, we tested the hypothesis that pain scores during the initial 60 minutes of recovery are lower in patients managed with NOL-guided fentanyl than in patients given fentanyl per clinical routine. METHODS: We conducted a randomized, single-center trial of patients having major abdominal open and laparoscopic surgeries. Patients were randomly assigned 1:1 to intraoperative NOL-guided fentanyl administration or fentanyl given per clinical routine. The primary outcome was pain score (0-10 verbal response scale) at 10-minute intervals during the initial 60 minutes of recovery. Our secondary outcome was a measure of adequate analgesia, defined as a pain score <5, assessed separately at each interval. RESULTS: With a planned maximum sample size of 144, the study was stopped for futility after enrolling 72 patients from November 2020 to October 2021. Thirty-five patients were assigned to NOL-guided analgesic dosing and 37 to routine care. Patients in the NOL group spent significantly less time with a NOL index >25 (median reduction [95% confidence interval {CI}] of 14 [4-25] minutes) were given nearly twice as much intraoperative fentanyl (median [quartiles] 500 [330, 780] vs 300 [200, 330] µg), and required about half as much morphine in the recovery period (3.3 [0, 8] vs 7.7 [0, 13] mg). However, in the primary outcome analysis, NOL did not reduce pain scores in the first 60 minutes after awakening, assessed in a linear mixed effects model with mean (standard error [SE]) of 4.12 (0.59) for NOL and 4.04 (0.58) for routine care, and estimated difference in means of 0.08 (-1.43, 1.58), P = .895. CONCLUSIONS: More intraoperative fentanyl was given in NOL-guided patients, but NOL guidance did not reduce initial postoperative pain scores.

Postoperative Risk of Transfusion After Reversal of Residual Neuromuscular Block With Sugammadex Versus Neostigmine: A Retrospective Cohort Study.

BACKGROUND: Sugammadex and neostigmine are routinely used to reverse residual neuromuscular blocks at the end of surgery. Sugammadex has been linked with prolongation of laboratory coagulation markers, but clinical relevance on postoperative blood loss and transfusions remains unclear. METHODS: In this retrospective, single-center, cohort study, we analyzed medical records of adult patients having noncardiac surgery who were given sugammadex or neostigmine from May 2016 to December 2020. Our primary outcome was the incidence of any postoperative transfusion of red blood cells, and/or fresh-frozen plasma, and/or platelets. Secondary outcomes were duration of hospitalization, need for resurgery, and postoperative intensive care unit (ICU) admission. After propensity score weighting, the odds ratio (OR) for postoperative transfusion was assessed in both groups (sugammadex versus neostigmine) using a generalized estimation equation to count within-subject correlation weighted by the inverse propensity score. RESULTS: Out of 39,325 eligible surgeries, 33,903 surgeries in 29,062 patients were included in the analysis; with 4581 patients receiving sugammadex and 29,322 patients receiving neostigmine. The raw incidence of postoperative transfusion was 7.40% in sugammadex and 7.45% in the neostigmine group. After weighting by propensity score, the incidence of postoperative transfusion was 8.01% in the sugammadex and 7.38% in the neostigmine group (OR, 1.11 [95% confidence interval [CI], 0.97-1.26; P = .118]). There was no difference in duration of hospitalization and need for resurgery, but odds of postoperative ICU admission were significantly higher for patients receiving sugammadex than those receiving neostigmine (OR, 1.33 [98.33% CI, 1.17-1.52; P < .0001]). Our a priori planned analysis of coagulation laboratory parameters could not be completed because of a high amount of missing laboratory data. CONCLUSIONS: There is no statistically significant nor clinically important difference in the risk of postoperative transfusion in patients receiving sugammadex or neostigmine.

The impact of direct oral anticoagulants on viscoelastic testing - A systematic review.

Background: In case of bleeding patients and in acute care, the assessment of residual direct oral anticoagulant (DOAC) activity is essential for evaluating the potential impact on hemostasis, especially when a timely decision on urgent surgery or intervention is required. Viscoelastic tests are crucial in a modern goal-directed coagulation management to assess patients' coagulation status. However, the role of viscoelastic test to detect and quantify residual DOAC plasma levels is controversially discussed. The aim of this review was to systematically summarize the evidence of viscoelastic tests for the assessment of residual DOAC activity. Method: PubMed, Embase, Scopus, and the Cochrane Library were searched for original articles investigating the effect of rivaroxaban, apixaban, edoxaban, or dabigatran plasma levels on different viscoelastic tests of the adult population from database inception to December 31, 2021. Results: We included 53 studies from which 31 assessed rivaroxaban, 22 apixaban, six edoxaban, and 29 dabigatran. The performance of viscoelastic tests varied across DOACs and assays. DOAC specific assays are more sensitive than unspecific assays. The plasma concentration of rivaroxaban and dabigatran correlates strongly with the ROTEM EXTEM, ClotPro RVV-test or ECA-test clotting time (CT) and TEG 6s anti-factor Xa (AFXa) or direct thrombin inhibitor (DTI) channel reaction time (R). Results of clotting time (CT) and reaction time (R) within the normal range do not reliable exclude relevant residual DOAC plasma levels limiting the clinical utility of viscoelastic assays in this context. Conclusion: Viscoelastic test assays can provide fast and essential point-of-care information regarding DOAC activity, especially DOAC specific assays. The identification and quantification of residual DOAC plasma concentration with DOAC unspecific viscoelastic assays are not sensitive enough, compared to recommended anti-Xa activity laboratory measurements. Systematic review registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=320629], identifier [CRD42022320629].

Predictors associated with mortality of extracorporeal life support therapy for acute heart failure: single-center experience with 679 patients.

Background: Extracorporeal life support (ECLS) therapy is increasingly used for cardiac and respiratory support postcardiotomy, refractory cardiogenic shock and cardiopulmonary resuscitation. This study aims to describe in-hospital mortality of patients requiring ECLS, identify independent predictors associated with mortality and analyze changes of mortality over time. Methods: This retrospective study includes all adult ECLS cases at the University Hospital Zurich, a designated ECLS center in Switzerland, in the period 2007 to 2019. Results: ECLS therapy was required in 679 patients (median age 60 years, 27.5% female). In-hospital mortality was 55.5%. Cubic spline interpolation did not detect evidence for a change in mortality over the whole period of 13 years. In-hospital mortality significantly varied between ECLS indications: 70.7% (152/215) for postcardiotomy, 67.9% (108/159) for cardiopulmonary resuscitation, 47.0% (110/234) for refractory cardiogenic shock, and 9.9% (7/71) for lung transplantation and expansive thoracic surgery (P<0.001). Logistic regression modelling showed excellent discrimination in the receiver operating characteristic (ROC) area under the curve (AUC) of 0.89 [95% confidence interval (CI): 0.87-0.92] and identified significant mortality predictors: age, simplified acute physiology score (SAPS) II, as well as new liver failure and each allogenic blood transfusion unit given per day. ECLS after cardiopulmonary resuscitation was associated with significantly higher mortality compared to ECLS for refractory cardiogenic shock. Conclusions: In-hospital mortality of patients treated with ECLS therapy is high. Outcomes have not changed significantly in the observed period. We identified age, SAPS II, new liver failure and each allogenic blood transfusion unit given per day as independent mortality predictors. Knowledge of predictors strongly associated with in-hospital mortality may affect future decisions about ECLS indications and the respective management to use this elaborate therapy more effectively.

The Interplay Between Postsynaptic Striatal D2/3 Receptor Availability, Adversity Exposure and Odd Beliefs: A [11C]-Raclopride PET Study.

BACKGROUND: Between unaffected mental health and diagnosable psychiatric disorders, there is a vast continuum of functioning. The hypothesized link between striatal dopamine signaling and psychosis has guided a prolific body of research. However, it has been understudied in the context of multiple interacting factors, subclinical phenotypes, and pre-postsynaptic dynamics. METHOD: This work investigated psychotic-like experiences and D2/3 dopamine postsynaptic receptor availability in the dorsal striatum, quantified by in vivo [11C]-raclopride positron emission tomography, in a sample of 24 healthy male individuals. Additional mediation and moderation effects with childhood trauma and key dopamine-regulating genes were examined. RESULTS: An inverse relationship between nondisplaceable binding potential and subclinical symptoms was identified. D2/3 receptor availability in the left putamen fully mediated the association between traumatic childhood experiences and odd beliefs, that is, inclinations to see meaning in randomness and unfounded interpretations. Moreover, the effect of early adversity was moderated by a DRD2 functional variant (rs1076560). The results link environmental and neurobiological influences in the striatum to the origination of psychosis spectrum symptomology, consistent with the social defeat and diathesis-stress models. CONCLUSIONS: Adversity exposure may affect the dopamine system as in association with biases in probabilistic reasoning, attributional style, and salience processing. The inverse relationship between D2/3 availability and symptomology may be explained by endogenous dopamine occupying the receptor, postsynaptic compensatory mechanisms, and/or altered receptor sensitivity. This may also reflect a cognitively stabilizing mechanism in non-help-seeking individuals. Future research should comprehensively characterize molecular parameters of dopamine neurotransmission along the psychosis spectrum and according to subtype profiling.

Physicians' Perceptions of a Situation Awareness-Oriented Visualization Technology for Viscoelastic Blood Coagulation Management (Visual Clot): Mixed Methods Study.

BACKGROUND: Viscoelastic tests enable a time-efficient analysis of coagulation properties. An important limitation of viscoelastic tests is the complicated presentation of their results in the form of abstract graphs with a multitude of numbers. We developed Visual Clot to simplify the interpretation of presented clotting information. This visualization technology applies user-centered design principles to create an animated model of a blood clot during the hemostatic cascade. In a previous simulation study, we found Visual Clot to double diagnostic accuracy, reduce time to decision making and perceived workload, and improve care providers' confidence. OBJECTIVE: This study aimed to investigate the opinions of physicians on Visual Clot technology. It further aimed to assess its strengths, limitations, and clinical applicability as a support tool for coagulation management. METHODS: This was a researcher-initiated, international, double-center, mixed qualitative-quantitative study that included the anesthesiologists and intensive care physicians who participated in the previous Visual Clot study. After the participants solved six coagulation scenarios using Visual Clot, we questioned them about the perceived pros and cons of this new tool. Employing qualitative research methods, we identified recurring answer patterns, and derived major topics and subthemes through inductive coding. Based on them, we defined six statements. The study participants later rated their agreement to these statements on five-point Likert scales in an online survey, which represented the quantitative part of this study. RESULTS: A total of 60 physicians participated in the primary Visual Clot study. Among these, 36 gave an interview and 42 completed the online survey. In total, eight different major topics were derived from the interview field note responses. The three most common topics were "positive design features" (29/36, 81%), "facilitates decision making" (17/36, 47%), and "quantification not made" (17/36, 47%). In the online survey, 93% (39/42) agreed to the statement that Visual Clot is intuitive and easy to learn. Moreover, 90% (38/42) of the participants agreed that they would like the standard result and Visual Clot displayed on the screen side by side. Furthermore, 86% (36/42) indicated that Visual Clot allows them to deal with complex coagulation situations more quickly. CONCLUSIONS: A group of anesthesia and intensive care physicians from two university hospitals in central Europe considered Visual Clot technology to be intuitive, easy to learn, and useful for decision making in situations of active bleeding. From the responses of these possible future users, Visual Clot appears to constitute an efficient and well-accepted way to streamline the decision-making process in viscoelastic test-based coagulation management.

Correction: Comparing Classroom Instruction to Individual Instruction as an Approach to Teach Avatar-Based Patient Monitoring With Visual Patient: Simulation Study.

[This corrects the article DOI: 10.2196/17922.].

Validation of the Raw National Aeronautics and Space Administration Task Load Index (NASA-TLX) Questionnaire to Assess Perceived Workload in Patient Monitoring Tasks: Pooled Analysis Study Using Mixed Models.

BACKGROUND: Patient monitoring is indispensable in any operating room to follow the patient's current health state based on measured physiological parameters. Reducing workload helps to free cognitive resources and thus influences human performance, which ultimately improves the quality of care. Among the many methods available to assess perceived workload, the National Aeronautics and Space Administration Task Load Index (NASA-TLX) provides the most widely accepted tool. However, only few studies have investigated the validity of the NASA-TLX in the health care sector. OBJECTIVE: This study aimed to validate a modified version of the raw NASA-TLX in patient monitoring tasks by investigating its correspondence with expected lower and higher workload situations and its robustness against nonworkload-related covariates. This defines criterion validity. METHODS: In this pooled analysis, we evaluated raw NASA-TLX scores collected after performing patient monitoring tasks in four different investigator-initiated, computer-based, prospective, multicenter studies. All of them were conducted in three hospitals with a high standard of care in central Europe. In these already published studies, we compared conventional patient monitoring with two newly developed situation awareness-oriented monitoring technologies called Visual Patient and Visual Clot. The participants were resident and staff anesthesia and intensive care physicians, and nurse anesthetists with completed specialization qualification. We analyzed the raw NASA-TLX scores by fitting mixed linear regression models and univariate models with different covariates. RESULTS: We assessed a total of 1160 raw NASA-TLX questionnaires after performing specific patient monitoring tasks. Good test performance and higher self-rated diagnostic confidence correlated significantly with lower raw NASA-TLX scores and the subscores (all P<.001). Staff physicians rated significantly lower workload scores than residents (P=.001), whereas nurse anesthetists did not show any difference in the same comparison (P=.83). Standardized distraction resulted in higher rated total raw NASA-TLX scores (P<.001) and subscores. There was no gender difference regarding perceived workload (P=.26). The new visualization technologies Visual Patient and Visual Clot resulted in significantly lower total raw NASA-TLX scores and all subscores, including high self-rated performance, when compared with conventional monitoring (all P<.001). CONCLUSIONS: This study validated a modified raw NASA-TLX questionnaire for patient monitoring tasks. The scores obtained correctly represented the assumed influences of the examined covariates on the perceived workload. We reported high criterion validity. The NASA-TLX questionnaire appears to be a reliable tool for measuring subjective workload. Further research should focus on its applicability in a clinical setting.

Point-of-Care Diagnostics in Coagulation Management.

This review provides a comprehensive and up-to-date overview of point-of-care (POC) devices most commonly used for coagulation analyses in the acute settings. Fast and reliable assessment of hemostasis is essential for the management of trauma and other bleeding patients. Routine coagulation assays are not designed to visualize the process of clot formation, and their results are obtained only after 30-90 m due to the requirements of sample preparation and the analytical process. POC devices such as viscoelastic coagulation tests, platelet function tests, blood gas analysis and other coagulometers provide new options for the assessment of hemostasis, and are important tools for an individualized, goal-directed, and factor-based substitution therapy. We give a detailed overview of the related tests, their characteristics and clinical implications. This review emphasizes the evident advantages of the speed and predictive power of POC clot measurement in the context of a goal-directed and algorithm-based therapy to improve the patient's outcome. Interpretation of viscoelastic tests is facilitated by a new visualization technology.

Situation Awareness-Oriented Patient Monitoring with Visual Patient Technology: A Qualitative Review of the Primary Research.

Visual Patient technology is a situation awareness-oriented visualization technology that translates numerical and waveform patient monitoring data into a new user-centered visual language. Vital sign values are converted into colors, shapes, and rhythmic movements-a language humans can easily perceive and interpret-on a patient avatar model in real time. In this review, we summarize the current state of the research on the Visual Patient, including the technology, its history, and its scientific context. We also provide a summary of our primary research and a brief overview of research work on similar user-centered visualizations in medicine. In several computer-based studies under various experimental conditions, Visual Patient transferred more information per unit time, increased perceived diagnostic certainty, and lowered perceived workload. Eye tracking showed the technology worked because of the way it synthesizes and transforms vital sign information into new and logical forms corresponding to the real phenomena. The technology could be particularly useful for improving situation awareness in settings with high cognitive demand or when users must make quick decisions. This comprehensive review of Visual Patient research is the foundation for an evaluation of the technology in clinical applications, starting with a high-fidelity simulation study in early 2020.