Reliability of continuous vital sign monitoring in post-operative patients employing consumer-grade fitness trackers: A randomised pilot trial.

Introduction: Fitness trackers can provide continuous monitoring of vital signs and thus have the potential to become a complementary, mobile and effective tool for early detection of patient deterioration and post-operative complications. Methods: To evaluate potential implementations in acute care setting, we included 36 patients after moderate to major surgery in a recent randomised pilot trial to compare the performance of vital sign monitoring by three different fitness trackers (Apple Watch 7, Garmin Fenix 6pro and Withings ScanWatch) with established standard clinical monitors in post-anaesthesia care units and monitoring wards. Results: During a cumulative period of 56 days, a total of 53,197 heart rate (HR) measurements, as well as 12,219 measurements of the peripheral blood oxygen saturation (SpO2) and 28,954 respiratory rate (RR) measurements were collected by fitness trackers. Under real-world conditions, HR monitoring was accurate and reliable across all benchmarked devices (r = [0.95;0.98], p < 0.001; Bias = [-0.74 bpm;-0.01 bpm]; MAPE∼2%). However, the performance of SpO2 (r = [0.21;0.68]; p < 0.001; Bias = [-0.46%;-2.29%]; root-mean-square error = [2.82%;4.1%]) monitoring was substantially inferior. RR measurements could not be obtained for two of the devices, therefore exclusively the accuracy of the Garmin tracker could be evaluated (r = 0.28, p < 0.001; Bias = -1.46/min). Moreover, the time resolution of the vital sign measurements highly depends on the tracking device, ranging from 0.7 to 117.94 data points per hour. Conclusion: According to the results of the present study, tracker devices are generally reliable and accurate for HR monitoring, whereas SpO2 and RR measurements should be interpreted carefully, considering the clinical context of the respective patients.

Isolation of Extracellular Vesicles Using Formulas to Adapt Centrifugation to Different Centrifuges.

Extracellular vesicles (EVs) are small lipid bilayer vesicles released by cells to facilitate cell-to-cell communication. To study their biological roles and functions, they need to be isolated and purified, which can be achieved through a variety of methods. Here, we describe different methods for isolating and purifying EVs, with a focus on calculating the required g-force and centrifugation time with different centrifuges and rotors. We have compiled key formulas and tested predicted parameters for EV acquisitions to provide a comprehensive guide for EV isolation.

Adjusting Current Hemoglobin Thresholds: A Way to Improve Outcome in Women Undergoing Major Surgery.

Background/Objective: In the perioperative setting, a suboptimal total hemoglobin (Hb) mass puts women and men at an unreasonable disadvantage. Anemia is an independent risk factor for transfusion, postoperative complications, and mortality. The Hb cut-off value for women was set at <12.0 g/dL by the World Health Organization (WHO) and has been rigorously debated for decades. The aim of this study was to elucidate the risk for postoperative complications in female patients with Hb levels < 12.0, 12.0-12.9, and ≥13.0 g/dL. Material and Methods: Single-center retrospective analysis of female patients undergoing major surgery. Results: In total, 6,516 patients ≥18 years of age had major surgery between 2018 and 2019 and 2,446 female patients were included in analysis. Mean age was 67.4 ± 16.6, 66.4 ± 15.6, and 64.5 ± 15.5 years in female patients with preoperative Hb levels <12.0, 12.0-12.9 and ≥13.0 g/dL, respectively. The transfusion rate of red blood cells (RBCs) was significantly higher in female patients with Hb <12.0 g/dL (53%) and with Hb 12.0-12.9 g/dL (31%) compared to female patients ≥13.0 g/dL (22%). Rates of pneumonia, acute kidney injury, and sepsis were significantly higher in patients with Hb <12.0 and 12.0-12.9 g/dL compared to patients with Hb ≥13.0 g/dL. Total length of hospital stay was significantly longer in female patients with Hb <12.0 g/dL than patients with Hb 12.0-12.9 g/dL and Hb ≥13.0 g/dL (10 days vs. 8 days). Conclusion: Taken together, our data show that Hb values below 12.9 g/dL are associated with increased probability of RBC transfusions and increased risk of postoperative complications. In addition, our results indicate that postoperative outcomes for women might be optimized by increasing cut-off values for anemia. The call to revise the anemia threshold for women by the WHO can no longer be disregarded.

Preoperative hemoglobin thresholds for survival equity in women and men.

Anemia affects humans throughout life, and is linked to higher morbidity and mortality. Unclear is whether hemoglobin values are equivalent between women and men. This study evaluates the association of preoperative hemoglobin levels with in-hospital mortality and estimates thresholds for survival equity between men and women. All adult patients undergoing surgery between 2010 and 2019 from 14 German hospitals were included in the study. Thresholds for survival equity were determined with generalized additive models. In total, 842,130 patients with a median in-hospital follow-up time of 7 days were analyzed. During follow-up 20,370 deaths occurred. Preoperative hemoglobin stratified in-hospital mortality (log-rank test p < 0.001) and was associated with mortality independently of demographic risk, surgical risk and health status. For each 1 g/dL reduction in preoperative hemoglobin, the odds of mortality increased by a factor of 1.22 (95% CI 1.21-1.23, p < 0.001). A preoperative hemoglobin threshold of 10.5 g/dL reflected equivalent risk for both male and female patients. Hemoglobin levels below 10.5 g/dL had higher risk of mortality for women than for men. The findings from this study aid evidence-based thresholds, inform anemia management and promote equitable care, thus enhancing patient outcomes.

Reported outcomes in patients with iron deficiency or iron deficiency anemia undergoing major surgery: a systematic review of outcomes.

BACKGROUND: Iron deficiency (ID) is the leading cause of anemia worldwide. The prevalence of preoperative ID ranges from 23 to 33%. Preoperative anemia is associated with worse outcomes, making it important to diagnose and treat ID before elective surgery. Several studies indicated the effectiveness of intravenous iron supplementation in iron deficiency with or without anemia (ID(A)). However, it remains challenging to establish reliable evidence due to heterogeneity in utilized study outcomes. The development of a core outcome set (COS) can help to reduce this heterogeneity by proposing a minimal set of meaningful and standardized outcomes. The aim of our systematic review was to identify and assess outcomes reported in randomized controlled trials (RCTs) and observational studies investigating iron supplementation in iron-deficient patients with or without anemia. METHODS: We searched MEDLINE, CENTRAL, and ClinicalTrials.gov systematically from 2000 to April 1, 2022. RCTs and observational studies investigating iron supplementation in patients with a preoperative diagnosis of ID(A), were included. Study characteristics and reported outcomes were extracted. Outcomes were categorized according to an established outcome taxonomy. Quality of outcome reporting was assessed with a pre-specified tool. Reported clinically relevant differences for sample size calculation were extracted. RESULTS: Out of 2898 records, 346 underwent full-text screening and 13 studies (five RCTs, eight observational studies) with sufficient diagnostic inclusion criteria for iron deficiency with or without anemia (ID(A)) were eligible. It is noteworthy to mention that 49 studies were excluded due to no confirmed diagnosis of ID(A). Overall, 111 outcomes were structured into five core areas including nine domains. Most studies (92%) reported outcomes within the 'blood and lymphatic system' domain, followed by "adverse event" (77%) and "need for further resources" (77%). All of the latter reported on the need for blood transfusion. Reported outcomes were heterogeneous in measures and timing. Merely, two (33%) of six prospective studies were registered prospectively of which one (17%) showed no signs of selective outcome reporting. CONCLUSION: This systematic review comprehensively depicts the heterogeneity of reported outcomes in studies investigating iron supplementation in ID(A) patients regarding exact definitions and timing. Our analysis provides a systematic base for consenting to a minimal COS. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020214247.

Effect of using smaller blood volume tubes and closed blood collection devices on total blood loss in patients undergoing major cardiac and vascular surgery.

BACKGROUND: Diagnostic laboratory tests are an integral part of managing hospitalized patients. In particular, patients in the intensive care units (ICUs) can experience a concerning amount of blood loss due to diagnostic testing, which can increase the risk developing iatrogenic anemia. Several interventions exist to curtail avoidable blood loss, for example computerized decision support, smaller phlebotomy tubes, and other blood conservation devices. Nevertheless, use of these interventions is not standardized. Therefore, the objective of our study was to quantify the daily phlebotomy volume taken from patients who had undergone major cardiac or vascular surgery. METHODS: We estimated the number of blood analyses and volumes of drawn blood of 400 consecutive patients (≥ 18 yr) undergoing major cardiac or vascular surgery. The amount of blood saved using small-volume tubes and in combination with blood conservation device rather than standard-volume tubes was estimated for serum chemistry (serum), ethylenediaminetetraacetic acid (EDTA) tubes, sodium citrate coagulation (SCC) tubes, and arterial blood gas (ABG) analysis. RESULTS: The mean total blood loss due to phlebotomy drawing using standard-volume tubes during hospitalization was 167.9 mL (95% confidence interval [CI], 158.0 to 177.8), 255.6 mL (95% CI, 226.5 to 284.6), and 695.3 mL (95% CI, 544.1 to 846.4) for patients undergoing cardiac surgery with a hospital length of stay (LOS) of 0-10, 11-20, and ≥ 21 days, respectively. The mean total blood loss due to phlebotomy during hospitalization was 80.5 mL (95% CI, 70.5 to 90.6), 225.0 mL (95% CI, 135.1 to 314.8 mL) and 470.3 mL (95% CI, 333.5 to 607.1) for vascular surgery patients with LOS 0-10, 11-20, and ≥ 21 days, respectively. Patients with at least a two-day stay at the ICU had a mean blood loss of 146.6 mL (95% CI, 134.6 to 158.6 mL) and those with ≥ 11 days incurred a loss of 1,428 mL (95% CI, 1,117.8 to 1,739.2). The use of closed blood collection device and small-volume tubes (serum, EDTA, SCC, and ABG) reduced blood loss by 82.8 mL for patients with an ICU stay of 2 days and up to 824.0 mL for patients with a ICU stay of ≥ 11 days. CONCLUSION: Diagnostic laboratory tests are associated with significant patient blood loss, but are a modifiable risk factor. The use of small-volume tubes and closed blood collection devices decreases the volume of patient blood drawn for analysis and prevents blood waste.

RéSUMé: CONTEXTE: Les tests diagnostiques de laboratoire font partie intégrante de la prise en charge des personnes hospitalisées. Plus spécifiquement, la patientèle des unités de soins intensifs (USI) peut perdre une quantité inquiétante de sang en raison des tests de diagnostic, ce qui peut augmenter le risque d'anémie iatrogène. Plusieurs interventions existent pour réduire les pertes de sang évitables, par exemple une aide à la décision informatisée, des tubes de phlébotomie plus petits et d'autres dispositifs de conservation du sang. Néanmoins, le recours à ces interventions n'est pas normalisé. Par conséquent, l'objectif de notre étude était de quantifier le volume quotidien de phlébotomie prélevée chez des patient·es ayant bénéficié d'une chirurgie cardiaque ou vasculaire majeure. MéTHODE: Nous avons estimé le nombre d'analyses sanguines et les volumes de sang prélevés de 400 personnes consécutives (≥ 18 ans) bénéficiant d'une chirurgie cardiaque ou vasculaire majeure. La quantité de sang économisée à l'aide de tubes de petit volume et en combinaison avec un dispositif de conservation du sang plutôt que des tubes de volume standard a été estimée pour la chimie sérique (sérum), les tubes d'acide éthylène-diamine-tétra-acétique (EDTA), les tubes de coagulation au citrate de sodium (CCS) et l'analyse des gaz du sang artériel (GSA). RéSULTATS: La perte sanguine totale moyenne due au prélèvement de phlébotomie à l'aide de tubes de volume standard pendant l'hospitalisation était de 167,9 mL (intervalle de confiance [IC] à 95 %, 158,0 à 177,8), 255,6 mL (IC 95 %, 226,5 à 284,6) et 695,3 mL (IC 95 %, 544,1 à 846,4) chez les patient·es bénéficiant d'une chirurgie cardiaque avec une durée de séjour à l'hôpital de 0 à 10, 11 à 20, et ≥ 21 jours, respectivement. La perte sanguine totale moyenne due à la phlébotomie pendant l'hospitalisation était de 80,5 mL (IC 95 %, 70,5 à 90,6), 225,0 mL (IC 95 %, 135,1 à 314,8 mL) et 470,3 mL (IC 95 %, 333,5 à 607,1) chez les patient·es ayant bénéficié d'une chirurgie vasculaire avec des durées de séjour de 0-10, 11-20 et ≥ 21 jours, respectivement. Les patient·es ayant séjourné au moins deux jours à l'USI ont eu une perte de sang moyenne de 146,6 mL (IC 95 %, 134,6 à 158,6 mL) et celles et ceux ayant séjourné ≥ 11 jours ont subi une perte de 1428 mL (IC 95 %, 1117,8 à 1739,2). L'utilisation d'un dispositif de prélèvement sanguin fermé et de tubes de petit volume (sérum, EDTA, SCC et gsa) a réduit la perte de sang de 82,8 mL pour les patient·es ayant séjourné à l'USI 2 jours et jusqu'à 824,0 mL pour les patient·es ayant séjourné en USI ≥ 11 jours. CONCLUSION: Les tests de laboratoire diagnostiques sont associés à une perte de sang importante chez les patient·es, mais constituent un facteur de risque modifiable. L'utilisation de tubes de petit volume et de dispositifs fermés de prélèvement sanguin diminue le volume de sang prélevé pour analyse et prévient le gaspillage de sang.

Clinical Course and Management of Patients with Emergency Surgery Treated with Direct Oral Anticoagulants or Vitamin K Antagonists-Results of the German Prospective RADOA-Registry.

(1) Background: The clinical management of anticoagulated patients treated with direct oral anticoagulants (DOAC) or Vitamin K antagonists (VKA) needing emergency surgery is challenging. (2) Methods: The prospective German RADOA registry investigated treatment strategies in DOAC- or VKA-treated patients needing emergency surgery within 24 h after admission. Effectiveness was analysed by clinical endpoints including major bleeding. Primary observation endpoint was in hospital mortality until 30 days after admission. (3) Results: A total of 78 patients were included (DOAC: 44; VKA: 34). Median age was 76 years. Overall, 43% of the DOAC patients and 79% of the VKA patients were treated with prothrombin complex concentrates (PCC) (p = 0.002). Out of the DOAC patients, 30% received no hemostatic treatment compared to 3% (1/34) of the VKA patients (p = 0.002), and 7% of the DOAC patients and 21% of the VKA patients developed major or clinically relevant non-major bleeding at the surgical site (p = 0.093). In-hospital mortality was 13% with no significant difference between the two treatment groups (DOAC: 11%, VKA: 15%; p > 0.20). (4) Conclusions: The 30-day in-hospital mortality rate was comparable between both patient groups. VKA patients required significantly more hemostatic agents than DOAC patients in the peri- and postoperative surgery period.

[Analysis of a differentiated resuscitation room activation at a national trauma center]. / Analyse einer differenzierten Schockraumalarmierung an einem überregionalen Traumazentrum.

BACKGROUND: In order to continue to efficiently provide both personnel-intensive and resource-intensive care to severely injured patients, some hospitals have introduced individually differentiated systems for resuscitation room treatment. The aim of this study was to evaluate the concept of the A and B classifications in terms of practicability, indications, and potential complications at a national trauma center in Bavaria. METHODS: In a retrospective study, data from resuscitation room trauma patients in the year 2020 were collected. The assignment to A and B was made by the prehospital emergency physician. Parameters such as the injury severity score (ISS), Glasgow outcome scale (GOS), upgrade rate, and the indication criteria according to the S3 guidelines were recorded. Statistical data comparisons were made using t­tests, χ2-tests, or Mann-Whitney U­tests. RESULTS: A total of 879 resuscitation room treatments (A 473, B 406) met the inclusion criteria. It was found that 94.5% of resuscitation room A cases had physician accompaniment, compared to 48% in resuscitation room B assignments. In addition to significantly lower ISS scores (4.1 vs. 13.9), 29.8% of B patients did not meet the treatment criteria defined in the S3 guidelines. With a low upgrade rate of 4.9%, 98% of B patients had a GOS score of 4 or 5. CONCLUSION: The presented categorization is an effective and safe way to manage the increasing number of resuscitation room alerts in a resource-optimized manner.

Identifying a target group for selenium supplementation in high-risk cardiac surgery: a secondary analysis of the SUSTAIN CSX trial.

BACKGROUND: Recent data from the randomized SUSTAIN CSX trial could not confirm clinical benefits from perioperative selenium treatment in high-risk cardiac surgery patients. Underlying reasons may involve inadequate biosynthesis of glutathione peroxidase (GPx3), which is a key mediator of selenium's antioxidant effects. This secondary analysis aimed to identify patients with an increase in GPx3 activity following selenium treatment. We hypothesize that these responders might benefit from perioperative selenium treatment. METHODS: Patients were selected based on the availability of selenium biomarker information. Four subgroups were defined according to the patient's baseline status, including those with normal kidney function, reduced kidney function, selenium deficiency, and submaximal GPx3 activity. RESULTS: Two hundred and forty-four patients were included in this analysis. Overall, higher serum concentrations of selenium, selenoprotein P (SELENOP) and GPx3 were correlated with less organ injury. GPx3 activity at baseline was predictive of 6-month survival (AUC 0.73; p = 0.03). While selenium treatment elevated serum selenium and SELENOP concentrations but not GPx3 activity in the full patient cohort, subgroup analyses revealed that GPx3 activity increased in patients with reduced kidney function, selenium deficiency and low to moderate GPx3 activity. Clinical outcomes did not vary between selenium treatment and placebo in any of these subgroups, though the study was not powered to conclusively detect differences in outcomes. CONCLUSIONS: The identification of GPx3 responders encourages further refined investigations into the treatment effects of selenium in high-risk cardiac surgery patients.

User Perceptions of Visual Blood: An International Mixed Methods Study on Novel Blood Gas Analysis Visualization.

Blood gas analysis plays a central role in modern medicine. Advances in technology have expanded the range of available parameters and increased the complexity of their interpretation. By applying user-centered design principles, it is possible to reduce the cognitive load associated with interpreting blood gas analysis. In this international, multicenter study, we explored anesthesiologists' perspectives on Visual Blood, a novel visualization technique for presenting blood gas analysis results. We conducted interviews with participants following two computer-based simulation studies, the first utilizing virtual reality (VR) (50 participants) and the second without VR (70 participants). Employing the template approach, we identified key themes in the interview responses and formulated six statements, which were rated using Likert scales from 1 (strongly disagree) to 5 (strongly agree) in an online questionnaire. The most frequently mentioned theme was the positive usability features of Visual Blood. The online survey revealed that participants found Visual Blood to be an intuitive method for interpreting blood gas analysis (median 4, interquartile range (IQR) 4-4, p < 0.001). Participants noted that minimal training was required to effectively learn how to interpret Visual Blood (median 4, IQR 4-4, p < 0.001). However, adjustments are necessary to reduce visual overload (median 4, IQR 2-4, p < 0.001). Overall, Visual Blood received a favorable response. The strengths and weaknesses derived from these data will help optimize future versions of Visual Blood to improve the presentation of blood gas analysis results.

Effects of Different Hemoglobin Levels on Near-Infrared Spectroscopy-Derived Cerebral Oxygen Saturation in Elderly Patients Undergoing Noncardiac Surgery.

Background: Near-infrared spectroscopy (NIRS) is a commonly used technique to evaluate tissue oxygenation and prevent harmful cerebral desaturation in the perioperative setting. The aims of the present study were to assess whether surgery-related anemia can be detected via NIRS of cerebral oxygen saturation and to investigate the effects of different perioperative transfusion strategies on cerebral oxygenation, potentially affecting transfusion decision-making. Study Design and Methods: Data from the ongoing multicenter LIBERAL-Trial (liberal transfusion strategy to prevent mortality and anemia-associated ischemic events in elderly noncardiac surgical patients, LIBERAL) were used. In this single-center sub-study, regional cerebral oxygenation saturation (rSO2) was evaluated by NIRS at baseline, pre-, and post-RBC transfusion. The obtained values were correlated with blood gas analysis-measured Hb concentrations. Results: rSO2 correlated with Hb decline during surgery (r = 0.35, p < 0.0001). Different RBC transfusion strategies impacted rSO2 such that higher Hb values resulted in higher rSO2. Cerebral desaturation occurred at lower Hb values more often. Discussion: Cerebral oxygenation monitoring using NIRS provides noninvasive rapid and continuous information regarding perioperative alterations in Hb concentration without the utilization of patients' blood for blood sampling. Further investigations are required to demonstrate if cerebral rSO2 may be included in future individualized transfusion decision strategies.

German Patient Blood Management Network: effectiveness and safety analysis in 1.2 million patients.

BACKGROUND: Patient Blood Management (PBM) is a patient-centred, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood whilst promoting patient safety and empowerment. The effectiveness and safety of PBM over a longer period have not yet been investigated. METHODS: We performed a prospectively designed, multicentre follow-up study with non-inferiority design. Data were retrospectively extracted case-based from electronic hospital information systems. All in-hospital patients (≥18 yr) undergoing surgery and discharged between January 1, 2010 and December 31, 2019 were included in the analysis. The PBM programme focused on three domains: preoperative optimisation of haemoglobin concentrations, blood-sparing techniques, and guideline adherence/standardisation of allogeneic blood product transfusions. The outcomes were utilisation of blood products, composite endpoint of in-hospital mortality and postoperative complications (myocardial infarction/ischaemic stroke/acute renal failure with renal replacement therapy/sepsis/pneumonia), anaemia rate at admission and discharge, and hospital length of stay. RESULTS: A total of 1 201 817 (pre-PBM: n=441 082 vs PBM: n=760 735) patients from 14 (five university/nine non-university) hospitals were analysed. Implementation of PBM resulted in a substantial reduction of red blood cell utilisation. The mean number of red blood cell units transfused per 1000 patients was 547 in the PBM cohort vs 635 in the pre-PBM cohort (relative reduction of 13.9%). The red blood cell transfusion rate was significantly lower (P<0.001) with odds ratio 0.86 (0.85-0.87). The composite endpoint was 5.8% in the PBM vs 5.6% in the pre-PBM cohort. The non-inferiority aim (safety of PBM) was achieved (P<0.001). CONCLUSIONS: Analysis of >1 million surgical patients showed that the non-inferiority condition (safety of Patient Blood Management) was fulfilled, and PBM was superior with respect to red blood cell transfusion. CLINICAL TRIAL REGISTRATION: NCT02147795.

[Intraaortic Ballon-pump: Physiology, Indication, Management]. / Intraaortale Ballonpumpe: Physiologie, Indikationen, Management.

The intraaortic ballon-pump (IABP) is a percutaneous mechanical circulatory support device, which is used in patients either with insufficient cardiac output or in patients with high-risk situation before cardiac intervention, like surgical revascularisation or percutaneous coronary intervention (PCI). Due to electrocardiographic or arterial pressure pulse the IABP augments diastolic coronary perfusion pressure and reduces systolic afterload. Thereby, myocardial oxygen supply-demand ratio is improved and cardiac output is increased. Many national and international cardiology, cardiothoracic and intensive care medicine societies and associations worked together in order to develop evidence-based recommendations and guidelines for the preoperative, intraoperative and postoperative management of the IABP. This manuscript is mainly based on the S3 guideline "Use of intraaortic balloon-pump in cardiac surgery" from the German Society for Thoracic and Cardiovascular Surgery (DGTHG).

Penny-wise and pound-foolish: the challenges of preoperative anaemia management.

The timely correction of anaemia before major surgery is important for optimising perioperative patient outcomes. However, multiple barriers have precluded the global expansion of preoperative anaemia treatment programmes, including misconceptions about the true cost/benefit ratio for patient care and health system economics. Institutional investment and buy-in from stakeholders could lead to significant cost savings through avoided complications of anaemia and red blood cell transfusions, and through containment of direct and variable costs of blood bank laboratories. In some health systems, billing for iron infusions could generate revenue and promote growth of treatment programmes. The aim of this work is to galvanise integrated health systems worldwide to diagnose and treat anaemia before major surgery.

Multidisciplinary paper on patient blood management in cardiothoracic surgery in the UK: perspectives on practice during COVID-19.

The coronavirus (COVID-19) pandemic disrupted all surgical specialties significantly and exerted additional pressures on the overburdened United Kingdom (UK) National Health Service. Healthcare professionals in the UK have had to adapt their practice. In particular, surgeons have faced organisational and technical challenges treating patients who carried higher risks, were more urgent and could not wait for prehabilitation or optimisation before their intervention. Furthermore, there were implications for blood transfusion with uncertain patterns of demand, reductions in donations and loss of crucial staff because of sickness and public health restrictions. Previous guidelines have attempted to address the control of bleeding and its consequences after cardiothoracic surgery, but there have been no targeted recommendations in light of the recent COVID-19 challenges. In this context, and with a focus on the perioperative period, an expert multidisciplinary Task Force reviewed the impact of bleeding in cardiothoracic surgery, explored different aspects of patient blood management with a focus on the use of haemostats as adjuncts to conventional surgical techniques and proposed best practice recommendations in the UK.

Conventional versus video-assisted laryngoscopy for perioperative endotracheal intubation (COVALENT) - a randomized, controlled multicenter trial.

BACKGROUND: Data on the routine use of video-assisted laryngoscopy in peri-operative intubations are rather inconsistent and ambiguous, in part due to small populations and non-uniform outcome measures in past trials. Failed or prolonged intubation procedures are a reason for relevant morbidity and mortality. This study aims to determine whether video-assisted laryngoscopy (with both Macintosh-shaped and hyperangulated blades) is at least equal to the standard method of direct laryngoscopy with respect to the first-pass success rate. Furthermore, validated tools from the field of human factors will be applied to examine within-team communication and task load during this critical medical procedure. METHODS: In this randomized, controlled, three-armed parallel group design, multi-centre trial, a total of more than 2500 adult patients scheduled for perioperative endotracheal intubation will be randomized. In equally large arms, video-assisted laryngoscopy with a Macintosh-shaped or a hyperangulated blade will be compared to the standard of care (direct laryngoscopy with Macintosh blade). In a pre-defined hierarchical analysis, we will test the primary outcome for non-inferiority first. If this goal should be met, the design and projected statistical power also allow for subsequent testing for superiority of one of the interventions. Various secondary outcomes will account for patient safety considerations as well as human factors interactions within the provider team and will allow for further exploratory data analysis and hypothesis generation. DISCUSSION: This randomized controlled trial will provide a solid base of data in a field where reliable evidence is of major clinical importance. With thousands of endotracheal intubations performed every day in operating rooms around the world, every bit of performance improvement translates into increased patient safety and comfort and may eventually prevent significant burden of disease. Therefore, we feel confident that a large trial has the potential to considerably benefit patients and anaesthetists alike. TRIAL REGISTRATION: ClincalTrials.gov NCT05228288. PROTOCOL VERSION: 1.1, November 15, 2021.

Visual Blood, a 3D Animated Computer Model to Optimize the Interpretation of Blood Gas Analysis.

Acid-base homeostasis is crucial for all physiological processes in the body and is evaluated using arterial blood gas (ABG) analysis. Screens or printouts of ABG results require the interpretation of many textual elements and numbers, which may delay intuitive comprehension. To optimise the presentation of the results for the specific strengths of human perception, we developed Visual Blood, an animated virtual model of ABG results. In this study, we compared its performance with a conventional result printout. Seventy physicians from three European university hospitals participated in a computer-based simulation study. Initially, after an educational video, we tested the participants' ability to assign individual Visual Blood visualisations to their corresponding ABG parameters. As the primary outcome, we tested caregivers' ability to correctly diagnose simulated clinical ABG scenarios with Visual Blood or conventional ABG printouts. For user feedback, participants rated their agreement with statements at the end of the study. Physicians correctly assigned 90% of the individual Visual Blood visualisations. Regarding the primary outcome, the participants made the correct diagnosis 86% of the time when using Visual Blood, compared to 68% when using the conventional ABG printout. A mixed logistic regression model showed an odds ratio for correct diagnosis of 3.4 (95%CI 2.00-5.79, p < 0.001) and an odds ratio for perceived diagnostic confidence of 1.88 (95%CI 1.67-2.11, p < 0.001) in favour of Visual Blood. A linear mixed model showed a coefficient for perceived workload of -3.2 (95%CI -3.77 to -2.64) in favour of Visual Blood. Fifty-one of seventy (73%) participants agreed or strongly agreed that Visual Blood was easy to use, and fifty-five of seventy (79%) agreed that it was fun to use. In conclusion, Visual Blood improved physicians' ability to diagnose ABG results. It also increased perceived diagnostic confidence and reduced perceived workload. This study adds to the growing body of research showing that decision-support tools developed around human cognitive abilities can streamline caregivers' decision-making and may improve patient care.

Visual Blood, Visualisation of Blood Gas Analysis in Virtual Reality, Leads to More Correct Diagnoses: A Computer-Based, Multicentre, Simulation Study.

Interpreting blood gas analysis results can be challenging for the clinician, especially in stressful situations under time pressure. To foster fast and correct interpretation of blood gas results, we developed Visual Blood. This computer-based, multicentre, noninferiority study compared Visual Blood and conventional arterial blood gas (ABG) printouts. We presented six scenarios to anaesthesiologists, once with Visual Blood and once with the conventional ABG printout. The primary outcome was ABG parameter perception. The secondary outcomes included correct clinical diagnoses, perceived diagnostic confidence, and perceived workload. To analyse the results, we used mixed models and matched odds ratios. Analysing 300 within-subject cases, we showed noninferiority of Visual Blood compared to ABG printouts concerning the rate of correctly perceived ABG parameters (rate ratio, 0.96; 95% CI, 0.92-1.00; p = 0.06). Additionally, the study revealed two times higher odds of making the correct clinical diagnosis using Visual Blood (OR, 2.16; 95% CI, 1.42-3.29; p < 0.001) than using ABG printouts. There was no or, respectively, weak evidence for a difference in diagnostic confidence (OR, 0.84; 95% CI, 0.58-1.21; p = 0.34) and perceived workload (Coefficient, 2.44; 95% CI, -0.09-4.98; p = 0.06). This study showed that participants did not perceive the ABG parameters better, but using Visual Blood resulted in more correct clinical diagnoses than using conventional ABG printouts. This suggests that Visual Blood allows for a higher level of situation awareness beyond individual parameters' perception. However, the study also highlighted the limitations of today's virtual reality headsets and Visual Blood.

Current practices in nutrition therapy in cardiac surgery patients: An international multicenter observational study.

BACKGROUND: Cardiac surgery patients with a prolonged stay in the intensive care unit (ICU) are at high risk for acquired malnutrition. Medical nutrition therapy practices for cardiac surgery patients are unknown. The objective of this study is to describe the current nutrition practices in critically ill cardiac surgery patients worldwide. METHODS: We conducted a prospective observational study in 13 international ICUs involving mechanically ventilated cardiac surgery patients with an ICU stay of at least 72 h. Collected data included the energy and protein prescription, type of and time to the initiation of nutrition, and actual quantity of energy and protein delivered (maximum: 12 days). RESULTS: Among 237 enrolled patients, enteral nutrition (EN) was started, on average, 45 h after ICU admission (range, 0-277 h; site average, 53 [range, 10-79 h]). EN was prescribed for 187 (79%) patients and combined EN and parenteral nutrition in 33 (14%). Overall, patients received 44.2% (0.0%-117.2%) of the prescribed energy and 39.7% (0.0%-122.8%) of the prescribed protein. At a site level, the average nutrition adequacy was 47.5% (30.5%-78.6%) for energy and 43.6% (21.7%-76.6%) for protein received from all nutrition sources. CONCLUSION: Critically ill cardiac surgery patients with prolonged ICU stay experience significant delays in starting EN and receive low levels of energy and protein. There exists tremendous variability in site performance, whereas achieving optimal nutrition performance is doable.