Evaluation of a Clinical Decision Support System for the most evidence-based approach to managing perioperative anticoagulation.

STUDY OBJECTIVE: We explored the feasibility of a Clinical Decision Support System (CDSS) to guide evidence-based perioperative anticoagulation. DESIGN: Prospective randomised clinical management simulation multicentre study. SETTING: Five University and 11 general hospitals in Germany. PARTICIPANTS: We enrolled physicians (anaesthesiologist (n = 73), trauma surgeons (n = 2), unknown (n = 1)) with different professional experience. INTERVENTIONS: A CDSS based on a multiple-choice test was developed and validated at the University Hospital of Frankfurt (phase-I). The CDSS comprised European guidelines for the management of anticoagulation in cardiology, cardio-thoracic, non-cardio-thoracic surgery and anaesthesiology. Phase-II compared the efficiency of physicians in identifying evidence-based approach of managing perioperative anticoagulation. In total 168 physicians were randomised to CDSS (PERI-KOAG) or CONTROL. MEASUREMENTS: Overall mean score and association of processing time and professional experience were analysed. The multiple-choice test consists of 11 cases and two correct answers per question were required to gain 100% success rate (=22 points). MAIN RESULTS: In total 76 physicians completed the questionnaire (n = 42 PERI-KOAG; n = 34 CONTROL; attrition rate 54%). Overall mean score (max. 100% = 22 points) was significantly higher in PERI-KOAG compared to CONTROL (82 ± 15% vs. 70 ± 10%; 18 ± 3 vs. 15 ± 2 points; P = 0.0003). A longer processing time is associated with significantly increased overall mean scores in PERI-KOAG (≥33 min. 89 ± 10% (20 ± 2 points) vs. <33 min. 73 ± 15% (16 ± 3 points), P = 0.0005) but not in CONTROL (≥33 min. 74 ± 13% (16 ± 3 points) vs. <33 min. 69 ± 9% (15 ± 2 points), P = 0.11). Within PERI-KOAG, there is a tendency towards higher results within the more experienced group (>5 years), but no significant difference to less (≤5 years) experienced colleagues (87 ± 10% (19 ± 2 points) vs. 78 ± 17% (17 ± 4 points), P = 0.08). However, an association between professional experience and success rate in CONTROL has not been shown (71 ± 8% vs. 70 ± 13%, 16 ± 2 vs. 15 ± 3 points; P = 0.66). CONCLUSIONS: CDSS significantly improved the identification of evidence-based treatment approaches. A precise usage of CDSS is mandatory to maximise efficiency.

Effectiveness of Preoperative Iron Supplementation in Major Surgical Patients With Iron Deficiency: A Prospective Observational Study.

OBJECTIVE: To evaluate the effectiveness of routine intravenous iron in surgical patients with iron deficiency anemia (IDA). BACKGROUND: Anemia is the most common medical disease in the world and is an independent risk factor for morbidity and mortality. Iron deficiency (ID) is the main cause for anemia and constitutes a potentially preventable condition with great impact on surgical outcome. METHODS: In this prospective single-center observational study, surgical patients were screened for the presence of anemia and ID. Patients were assigned to 1 of 4 study groups: A- (no anemia); A-, ID+, T+ (no anemia, iron-deficient, iron supplementation); A+ (anemia); and A+, ID+, T+ (anemia, iron-deficient, iron supplementation) according to hemoglobin level, iron status, and supplementation with iron. RESULTS: Among 1728 patients, 1028 were assigned to A-; 55 to A-, ID+, T+; 461 to A+; and 184 to A+, ID+, T+. While all iron-supplemented IDA patients required less red blood cell (RBC) transfusion during the postoperative period (A+ 42.5% vs A+, ID+, T+ 31.5%), a reduced intraoperative transfusion rate was observed for ID and IDA patients only if iron was supplemented >7 days before surgery. Hospital stay was significantly reduced by 2.8 days in iron-supplemented patients (P < 0.01 comparing 13.9 ±â€Š0.8 days for A+, ID+, T+ vs. 16.7 ±â€Š0.7 days for A+). CONCLUSION: Preoperative IDA management with intravenous iron is effective in improving hemoglobin level, thereby reducing intraoperative RBC transfusion rate particular if iron is administrated >7 days before surgery. Hospital length of stay was reduced in all preoperatively iron-supplemented IDA patients.

Factors influencing the bias between blood gas analysis versus central laboratory hemoglobin testing. A secondary analysis of a randomized controlled trial.

BACKGROUND: Anemia is the most important complication during major surgery and transfusion of red blood cells is the mainstay to compensate for life threating blood loss. Therefore, accurate measurement of hemoglobin (Hb) concentration should be provided in real-time. Blood Gas Analysis (BGA) provides rapid point-of-care assessment using smaller sampling tubes compared to central laboratory (CL) services. OBJECTIVE: This study aimed to investigate the accuracy of BGA hemoglobin testing as compared to CL services. METHODS: Data of the ongoing LIBERAL-Trial (Liberal transfusion strategy to prevent mortality and anemia-associated ischemic events in elderly non-cardiac surgical patients, LIBERAL) was used to assess the bias for Hb level measured by BGA devices (ABL800 Flex analyzer®, GEM series® and RapidPoint 500®) and CL as the reference method. For that, we analyzed pairs of Hb level measured by CL and BGA within two hours. Furthermore, the impact of various confounding factors including age, gender, BMI, smoker status, transfusion of RBC, intraoperative hemodilution, and co-medication was elucidated. In order to ensure adequate statistical analysis, only data of participating centers providing more than 200 Hb pairs were used. RESULTS: In total, three centers including 963 patients with 1,814 pairs of Hb measurements were analyzed. Mean bias was comparable between ABL800 Flex analyzer® and GEM series®: - 0.38 ± 0.15 g/dl whereas RapidPoint 500® showed a smaller bias (-0.09 g/dl) but greater median absolute deviation (± 0.45 g/dl). In order to avoid interference with different standard deviations caused by the different analytic devices, we focused on two centers using the same BGA technique (309 patients and 1,570 Hb pairs). A Bland-Altman analysis and LOWESS curve showed that bias decreased with smaller Hb values in absolute numbers but increased relatively. The smoker status showed the greatest reduction in bias (0.1 g/dl, p<0.001) whereas BMI (0.07 g/dl, p = 0.0178), RBC transfusion (0.06 g/dl, p<0.001), statins (0.04 g/dl, p<0.05) and beta blocker (0.03 g/dl, p = 0.02) showed a slight effect on bias. Intraoperative substitution of volume and other co-medications did not influence the bias significantly. CONCLUSION: Many interventions like substitution of fluids, coagulating factors or RBC units rely on the accuracy of laboratory measurement devices. Although BGA Hb testing showed a consistently stable difference to CL, our data confirm that BGA devices are associated with different bias. Therefore, we suggest that hospitals assess their individual bias before implementing BGA as valid and stable supplement to CL. However, based on the finding that bias decreased with smaller Hb values, which in turn are used for transfusion decision, we expect no unnecessary or delayed RBC transfusion, and no major impact on the LIBERAL trial performance.

Preoperative Anaemia in Primary Hip and Knee Arthroplasty. / Präoperative Anämie in der Hüft- und Kniegelenkendoprothetik.

INTRODUCTION: Approximately one in three patients has untreated preoperative anaemia, which in turn is associated with an increased need for transfusion of allogenic red blood cell concentrates (RBC) and complications in the context of a surgical intervention. Here, the prevalence of preoperative and postoperative anaemia as well as their effects on transfusion rate, hospital length of stay and hospital mortality in primary hip and knee arthroplasty has been analysed. METHODS: From January 2012 to September 2018, 378,069 adult inpatients from 13 German hospitals were analysed on the basis of an anonymized registry. Of these, n = 10,017 patients had a hip and knee joint primary arthroplasty. The primary endpoint was the incidence of preoperative anaemia, which was analysed by the first available preoperative haemoglobin value according to the WHO definition. Secondary endpoints included in-hospital length of stay, number of patients with red blood cell concentrate transfusion, incidence of hospital-acquired anaemia, number of deceased patients, and postoperative complications. RESULTS: The preoperative anaemia rate was 14.8% for elective knee joint arthroplasty, 22.9% for elective hip joint arthroplasty and 45.0% for duo-prosthesis implantation. Preoperative anaemia led to a significantly higher transfusion rate (knee: 8.3 vs. 1.8%; hip: 34.5 vs. 8.1%; duo-prosthesis: 42.3 vs. 17.4%), an increased red blood cell concentrate consumption (knee: 256 ± 107 vs. 29 ± 5 RBC/1000 patients; hip: 929 ± 60 vs. 190 ± 16 RBC/1000 patients; duo-prosthesis: 1411 ± 98 vs. 453 ± 42 RBC/1000 patients). Pre-operative anaemia was associated with prolonged hospital stay (12.0 [10.0; 17.0] d vs. 11.0 [9.0; 13.0] d; p < 0.001) and increased mortality (5.5% [4.6 - 6.5%] vs. 0.9% [0.7 - 1.2%]; Fisher p < 0.001) compared to non-anaemic patients. In patients aged 80 years and older, the incidence of preoperative anaemia and thus the transfusion rate was almost twice as high as in patients under 80 years of age. SUMMARY: Preoperative anaemia is common in knee and hip primary arthroplasty and was associated with a relevant increase in red blood cell concentrate consumption. In the context of patient blood management, a relevant potential arises, especially in elective orthopaedic surgery, to better prepare elective patients, to avoid unnecessary transfusions and thus to conserve the valuable resource blood.

Health economics of Patient Blood Management: a cost-benefit analysis based on a meta-analysis.

BACKGROUND AND OBJECTIVES: Patient Blood Management (PBM) is the timely application of evidence-based medical and surgical concepts designed to improve haemoglobin concentration, optimize haemostasis and minimize blood loss in an effort to improve patient outcomes. The focus of this cost-benefit analysis is to analyse the economic benefit of widespread implementation of a multimodal PBM programme. MATERIALS AND METHODS: Based on a recent meta-analysis including 17 studies (>235 000 patients) comparing PBM with control care and data from the University Hospital Frankfurt, a cost-benefit analysis was performed. Outcome data were red blood cell (RBC) transfusion rate, number of transfused RBC units, and length of hospital stay (LOS). Costs were considered for the following three PBM interventions as examples: anaemia management including therapy of iron deficiency, use of cell salvage and tranexamic acid. For sensitivity analysis, a Monte Carlo simulation was performed. RESULTS: Iron supplementation was applied in 3·1%, cell salvage in 65% and tranexamic acid in 89% of the PBM patients. In total, applying these three PBM interventions costs €129·04 per patient. However, PBM was associated with a reduction in transfusion rate, transfused RBC units per patient, and LOS which yielded to mean savings of €150·64 per patient. Thus, the overall benefit of PBM implementation was €21·60 per patient. In the Monte Carlo simulation, the cost savings on the outcome side exceeded the PBM costs in approximately 2/3 of all repetitions and the total benefit was €1 878 000 in 100·000 simulated patients. CONCLUSION: Resources to implement a multimodal PBM concept optimizing patient care and safety can be cost-effectively.

Screening for iron deficiency in surgical patients based on noninvasive zinc protoporphyrin measurements.

BACKGROUND: Approximately every third surgical patient is anemic. The most common form, iron deficiency anemia, results from persisting iron-deficient erythropoiesis (IDE). Zinc protoporphyrin (ZnPP) is a promising parameter for diagnosing IDE, hitherto requiring blood drawing and laboratory workup. STUDY DESIGN AND METHODS: Noninvasive ZnPP (ZnPP-NI) measurements are compared to ZnPP reference determination of the ZnPP/heme ratio by high-performance liquid chromatography (ZnPP-HPLC) and the analytical performance in detecting IDE is evaluated against traditional iron status parameters (ferritin, transferrin saturation [TSAT], soluble transferrin receptor-ferritin index [sTfR-F], soluble transferrin receptor [sTfR]), likewise measured in blood. The study was conducted at the University Hospitals of Frankfurt and Zurich. RESULTS: Limits of agreement between ZnPP-NI and ZnPP-HPLC measurements for 584 cardiac and noncardiac surgical patients equaled 19.7 µmol/mol heme (95% confidence interval, 18.0-21.3; acceptance criteria, 23.2 µmol/mol heme; absolute bias, 0 µmol/mol heme). Analytical performance for detecting IDE (inferred from area under the curve receiver operating characteristics) of parameters measured in blood was: ZnPP-HPLC (0.95), sTfR (0.92), sTfR-F (0.89), TSAT (0.87), and ferritin (0.67). Noninvasively measured ZnPP-NI yielded results of 0.90. CONCLUSION: ZnPP-NI appears well suited for an initial IDE screening, informing on the state of erythropoiesis at the point of care without blood drawing and laboratory analysis. Comparison with a multiparameter IDE test revealed that ZnPP-NI values of 40 µmol/mol heme or less allows exclusion of IDE, whereas for 65 µmol/mol heme or greater, IDE is very likely if other causes of increased values are excluded. In these cases (77% of our patients) ZnPP-NI may suffice for a diagnosis, while values in between require analyses of additional iron status parameters.

Programmes for the management of preoperative anaemia: audit in ten European hospitals within the PaBloE (Patient Blood Management in Europe) Working Group.

BACKGROUND AND OBJECTIVES: Preoperative anaemia is an independent risk factor for a higher morbidity and mortality, a longer hospitalization and increased perioperative transfusion rates. Managing preoperative anaemia is the first of three pillars of Patient Blood Management (PBM), a multidisciplinary concept to improve patient safety. While various studies provide medical information on (successful) anaemia treatment pathways, knowledge of organizational details of diagnosis and management of preoperative anaemia across Europe is scarce. MATERIALS AND METHODS: To gain information on various aspects of preoperative anaemia management including organization, financing, diagnostics and treatment, we conducted a survey (74 questions) in ten hospitals from seven European nations within the PaBloE (Patient Blood Management in Europe) working group covering the year 2016. RESULTS: Organization and activity in the field of preoperative anaemia management were heterogeneous in the participating hospitals. Almost all hospitals had pathways for managing preoperative anaemia in place, however, only two nations had national guidelines. In six of the ten participating hospitals, preoperative anaemia management was organized by anaesthetists. Diagnostics and treatment focused on iron deficiency anaemia which, in most hospitals, was corrected with intravenous iron. CONCLUSION: Implementation and approaches of preoperative anaemia management vary across Europe with a primary focus on treating iron deficiency anaemia. Findings of this survey motivated the hospitals involved to critically evaluate their practice and may also help other hospitals interested in PBM to develop action plans for diagnosis and management of preoperative anaemia.

[Cell Salvage in Anesthesiology]. / Patient Blood Management: die maschinelle Autotransfusion in der Anästhesiologie.

Re-infusion of washed autologous blood cell salvage from the operative field and wound drainages is used as part of blood conservation strategy within Patient Blood Management (PBM). Cell salvage is an effective method to reduce allogeneic blood transfusion. A main advantage of cell salvage is the prevention of storage-related damage to the erythrocytes.Cell salvage has wide applications in surgeries with expected blood loss higher than 500 ml like cardiac, vascular, orthopedic surgery, and by the use of blood irradiation also in cancer surgery.

[Patient Blood Management: Preoperative Anemia and Case Reports from the Anemia Walk-In Clinic]. / Patient Blood Management: präoperative Anämie und Fälle aus der Anämieambulanz.

Preoperative anemia is independently associated with increased morbidity and mortality and represents the strongest predictor for transfusion of red blood cells. Iron deficiency anemia is the most frequent form of anemia and could easily be treated by supplementation with iron. Patient Blood Management (PBM) focusses on prevention and management of anemia to optimize the patient and reduce unnecessary allogeneic blood products.

Multimodal Patient Blood Management Program Based on a Three-pillar Strategy: A Systematic Review and Meta-analysis.

OBJECTIVES: To determine whether a multidisciplinary, multimodal Patient Blood Management (PBM) program for patients undergoing surgery is effective in reducing perioperative complication rate, and thereby is effective in improving clinical outcome. BACKGROUND: PBM is a medical concept with the focus on a comprehensive anemia management, to minimize iatrogenic (unnecessary) blood loss, and to harness and optimize patient-specific physiological tolerance of anemia. METHODS: A systematic review and meta-analysis was performed. Eligible studies had to address each of the 3 PBM pillars with at least 1 measure per pillar, for example, preoperative anemia management plus cell salvage plus rational transfusion strategy. The study protocol has been registered with PROSPERO (CRD42017079217). RESULTS: Seventeen studies comprising 235,779 surgical patients were included in this meta-analysis (100,886 pre-PBM group and 134,893 PBM group). Implementation of PBM significantly reduced transfusion rates by 39% [risk ratio (RR) 0.61, 95% confidence interval (CI) 0.55-0.68, P < 0.00001], 0.43 red blood cell units per patient (mean difference -0.43, 95% CI -0.54 to -0.31, P < 0.00001), hospital length of stay (mean difference -0.45, 95% CI -0.65 to -0.25, P < 0,00001), total number of complications (RR 0.80, 95% CI 0.74-0.88, P <0.00001), and mortality rate (RR 0.89, 95% CI 0.80-0.98, P = 0.02). CONCLUSIONS: Overall, a comprehensive PBM program addressing all 3 PBM pillars is associated with reduced transfusion need of red blood cell units, lower complication and mortality rate, and thereby improving clinical outcome. Thus, this first meta-analysis investigating a multimodal approach should motivate all executives and health care providers to support further PBM activities.

[Point-of-care Coagulation Testing in Neurosurgery]. / Point-of-Care-Gerinnungsdiagnostik in der Neurochirurgie.

Disorders of the coagulation system can seriously impact the clinical course and outcome of neurosurgical patients. Due to the anatomical location of the central nervous system within the closed skull, bleeding complications can lead to devastating consequences such as an increase in intracranial pressure or enlargement of intracranial hematoma. Point-of-care (POC) devices for the testing of haemostatic parameters have been implemented in various fields of medicine. Major advantages of these devices are that results are available quickly and that analysis can be performed at the bedside, directly affecting patient management. POC devices allow identification of increased bleeding tendencies and therefore may enable an assessment of hemorrhagic risks in neurosurgical patients. Although data regarding the use of POC testing in neurosurgical patients are limited, they suggest that coagulation testing and hemostatic therapy using POC devices might have beneficial effects in this patient population. This article provides an overview of the application of point-of-care coagulation testing in clinical practice in neurosurgical patients.

Improving outcome of trauma patients by implementing patient blood management.

PURPOSE OF REVIEW: Patient blood management aims to improve patient outcome and safety by reducing the number of unnecessary red blood cell transfusions and vitalizing patient-specific anemia reserves. While this is increasingly recognized as best clinical practice in elective surgery, the implementation in the setting of trauma is restrained because of typically nonelective (emergency) surgery and, in specific circumstances, allogeneic blood transfusions as life-saving therapy. RECENT FINDINGS: Viscoelastic diagnostics allow a precise identification of trauma-induced coagulopathy. A coagulation factor concentrate-based therapy is increasingly recognized as a fast and effective concept to correct coagulopathy and minimize blood loss. Using smaller tubes has a great potential to reduce the severity of phlebotomy-induced anemia. Washed cell salvage may reduce the number of allogeneic blood transfusions. Intravenous iron (with or without erythropoietin) may result in an increase of hemoglobin levels and reduced red blood cell transfusion requirements. Although a restrictive transfusion strategy is recommended in general, a target hemoglobin level of 7-9 g/dl is recommended in acute bleeding patients. SUMMARY: In the setting of trauma, options to avoid unnecessary blood loss and reduce blood transfusion are manifold. These are likely to improve safety and outcome of trauma patients while potentially reducing therapeutic costs.

Microstructures in shells of the freshwater gastropod Viviparus viviparus: a potential sensor for temperature change?

Mollusk shells contain a plethora of information on past climate variability. However, only a limited toolkit is currently available to reconstruct such data from the shells. The environmental data of some proxies (e.g. Sr/Ca ratios) is obscured by physiological effects, whereas other proxies, such as δ(18)O, simultaneously provide information on two or more different environmental variables. The present study investigates whether microstructures of the freshwater gastropod Viviparus viviparus provide an alternative means to reconstruct past water temperature. Cold and highly variable temperature regimes resulted in the precipitation of highly unordered first-order lamellae of simple crossed-lamellar (XLM) structures if new shell formed from scratch. However, during stable and warm conditions, well-ordered first-order lamellae were laid down irrespective of pre-existing shell material. Homogeneous first-order lamellae also formed during times of cold and highly variable temperatures if the new shell was deposited onto existing shell material with well-ordered first-order lamellae. The growth front seems to contain instructions for building specific microstructure variants, irrespective of environmental conditions. However, if this template is missing, the animal forms a deviating microstructure. Under extremely stressful situations (e.g. removal from habitat, calcein staining, extreme temperature shifts), the gastropod precipitates an evolutionarily older microstructure (irregular simple prisms) rather than XLM structures. These shell portions were macroscopically described as disturbance lines. In addition, repetitive, presumably periodic growth patterns were observed, which consisted of gradually changing third-order lamellae between consecutive faint, organic-rich growth lines. These growth patterns were probably controlled by intrinsic biological clocks and exhibited a two-daily periodicity. The results of this study may provide the basis for using changes in the microstructure of shell sections as a new sensor (environmental proxy) for past water temperature.