Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022.

BACKGROUND: Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management. DESIGN: A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline. RESULTS: These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%. DISCUSSION: Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality. CONCLUSION: All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Management and outcomes of pregnant ICU patients with severe COVID-19 pneumonia in Qatar: A retrospective cohort study.

INTRODUCTION: Pregnant women are considered a high-risk group for COVID-19 due to their increased vulnerability to viral infections. The impact of COVID-19 on pregnant women is not well understood, and there is a need for data on managing severe COVID-19 in pregnant patients. This retrospective descriptive cohort study described the characteristics, hospital stay, interventions, and outcomes of pregnant patients admitted to the intensive care units (ICUs) with severe COVID-19 pneumonia in Qatar. METHODS: Data were collected from medical records and chart reviews of pregnant women admitted to Hamad Medical Corporation (HMC) with COVID-19 pneumonia from March 01, 2020, to July 31, 2021. The inclusion criteria encompassed pregnant women with a positive polymerase chain reaction (PCR) antigen test or radiological changes at admission, requiring respiratory support, and hospitalized for more than 24 hours. RESULTS: A total of 43 pregnant women were included in this study. Most patients were admitted during the first wave of the pandemic, with a median gestational age of 212 days [interquartile range 178-242 days] at presentation. The most common respiratory support methods were high-flow nasal cannula, non-invasive positive pressure ventilation, and invasive positive pressure ventilation. Convalescent plasma therapy was administered to 58% of patients, and tocilizumab was used in 28%. Renal replacement therapy was required by 4.6% of patients and 7% required extracorporeal membrane oxygenation. CONCLUSION: This study provides valuable insights into the impact of COVID-19 on pregnant patients admitted to the ICUs in Qatar. The results suggest that pregnant patients with COVID-19 pneumonia require close monitoring and appropriate interventions to minimize adverse outcomes for both mother and fetus. The data may contribute to future guidelines and management strategies for severe COVID-19 in pregnant patients.

Point-of-Care Platelet Function Monitoring: Implications for Patients With Platelet Inhibitors in Cardiac Surgery.

Although most physicians are comfortable managing the limited anticoagulant effect of aspirin, the recent administration of potent P2Y12 receptor inhibitors in patients undergoing cardiac surgery remains a dilemma. Guidelines recommend discontinuation of potent P2Y12 inhibitors 5- to- 7 days before surgery to reduce the risk of postoperative hemorrhage. Such a strategy might not be feasible before urgent surgery, due to ongoing myocardial ischemia or in patients at high risk for thromboembolic events. Recently, different point-of-care devices to assess functional platelet quality have become available for clinical use. The aim of this narrative review was to evaluate the implications and potential benefits of platelet function monitoring in guiding perioperative management and therapeutic options in patients treated with antiplatelets, including aspirin or P2Y12 receptor inhibitors, undergoing cardiac surgery. No objective superiority of one point-of-care device over another was found in a large meta-analysis. Their accuracy and reliability are generally limited in the perioperative period. In particular, preoperative platelet function testing has been used to assess platelet contribution to bleeding after cardiac surgery. However, predictive values for postoperative hemorrhage and transfusion requirements are low, and there is a significant variability between and within these tests. Further, platelet function monitoring has been used to optimize the preoperative waiting period after cessation of dual antiplatelet therapy before urgent cardiac surgery. Furthermore, studies assessing their value in therapeutic decisions in bleeding patients after cardiac surgery are scarce. A general and liberal use of perioperative platelet function testing is not yet recommended.

Shifts of Transfusion Demand in Cardiac Surgery After Implementation of Rotational Thromboelastometry-Guided Transfusion Protocols: Analysis of the HEROES-CS (HEmostasis Registry of patiEntS in Cardiac Surgery) Observational, Prospective Open Cohort Database.

OBJECTIVES: Rotational thromboelastometry (ROTEM)-guided transfusion algorithms in cardiac surgery have been proven to be successful in reducing blood loss in randomized controlled trials. Using an institutional hemostasis registry of patients in cardiac surgery (HEROES-CS), the authors hypothesized that the use of ROTEM-guided transfusion algorithms would save blood products and overall costs in cardiac surgery in every day practice. DESIGN: Observational, prospective open cohort database. SETTING: Single-center academic hospital. PARTICIPANTS: Cardiac surgery patients. INTERVENTIONS: Implementation of ROTEM-guided bleeding management. MEASUREMENTS AND MAIN RESULTS: A classical-guided algorithm and a ROTEM-guided algorithm were used for patient blood management in 2 cohorts. Primary outcome was the use and amount of blood products and hemostatic medication. Secondary outcomes were amount of rethoracotomies, length of stay, and 30-day mortality. Finally, costs and savings were calculated. The classical-guided cohort comprised 204 patients, and ROTEM-guided cohort comprised 151 patients. Baseline characteristics showed excellent similarities after propensity score matching of 202 patients. Blood loss was lower after ROTEM guidance (p < 0.001). Absolute risk reduction was 17% for red blood cells (p = 0.024), 12% for fresh frozen plasma (p = 0.019), and 4% for thrombocyte concentrates (p = 0.582). More tranexamic acid was given, but not more fibrinogen concentrate, while desmopressin was given less often. Hospital length of stay was reduced by an overall median of 2 and a mean of 4 days (p < 0.001). Mortality and rethoracotomy rates were not affected. Potential savings were about €4,800 ($5,630) per patient. CONCLUSIONS: Implementation of a ROTEM-guided transfusion algorithm in cardiac surgery patients reduced the use of blood products and hemostatic medication, hereby saving costs. Reductions in mortality and rethoracotomy rates could not be found.

Surgical intensive care - current and future challenges?

Bjorn Ibsen, an anesthetist who pioneered positive pressure ventilation as a treatment option during the Copenhagen polio epidemic of 1952, set up the first Intensive Care Unit (ICU) in Europe in 1953. He managed polio patients on positive pressure ventilation together with physicians and physiologists in a dedicated ward, where one nurse was assigned to each patient. In that sense Ibsen is more or less the father of intensive care medicine as a specialty and also an advocate of the one-to-one nursing ratio for critically ill patients. Nowadays, the Surgical Intensive Care Unit (SICU) offers critical care treatment to unstable, severely, or potentially severely ill patients in the perioperative setting, who have life-threatening conditions and require comprehensive care, constant monitoring, and possible emergency interventions. Hence there is one very specific challenge in the surgical setting: the intensivist has to manage the patient flow starting from admission to the hospital through to the operating theater, in the SICU, and postoperatively for the discharge to the ward. In other words, the planning of the resources (most frequently availability of beds) has to be optimized to prevent cancellations of elective surgical procedures but also to facilitate other emergency admissions. SICU intensivists take the role of arbitrators between surgical demand and patient's interests. This means they supervise the safety, efficacy, and workability of the process with respect to all stakeholders. This notion was reported in 2007 when Stawicki and co-workers performed a small prospective study concluding that it appears safe if the dedicated intensivist takes over the role of the last arbitrator supported by a multidisciplinary team.1 However, demographic changes in many countries during the last few decades have given rise to populations which are more elderly and sicker than before. This impacts on the healthcare system in general but on the intensivist and the ICU team too. In addition, in a society with an increased life expectancy, the balance between treatable disease, outcome, and utilization of resources must be maintained. This fact gains even more importance as patients and their families claim "high end" treatment. Such a demand is reflected looking at the developments that have taken place over the last 25 years. Mainly, the focus of intensive care medicine was on technical support or even replacement of failing organ systems such as the lungs, the heart, or the kidneys by veno-venous extracorporeal membrane oxygenation (VV-ECMO), veno-arterial ECMO (VA-ECMO), and continuous veno-venous hemofiltration (CVVH) respectively. This means "technical care" became a core capability and expectation of critical care medicine. In parallel, medical treatment became more standardized. For example, lung protective ventilation strategies, early enteral feeding, and daily sedation vacation are part of modern protocols. As a consequence, ventilator time has been reduced and patients therefore develop delirium less frequently. These measures, beside others, are implemented in care bundles to improve the quality of care of patients by the whole ICU team. The importance of specialty trained teams was already pointed out 35 years ago when Li et al.,2 demonstrated in a study performed in a community hospital that the mortality was decreased if an ICU was managed 24/7 by an on-site physician. The association of improved outcomes and presence of a critical care trained physician (intensivist) has been shown in several studies since that time.3,4,5,6 A modern multidisciplinary critical care team consists at least of an intensivist, ICU nurse, pharmacist, respiratory therapist, physiotherapist, and the primary team physician. Based on clinical needs, the team can be supplemented by oncologists, cardiologists, or other specialties. Again, this approach is supported by research: a recent retrospective cohort study from the California Hospital Assessment and Reporting Taskforce (CHART) on 60,330 patients confirmed the association between improved patient outcome and such a multidisciplinary team.7 If such an intensive care team makes a difference, why do not all patients at risk receive advanced ICU-care? It was already demonstrated by Esteban et al., in a prospective study that patients with severe sepsis had a mortality rate of 26% when not admitted to an ICU in comparison to 11% when they were admitted to an ICU.8 Meanwhile, we know that early referral is particularly important, because for ischemic diseases the timing appears to make a difference in terms of full recovery. So, the following questions arise: Should intensive care be rolled out to each ward and physical admission to an ICU or be restricted to special cases only? For this purpose, the so-called "Rapid Response Teams" (RRT) or "Medical Emergency Team" (MET), which essentially are a form of an ICU outreach team, were implemented. The name, composition, or exact role of such team varies from institution to institution and country to country. Alternatively, should all ward staff be educated to recognize sick patients earlier for a timely transfer to a dedicated area? This would mean that ICU-care would be introduced in the ward. A first attempt to answer this question, whether to deploy critical care resources to deteriorating patients outside the ICU 24/7, was given by Churpek et al.9 The success of the rapid response teams could be related to decreased rates of cardiac arrest outside the ICU setting and in-hospital mortality. Interestingly, an analysis of the registry database of the RRT calls in this study showed that the lowest frequency of calls occurred between 1:00 AM to 6:59 AM time period. In contrast, the mortality was highest around 7 AM and lowest during noon hour. This indicates that not simply the availability of such a team makes a difference but also the alertness of the ward-teams is of high importance to identify deteriorating patients in a timely manner. Essentially, this would necessitate ward staff being trained to provide a higher level of care enabling them to better recognize when patients become sicker to avoid a delayed call to the ICU. Alternatively, a system in which the intensivist plays a major role in daily ward rounds could be beneficial. So, the ward doctor should become an intensivist. However, the latter means the ICU is rolled out across the whole hospital which would consume a huge amount of resources. Another option would be 24/7 remote monitoring of patients at risk that notifies the intensivist or RRT in case of need. The infrastructure, technology, and manpower to put this in place also has associated costs. As the demand for ICU care will rise further in the future, intensivists will play an even more important role in the healthcare system that itself is under enormous economic pressure to ensure the best quality of care for critically ill patients. Besides excellent knowledge and hard skills, intensivists need to be team players, communicators, facilitators, and arbitrators to achieve the best results in collaboration with all involved in patient treatment.

Plasminogen associates with phosphatidylserine-exposing platelets and contributes to thrombus lysis under flow.

The interaction of plasminogen with platelets and their localization during thrombus formation and fibrinolysis under flow are not defined. Using a novel model of whole blood thrombi, formed under flow, we examine dose-dependent fibrinolysis using fluorescence microscopy. Fibrinolysis was dependent upon flow and the balance between fibrin formation and plasminogen activation, with tissue plasminogen activator-mediated lysis being more efficient than urokinase plasminogen activator-mediated lysis. Fluorescently labeled plasminogen radiates from platelet aggregates at the base of thrombi, primarily in association with fibrin. Hirudin attenuates, but does not abolish plasminogen binding, denoting the importance of fibrin. Flow cytometry revealed that stimulation of platelets with thrombin/convulxin significantly increased the plasminogen signal associated with phosphatidylserine (PS)-exposing platelets. Binding was attenuated by tirofiban and Gly-Pro-Arg-Pro amide, confirming a role for fibrin in amplifying plasminogen binding to PS-exposing platelets. Confocal microscopy revealed direct binding of plasminogen and fibrinogen to different platelet subpopulations. Binding of plasminogen and fibrinogen co-localized with PAC-1 in the center of spread platelets. In contrast, PS-exposing platelets were PAC-1 negative, and bound plasminogen and fibrinogen in a protruding "cap." These data show that different subpopulations of platelets harbor plasminogen by diverse mechanisms and provide an essential scaffold for the accumulation of fibrinolytic proteins that mediate fibrinolysis under flow.

Platelet Control of Fibrin Distribution and Microelasticity in Thrombus Formation Under Flow.

OBJECTIVE: Platelet- and fibrin-dependent thrombus formation is regulated by blood flow and exposure of collagen and tissue factor. However, interactions between these blood-borne and vascular components are not well understood. APPROACH AND RESULTS: Here, we developed a method to assess whole-blood thrombus formation on microspots with defined amounts of collagen and tissue factor, allowing determination of the mechanical properties and intrathrombus composition. Confining the collagen content resulted in diminished platelet deposition and fibrin formation at high shear flow conditions, but this effect was compensated by a larger thrombus size and increased accumulation of fibrin in the luminal regions of the thrombi at the expense of the base regions. These thrombi were more dependent on tissue factor-triggered thrombin generation. Microforce nanoindentation analysis revealed a significantly increased microelasticity of thrombi with luminal-oriented fibrin. At a low shear rate, fibrin fibers tended to luminally cover the thrombi, again resulting in a higher microelasticity. Studies with blood from patients with distinct hemostatic insufficiencies indicated an impairment in the formation of a platelet-fibrin thrombus in the cases of dilutional coagulopathy, thrombocytopenia, Scott syndrome, and hemophilia B. CONCLUSIONS: Taken together, our data indicate that (1) thrombin increases the platelet thrombus volume; (2) tissue factor drives the formation of fibrin outside of the platelet thrombus; (3) limitation of platelet adhesion redirects fibrin from bottom to top of the thrombus; (4) a lower shear rate promotes thrombus coverage with fibrin; (5) the fibrin distribution pattern determines thrombus microelasticity; and (6) the thrombus-forming process is reduced in patients with diverse hemostatic defects.

The use of regression analysis in determining reference intervals for low hematocrit and thrombocyte count in multiple electrode aggregometry and platelet function analyzer 100 testing of platelet function.

Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r2 ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r2 = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.

Management of severe perioperative bleeding: guidelines from the European Society of Anaesthesiology: First update 2016.

: The management of perioperative bleeding involves multiple assessments and strategies to ensure appropriate patient care. Initially, it is important to identify those patients with an increased risk of perioperative bleeding. Next, strategies should be employed to correct preoperative anaemia and to stabilise macrocirculation and microcirculation to optimise the patient's tolerance to bleeding. Finally, targeted interventions should be used to reduce intraoperative and postoperative bleeding, and so prevent subsequent morbidity and mortality. The objective of these updated guidelines is to provide healthcare professionals with an overview of the most recent evidence to help ensure improved clinical management of patients. For this update, electronic databases were searched without language restrictions from 2011 or 2012 (depending on the search) until 2015. These searches produced 18 334 articles. All articles were assessed and the existing 2013 guidelines were revised to take account of new evidence. This update includes revisions to existing recommendations with respect to the wording, or changes in the grade of recommendation, and also the addition of new recommendations. The final draft guideline was posted on the European Society of Anaesthesiology website for four weeks for review. All comments were collated and the guidelines were amended as appropriate. This publication reflects the output of this work.

Validation of a modified thromboelastometry approach to detect changes in fibrinolytic activity.

BACKGROUND: Thus far, validated whole blood assays used in in vitro fibrinolysis experiments using thromboelastometry (ROTEM) are lacking or have yet to be tested in humans. The objective was first, to establish a standardized modified ROTEM approach to detect both hypo- and hyperfibrinolysis. And second, to perform a technical and clinical validation of the assay. METHODS: Blood was used of healthy volunteers, patients with sepsis, patients after cardiothoracic surgery, pregnant women, and cirrhotic liver disease patients. A whole blood tissue factor (TF) activated ROTEM assay with and without the addition of recombinant tissue plasminogen activator (rTPA) was developed. Plasma fibrinolysis determinants were measured in all volunteers and patients. RESULTS: Thirty five pM TF and additions of 125 and 175 ng/ml rTPA resulted in full lysis within 60 min in healthy volunteers. Coefficients of variation were below 10 % without and below 20 % with rTPA addition. In sepsis the hypofibrinolytic ROTEM profiles with 175 ng/ml rTPA were in line with the plasma determinants (high PAI-1, high fibrinogen, low tPA activity, and high d-dimers). After cardiothoracic surgery, reduced fibrinogen and platelet levels accounted for the reduced maximum clot firmness. The hypofibrinolytic profile is attributed to tranexamic acid use and elevated PAI-1 levels. The lowest rTPA concentration in cirrhosis resulted in hyperfibrinolysis in only few of the patients. In pregnancy normal profiles were found. DISCUSSION: Our high rTPA concentration demonstrates hypofibrinolytic profiles adequately in sepsis and after cardiothoracic surgery. Our low rTPA concentration of 125 ng/ml seems too high for demonstrating hyperfibrinolysis in cirrhotic liver disease. CONCLUSIONS: We were able to present a validated whole blood ROTEM approach to fibrinolysis testing using added rTPA, which can be of added value next to classical plasma based fibrinolysis assays.

A general review of major global coagulation assays: thrombelastography, thrombin generation test and clot waveform analysis.

Thrombosis and hemorrhage are major contributors to morbidity and mortality. The traditional laboratory tests do not supply enough information to diagnose and treat patients timely and according to their phenotype. Global hemostasis tests might improve this circumstance. The viscoelastic tests (ROTEM/TEG) demonstrated to ameliorate treatment of acute hemorrhage in terms of decreased amount of transfusion and lowered costs. Thrombin generation measurement is indicative for thrombosis and might also become an important tool in managing hemorrhage. While the clot waveform analysis is less well known it could be of worth in staging sepsis patients, early detection of DIC and also in diagnosis and treatment monitoring of hemophiliac patients. Although in different degree all three methods still need more background, standardization and acceptance before a wide clinical application.

Cardiac output measurement by bioimpedance and noninvasive pulse contour analysis compared with the continuous pulmonary artery thermodilution technique.

OBJECTIVE: The aim of the present study was to compare 2 noninvasive cardiac output measurement methods with the continuous cardiac output thermodilution (CCO-TD) method. DESIGN: A single-center prospective design. SETTING: A university hospital. PARTICIPANTS: Fifty-three consecutive patients scheduled for elective, non-emergent cardiac surgery. INTERVENTIONS: With each participant the cardiac output was measured using 3 methods: CCO-TD, the Endotracheal Cardiac Output Monitor (ECOM), and the Nexfin monitor. MEASUREMENTS AND MAIN RESULTS: Measurements were performed simultaneously at 7 time points: After induction, before cardiopulmonary bypass, after cardiopulmonary bypass, after protamine, after arrival in the intensive care unit, and before extubation on postoperative day 1. Statistical analysis was performed using Pearson's correlation, Bland-Altman, percent error, and polar plots. Compared to CCO-TD, ECOM showed significant correlation of R0.619 with a bias of -0.13 L/min (95% confidence interval -2.19-1.93 L/min), a percent error of 40%, and trending ability of 87% and 97% within 0.5 L/min and 1.0 L/min, respectively. The Nexfin monitor showed significant correlation of R0.535 with a bias of-0.35 L/min (95% confidence interval-3.36-2.66 L/min), a percent error of 58% and trending ability of 84% and 97% were within 0.5 L/min and 1.0 L/min limits of agreement. CONCLUSIONS: Neither the ECOM nor the Nexfin had the ability to replace the thermodilution-based continuous cardiac output monitor. The ECOM did not have acceptable accuracy or trending ability and only could be utilized for intubated patients. The Nexfin lacked reliability and trending ability. Also, the Nexfin did not provide consistent results.

Rapid and correct prediction of thrombocytopenia and hypofibrinogenemia with rotational thromboelastometry in cardiac surgery.

OBJECTIVES: In the present study, the authors have investigated whether rotational thromboelastometry (ROTEM) could predict thrombocytopenia and hypofibrinogenemia in cardiac surgery using the clot amplitude after 5 minutes (A5). Another parameter, PLTEM, in which the contribution of fibrinogen is eliminated by subtracting a fibrin-specific ROTEM test (FIBTEM) from an extrinsically-activated ROTEM test (EXTEM), was investigated. Furthermore, the turnaround time of ROTEM was compared to conventional laboratory tests. DESIGN: Prospective cohort study. SETTING: Single academic medical center. PARTICIPANTS: Ninety-seven patients undergoing cardiac surgery between July 2011 until August 2012. INTERVENTIONS: The correlations between EXTEM/FIBTEM A5, A10, and maximal clot formation (MCF), EXTEM/PLTEM (A5/A10, and MCF) and platelet count, and FIBTEM (A5/A10, and MCF) and fibrinogen were evaluated using the Pearson's correlation coefficient and receiver-operating characteristic curves. Turnaround times of ROTEM tests and conventional laboratory tests were assessed in the central laboratory. MEASUREMENTS AND MAIN RESULTS: EXTEM A5 and FIBTEM A5 showed an excellent correlation with A10 (R:0.99/1.00) and MCF (R:0.97/0.99). The correlation between EXTEM A5 and platelet count (R:0.74) was comparable with the correlation of A10 (R:0.73) and MCF (R:0.70) with platelet count. FIBTEM A5 predicted fibrinogen levels (R:0.87) as well as A10 (R:0.86) and MCF (R:0.87). PLTEM A5 (R:0.85) correlated better with platelet count than EXTEM A5 (R:0.74; p = 0.04) and showed significantly better area under the curve values than EXTEM for predicting thrombocytopenia (A5 p = 0.012, A10 p = 0.019). Turnaround time for ROTEM tests, 12 minutes, was comparable with emergency requests for platelet count, 13 minutes, and shorter than emergency requests for fibrinogen levels, 37 minutes. CONCLUSIONS: Implementation of PLTEM and FIBTEM A5 in ROTEM-guided transfusion protocols may improve transfusion management.

Fibrinogen contribution to clot strength in patients with sepsis and hematologic malignancies and thrombocytopenia-a prospective, single-center, analytical, cross-sectional study.

Background: Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels. Objectives: To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia. Methods: We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF. Results: Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group. Conclusion: Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

Do blood collection methods influence whole-blood platelet function analysis?

Pre-analytical variables interact with standard coagulation parameters. How these variables affect the platelet function analysis is not completely known. How collection site and puncture method affect multiple electrode aggregometry (MEA) and platelet function analyzer (PFA-100®) was compared regarding contact activation. First, volunteers scheduled for elective cardiac surgery had blood collected from four lines: venous, arterial, central venous and by venipuncture. MEA and PFA-100® were analysed blinded for site origin. Second, two samples (citrate, Corn Trypsin Inhibitor, CTI) were collected in syringe or vacuum tubes. Thrombin generation (TG) was determined. MEA was triggered by adenosine diphosphate (ADP, 6.4 µM), arachidonic acid (ASPI, 0.5 mM), collagen (Col, 3.2 µg/ml), ristocetin (Risto, 0.2 mg/ml) and thrombin receptor-activating peptide (TRAP, 32 µM). PFA-100® was triggered by collagen/epinephrine and collagen/ADP. TG was assessed in platelet-poor plasma with 1 pM tissue factor and 4 µM phospholipids and without trigger. Data were analysed using a two-way mixed-effects model for the intraclass correlation (ICC) and by the Mann-Whitney U-test. MEA and PFA-100® revealed good correlation (ICC) between the sites. CTI inhibited TG significantly more effective than citrate. Contact activation was independent of the collection method. Only the MEA ASPI test revealed significant differences between the two collection methods. Blood sampling from all lines for MEA and PFA-100® assays is justified. Contact activation is always present. Apparently this does not influence platelet function test results. Collection methods do not seem relevant, although, one should always consider using a standardized method.

The effect of different lung-protective strategies in patients during cardiopulmonary bypass: a meta-analysis and semiquantitative review of randomized trials.

OBJECTIVES: A variety of lung-protective techniques, including continuous positive airway pressure and vital capacity maneuvers, have been suggested as beneficial when applied during cardiopulmonary bypass (CPB). To better define the efficacy of these techniques, a systematic review of different ventilation strategies during and after CPB was performed. DESIGN: A systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. SETTING: Hospitals. PARTICIPANTS: Eight hundred fourteen participants of 16 randomized controlled trials. INTERVENTIONS: Continuous positive airway pressure (CPAP), low-volume ventilation, or vital capacity maneuvers (VCMs) during CPB. MEASUREMENTS AND MAIN RESULTS: The methodologic validity of the included trials was scored according to the Oxford scale. Included trials had to report on at least 1 of the following parameters: oxygenation, oxygenation index, alveolar-arterial oxygen difference, or shunt fraction. The average quality of the included trials was as low as 2 on a scale from 1 to 5. The use of CPAP or VCM during CPB led to a significant increase in oxygenation parameters immediately after weaning from CPB, but this effect was not sustainable and did not improve patient outcome. CONCLUSIONS: This meta-analysis showed that the positive effects of the designated techniques are probably short-lived with a questionable impact on the long-term clinical outcome of the treated patients. Based on the available data, it might be impossible to advise an optimal or best-evidence strategy of lung preservation during CPB.

Platelet monitoring follow-up in a pregnant patient with HELLP syndrome.

Monitoring the course of platelet function in HELLP (haemolysis, elevated liver-enzymes and low platelets) syndrome is important for clinical decision-making. We present a primigravid woman developing HELLP syndrome at 29 weeks and 6 days. Platelet function was monitored by multiple electrode aggregometry (MEA), platelet function analyzer (PFA-100®), platelet count and mean platelet volume (MPV) over an 11-day period. MPV and PFA-100® seem better predictors for platelet function than platelet levels.

Nurse-run preanaesthesia assessment clinics: an initiative towards improving the quality of perioperative care at the ambulatory care centre.

INTRODUCTION: Nurse-run preanaesthesia assessment is well established in ambulatory surgery. However, in the Middle East the implementation of such a service is new and needed careful preparation. Aim of this audit is to assess the feasibility and the quality of preoperative assessments by the specially trained nurses, patient and nurse satisfaction and overall perioperative quality of recovery. METHODS: The nurses were selected and trained first in an accredited programme. Then an implementation period of 3 month was used for them to gain experience. Hereafter, we performed a four-step audit on the quality of preassessment, the patient's satisfaction, the quality of recovery and adverse events if any. Finally, we also monitored the nurse's satisfaction of their new advanced role. RESULTS: The quality of preanaesthesia assessment was high as with 95% compliance to the accepted standards. In the patient satisfaction survey, all 152 patients were either highly satisfied or satisfied with the nurse-run service. The nurses were also highly satisfied and felt that they were either highly or moderately valued. All the patients who were operated at the ambulatory care services were followed up postoperatively by telephone calls which revealed that most of them were highly satisfied. No major or minor adverse events occurred. CONCLUSION: Our specially trained nurses perform preoperative assessments on high standard without adverse events, while patient and staff satisfaction is very high. Future projects will focus on reducing the rate of cancellation of surgeries, investigating the cost-effectiveness of this approach as well as training the specialised nurses for paediatric preoperative anaesthesia assessments. This model of care could induce further nurse-run models of care in the Middle East.

Do we need time adjusted mean platelet volume measurements?

Mean platelet volume (MPV) is associated with various diseases. Several authors reported anticoagulant and time dependency. Therefore, standardized laboratory methods are essential. The aim of this study was to standardize the MPV measurement. Blood was collected in potassium-ethylenediaminetetra-acid (EDTA) and sodium-citrate tubes. First, MPV and platelet count were determined every half hour for 4 hours in 20 healthy volunteers. The same parameters were acquired from a second group of 100 healthy donors. We measured at the point of highest stability determined in the first step and aimed to determine a reference range. Citrate samples revealed significantly smaller MPV (7.0 fL ± 0.69 standard deviation [SD]) than EDTA (8.0 fL ± 0.8 SD). Platelets swell until 120 minutes in EDTA and until 60 minutes in citrate. Mean platelet count changed significantly in citrate. In the second group, no inverse correlation between MPV and platelet count was seen. A reference range was calculated (EDTA, 7.2-10.8 fL; citrate, 6.1-9.5 fL). Platelets stored in citrate are significantly smaller compared to those stored in EDTA. Timing is important when measuring platelet volume. Optimal measuring time should be 120 minutes after venipuncture. For this we depicted a reference range. Platelet count is most stable in EDTA. There was no inverse relation between MPV and platelet count.