The Adherence to an Intraoperative Blood Product Transfusion Algorithm Is Associated With Reduced Blood Product Transfusions in Cardiac Surgical Patients Undergoing Coronary Artery Bypass Grafts and Aortic and/or Valve Replacement Surgery: A Single-Center, Observational Study

OBJECTIVE

To demonstrate the value of a viscoelastic-based intraoperative transfusion algorithm to reduce non-RBC product administration in adult cardiac surgical patients.

DESIGN

A prospective observational study.

SETTING

At a quaternary academic teaching hospital.

PARTICIPANTS

Cardiac surgical patients.

INTERVENTIONS

Viscoelastic-based intraoperative transfusion algorithm.

MEASUREMENTS AND MAIN RESULTS

The study authors compared intraoperative blood product transfusion rates in 184 cardiac surgical patients to 236 historic controls after implementing a viscoelastic-based algorithm. The authors found a non-significant reduction in transfusion of 23.8% for fresh frozen plasma (FFP) units (0.84 ± 1.4 v 0.64 ± 1.38; p = ns), 33.4% for platelet units (0.90 ± 1.39 v 0.60 ± 131; p = ns), and 15.8% for cryoprecipitate units (0.19 ± 0.54 v 0.16 ± 0.50; p = ns). They found a 43.9% reduction in red blood cell (RBC) units transfused (1.98 ± 2.24 v 0.55 ± 1.36; p = 0.008). There were no statistically significant differences in time to extubation (8.0 hours (4.0-21.0) v 8.0 (4.0-22.3), reoperation for bleeding (15 [12.3%] v 10 [10.6%]), intensive care unit length of stay (ICU LOS) (51.0 hours [28.0-100.5] v 53.5 [33.3-99.0]) or hospital LOS (9.0 days [6.0-15.0] v 10.0 [7.0-17.0]). Deviation from algorithm adherence was 32.7% (48/147). Packed RBC, FFP, platelets, cryoprecipitate, and cell saver were significantly reduced in the Algorithm Compliant Cohort compared with historic controls, whereas times to extubation, ICU LOS, and hospital LOS did not reach significance.

CONCLUSIONS

After the implementation of a viscoelastic-based algorithm, patients received fewer packed RBC, FFP, platelets, cryoprecipitate, and cell saver. Algorithm-compliant patients received fewer transfusions; however, reductions in times to extubation, ICU LOS, and hospital LOS were not statistically significant compared with historic controls.

Treating periprocedural bleeding in patients with cirrhosis

Patients with cirrhosis are known to have an abnormal coagulation status, which is a particular concern when planning invasive procedures in which blood loss is possible or predictable. Careful consideration must be given to the bleeding risk for each individual patient and coagulation management strategies should be established in advance of procedural interventions, where possible. Perioperative clinical decision-making should utilize viscoelastic testing in addition to usual assessments, where possible, and focus on the well-established three pillars of patient blood management: optimization of erythropoiesis, minimization of bleeding and blood loss, and management of anemia. Restrictive transfusion policies, careful hemostatic monitoring, and a proactive approach to predicting and preventing bleeding on an individual patient basis should be central to managing perioperative bleeding in the fragile patient population with cirrhosis. This review discusses coagulation assessments and bleeding management techniques necessary before, during, and after surgical interventions in patients with cirrhosis, and provides expert clinical opinion and physician experience on the perioperative management of these patients.

Implementation of a Bleeding Management Algorithm in Liver Transplantation: A Pilot Study

Objectives

The aims of the study were to compare the consumption of blood products before and after the implementation of a bleeding management algorithm in patients undergoing liver transplantation and to determine the feasibility of a multicentre, randomized study.

Background

Liver transplantation remains the only curative therapy for patients with end-stage liver disease, but it carries a high risk of surgical bleeding.

Materials and Methods

Retrospective study of patients treated before (group 1) and after (group 2) implementation of a haemostatic algorithm guided by viscoelastic testing, including use of lyophilized coagulation factor concentrates (prothrombin complex and fibrinogen concentrates). Primary outcome was the number of units of blood products transfused in 24 h after surgery. Secondary outcomes included hospital stay, mortality, and cost.

Results

Data from 30 consecutive patients was analysed; 14 in group 1 and 16 in group 2. Baseline data were similar between groups. Median total blood product consumption 24 h after surgery was 33 U (IQR: 11-57) in group 1 and 1.5 (0-23.5) in group 2 (p = 0.028). Significantly fewer units of red blood cells, fresh frozen plasma, and cryoprecipitate were transfused in group 2 versus group 1. There was no significant difference in complications, hospital stay, or in-hospital mortality between groups. The cost of haemostatic therapy was non-significantly lower in group 2 versus group 1 (7,400 vs. 15,500 USD; p = 0.454).

Conclusion

The haemostatic management algorithm was associated with a significant reduction in blood product use during 24 h after liver transplantation. This study demonstrated the feasibility and provided a sample size calculation for a larger, randomized study.

Evaluation of coagulopathy in cirrhotic patients: A scoping review of the utility of viscoelastic testing

BACKGROUND

Cirrhosis causes significant coagulopathy. Traditional coagulation tests may not accurately measure coagulopathy in well-compensated patients with cirrhosis. Viscoelastic tests are functional tests that may better assess coagulopathy in cirrhotic patients.

METHODS

We searched PubMed, ScienceDirect, Google Scholar, and grey literature using terms meaning viscoelastic testing and cirrhosis. After reviewing over 500 titles and abstracts, 40 full-text papers met inclusion criteria.

RESULTS

Twenty-two papers found viscoelastic testing was a better indicator of baseline coagulation than traditional testing in cirrhosis. Nineteen additional papers evaluated the utility of peri-procedural viscoelastic testing and found they led to a reduction in blood product administration without increasing risk of hemorrhage, thrombotic events, or other complications.

CONCLUSIONS

The usage of viscoelastic testing in patients with cirrhosis allows for better assessment of coagulopathy, resulting in improved outcomes. Educating physicians to optimize care of this high-risk group is necessary to further improve their treatment.

Use of viscoelastic tests in the principle bleeding scenarios in Spanish hospitals

Viscoelastic tests are designed to study the dynamics of clot formation, identify coagulopathies in real time, arrive at a diagnosis, and guide patient-specific administration of haemostatics. They are mainly used to treat clinically significant bleeding in any setting, and are also used in other situations involving clinically relevant alterations in haemostasis, such as coagulopathy in critically ill patients. These tests are administered following evidence-based algorithms that vary depending on the clinical context. This review summarises the results of a survey conducted in several hospitals to determine the prevalence and standardisation of viscoelastic tests in cardiac surgery, liver transplantation, and multiple trauma patients in Spain. The results reveal divergent opinions on key aspects, ranging from the diagnostic capacity of these tests to the interpretation of the basic parameters. On the basis of these findings, we propose a number of potential areas in which further research will improve the performance of these tests.

Point-of-care diagnosis and monitoring of fibrinolysis resistance in the critically ill: results from a feasibility study

BACKGROUND

Fibrinolysisis is essential for vascular blood flow maintenance and is triggered by endothelial and platelet release of tissue plasminogen activator (t-PA). In certain critical conditions, e.g. sepsis, acute respiratory failure (ARF) and trauma, the fibrinolytic response is reduced and may lead to widespread thrombosis and multi-organ failure. The mechanisms underpinning fibrinolysis resistance include reduced t-PA expression and/or release, reduced t-PA and/or plasmin effect due to elevated inhibitor levels, increased consumption and/or clearance. This study in critically ill patients with fibrinolysis resistance aimed to evaluate the ability of t-PA and plasminogen supplementation to restore fibrinolysis with assessment using point-of-care ClotPro viscoelastic testing (VET).

METHODS

In prospective, observational studies, whole-blood ClotPro VET evaluation was carried out in 105 critically ill patients. In 32 of 58 patients identified as fibrinolysis-resistant (clot lysis time > 300 s on the TPA-test: tissue factor activated coagulation with t-PA accelerated fibrinolysis), consecutive experimental whole-blood VET was carried out with repeat TPA-tests spiked with additional t-PA and/or plasminogen and the effect on lysis time determined. In an interventional study in a patient with ARF and fibrinolysis resistance, the impact of a 24 h intravenous low-dose alteplase infusion on coagulation and fibrinolysis was prospectively monitored using standard ClotPro VET.

RESULTS

Distinct response groups emerged in the ex vivo experimental VET, with increased fibrinolysis observed following supplementation with (i) t-PA only or (ii) plasminogen and t-PA. A baseline TPA-test lysis time of > 1000 s was associated with the latter group. In the interventional study, a gradual reduction (25%) in serial TPA-test lysis times was observed during the 24 h low-dose alteplase infusion.

CONCLUSIONS

ClotPro viscoelastic testing, the associated TPA-test and the novel experimental assays may be utilised to (i) investigate the potential mechanisms of fibrinolysis resistance, (ii) guide corrective treatment and (iii) monitor in real-time the treatment effect. Such a precision medicine and personalised treatment approach to the management of fibrinolysis resistance has the potential to increase treatment benefit, while minimising adverse events in critically ill patients.

TRIAL REGISTRATION

VETtiPAT-ARF, a clinical trial evaluating ClotPro-guided t-PA (alteplase) administration in fibrinolysis-resistant patients with ARF, is ongoing (ClinicalTrials.gov NCT05540834 ; retrospectively registered September 15th 2022).

The Quantra System: System Description and Protocols for Measurements

Over the past two decades, the TEG 5000 (Haemonetics Corp, Braintree, MA) and ROTEM delta (Werfen, Bedford, MA) have been the principal viscoelastic (VET) technologies. These legacy technologies are based on the "cup and pin" principle. The Quantra System (HemoSonics, LLC, Durham, NC) is a new device that assesses blood viscoelastic properties by ultrasound (SEER Sonorheometry). It is cartridge based, automated device that provides simplified specimen management and increased results reproducibility. In the present chapter, we provide a description of the Quantra and its principle of operation, currently available cartridges/assays with their respective clinical indications, device operation, and results interpretation.

The TEG 6s System: System Description and Protocol for Measurements

A new generation of thromboelastography, TEG 6s (Haemonetics, Boston, MA), that assesses blood viscoelastic properties by resonance technology has recently been developed. This newer methodology represents a cartridge-based, automated assay aimed to improve on historical TEG performance and precision. In a previous chapter, we reviewed the advantages and limitations of TEG 6s as well as factors that affect TEG 6s and which must be considered when interpreting tracings. In the present chapter, we provide a description of the TEG 6s principle and its operation protocol.

The TEG 5000 System: System Description and Protocol for Measurements

The thromboelastograph (TEG) has undergone several modifications, but the concept on which the original TEG was based (cup and pin technology) remained up to the TEG 5000 analyzer (Haemonetics, Braintree, MA). In a previous chapter, we reviewed the advantages and limitations of TEG 5000 as well as factors that affect TEG and which must be considered when interpreting tracings. In the present chapter, we provide a description of the TEG 5000 principle and its operation protocol.

Measurement of Blood Viscoelasticity Using Thromboelastography

Thromboelastography (TEG) was the first viscoelastic test (VET), invented in Germany in 1948 by Dr. Hartert, and which evaluates the hemostatic competence of whole blood. Thromboelastography was introduced before the activated partial thromboplastin time (aPTT), which was devised in 1953. TEG was not widely used until the introduction of a cell-based model of hemostasis (1994) showing the importance of platelets and tissue factor in hemostasis. Nowadays, VET has become an essential method for assessing hemostatic competence in cardiac surgery, liver transplantation, and trauma. TEG has undergone several modifications, but the concept on which the original TEG was based (cup and pin technology) remained in up to the TEG 5000 analyzer (Haemonetics, Braintree, MA). A new generation of thromboelastography, TEG 6s (Haemonetics, Boston, MA), that assesses blood viscoelastic properties by resonance technology has recently been developed. This newer methodology represents a cartridge-based, automated assay aimed to improve on historical TEG performance and precision. In the present chapter, we will review the advantages and limitations of TEG 5000 and TEG 6s systems as well as factors that affect TEG and which must be considered when interpreting TEG tracings.

Predictive ability of viscoelastic testing using ClotPro® for short-term outcome in patients with severe Covid-19 ARDS with or without ECMO therapy: a retrospective study

BACKGROUND

SARS-CoV-2 infections are suspected to trigger the coagulation system through various pathways leading to a high incidence of thromboembolic complications, hypercoagulation and impaired fibrinolytic capacity were previously identified as potentially mechanisms. A reliable diagnostic tool for detecting both is still under discussion. This retrospective study is aimed to examine the prognostic relevance of early viscoelastic testing compared to conventional laboratory tests in COVID-19 patients with acute respiratory distress syndrome (ARDS).

METHODS

All mechanically ventilated patients with COVID-19 related ARDS treated in our intensive care unit (ICU) between January and March 2021 were included in this study. Viscoelastic testing (VET) was performed using the ClotPro® system after admission to our ICU. Prevalence of thromboembolic events was observed by standardized screening for venous and pulmonary thromboembolism using complete compression ultrasound and thoracic computed tomography pulmonary angiography at ICU admission, respectively. We examined associations between the severity of ARDS at admission to our ICU, in-hospital mortality and the incidence of thromboembolic events comparing conventional laboratory analysis and VET. ECMO related coagulopathy was investigated in a subgroup analysis. The data were analyzed using the Mann-Whitney U test.

RESULTS

Of 55 patients enrolled in this study, 22 patients required treatment with ECMO. Thromboembolic complications occurred in 51% of all patients. Overall hospital mortality was 55%. In patients with thromboembolic complications, signs of reduced fibrinolytic capacity could be detected in the TPA assay with prolonged lysis time, median 460 s (IQR 350-560) vs 359 s (IQR 287-521, p = 0.073). Patients with moderate to severe ARDS at admission to our ICU showed increased maximum clot firmness as a sign of hypercoagulation in the EX-test (70 vs 67 mm, p < 0.05), FIB-test (35 vs 24 mm, p < 0.05) and TPA-test (52 vs 36 mm, p < 0.05) as well as higher values of inflammatory markers (CRP, PCT and IL6). ECMO patients suffered more frequently from bleeding complications (32% vs 15%).

CONCLUSION

Although, the predictive value for thromboembolic complications or mortality seems limited, point-of-care viscoelastic coagulation testing might be useful in detecting hypercoagulable states and impaired fibrinolysis in critically ill COVID-19 ARDS patients and could be helpful in identifying patients with a potentially very severe course of the disease.

Comparison of the resonance sonorheometry based Quantra® system with rotational thromboelastometry ROTEM® sigma in cardiac surgery - a prospective observational study

BACKGROUND

Measures of the sonorheometry based Quantra® viscoelastic hemostatic analyzer (HemoSonics, LCC, Charlottesville, VA, USA) were compared with corresponding results of the ROTEM® sigma device (Instrumentation Laboratory, Bedford, MA, USA).

METHODS

In thirty-eight patients scheduled for elective cardiac surgery between December 2018 and October 2019, blood samples were taken after induction of anesthesia (sample 1) and after heparin neutralization (sample 2) and measured on Quantra (QPlus® Cartridge) and ROTEM sigma (ROTEM® sigma complete + hep Cartridge). Clot times and clot stiffness values were recorded. Clot stiffness values of ROTEM amplitudes (A in mm) were converted to shear modulus (G) in hectoPascal (hPa): G (hPa) = (5 x A)/(100-A). Additionally, time-to-results was recorded. Spearman rank test correlation and Bland Altman analysis were performed.

RESULTS

Clot stiffness parameters of the Quantra correlated strongly with corresponding measurements of the ROTEM with r = 0.93 and 0.94 for EXTEM A10 vs CS and r = 0.94 and 0.96 for FIBTEM A10 vs FCS for sample 1 and 2, respectively. Quantra clot time correlated strongly with ROTEM INTEM CT with r = 0.71 for sample 1 and r = 0.75 for sample 2. However, Bland Altman analysis showed no agreement in all compared assays of both methods. The median time to delivery of first and complete results was significantly shorter for Quantra (412 and 658 s) compared to ROTEM sigma (839 and 1290 s).

CONCLUSIONS

The Quantra showed a strong correlation with the ROTEM sigma for determining clot times and clot stiffness and the parameters assess similar aspects of clot development. However, these parameters are not directly interchangeable and implicate that separate cut-off values need to be established for users of the Quantra device. Word count: 278.

TRIAL REGISTRATION

The study was retrospectively registered with ClinicalTrials.gov (ID: NCT04210830 ) at December 20th 2019.

Comparison of Viscoelastic Testing by Rotational Torsion and Harmonic Resonance Methods

OBJECTIVES

To compare the performance of the TEG 5000 and TEG 6S Global Hemostasis cartridge.

METHODS

We reviewed validation data of the TEG 5000 and TEG 6S Global Hemostasis cartridge. The specimens were analyzed in parallel according to the manufacturer's operating instructions.

RESULTS

Fifty-four healthy donors and 13 donors with known hemostatic abnormalities were included. The correlations between instrument types were only moderate-the Spearman rank correlations were 0.55, 0.62, 0.64, and 0.72, respectively, for CK R, K, angle, and maximum amplitude (MA) parameters. Using the manufacturer's device-specific reference ranges to classify results as normal/abnormal, there was weak agreement in the qualitative interpretation of all parameters (Cohen's κ for agreement for CK R, K, angle, and MA was 0.418, 0.154, -0.083, and 0.127, respectively). This could lead to discordant transfusion decisions.

CONCLUSIONS

These findings indicate that the TEG 5000 and TEG 6S may not be used interchangeably.

Clinical utility of viscoelastic testing in chronic liver disease: A systematic review

BACKGROUND

Conventional coagulation tests are widely used in chronic liver disease to assess haemostasis and to guide blood product transfusion. This is despite the fact that conventional tests do not reliably separate those with a clinically significant coagulopathy from those who do not. Viscoelastic testing such as thromboelastography (TEG) correlate with bleeding risk and are more accurate in identifying those who will benefit from blood product transfusion. Despite this, viscoelastic tests have not been widely used in patients with chronic liver disease outside the transplant setting.

AIM

To assess the utility of Viscoelastic Testing guided transfusion in chronic liver disease patients presenting with bleeding or who require an invasive procedure.

METHODS

PubMed and Google Scholar searches were performed using the key words “thromboelastography”, “TEG” or “viscoelastic” and “liver transplantation”, “cirrhosis” or “liver disease” and “transfusion”, “haemostasis”, “blood management” or “haemorrhage”. A full text review was undertaken and data was extracted from randomised control trials that evaluated the outcomes of viscoelastic test guided transfusion in those with liver disease. The study subjects, inclusion and exclusion criteria, methods, outcomes and length of follow up were examined. Data was extracted by two independent individuals using a standardized collection form. The risk of bias was assessed in the included studies.

RESULTS

A total of five randomised control trials included in the analysis examined the use of TEG guided blood product transfusion in cirrhosis prior to invasive procedures (n = 118), non-variceal haemorrhage (n = 96), variceal haemorrhage (n = 60) and liver transplantation (n = 28). TEG guided transfusion was effective in all five studies with a statistically significant reduction in overall blood product transfusion compared to standard of care. Four of the five studies reported a significant reduction in transfusion of fresh frozen plasma and platelets. Two studies showed a significant reduction in cryoprecipitate transfusion. No increased risk of bleeding was reported in the three trials where TEG was used perioperatively or prior to an invasive procedure. Two trials in the setting of cirrhotic variceal and non-variceal bleeding showed no difference in control of initial bleeding. In those with variceal bleeding, there was a statistically significant reduction in rate of re-bleeding at 42 d in the TEG arm 10% (vs 26.7% in the standard of care arm P = 0.012). Mortality data reported at various time points for all five trials from 6 wk up to 3 years was not statistically different between each arm. One trial in the setting of non-variceal bleeding demonstrated a significant reduction in adverse transfusion events in the TEG arm 30.6% (vs 74.5% in the control arm P < 0.01). In this study there was no significant difference in total hospital stay although length of stay in intensive care unit was reduced by an average of 2 d in the TEG arm (P = 0.012).

CONCLUSION

Viscoelastic testing has been shown to reduce blood product usage in chronic liver disease without compromising safety and may enable guidelines to be developed to ensure patients with liver disease are optimally managed.

Evaluation of coagulation status using viscoelastic testing in intensive care patients with coronavirus disease 2019 (COVID-19): An observational point prevalence cohort study

Background

Coronavirus Disease-19 (COVID-19) is associated with a high rate of thrombosis, the pathophysiology of which is not well defined. Viscoelastic testing may identify and characterise hypercoagulable states which are not apparent using conventional coagulation assays.

Objectives

The objective of this study was to undertake viscoelastic evaluation of the coagulation state in critically ill adults with COVID-19–associated respiratory failure

Methods

This was a single-centre observational point prevalence cohort study of adults with COVID-19–associated respiratory failure requiring respiratory support in the intensive care unit. Coagulation status was evaluated using rotational thromboelastometry (ROTEM®) in conjunction with laboratory markers of coagulation.

Results

Six patients fulfilled inclusion criteria. Each patient had one ROTEM® performed. All patients had supranormal clot amplitude at 10 min (A10) and supranormal clot firmness (maximal clot firmness) measured in at least one ROTEM® pathway, and five were supranormal on all pathways. Minimal clot lysis was present on all analyses. Fibrinogen and D-dimer were elevated and routine markers of coagulation within normal ranges in all patients.

Conclusion

Patients with COVID-19–associated respiratory failure admitted to the intensive care unit exhibit a hypercoagulable state which is not appreciable on conventional tests of coagulation. Supranormal clot firmness, minimal fibrinolysis, and hyperfibrinogenaemia are key findings. Further research is required into the pathophysiology of this hypercoagulable state, as well as the harms and benefits of different anticoagulation strategies.

Viscoelastic Monitoring to Guide the Correction of Perioperative Coagulopathy and Massive Transfusion in Patients with Life-Threatening Hemorrhage

The resuscitation of patients with traumatic hemorrhage remains a challenging clinical scenario. The appropriate and aggressive support of the patient's coagulation is of critical importance. Conventional coagulation assays present several shortcomings in this setting. The integration of viscoelastic monitoring in clinical practice has the potential to result in significant improvements. In order to be successful, the provider must understand basics of the methodology, read outs, and the limitations of the technique.

Viscoelastic testing inside and beyond the operating room

Hemorrhage is a major contributor to morbidity and mortality during the perioperative period. Current methods of diagnosing coagulopathy have various limitations including long laboratory runtimes, lack of information on specific abnormalities of the coagulation cascade, lack of in vivo applicability, and lack of ability to guide the transfusion of blood products. Viscoelastic testing offers a promising solution to many of these problems. The two most-studied systems, thromboelastography (TEG) and rotational thromboelastometry (ROTEM), offer similar graphical and numerical representations of the initiation, formation, and lysis of clot. In systematic reviews on the clinical efficacy of viscoelastic tests, the majority of trials analyzed were in cardiac surgery patients. Reviews of the literature suggest that transfusions of packed red blood cells (pRBC), plasma, and platelets are all decreased in patients whose transfusions were guided by viscoelastic tests rather than by clinical judgement or conventional laboratory tests. Mortality appears to be lower in the viscoelastic testing groups, despite no difference in surgical re-intervention rates and massive transfusion rates. Cost-effectiveness studies also seem to favor viscoelastic testing. Viscoelastic testing has also been investigated in small studies in other clinical contexts, such as sepsis, obstetric hemorrhage, inherited bleeding disorders, perioperative thromboembolism risk assessment, and management of anticoagulation for patients on mechanical circulatory support systems or direct oral anticoagulants (DOACs). While the results are intriguing, no systematic, larger trials have taken place to date. Viscoelastic testing remains a relatively novel method to assess coagulation status, and evidence for its use appears favorable in reducing blood product transfusions, especially in cardiac surgery patients.

Viscoelastic monitoring in pediatric trauma: a survey of pediatric trauma society members

BACKGROUND

Viscoelastic monitoring (VEM), including thromboelastography (TEG) and rotational thromboelastometry (ROTEM) in the setting of goal-directed hemostatic resuscitation has been shown to improve outcomes in adult trauma. The American College of Surgeons (ACS) Committee on Trauma recommends that "thromboelastography should be available at level I and level II trauma centers". The purpose of this study is to determine the current availability and utilization of VEM in pediatric trauma.

METHODS

After IRB and Pediatric Trauma Society (PTS) approval, a survey was administered to the current members of the PTS via Survey Monkey. The survey collected demographic information, hospital and trauma program type, volume of trauma admissions, and use and/or availability of VEM for pediatric trauma patients.

RESULTS

We received 107 responses representing 77 unique hospitals. Survey respondents were: 61% physicians, 29% nurses, 6% trauma program managers, and 4% nurse practitioners/physician assistants. Over half of providers worked in a free standing children's hospital. Seventy-seven percent of respondents were from hospitals that had >200 trauma admissions/year, 42% were providers at ACS level 1 pediatric trauma centers, and 62% practiced at state level 1 designated centers. VEM was available to 63% of providers, but only 31% employed VEM in pediatric trauma patients. For those who had no VEM available, over 73% would utilize this technology if it was available. Seventy-one percent of providers continue to rely on conventional coagulation assays to monitor coagulopathy in pediatric trauma patients after admission.

CONCLUSIONS

While a growing body of evidence demonstrates the benefit of viscoelastic hemostatic assays in management of adult traumatic injuries, VEM during active resuscitation is infrequently used by pediatric trauma providers, even when the technology is readily available. This represents a timely and unique opportunity for quality improvement in pediatric trauma.

Viscoelastic testing for hepatic surgery: a systematic review with meta-analysis-a protocol

BACKGROUND

Viscoelastic tests, including thromboelastography (TEG) and rotational thromboelastometry (ROTEM), provide a global assessment of haemostatic function at the point of care. The use of a TEG or ROTEM system to guide blood product administration has been shown in some surgical settings to reduce transfusion requirements. The aim of this review is to evaluate all published evidence regarding viscoelastic testing in the setting of hepatic surgery.

METHODS

We will search MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials databases to identify randomised controlled trials examining the use of viscoelastic testing for hepatic surgery. Two reviewers will independently screen titles and abstracts of studies identified and will independently extract data. Any disagreements will be resolved by discussion with a third reviewer. A meta-analysis will be conducted if feasible.

DISCUSSION

Viscoelastic devices such as TEG and ROTEM are increasingly available to clinicians as a bedside test. Patients undergoing hepatic surgery have a significant risk of blood loss and coagulopathy requiring transfusion. Theoretical benefits of use of a TEG or ROTEM system in the hepatic surgical setting include a rationalisation of blood products, a reduction in transfusion-related side effects, an improvement in patient outcomes including mortality, and a reduction in cost. This systematic review will summarise the current evidence regarding the use of viscoelastic testing for hepatic surgery.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016036732.