Viscoelastic Tests Research Articles

Anticoagulation and Transfusion Management During Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Survey of Medical Directors in the United States.

To compare current practices within the United States of anticoagulation management and blood transfusion in neonatal and pediatric extracorporeal membrane oxygenation patients with a 2013 international report. Cross-sectional survey distributed between August and December 2019. Extracorporeal Life Support Organization-registered neonatal and pediatric extracorporeal membrane oxygenation centers in the United States. Extracorporeal membrane oxygenation medical directors. None. Eighty-three medical directors at 108 centers responded. After removing four duplicate responses, 79 surveys were analyzed. Seventy-nine percent (n = 62) report a written extracorporeal membrane oxygenation protocol for both anticoagulation and blood product management. Ninety-four percent (n = 74) report unfractionated heparin as their primary anticoagulant; the remaining use the direct thrombin inhibitor, bivalirudin. Ninety percent (n = 71) report measuring antifactor Xa levels. Most centers report using a combination of assays to monitor heparin therapy, either antifactor Xa and activated partial thromboplastin time (54%) or more commonly antifactor Xa and activated clotting time (68%). Forty-one percent use viscoelastic tests to aid management. Goal monitoring levels and interventions generated by out of range values are variable. Fifty-one percent will replace antithrombin. Platelet transfusion thresholds vary by age and center with ranges from 50,000 to 100,000 cells/µL. Eighty-two percent of respondents are willing to participate in a randomized controlled trial comparing anticoagulation strategies for patients receiving extracorporeal membrane oxygenation. Compared with the 2013 pediatric population, extracorporeal membrane oxygenation center anticoagulation and blood transfusion approaches continue to vary widely. Most report continued use of heparin as their primary anticoagulant and follow a combination of monitoring assays with the majority using the antifactor Xa assay in their practices, a significant shift from prior results. Antithrombin activity levels and viscoelastic tests are followed by a growing number of centers. Platelet transfusion thresholds continue to vary widely. Future research is needed to establish optimal anticoagulation and blood transfusion management.

The use of ‘viscoelastic tests’ in driving transfusion needs in major trauma patients

Haemorrhage can be attributed to approximately 50% of the 5 million trauma deaths worldwide every year. The development of damage control resuscitation techniques and major haemorrhage protocols has revolutionized trauma resuscitation. In this review we aim to explore the phenomenon of acute traumatic coagulopathy, the history and development of ‘viscoelastic tests’, the theory behind their use, the basic nomenclature and the role of these tests within the clotting cascade. We also look at the assessment of acute traumatic coagulopathy and the role of viscoelastic tests within goal-directed trauma resuscitation. Of particular interest is a review of the current recommendations for the implementation of thromboelastic tests in major haemorrhage guidelines and protocols.

A novel design for nanocellulose reinforced urea–formaldehyde resin: a breakthrough in amino resin synthesis and biocomposite manufacturing

Urea–formaldehyde (UF) resins are often reinforced with natural fibers or nanostructures such as cellulose microfibrils (CMFs) to improve their mechanical and physical properties in wood panels. However, the high-water content in these suspensions is a limitation on applications in thermosetting resins. The innovative technology investigated here consists of the in-situ production of a methanediol-based suspension of CMFs through a mechanical process and its incorporation during resin synthesis. We sought to maintain the physicochemical properties and the basic chemical composition of the resin. The synergy between the resin and CMFs provided a shielding effect and a greater storage modulus (E’). We demonstrate that this approach is robust through standard viscoelastic, physical, and mechanical tests. Likewise, a methanediol-based CMF suspension used to synthesize UF resin was effective to reduce formaldehyde emission during the resin cure reactions. Finally, the bio-based composites manufactured with this UF resin containing CMF had better performance due to increased internal bond strength by up to 15%, reduced water absorption by up to 8%, and reduced formaldehyde emission by 30% at environmental temperature.

P0329 / #717: COMPARISON OF TRANSFUSIONAL PRACTICE WITH VISCOELASTIC TESTS VERSUS CONVENTIONAL COAGULATION TESTS IN CONGENITAL HEART SURGERY PATIENT

Aims & Objectives: Analyze transfusion therapy in patients with congenital heart disease who undergo cardiovascular surgery and admitted to Pediatric Cardiac Intensive Care Unit (PCICU) UMAE CMN Siglo XXI Cardiology Hospital during the study period. Methods: Patients over 4 years of age up to adult age with congenital heart disease scheduled for elective cardiac surgery at the UMAE Cardiology Hospital of the National Medical Center “Siglo XXI” of the Mexican Social Security Institute (IMSS) in Mexico City, during the study period (May - December 2019). Cohort, observational, comparative, prospective, longitudinal study. Results: There were 98 patients, female sex prevailed with 57%, median age of 21 years. Predominating acianogenic heart disease (57%) such as interatrial communication. 26% of the patients were transfused, 8% had viscoelastic tests, the rest had conventional coagulation tests, 8 patients had significant post-surgical bleeding, performing viscoelastic tests using a management algorithm, only 2 were the patients who required surgical reintervention. Conclusions: In our unit, blood components continue to be transfused based on conventional coagulation tests. Viscoelastic tests applied to patients who presented significant postsurgical bleeding in our study significantly reduced surgical reoperation for bleeding. The viscoelastic test management algorithm is applied in 100% of cases.

Acute traumatic coagulopathy and the relationship to prehospital care and on-scene red blood cell transfusion.

To identify the incidence of acute traumatic coagulopathy (ATC) in trauma patients presenting to the Royal Adelaide Hospital, analyse prehospital contributors, including red blood cell transfusion and assess the clinical significance of ATC. A retrospective database review was undertaken using conventional coagulation assays and viscoelastic testing (ROTEM) for diagnosis of ATC. Baseline ATC incidence is 10% in trauma patients, increasing to over 80% among those where the prehospital team has attended and given a transfusion of red cells. ATC was significantly associated with higher severity of trauma (odds ratio [OR] 1.11, P< 0.0001), prehospital (OR 11.8, P< 0.0001) and in-hospital blood transfusions (OR17.9, P< 0.0001), and massive transfusions (P< 0.001). Prehospital blood transfusions are given to the most severely injured trauma patients and the incidence of ATC in this group is more than 80%. There is an association with prehospital blood transfusion and increased ATC in part related to patient selection and severity of trauma, with the contribution of red cell transfusions to ATC unclear. This association should allow earlier identification of patients at increased risk of ATC to ensure rapid correction of coagulopathy to decrease the morbidity and mortality of trauma.

Laboratory cracking performance evaluation of SM-4.75 asphalt mixtures

SM-4.75 asphalt mixtures incorporate a 4.75-mm nominal maximum aggregate size along with a corresponding fine gradation that accommodates higher liquid asphalt contents, which promotes durability. The SM-4.75 materials are suited to take advantage of the lower cost finer fractions of the stone-crushing process. The fine gradation also permits very thin applications (19 mm to 25 mm), thereby reducing the quantity and cost of materials, as well as construction time. Mixtures with 4.75-mm nominal maximum aggregate size have the potential to improve riding quality, extend pavement life, increase durability, and reduce permeability and road-tire noise. This study evaluated the laboratory cracking performance of SM-4.75 mixtures. It was done through sampling and testing of plant-produced mixtures that were placed on low volume traffic routes. Several tests were used to characterize the mixtures including the simplified viscoelastic continuum damage test, indirect tensile asphalt cracking tests, the semi-circular bend test, and the overlay test. Laboratory cracking tests indicated that SM-4.75 mixtures are crack susceptible and would benefit from higher binder contents. However, field performance data for the tested mixtures are needed to validate the crack susceptibility of the mixtures. In general, laboratory performance ranking order among different tests is not consistent for different mixtures. Binder testing results indicated that the majority of the mixtures should be resistant to non-load related cracking, even though the mixtures contained 20% and 30% recycled asphalt pavement.

The Role of TEG Analysis in Patients with COVID-19-Associated Coagulopathy: A Systematic Review.

Coronavirus disease 2019 (COVID-19)-associated coagulopathy (CAC), characterized by hypercoagulability and an increased risk of thrombotic complications, is an important consideration in the management of patients with COVID-19. As COVID-19 is a new disease, no standard of care for the diagnosis or management of its associated coagulopathy is yet established. Whole blood viscoelastic tests, such as thromboelastography (TEG® hemostasis analyzer), analyze whole blood to provide a complete overview of the coagulation status. We conducted a systematic review of thromboelastography for management of patients with COVID-19, using MEDLINE (PubMed) and Cochrane databases. TEG® parameter measurements and clinical outcomes data were extracted for analysis. Our review found 15 publications, with overall results showing thromboelastography can identify and assess a hypercoagulable state in patients with COVID-19. Furthermore, utilization of thromboelastography in this patient population was shown to predict thrombotic complications. The benefits of thromboelastography presented here, in addition to advantages compared with laboratory coagulation tests, position thromboelastography as an important opportunity for optimizing diagnosis of CAC and improving patient management in COVID-19. Given that the benefits of thromboelastography have already been demonstrated in several other clinical applications, we anticipate that clinical data from future studies in patients with COVID-19 will further elucidate the optimal use of thromboelastography in this patient population.

Corrigendum to Unique Approach to Quality Assurance in Viscoelastic Testing.

Corrigendum to Unique Approach to Quality Assurance in Viscoelastic Testing.

Whole Blood, Fixed Ratio, or Goal-Directed Blood Component Therapy for the Initial Resuscitation of Severely Hemorrhaging Trauma Patients: A Narrative Review.

This narrative review explores the pathophysiology, geographic variation, and historical developments underlying the selection of fixed ratio versus whole blood resuscitation for hemorrhaging trauma patients. We also detail a physiologically driven and goal-directed alternative to fixed ratio and whole blood, whereby viscoelastic testing guides the administration of blood components and factor concentrates to the severely bleeding trauma patient. The major studies of each resuscitation method are highlighted, and upcoming comparative trials are detailed.

The role of rotational thromboelastometry during the COVID-19 pandemic: a narrative review.

The coronavirus disease 2019 (COVID-19) pandemic is currently recognized as a global health crisis. This viral infection is frequently associated with hypercoagulability, with a high incidence of thromboembolic complications that can be fatal. In many situations, the standard coagulation tests (SCT) fail to detect this state of hypercoagulability in patients with COVID-19 since clotting times are either not or only mildly affected. The role of viscoelastic tests such as rotational thromboelastometry (ROTEM®) during this pandemic is explored in this review. COVID-19-associated coagulopathy, as measured using the rotational thromboelastometry parameters, can vary from hypercoagulability due to increased fibrin polymerization and decreased fibrinolysis to bleeding from hypocoagulability. The use of a multimodal diagnostic and monitoring approach, including both rotational thromboelastometry and SCT, such as plasma fibrinogen and D-dimer concentrations, is recommended. Rotational thromboelastometry provides comprehensive information about the full coagulation status of each patient and detects individual variations. Since COVID-19-associated coagulopathy is a very dynamic process, the phenotype can change during the course of infection and in response to anticoagulation therapy. Data from published literature provide evidence that the combination of rotational thromboelastometry and SCT analysis is helpful in detecting hemostasis issues, guiding anticoagulant therapy, and improving outcomes in COVID-19 patients. However, more research is needed to develop evidence-based guidelines and protocols.

Pharmacokinetics, surrogate efficacy and safety evaluations of a new human plasma-derived fibrinogen concentrate (FIB Grifols) in adult patients with congenital afibrinogenemia

Background and aimsCongenital afibrinogenemia is a rare coagulation disorder resulting from a deficiency in fibrinogen. This study assessed the pharmacokinetics, surrogate efficacy and safety of FIB Grifols, a new human plasma-derived fibrinogen concentrate, to treat congenital afibrinogenemia. MethodsEleven adult patients from a multinational, phase 1–2, prospective, open-label, single-arm, uncontrolled clinical study received a single infusion of FIB Grifols, 70 mg/kg bw. Fibrinogen pharmacokinetics (fibrinogen activity: Clauss method; antigen plasma concentrations: ELISA) and efficacy parameters were determined over 14 days after infusion. Efficacy endpoints were the mean change on plasma maximum clot firmness (MCF) on viscoelastic testing and coagulation tests 1-hour post-infusion, and correlation with fibrinogen levels throughout. Safety parameters were also assessed. ResultsFor the Clauss method, (mean [standard deviation]) baseline adjusted Cmax was 1.99 (0.40) g/L, reached 1.76 (1.00) h after infusion, and half-life was 76.94 (20.21) h. Using ELISA, Cmax after FIB Grifols infusion was 2.88 (0.86) mg/mL, with a tmax of 3.06 (2.24) h. Fibrinogen activity and antigen concentrations showed statistically significant correlation of 0.9120 (P < 0.001). Surrogate efficacy was demonstrated by a significant increase of 12.35 (3.85) mm in MCF. Prothrombin time, activated partial thromboplastin time and thrombin time, returned to normal ranges over time, indicating restoration of functionally active fibrinogen. There were no treatment-related adverse events, allergic reactions, serious adverse events, or discontinuations. ConclusionsThe pharmacokinetic profile of functionally active FIB Grifols was established, hemostasis was restored, and FIB Grifols was safe and well tolerated in fibrinogen-deficient patients.

Viscoelastic Tests in the Evaluation of Haemostasis Disturbances in SARS-CoV2 Infection.

COVID-19 associated coagulopathy is a dysfunction of severe SARS-CoV-2 infection, characterized by significantly increased fibrinogen, D-dimer and C reactive protein and normal to near-normal prothrombin time, activated partial thromboplastin time and platelet count. Hypercoagulopathy and hypofibrinolysis coexist and are detected by viscoelastic tests. These features, when associated with immobilization and intrinsic risk factors (age, obesity, comorbidities, drugs) of the patient, can trigger thromboembolic events, despite thromboprophylaxis. The lungs are the first and most severely damaged organ. To date, most patients have exhibited hypercoagulability on viscoelastic tests not detected by standard coagulation tests. A high rate of thrombotic events was reported, suggesting that it should be considered as a cause of clinical deterioration in intensive care and potentially other clinical settings. In advanced stage, COVID-19 associated coagulopathy, fibrinogen and platelet count can decrease significantly, depending on the severity of clinical status resembling consumptive coagulopathy. In this stage, bleeding events can occur, especially if the patient is under extracorporeal membrane oxygenation (ECMO). Viscoelastic tests are very useful tools to assess hypercoagulability and hypofibrinolysis (not detectable by standard coagulation tests) in critically ill SARS-CoV-2 patients with COVID-19 associated coagulopathy and look like very promising tools for anticoagulation management. However, further research needs to be carried out to determine whether abnormal viscoelastic tests alone or in combination with other clinical or laboratory findings can identify patients at increased thrombotic risk. Clinical trials to evaluate hypercoagulability using viscoelastic tests and the need for personalized dosage of anticoagulation in SARS-CoV-2 patientsare quickly emerging.

Experimental Characterization of Viscoelastic Behaviors of Nano-TiO2/CaCO3 Modified Asphalt and Asphalt Mixture.

The purpose of this paper is to promote the application of nano-TiO2/CaCO3 in bituminous materials and present an experimental characterization of viscoelastic behaviors of bitumen and bituminous mixture modified by nano-TiO2/CaCO3. In this work, a series of viscoelastic behavior characterization tests were conducted, including dynamic shear rheometer (DSR) test for bitumen, uniaxial static compression creep test and dynamic modulus test for bituminous mixture. Moreover, various viscoelastic models with clear physical meanings were used to evaluate the influence of nano-TiO2/CaCO3 on the macroscopic performance of bitumen and bituminous mixture. The results show that bitumen and its mixtures are time-temperature dependent. The Christensen-Anderson-Marasteanu (CAM) model of frequency sweep based on DSR test indicated that adding nano-TiO2/CaCO3 can effectively capture the sensitivity of temperature. In addition, the incorporation of nano-TiO2/CaCO3 in bituminous mixture can significantly enhance the high-temperature anti-rutting, and slightly improve the low-temperature anti-cracking as well. At the same time, the modified Burgers model can accurately describe the viscoelastic behavior of bituminous mixtures in the first two creep stages, reflecting the consolidation effect of bituminous mixture. Also, the generalized Sigmoidal model can accurately grasp the characteristics of the relationship between dynamic modulus and reduced frequency and achieve good prediction effects in a wider frequency range.

Association of Plasma Fibrinogen and Thromboelastography With Blood Loss in Complex Cardiac Surgery.

Postoperative coagulopathic bleeding is common in cardiac surgery and is associated with increased morbidity and mortality. Ideally, real-time information on in-vivo coagulation should be available. However, up to now it is unclear which perioperative coagulation parameters can be used best to accurately identify patients at increased risk of bleeding. The present study analyzed the associations of perioperative fibrinogen concentrations and whole blood viscoelastic tests with postoperative bleeding in 89 patients undergoing combined cardiac surgery procedures. Postoperative bleeding was recorded until 24 hours after surgery. Regression analyses were performed to establish associations between blood loss and coagulation parameters after cardiopulmonary bypass including a prediction model with known confounding factors for bleeding. Coagulation tests show large changes over the perioperative course with the strongest coagulopathic deviations from baseline after cardiopulmonary bypass. After adjustment for multiple confounders, viscoelastic clot strength instead of fibrinogen concentration showed a similar performance for 24 hour blood loss and a better performance for 6 hour blood loss. This makes intraoperative viscoelastic testing a useful tool to strengthen early clinical decision-making with the potential to reduce perioperative blood transfusions.

Patient blood management in India - Review of current practices and feasibility of applying appropriate standard of care guidelines. A position paper by an interdisciplinary expert group.

In a developing country like India, with limited resources and access to healthcare facilities, dealing with massive hemorrhage is a major challenge. This challenge gets compounded by pre-existing anemia, hemostatic disorders, and logistic issues of timely transfer of such patients from peripheral hospitals to centers with adequate resources and management expertise. Despite the awareness amongst healthcare providers regarding management modalities of bleeding patients, no uniform Patient Blood Management (PBM) or perioperative bleeding management protocols have been implemented in India, yet. In light of this, an interdisciplinary expert group came together, comprising of experts working in transfusion medicine, hematology, obstetrics, anesthesiology and intensive care, to review current practices in management of bleeding in Indian healthcare institutions and evaluating the feasibility of implementing uniform PBM guidelines. The specific intent was to perform a gap analysis between the ideal and the current status in terms of practices and resources. The expert group identified interdisciplinary education in PBM and bleeding management, bleeding history, viscoelastic and platelet function testing, and the implementation of validated, setting-specific bleeding management protocols (algorithms) as important tools in PBM and perioperative bleeding management. Here, trauma, major surgery, postpartum hemorrhage, cardiac and liver surgery are the most common clinical settings associated with massive blood loss. Accordingly, PBM should be implemented as a multidisciplinary and practically applicable concept in India in a timely manner in order to optimize the use the precious resource blood and to increase patients' safety.

Thromboelastography Profile of Patients with COVID-19 Admitted to Intensive Care Unit: A Single-center Retrospective Study from India.

Coronavirus disease (COVID-19) causes thromboinflammation resulting in a high incidence of venous thromboembolism (VTE) events, which occur in significant numbers despite giving standard thromboprophylaxis with low-molecular-weight heparins. Various markers and tests have been evaluated and found to have a strong association with the worse prognosis of the disease. Common coagulation markers like D-dimer and fibrinogen give more of a static picture of coagulation, whereas viscoelastic tests like thromboelastography (TEG) provide an understanding of the coagulation function and help in better interpretation. We conducted a retrospective analysis of TEG values of 32 patients with COVID-19 admitted to the intensive care unit (ICU). Hypercoagulation as defined by TEG-coagulation index (CI) higher than the upper limit of the normal reference range (NRR) is found in 62.5% of the patients. There is also a clear representation of hypercoagulability as reflected by TEG-R, TEG-K, and TEG-LY30 values lower than or toward the lower limit of NRR, and TEG-ANGLE, TEG-MA, and TEG-CI values higher than or toward the upper limit of NRR which is more pronounced in severe forms of the disease, both in comparison to NRRs and other non-COVID ICU patients. Findings are similar to that of earlier studies in patients with COVID-19 except for the LY30, which is retained in the majority of our patients. Thromboelastography can be a useful tool to understand and screen for COVID-19-related hypercoagulability and may help predict VTE events. The potential of TEG to determine the optimal anticoagulant therapy needs to be evaluated in larger prospective studies.How to cite this article: Saseedharan S, Talla VB, Chiluka A. Thromboelastography Profile of Patients with COVID-19 Admitted to Intensive Care Unit: A Single-center Retrospective Study from India. Indian J Crit Care Med 2020;24(12):1218–1222.

The Clotting Trigger Is an Important Determinant for the Coagulation Pathway In Vivo or In Vitro-Inference from Data Review.

Blood coagulation comprises a series of enzymatic reactions leading to thrombin generation and fibrin formation. This process is commonly illustrated in a waterfall-like manner, referred to as the coagulation cascade. In vivo, this "cascade" is initiated through the tissue factor (TF) pathway, once subendothelial TF is exposed and bound to coagulation factor VII (FVII) in blood. In vitro, a diminutive concentration of recombinant TF (rTF) is used as a clotting trigger in various global hemostasis assays such as the calibrated automated thrombogram, methods that assess fibrin turbidity and fibrin viscoelasticity tests such as rotational thromboelastometry. These assays aim to mimic in vivo global coagulation, and are useful in assessing hyper-/hypocoagulable disorders or monitoring therapies with hemostatic agents. An excess of rTF, a sufficient amount of negatively charged surfaces, various concentrations of exogenous thrombin, recombinant activated FVII, or recombinant activated FIXa are also used to initiate activation of specific sub-processes of the coagulation cascade in vitro. These approaches offer important information on certain specific coagulation pathways, while alterations in pro-/anticoagulants not participating in these pathways remain undetectable by these methods. Reviewing available data, we sought to enhance our knowledge of how choice of clotting trigger affects the outcome of hemostasis assays, and address the call for further investigations on this topic.

Thromboelastography clot strength profiles and effect of systemic anticoagulation in COVID-19 acute respiratory distress syndrome: a prospective, observational study.

Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection may yield a hypercoagulable state with fibrinolysis impairment. We conducted a single-center observational study with the aim of analyzing the coagulation patterns of intensive care unit (ICU) COVID-19 patients with both standard laboratory and viscoelastic tests. The presence of coagulopathy at the onset of the infection and after seven days of systemic anticoagulant therapy was investigated. Forty consecutive SARS-CoV-2 patients, admitted to the ICU of a University hospital in Italy between 29th February and 30th March 2020 were enrolled in the study, providing they fulfilled the acute respiratory distress syndrome criteria. They received full-dose anticoagulation, including Enoxaparin 0.5 mg·kg-1 subcutaneously twice a day, unfractionated Heparin 7500 units subcutaneously three times daily, or low-intensity Heparin infusion. Thromboelastographic (TEG) and laboratory parameters were measured at admission and after seven days. At baseline, patients showed elevated fibrinogen activity [rTEG-Ang 80.5° (78.7 to 81.5); TEG-ACT 78.5 sec (69.2 to 87.9)] and an increase in the maximum amplitude of clot strength [FF-MA 42.2 mm (30.9 to 49.2)]. No alterations in time of the enzymatic phase of coagulation [CKH-K and CKH-R, 1.1 min (0.85 to 1.3) and 6.6 min (5.2 to 7.5), respectively] were observed. Absent lysis of the clot at 30 minutes (LY30) was observed in all the studied population. Standard coagulation parameters were within the physiological range: [INR 1.09 (1.01 to 1.20), aPTT 34.5 sec (29.7 to 42.2), antithrombin 97.5% (89.5 to 115)]. However, plasma fibrinogen [512.5 mg·dl-1 (303.5 to 605)], and D-dimer levels [1752.5 ng·ml-1 (698.5 to 4434.5)], were persistently increased above the reference range. After seven days of full-dose anticoagulation, average TEG parameters were not different from baseline (rTEG-Ang p = 0.13, TEG-ACT p = 0.58, FF-MA p = 0.24, CK-R p = 0.19, CKH-R p = 0.35), and a persistent increase in white blood cell count, platelet count and D-dimer was observed (white blood cell count p < 0.01, neutrophil count p = 0.02, lymphocyte count p < 0.01, platelet count p = 0.13 < 0.01, D-dimer levels p= 0.02). SARS-CoV-2 patients with acute respiratory distress syndrome show elevated fibrinogen activity, high D-dimer levels and maximum amplitude of clot strength. Platelet count, fibrinogen, and standard coagulation tests do not indicate a disseminated intravascular coagulation. At seven days, thromboelastographic abnormalities persist despite full-dose anticoagulation.

Optimal Tranexamic Acid Dosing Regimen in Cardiac Surgery: What Are the Missing Pieces?

Optimal Tranexamic Acid Dosing Regimen in Cardiac Surgery: What Are the Missing Pieces?

Application of Viscoelastic testing to the field of Otolaryngology Head and Neck Surgery: A Scoping Review

Background: &#x0D; In Otolaryngology Head and Neck Surgery (OHNS), hematologic management requires attention to the intricate nature of hemostatic competence. Elderly patients can experience drug induced coagulopathies. Strategies are needed in order to minimize hemorrhagic and thromboembolic risk and maximize positive outcomes. Viscoelastic tests (VETs) such as Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) have been used to guide blood component therapy. The purpose of this scoping review is to understand the utilization of VETs in OHNS. &#x0D; &#x0D; Methods: &#x0D; &#x0D; This scoping review included studies that discussed the utilization of VETs in the field of OHNS. The inclusion criteria was studies that discussed the application of VETs in Flap/Plastic Reconstruction, Facial Trauma/Resuscitation, Tonsillectomy, Obstructive Sleep Apnea (OSA), Epistaxis, Sinus Surgery, and HNC Resection. Studies that focused on general medical VET use were not included. &#x0D; &#x0D; Results: &#x0D; &#x0D; Fourteen articles met the study inclusion criteria from an initial pool of 45 articles. Seven articles discussed the use of VETs in free flap/reconstructive surgery, five articles explored use in HNC, two articles discussed use in facial trauma and resuscitation, one article mentioned use in OSA, and one article examined use in epistaxis. &#x0D; &#x0D; Conclusion and potential impact: &#x0D; &#x0D; Of the fourteen articles included, two articles found no clinically significant association between TEG parameters and flap loss or complications. Five studies found that TEG or ROTEM helpful in predicting coagulation clotting, a prothrombotic state, or a hyperfibrinolytic state in free flap and HNC patients. For facial trauma and HNC cancer patients two different studies found ROTEM helpful in guiding blood component resuscitation. Using the TEG, one study demonstrated a hypercoagulable state in OSA patients. This review encourages wider use of VETs in OHNS in order to monitor hemostasis and improve surgical outcomes. Further research is necessary to better understand how VETs can tailor hematologic management of OHNS patients.