Limitations of CCTs in burn patients

Traditionally, patients with extensive burns have been evaluated using CCTs, such as PT and PTT, to guide transfusion management. However, in burns affecting more than 30% of the total body surface area, a systemic inflammatory response is triggered, activating the coagulation cascade and potentially resulting in disseminated intravascular coagulation (DIC). Burn injuries induce a complex and dynamic coagulopathy that often escapes detection by conventional methods. Typical findings in burn trauma include prolonged PT and PTT, decreased platelet count, variable fibrinogen levels, and increased D-dimer. These results may vary depending on burn severity and may lead to microvascular thrombosis contributing to organ dysfunction. However, these tests are insufficient due to their low sensitivity, especially in detecting subtle hemostatic alterations. Moreover, it is common for these tests to return normal results despite significant coagulation disorders, or they may be falsely interpreted as indicative of bleeding risk, potentially leading to unnecessary interventions that worsen the patient’s condition [3, 10, 23].

This discrepancy is explained by the fact that CCTs analyze only plasma and are terminated at the formation of initial fibrin strands, whereas VETs assess whole blood and allow for evaluation of clot formation, quality and stability, providing a more comprehensive and representative view of the in vivo coagulation process [3, 8, 10].

Role of vets as dynamic tools

Given this scenario, the use of VET such as TEG and ROTEM has gained relevance, as these allow a more integrated and dynamic evaluation of the coagulation process. These tests have proven particularly useful in the context of severe burns, where a biphasic pattern has been described: an initial hypercoagulable state followed by hypocoagulability in later stages. This evolution is influenced by multiple factors, including burn depth, presence of inhalation injury, hypothermia, hemodilution during the resuscitation phase, and multiple required surgical interventions [2, 10].

Burn-induced coagulopathy exhibits a biphasic evolution, with a predominant hypercoagulable state during the first 48–72 h, attributed to the massive release of proinflammatory cytokines (e.g., IL-6, TNF-α), endothelial activation, tissue factor expression, and increased synthesis of acute-phase proteins like fibrinogen. This is often followed by a progressive hypocoagulable phase due to platelet dysfunction, coagulation factor consumption, hyperfibrinolysis, and dilutional effects from fluid resuscitation. The intensity and duration of each phase may vary according to factors such as TBSA, depth of injury, inhalation injury, and surgical interventions.

Endothelial injury and glycocalyx disruption also play a central role in the prothrombotic environment, contributing to activation of the contact pathway and impairment of natural anticoagulant mechanisms (e.g., antithrombin, protein C). These changes often go undetected by routine CCTs, further supporting the need for dynamic assessment tools. Moreover, in patients with extensive burns, complications such as sepsis and DIC are observed during the clinical course, specifically in patients with prolonged intensive care stays. For instance, DIC may develop as a maladaptive response, with the widespread microvascular thrombosis followed by consumption of clotting factors and platelets, leading to a paradoxical bleeding tendency. These events are accompanied by rapid, unpredictable fluctuation in coagulation status, TEG and ROTEM track the dynamic changes seen in septic and criticality burn patients [10].

During extensive surgical excisions, blood loss can be significant, necessitating transfusion or coagulopathy correction. In this context, VETs have emerged as valuable point-of-care tools, both intraoperatively and in intensive care units, facilitating rapid and personalized hemostatic decisions. While their use is well established in scenarios such as cardiac surgery or liver transplantation, their application in burn patients is expanding as a guide for correcting coagulopathy via appropriate factor replacement or transfusion of blood products [1, 2].

By analyzing whole blood, these tests offer a comprehensive assessment of hemostasis, from clot formation to stabilization and lysis. This capacity allows simultaneous evaluation of both coagulation factor contribution and platelet function, providing valuable information for clinical decision-making [2].

Furthermore, the rapid availability of results (within 10 to 20 min) determines their utility as POC tools, particularly valuable in acute bleeding scenarios requiring urgent clinical decisions. In surgical procedures involving burn patients, often associated with significant bleeding, these tests have proven effective in guiding rational administration of blood components and reducing transfusion requirements [1, 2, 4, 5, 7, 10, 11, 19].

Intraoperative bleeding may be extensive and secondary to undetected or uncorrected coagulopathy. However, recent recommendations advocate for a restrictive use of blood products, particularly allogeneic transfusions, due to their associated complications. Traditionally, a 1:1:1 transfusion ratio of red blood cells, platelets, and plasma is recommended, along with direct replacement of coagulation factors [1]. Nonetheless, most institutions lack established protocols for using VETs as point-of-care coagulation tests, which are defined as bedside diagnostic tools with the advantage of shorter turnaround times and ease of execution [10]. In this regard, ROTEM has been identified as the most widely available and commonly used test, particularly during surgical procedures, with estimated usage above 60% according to studies. However, its use upon emergency department admission remains limited, despite a growing trend in VET adoption over the years [1, 4].

Despite transfusion management recommendations, studies have shown that blood component replacement often does not follow a balanced-component approach, with lower use of platelets and plasma compared to red blood cells. Even when resuscitation involves blood products, a study using ROTEM showed that transfused products often resulted in abnormally weak clots, with clot strength below the reference range, although slight improvement was observed with products containing platelets. Therefore, assumptions regarding the hemostatic function of transfused products should be avoided, as these products, particularly platelets, may exhibit functional deficiencies, and tests like ROTEM may be critical for assessing clot quality [21].

One major coagulation issue that may go unnoticed is hypercoagulability, which can appear as early as the first week after burn injury, associated with increased fibrinogen synthesis. During the first 24 h post-burn, elevated levels of tissue type plasminogen activator inhibitor-1 have been observed [10]. In this regard, the ROTEM parameter FIBTEM MCF (maximum clot firmness) has shown correlation with fibrinogen levels measured via the Clauss method, indicating that VETs can more sensitively detect early procoagulant states than conventional methods. The time advantage is also significant, with approximately 20 min for ROTEM compared to one hour for CCTs, potentially reducing adverse events and costs by minimizing the unnecessary use of platelet and FFP concentrates through individualized coagulation management [23].

As previously mentioned, the hypercoagulable state may persist for up to two weeks post injury. Studies evaluating thrombin generation in thermal injury patients [22], using TGA parameters such as peak thrombin and velocity index, found significantly elevated levels peaking one week after the burn and returning to near normal levels by the second week. ROTEM also showed signs of hypercoagulability, such as increased alpha angle and MCF. However, CCT findings like PT, aPTT, and platelet count, remained within reference ranges and failed to detect the hypercoagulable state. This occurs because CCTs only assess the initial phase of thrombin generation, missing approximately 95% of thrombin produced later. Nonetheless, TGA is currently not widely available and is associated with high costs; thus, tests like ROTEM may offer substantial clinical utility [5].

Regarding the use and availability of rTEG, studies in patients with > 60% TBSA burns have evaluated changes in parameters such as alpha angle, maximum amplitude (MA), activated clotting time, and kinetic time, which significantly decreased, indicating increasing hypocoagulability and platelet dysfunction. The MA in rTEG is particularly important for reflecting platelet function. rTEG provides a basis for timely therapeutic interventions, such as targeted blood product transfusion, to counteract tissue hypoperfusion and restore coagulation balance [24].

Diagnostic variability and challenges in detecting DIC in burn patients

DIC is a consumptive coagulopathy characterized by systemic activation of coagulation, leading to platelet and clotting factor depletion, severe hemorrhage, and thrombotic obstruction of the microcirculation, which may promote organ dysfunction in burn patients. Although clinically overt DIC appears to occur in only a minority, its association with mortality is significant: 88.9% of deceased patients presented with DIC at the time of death, suggesting a decisive role in outcomes. Sepsis, present in 55.6% of cases, further contributes by inducing secondary DIC and septic shock, worsening hemostatic dysfunction [24].

Prevalence rates vary markedly by diagnostic criteria. Approximately 30% of severe burns are estimated to develop DIC [23], whereas retrospective series using the International Society of Thrombosis and Haemostasis (ISTH) criteria have reported incidences up to 91% in patients with > 25% TBSA burned. Conversely, other studies report much lower incidences (0.09% in the general population and 0.66% in TBSA > 20%), reflecting substantial heterogeneity in definition [10].

D-dimer and fibrin degradation product (FDP) levels are significantly higher in severe versus mild or moderate burns, suggesting increased thrombotic risk and early DIC [3]. Viscoelastic hemostatic assays (VHA) such as R-TEG® show that coagulopathy is progressive: hypocoagulability parameters (ACT, K, α, MA) are altered early post-injury, and by the second week, hyperfibrinolysis (elevated LY30) is frequently observed, consistent with progression toward DIC. These abnormalities can precede clinical diagnosis or fulfillment of ISTH criteria, underscoring the value of VHA for dynamic monitoring [23].

R-TEG® findings can also guide targeted transfusion strategies (e.g., fresh frozen plasma for prolonged ACT, platelets for reduced MA, antifibrinolytics for elevated LY30). However, in extensive burns with advanced coagulopathy, VHA parameters may not normalize after surgery or transfusion, highlighting the severity of the disorder and the need for VHA-based transfusion protocols [23]. In this setting, tranexamic acid administration should be guided by VHA results when available, following trauma standards [10].

In early thermal injury, additional mechanisms, including hemodilution from large-volume resuscitation, hypothermia due to skin barrier loss, and shock-associated hypoperfusion, also contribute to coagulopathy, typically manifested as prolonged PT and aPTT [10]. The heterogeneity in DIC presentation and diagnosis in burn patients highlights the need for standardized, dynamic approaches; VHAs represent a promising tool for early detection and optimized blood product use in this high-risk population [19].

Balancing thrombosis and bleeding: anticoagulation in the burn population

It is well known that both procoagulant and anticoagulant states can occur in various conditions, including burn patients, who are at risk of developing DIC. A strong correlation has been demonstrated between the use of VHA and both organ dysfunction and ICU survival. In critically ill patients, VHA can also be used to guide anticoagulation monitoring when aPTT and anti-Xa levels are inconclusive, offering an alternative for dose adjustment [10].

Anticoagulant management in burn patients has become increasingly complex due to the hypercoagulability and hypofibrinolysis that characterize burn-induced coagulopathy. This prothrombotic profile, combined with endothelial injury and venous stasis, increases the risk of deep vein thrombosis (DVT) and venous thromboembolism (VTE). However, the true incidence of these thrombotic events varies widely across studies (0.2–25%), partly because of methodological differences such as the inclusion of autopsy studies or systematic ultrasound screening. The reported incidence of pulmonary embolism is also highly variable, ranging from 0.001 to 3.3%.

The use of prophylactic anticoagulation remains controversial. While some studies have not demonstrated a reduction in VTE incidence and raise concerns about bleeding risk, others show clear benefits in reducing DVT without significant hemorrhagic complications. Moreover, pharmacodynamic studies have shown that standard enoxaparin dosing may be insufficient in this population, further complicating clinical decision-making [19]. These conflicting data highlight the need for more precise guidelines tailored to the pathophysiological context of burn patients. In this regard, viscoelastic testing could provide an additional tool to guide the safe and effective use of anticoagulants, personalizing treatment according to the patient’s real-time coagulation status [5, 19].

In patients with severe burns, red blood cell transfusion is initiated early to maintain hemoglobin levels between 5.6 and 6.2 mmol/L due to the risk of intraoperative bleeding. Fresh frozen plasma is administered in cases of active bleeding and laboratory evidence of INR > 1.5 and prolonged aPTT. Patients receiving therapeutic anticoagulation required 5–8 times more red blood cells and 2–4 times more plasma than those on prophylactic anticoagulation. Although no statistically significant association between transfusion volume and mortality was found, there was a trend toward improved survival with higher red blood cell transfusions and, conversely, a trend toward increased mortality with larger plasma volumes [7].

Advantages and challenges of ROTEM/TEG use

Finally, the use of VETs as rapid diagnostic tools for identifying coagulopathy and guiding the use of blood products during resuscitation in burn patients provides significant advantages over CCTs: Response times of 10–20 min, higher sensitivity and specificity, and the ability to reduce unnecessary blood component use, thereby lowering the risk of adverse events from massive transfusions. Nevertheless, implementation poses challenges such as technological availability, the need for periodic calibration, and clinical staff training for proper interpretation and application [2, 3].

Limitations

Several limitations must be considered when interpreting the findings. As this is a scoping review, it does not aim to establish causal relationships or issue clinical recommendations. The available evidence is scarce and of low quality, consisting mainly of small, heterogeneous studies, most of which are observational and at high risk of bias. In the case of surveys, results are based on subjective perceptions, with low representativeness and without a multidisciplinary approach, which further limits their applicability.