How is thromboelastography (TEG) used to guide blood product transfusion in patients with a history of coagulopathy, recent major surgery, or trauma?

Thromboelastography-Guided Blood Product Transfusion

In patients with coagulopathy, recent major surgery, or trauma, TEG/ROTEM should be used to guide blood product transfusion as it reduces mortality, decreases unnecessary transfusions, and enables faster, more targeted correction of specific coagulation defects compared to conventional coagulation tests alone. 1

Primary Recommendation for Clinical Practice

We recommend using TEG/ROTEM-guided transfusion protocols in bleeding patients with coagulopathy, trauma, or major surgery to direct specific blood component therapy rather than relying solely on conventional coagulation assays (PT/APTT/INR). 1, 2

• The 2023 European trauma guideline provides the strongest evidence that TEG-guided resuscitation significantly improves survival compared to conventional coagulation assay-guided therapy (higher survival with less plasma and platelet use in a prospective RCT of 111 trauma patients). 1
• TEG/ROTEM provides results 30-60 minutes faster than conventional laboratory testing, enabling more rapid therapeutic decision-making. 1
• Point-of-care viscoelastic monitoring is highly specific for hyperfibrinolysis (the most lethal coagulopathy phenotype in trauma) and more sensitive for detecting coagulopathy than conventional tests. 1

Specific Clinical Applications by Patient Population

Trauma Patients

TEG/ROTEM-guided transfusion in trauma reduces 24-hour mortality (13% vs 5%, p=0.006) and 30-day mortality (25% vs 11%, p=0.002) compared to conventional testing. 1, 2

• In the iTACTIC multicenter RCT of 690 trauma patients, viscoelastic monitoring showed particular benefit in traumatic brain injury patients (28-day mortality: VEM 44% vs conventional 74%, OR 0.28). 1
• TEG/ROTEM detects coagulopathy earlier and guides targeted factor replacement, reducing progression of intracranial hemorrhage in TBI patients requiring craniotomy. 1
• Transfusion should be guided by specific TEG parameters: prolonged R-time indicates factor deficiency requiring FFP/PCC; low maximum amplitude (MA) indicates need for platelets or fibrinogen; elevated LY30 >7.5% indicates hyperfibrinolysis requiring antifibrinolytic therapy. 3, 4

Major Surgery Patients

In cardiac surgery and other major surgical procedures, TEG/ROTEM-guided transfusion reduces blood product use without increasing surgical reintervention rates or bleeding complications. 5, 2

• Meta-analysis shows TEG/ROTEM reduces transfusion of packed red blood cells (RR 0.86), fresh frozen plasma (RR 0.57), and platelets (RR 0.73) compared to standard care. 5
• TEG/ROTEM-guided protocols reduce the need for additional invasive hemostatic interventions (angioembolization, endoscopy, or surgical re-exploration) in surgical patients. 2
• The transfusion-limiting effect occurs without increasing rebleeding risk or mortality. 1, 5

Patients with Pre-existing Coagulopathy

In cirrhotic patients with coagulopathy (INR >1.8 and/or platelets <50×10⁹/L) and nonvariceal bleeding, TEG-guided transfusion reduces blood component use by 60% without increasing failure to control bleeding or mortality. 6

• Only 26.5% of TEG-guided patients required all three blood components (FFP, platelets, cryoprecipitate) versus 87.2% in standard care (p<0.001). 6
• 14.3% of TEG-guided patients required no transfusion at all, demonstrating that conventional tests (INR/platelet count) significantly overestimate transfusion needs in cirrhosis. 6
• TEG provides more accurate assessment of global hemostasis in liver disease than PT/INR, which only measure 4% of thrombin production. 1

Practical Implementation Algorithm

Initial Assessment (Within 15 Minutes of Presentation)

Obtain simultaneous TEG/ROTEM and conventional coagulation tests (PT, APTT, fibrinogen, platelet count) immediately upon recognition of significant bleeding. 1

• TEG/ROTEM results are available 30-60 minutes faster than conventional laboratory tests, enabling earlier intervention. 1
• Do not wait for conventional test results to initiate TEG/ROTEM testing. 1
• For trauma patients with clinical signs of massive hemorrhage (systolic BP <100 mmHg, lactate ≥5 mmol/L, base excess ≤-6, or hemoglobin ≤9 g/dL), consider empiric administration of 2g fibrinogen concentrate while awaiting viscoelastic results. 4

Interpretation and Targeted Intervention

Use TEG/ROTEM parameters to guide specific blood product administration rather than empiric fixed-ratio protocols: 1, 3, 4

For Prolonged R-Time (>10 minutes on TEG) or Prolonged CT on ROTEM (>80 seconds):

• Indicates coagulation factor deficiency. 3, 4
• Administer fresh frozen plasma (FFP) 10-15 mL/kg or prothrombin complex concentrate (PCC) 15-25 units/kg. 4
• Target: PT/APTT <1.5 times normal. 1

For Low Maximum Amplitude (MA <50 mm on TEG) or Low MCF on ROTEM:

• First determine if due to thrombocytopenia or hypofibrinogenemia using functional fibrinogen TEG or FIBTEM on ROTEM. 3, 7
• If platelet count <50×10⁹/L or platelet dysfunction: transfuse 1 adult platelet dose (target >50×10⁹/L for most bleeding, >100×10⁹/L for TBI/neurosurgery). 3, 7
• If fibrinogen <1.5-2.0 g/L: administer fibrinogen concentrate 25-50 mg/kg (preferred) or cryoprecipitate 2 pools. 3, 7
• Avoid using FFP to correct hypofibrinogenemia if fibrinogen concentrate or cryoprecipitate are available. 1

For Elevated LY30 (>7.5% on TEG) or Elevated LI30/ML on ROTEM:

• Indicates hyperfibrinolysis. 3, 4
• Administer tranexamic acid 1g IV over 10 minutes, followed by 1g infusion over 8 hours. 1
• TEG/ROTEM is highly specific for detecting this lethal phenotype that conventional tests miss. 1

Reassessment Protocol

Repeat TEG/ROTEM 15-30 minutes after each intervention to assess treatment response and guide further therapy. 4, 7

• Continue goal-directed resuscitation until TEG/ROTEM parameters normalize or bleeding is controlled. 4
• Serial monitoring prevents both under-treatment and over-transfusion. 1

Critical Caveats and Limitations

Test Limitations to Recognize

Standard TEG/ROTEM cannot reliably detect platelet dysfunction from antiplatelet medications (aspirin, clopidogrel). 1

• If antiplatelet drug use is suspected, additional point-of-care platelet function testing (e.g., Multiplate, VerifyNow) may be needed, though evidence for their utility in guiding transfusion is limited. 1
• However, routine use of platelet function devices is NOT recommended as they have poor specificity in trauma patients. 1

TEG/ROTEM has significant inter-operator and inter-device variability (coefficients of variance 7-40%). 7

• Proper training and regular calibration are essential. 7
• Cartridge-based systems (TEG 6S, ROTEM Sigma) have improved reproducibility compared to older devices. 1

Anemia can paradoxically produce hypercoagulable TEG results due to decreased blood viscosity, potentially masking underlying coagulopathy. 7

• Do not rely solely on TEG/ROTEM in severely anemic patients; correlate with clinical bleeding and conventional tests. 7

Specific Clinical Scenarios Requiring Caution

In traumatic brain injury, TEG/ROTEM may show distinct patterns (prolonged ACT, reduced α-angle, low functional fibrinogen, normal MA, minimal fibrinolysis) that require aggressive correction. 1

• Maintain higher platelet targets (>100×10⁹/L) and fibrinogen targets (>2.0 g/L) in TBI patients. 3, 7
• The iTACTIC trial showed significant mortality benefit specifically in the TBI subgroup. 1

Current viscoelastic tests may be insensitive to early fibrinolytic activation, potentially limiting their ability to guide tranexamic acid administration. 3

• Consider empiric tranexamic acid in trauma patients with suspected hyperfibrinolysis even if LY30 is not yet elevated. 1

Evidence Quality Assessment

The 2023 European trauma guideline represents the highest quality and most recent evidence, though it acknowledges that supporting studies are of low to moderate quality with risk of bias. 1

• The Cochrane review and multiple meta-analyses confirm consistent benefits but note methodological limitations in most trials. 1, 5
• Most high-quality evidence comes from cardiac surgery populations; trauma and other acute bleeding scenarios have less robust data. 5, 2
• Despite methodological limitations, the consistency of benefit across multiple populations and outcomes supports clinical implementation. 1, 2

Cost-Effectiveness Considerations

TEG/ROTEM-guided transfusion strategies demonstrate cost savings in addition to clinical benefits through reduced blood product waste and fewer transfusion-related complications. 1, 3

• One study showed significantly less blood product wastage with TEG guidance (p=0.006). 1
• Reduced transfusion requirements and fewer complications (acute kidney injury, transfusion reactions) offset the cost of point-of-care testing devices. 1