What is the role of Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) in guiding transfusion strategies and hemostatic interventions?

Role of TEG and ROTEM in Guiding Transfusion Strategies and Hemostatic Interventions

Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) significantly improve patient outcomes by enabling goal-directed transfusion strategies that reduce mortality and optimize blood product use in bleeding patients. 1

Clinical Applications and Benefits

Trauma and Major Bleeding

• TEG/ROTEM provides real-time assessment of the entire clotting process, detecting coagulopathies (including hyperfibrinolysis and platelet dysfunction) that standard coagulation tests miss 1
• Early goal-directed hemostatic resuscitation guided by TEG has demonstrated significantly higher survival rates compared to conventional coagulation assay (CCA) groups, with reduced use of plasma and platelets 1
• A single-center pre- and post-implementation study showed TEG-guided therapy reduced mortality at 24 hours (13% vs. 5%; p=0.006) and 30 days (25% vs. 11%; p=0.002) with significantly less blood product wastage 1
• TEG/ROTEM-guided transfusions are associated with fewer additional invasive hemostatic interventions (angioembolic, endoscopic or surgical) in surgical patients 1

Specific Clinical Scenarios

• In traumatic brain injury (TBI) patients with coagulopathy requiring craniotomy, ROTEM-guided therapy significantly reduced progressive hemorrhagic injury and need for neurosurgical re-intervention 1
• In liver disease, TEG/ROTEM provides more valuable information than standard coagulation tests, as INR should not be used to gauge bleeding risk in cirrhosis patients 1, 2
• In obstetrics, the strongest evidence supports TEG/ROTEM use in guiding transfusion therapy for postpartum hemorrhage (PPH) 1

Transfusion Guidance Protocols

Fibrinogen Management

• When TEG/ROTEM indicates hypofibrinogenemia (functional fibrinogen TEG MA <20 mm), administer fibrinogen concentrate (first choice) or cryoprecipitate 3, 2
• Target fibrinogen levels of at least 1.5-2.0 g/L in most bleeding scenarios; higher targets (≥2.0 g/L) may be needed in liver disease 2, 4
• Avoid using FFP for hypofibrinogenemia correction if fibrinogen concentrate and/or cryoprecipitate are available 1, 2

Platelet Management

• Maintain platelet count >50,000/mm³ for patients with life-threatening hemorrhage; higher counts may be needed for neurosurgery or TBI 3, 5
• Include platelets in a balanced transfusion approach during initial massive transfusion 3, 5

Fresh Frozen Plasma (FFP)

• If using FFP-based coagulation resuscitation, guide further use by standard laboratory parameters (PT/APTT >1.5 times normal) or viscoelastic evidence of coagulation factor deficiency 1
• Early transfusion of plasma in a balanced ratio of 1:1 with pRBC is associated with higher rates of hemostasis and lower rates of mortality in critical hemorrhage 1

Evidence Quality and Limitations

• Despite growing evidence supporting TEG/ROTEM, most studies are single-center with moderate methodological quality 6, 7
• The Cochrane review and meta-analyses on TEG/ROTEM were of overall low to moderate quality 1, 6
• The iTACTIC trial found no difference between TEG/ROTEM and conventional tests in the intention-to-treat analysis, but showed a trend toward improved survival in coagulopathic patients (INR >1.2) 1
• Current viscoelastic tests may be insensitive to fibrinolytic activation, limiting their ability to guide tranexamic acid (TXA) use 1

Practical Implementation

• Point-of-care (POC) TEG/ROTEM enables faster decision-making and initiation of therapies to correct coagulopathy compared to conventional tests 1
• ROTEM measures results faster than TEG (mean time 24 minutes vs. 31 minutes), allowing for quicker clinical decisions in critical care cases 8
• New fully automated, cartridge-based versions (TEG 6s and ROTEM sigma) may expand point-of-care capabilities 1
• TEG/ROTEM-guided transfusion strategies have demonstrated cost savings in addition to clinical benefits 1

Future Directions

• Large prospective controlled multicenter trials are needed to further validate TEG/ROTEM-guided approaches and determine their effects on clinical outcomes 1
• More research is needed on TEG/ROTEM use in non-trauma settings, including obstetrics and management of hypercoagulable conditions 1
• Optimization of viscoelastic tests to better detect baseline fibrinolysis or potential for adequate fibrinolytic activity is needed 1