A patient presented with blunt trauma to the abdomen. On evaluation, liver injury was noted, for which primary repair was done. Coagulation function was monitored intraoperatively, using the method shown below. What is the method used? [image] [image]

Explanation

## Correct Answer: A. Thromboelastography Thromboelastography (TEG) is a point-of-care viscoelastic test that measures the dynamic properties of blood coagulation in real time. The characteristic tracing shown in the image displays the classic TEG waveform: initial lag phase (R time—reaction time until clot initiation), angle of clot formation (α angle—rate of fibrin polymerization), maximum amplitude (MA—clot strength), and lysis at 30 minutes (LY30). In acute liver trauma with primary repair, TEG is invaluable for intraoperative coagulation monitoring because it detects platelet dysfunction, fibrinogen depletion, and hyperfibrinolysis—all common in massive transfusion protocols and hepatic injury. Unlike conventional PT/INR and aPTT (which are static tests), TEG provides real-time assessment of clot formation kinetics and stability, guiding transfusion decisions and hemostatic interventions. This is the gold standard in trauma surgery across Indian trauma centers and aligns with current massive transfusion protocol guidelines. The visual waveform pattern is pathognomonic and directly correlates with clinical coagulation status. ## Why the other options are wrong **B. Plethysmography** — Plethysmography measures changes in blood volume and vascular compliance in limbs; it assesses peripheral perfusion and vascular tone, not coagulation function. It cannot detect clot formation kinetics, fibrinogen levels, or platelet dysfunction. This is a vascular physiology tool, not a hemostasis monitor—a common trap for students who confuse vascular assessment with coagulation testing. **C. Elastography** — Elastography (transient or shear-wave) measures tissue stiffness and fibrosis, primarily used for liver fibrosis staging in chronic liver disease. It has no role in acute coagulation assessment or intraoperative hemostasis monitoring. The visual waveform in the image is distinctly different from elastography patterns—this option exploits confusion between liver-related tests. **D. Sonography** — Sonography is an imaging modality for structural assessment of organs and tissues; it cannot measure coagulation function or clot dynamics. While ultrasound may be used to assess liver injury extent, it provides no real-time hemostatic data. The waveform shown is a functional coagulation tracing, not an anatomical image—a fundamental category error. ## High-Yield Facts - **TEG R time** (reaction time) reflects initiation phase; prolonged R suggests factor deficiency or anticoagulation. - **TEG MA** (maximum amplitude) reflects platelet count and function; low MA (<50 mm) indicates platelet dysfunction or thrombocytopenia requiring transfusion. - **TEG α angle** (angle of clot formation) reflects fibrinogen and platelet interaction; angle <55° suggests hypofibrinogenemia. - **TEG LY30** (lysis at 30 min) detects hyperfibrinolysis; LY30 >3% is abnormal and indicates need for antifibrinolytic therapy (tranexamic acid). - **Point-of-care TEG** guides massive transfusion protocol in trauma: RBC:FFP:PLT ratios adjusted based on real-time TEG parameters, not static PT/INR. - **TEG vs. PT/INR**: TEG detects platelet dysfunction and fibrinolysis (missed by PT/INR); superior for guiding hemostatic interventions in acute hemorrhage. ## Mnemonics **TEG Parameters (RAML)** **R** = Reaction time (clot initiation), **A** = Angle (fibrin polymerization rate), **M** = Maximum amplitude (clot strength), **L** = Lysis (fibrinolysis). Use this to recall the four key TEG variables in order of appearance on the tracing. **When TEG Beats PT/INR** TEG detects **Platelet dysfunction, Fibrinolysis, Hypofibrinogenemia** in real time; PT/INR misses these. In trauma, TEG guides transfusion; PT/INR does not. Remember: **TEG = Dynamic, PT/INR = Static**. ## NBE Trap NBE pairs liver trauma with coagulation monitoring to lure students into choosing imaging modalities (sonography, elastography) or vascular tests (plethysmography) instead of the functional hemostasis test. The waveform image is the key discriminator—only TEG produces this characteristic viscoelastic tracing. ## Clinical Pearl In Indian trauma centers managing blunt liver injuries with massive transfusion, TEG-guided resuscitation reduces mortality and morbidity compared to conventional PT/INR-based protocols. A single TEG tracing in the OR can detect occult hyperfibrinolysis (LY30 >3%) and prompt early tranexamic acid administration—a life-saving intervention often missed by static coagulation tests. _Reference: Bailey & Love Ch. 5 (Hemostasis & Transfusion); Harrison Ch. 179 (Coagulation Disorders); Indian Trauma Society Guidelines on Massive Transfusion Protocol_