Makindo Medical Notes

📋 About

• 🔍 Point-of-care viscoelastic hemostatic assay measuring whole blood coagulation
• ⚡ Real-time assessment of clot formation, stabilization, and fibrinolysis
• 🎯 European equivalent of TEG with enhanced standardization and automation
• 🏥 Widely used in cardiac surgery, trauma, liver transplantation, and obstetrics
• ⏱️ Results available in 10-20 minutes for emergency decision-making
• 🔬 More standardized reagents and protocols compared to TEG

🔬 Methodology

• 🩸 Sample: Citrated whole blood (300 μL)
• 🔄 Principle: Measures elasticity changes during clot formation using oscillating cup
• 📈 Output: Real-time temogram showing amplitude changes
• 🌡️ Temperature: Standardized at 37°C ± 1°C
• ⚙️ Rotation: Cup oscillates 4.75° every 6 seconds
• 🧪 Reagents: Standardized activators and inhibitors

📊 ROTEM Tests & Reagents

🟦 INTEM (Intrinsic Pathway):

• ⚗️ Activator: Ellagic acid (contact activation)
• 🔍 Assesses: Intrinsic pathway factors (VIII, IX, XI, XII)
• 💊 Sensitive to: Heparin, factor deficiencies
• 🎯 Clinical use: Screening test, heparin monitoring

🟨 EXTEM (Extrinsic Pathway):

• ⚗️ Activator: Tissue factor
• 🔍 Assesses: Extrinsic pathway (factor VII) and common pathway
• 💊 Sensitive to: Warfarin, factor deficiencies, fibrinogen
• 🎯 Clinical use: Most important for bleeding assessment

🟩 FIBTEM (Fibrinogen Function):

• ⚗️ Activator: Tissue factor + Cytochalasin D (platelet inhibitor)
• 🔍 Assesses: Fibrinogen function and concentration
• 🚫 Platelets blocked: Shows pure fibrin clot strength
• 🎯 Clinical use: Fibrinogen replacement decisions

🟪 APTEM (Antifibrinolytic):

• ⚗️ Activator: Tissue factor + Aprotinin
• 🔍 Assesses: Fibrinolysis by comparing to EXTEM
• 🛡️ Fibrinolysis blocked: Shows hyperfibrinolysis if EXTEM different
• 🎯 Clinical use: Antifibrinolytic therapy decisions

🟧 HEPTEM (Heparin Neutralization):

• ⚗️ Activator: Ellagic acid + Heparinase
• 🔍 Assesses: Coagulation without heparin interference
• 💉 Heparin neutralized: Compare to INTEM for heparin effect
• 🎯 Clinical use: Cardiac surgery, heparin monitoring

📊 ROTEM Parameters & Normal Values

⏱️ CT (Clotting Time):

• 🎯 EXTEM normal: 38-79 seconds
• 🎯 INTEM normal: 100-240 seconds
• 🔍 Measures: Time to 2mm amplitude (clot initiation)
• 📈 Prolonged CT: Factor deficiency, anticoagulation
• 📉 Shortened CT: Hypercoagulable state

⚡ CFT (Clot Formation Time):

• 🎯 EXTEM normal: 34-159 seconds
• 🎯 INTEM normal: 30-110 seconds
• 🔍 Measures: Time from 2mm to 20mm amplitude
• 📈 Prolonged CFT: Fibrinogen deficiency, platelet dysfunction
• 📉 Shortened CFT: Hypercoagulable, hyperfibrinogenemia

🔺 Alpha Angle:

• 🎯 EXTEM normal: 63-83 degrees
• 🎯 INTEM normal: 70-83 degrees
• 🔍 Measures: Rate of clot formation (tangent at 2mm)
• 📈 Low angle: Poor clot formation
• 📉 High angle: Rapid clot formation

💪 MCF (Maximum Clot Firmness):

• 🎯 EXTEM normal: 50-72 mm
• 🎯 INTEM normal: 50-72 mm
• 🎯 FIBTEM normal: 9-25 mm
• 🔍 Measures: Maximum clot strength
• 📈 High MCF: Thrombocytosis, hyperfibrinogenemia
• 📉 Low MCF: Thrombocytopenia, hypofibrinogenemia

📉 ML (Maximum Lysis):

• 🎯 Normal: 0-15%
• 🔍 Measures: Fibrinolysis at 60 minutes after MCF
• 📈 High ML (>15%): Hyperfibrinolysis
• 📊 Compare EXTEM vs APTEM: If difference >15%, hyperfibrinolysis present

🎯 ROTEM-Guided Treatment Algorithm

📈 Prolonged CT (EXTEM >79s or INTEM >240s):

• 💉 First-line: Fresh Frozen Plasma (FFP) 15-20 mL/kg
• 🅰️ Alternative: 4-Factor Prothrombin Complex Concentrate 20-30 U/kg
• 🎯 Target: Normalize CT values
• 💊 If on warfarin: Vitamin K 5-10mg IV + PCC

📐 Poor clot formation (CFT >159s or α <63°):

• 🧪 Check FIBTEM MCF:
• 📊 If FIBTEM MCF <9mm: Give fibrinogen concentrate 25-50 mg/kg
• 🧪 Alternative: Cryoprecipitate 15-20 units (or 1-2 units/10kg)
• 🎯 Target: FIBTEM MCF >12mm

💪 Low clot strength (EXTEM MCF <50mm):

• 🔍 Calculate platelet component: MCF(EXTEM) - MCF(FIBTEM)
• 🔴 If platelet component low: Platelets 1 adult dose (4-6 units)
• 💊 Consider DDAVP: 0.3 μg/kg if platelet dysfunction suspected
• 🎯 Target: EXTEM MCF >50mm

📉 Hyperfibrinolysis (ML >15% or EXTEM-APTEM difference >15%):

• 💊 Tranexamic acid: 1g IV bolus, then 1g over 8 hours
• ⚡ Severe cases: Consider higher dose TXA or aminocaproic acid
• 🎯 Target: ML <15%, normalize EXTEM-APTEM difference

🩺 Clinical Applications

🫀 Cardiac Surgery:

• 🔄 CPB monitoring: Heparin effect with HEPTEM vs INTEM
• 🩸 Post-bypass bleeding: Targeted component therapy
• 💉 Protamine titration: Optimal heparin reversal
• 🎯 Reduced transfusions: 20-50% reduction in studies

🚨 Trauma & Emergency:

• 🩸 Trauma-induced coagulopathy: Early detection and treatment
• ⚡ Massive transfusion: Guide component ratios
• 🧠 Brain injury: Rapid coagulation assessment
• 🎯 Mortality benefit: Demonstrated in trauma studies

🫀 Liver Transplantation:

• 🔄 Complex coagulopathy: Multiple pathway assessment
• 🩸 Intraoperative bleeding: Real-time guided therapy
• ⚡ Reperfusion syndrome: Monitor rapid changes
• 💰 Cost reduction: Reduced blood product usage

🤱 Obstetrics:

• 🩸 Postpartum hemorrhage: Guide specific therapy
• 🧬 HELLP syndrome: Monitor coagulation changes
• ⚡ DIC in pregnancy: Real-time assessment
• 🎯 Safety profile: Reduced maternal morbidity

✅ Advantages of ROTEM

• ⚡ Rapid results: 10-20 minutes vs 45-60 minutes for lab tests
• 🎯 Specific therapy: Targeted blood component usage
• 🔬 Standardized: Better reproducibility than TEG
• 🧪 Multiple tests: Comprehensive hemostatic assessment
• 💰 Cost-effective: Reduced inappropriate transfusions
• 🏥 Point-of-care: OR and ICU availability
• 📊 Quality control: Built-in QC measures

❌ Limitations

• 💰 High cost: Equipment and reagent expenses
• 👨‍⚕️ Training required: Proper interpretation needs education
• 🩸 Sample quality: Pre-analytical variables affect results
• ❄️ Temperature sensitive: Hypothermia impacts measurements
• 💊 Drug interference: Some medications affect results
• ⚙️ Maintenance: Regular calibration and QC required
• 📚 Evidence gaps: Limited data in some clinical scenarios

🔍 Common ROTEM Patterns

🩸 Bleeding Patterns:

• 📈 Factor deficiency: Prolonged CT, normal MCF
• 🧪 Fibrinogen deficiency: Low FIBTEM MCF, prolonged CFT
• 🔴 Platelet dysfunction: Normal FIBTEM, low EXTEM MCF
• 📉 Hyperfibrinolysis: High ML, EXTEM-APTEM difference

🧬 Hypercoagulable Patterns:

• 📉 Shortened CT: <38s EXTEM, <100s INTEM
• 📈 High MCF: >72mm suggests thrombotic risk
• ⚡ Shortened CFT: <34s suggests hypercoagulability
• 📊 Low ML: <5% suggests impaired fibrinolysis

🔄 ROTEM vs TEG Comparison

• 🌍 Origin: ROTEM (European) vs TEG (American)
• 🔬 Standardization: ROTEM more standardized reagents
• 🧪 Tests: ROTEM multiple specific tests vs TEG single test
• 📊 Parameters: CT/CFT/MCF vs R/K/MA (similar information)
• 💰 Cost: Similar equipment costs, different reagent pricing
• 🏥 Adoption: ROTEM more common in Europe, TEG in US

📚 References

• 📖 European Society of Anaesthesiology Guidelines on ROTEM
• 🏥 Society of Cardiovascular Anesthesiologists ROTEM Guidelines
• 📕 British Journal of Anaesthesia ROTEM Reviews
• 🔬 Thrombosis Research ROTEM Studies
• 📋 International Society on Thrombosis and Haemostasis
• 🩸 Transfusion Medicine and Hemotherapy
• 🫀 Journal of Cardiothoracic and Vascular Anesthesia

💡 KEY TAKEAWAY: ROTEM provides rapid, comprehensive, and standardized assessment of hemostasis with specific tests for targeted therapy, significantly improving patient outcomes and reducing unnecessary transfusions