Point-of-Care Coagulation Test
Point-of-Care Coagulation Testing in Pediatrics
Key Points
- Rapid bedside assessment of coagulation status
- Minimal blood volume requirement (10-50 μL)
- Results available within 2-10 minutes
- Critical for emergency and perioperative management
Introduction
Point-of-Care (POC) coagulation testing provides rapid assessment of hemostasis at the bedside, enabling immediate clinical decision-making in pediatric patients. These tests are particularly valuable in emergency situations, surgical procedures, and anticoagulation monitoring.
Testing Methods
Common POC Devices
- Thromboelastography (TEG):
- Measures viscoelastic properties
- Provides complete hemostasis assessment
- Sample volume: 340 μL
- Results in 10-20 minutes
- Rotational Thromboelastometry (ROTEM):
- Advanced viscoelastic testing
- Multiple assays available
- Sample volume: 300 μL
- Real-time results
- INR/PT Monitors:
- Fingerstick testing
- Sample volume: 10-15 μL
- Results in 2-3 minutes
- Warfarin monitoring
Sample Collection
- Capillary Blood:
- Warm site to ensure good flow
- First drop wiped away
- Avoid squeezing
- Direct application to device
- Whole Blood:
- Fresh venous sample
- Citrated or plain tube
- Minimal stasis during collection
- Immediate testing recommended
Coagulation Parameters
Basic Parameters
- PT/INR:
- Normal PT: 11-13.5 seconds
- Normal INR: 0.8-1.2
- Target INR for anticoagulation: 2.0-3.0
- aPTT:
- Normal range: 25-35 seconds
- Heparin therapeutic range: 1.5-2.5× normal
- ACT:
- Normal range: 90-130 seconds
- Target for bypass: 400-480 seconds
Viscoelastic Parameters
- Clot Formation:
- R-time/CT: Initiation of clotting
- K-time/CFT: Clot formation time
- α-angle: Rate of clot formation
- Clot Strength:
- MA/MCF: Maximum amplitude/firmness
- LY30/CLI: Clot lysis
Clinical Applications
Primary Indications
- Emergency Situations:
- Trauma assessment
- Active bleeding
- DIC evaluation
- Pre-procedure screening
- Perioperative Management:
- Pre-surgical screening
- Intraoperative monitoring
- Post-operative assessment
- Transfusion guidance
- Anticoagulation Monitoring:
- Warfarin therapy
- Heparin monitoring
- Novel anticoagulant assessment
Advantages
- Rapid results availability
- Minimal blood volume required
- Bedside testing capability
- Real-time monitoring
- Reduced laboratory turnaround time
Limitations and Considerations
- Technical Factors:
- Operator training required
- Regular quality control needed
- Temperature sensitivity
- Device maintenance
- Clinical Limitations:
- Cost per test higher than laboratory
- Limited test menu
- Potential accuracy variations
- Need for result confirmation
Quality Assurance
- Daily quality controls
- Regular proficiency testing
- Staff competency assessment
- Result documentation
- Device maintenance logs
