Capnography Monitors
Capnography Monitors
Capnography is the continuous measurement and graphical display of carbon dioxide (CO2) concentration in respiratory gases. It provides real-time monitoring of ventilation, perfusion, and metabolism in pediatric patients.
Key Points
- Measures end-tidal CO2 (ETCO2) and respiratory rate
- Normal ETCO2 range: 35-45 mmHg
- Provides continuous, non-invasive monitoring
- Essential for procedural sedation
- Critical for ventilation management
Types of Capnography
- Mainstream (in-line)
- Sensor directly in airway
- Faster response time
- Better for intubated patients
- Sidestream
- Samples gas from breathing circuit
- More versatile for different interfaces
- Suitable for non-intubated patients
Technology & Components
Hardware Components
- CO2 sensor
- Infrared absorption technology
- Rapid response time
- Temperature compensation
- Display unit
- Waveform display
- Numerical values
- Trend data
- Sampling system
- Tubing
- Water traps
- Filters
Technical Specifications
- Measurement range: 0-100 mmHg
- Response time: < 100ms
- Accuracy: ±2 mmHg
- Sample flow rate: 50-100 ml/min
- Operating temperature: 10-40°C
Waveform Analysis
Normal Capnogram Phases
- Phase I (Inspiratory Baseline)
- No CO2 detected
- Fresh gas inspiration
- Phase II (Expiratory Upstroke)
- Rapid rise in CO2
- Mixed dead space and alveolar gas
- Phase III (Alveolar Plateau)
- Peak CO2 concentration
- End-tidal measurement point
- Phase IV (Inspiratory Downstroke)
- Rapid fall in CO2
- Fresh gas inspiration begins
Abnormal Patterns
- Bronchospasm
- Shark fin appearance
- Prolonged Phase III
- Hypoventilation
- Elevated baseline
- Increased ETCO2
- Airway Obstruction
- Prolonged expiration
- Irregular waveform
Clinical Applications
Primary Uses
- Procedural Sedation
- Early detection of respiratory depression
- Continuous ventilation monitoring
- Mechanical Ventilation
- ETT position verification
- Ventilation adequacy
- Weaning assessment
- Critical Care
- CPR quality assessment
- Shock monitoring
- Metabolic status
Age-Specific Considerations
- Neonates
- Lower normal ETCO2 values
- Smaller sampling volumes
- Special interface requirements
- Infants and Toddlers
- Higher respiratory rates
- Modified sampling techniques
- Special nasal cannulas
Troubleshooting & Maintenance
Common Issues
- Water Condensation
- Empty water trap regularly
- Check tubing position
- Monitor humidity levels
- Signal Loss
- Check connections
- Verify sampling line patency
- Assess for leaks
- Calibration Errors
- Zero calibration check
- Environmental factors
- Sensor maintenance
Preventive Maintenance
- Daily Tasks
- Check connections
- Empty water traps
- Verify calibration
- Weekly Tasks
- Clean external surfaces
- Check filter condition
- Review error logs
- Monthly Tasks
- Full system check
- Replace filters
- Software updates
