Pulmonary Function Test
Pulmonary Function Testing in Pediatrics
Pulmonary Function Testing (PFT) is a comprehensive evaluation of respiratory mechanics and gas exchange. In pediatrics, it serves as a vital tool for diagnosis, monitoring, and management of respiratory conditions.
Key Points
- Typically performed in children >5 years who can follow instructions
- Requires specific pediatric reference values
- Essential for monitoring chronic respiratory conditions
- Must be performed by trained pediatric personnel
Types of Pulmonary Function Tests
1. Spirometry
- Measures FEV1, FVC, FEV1/FVC ratio
- Flow-volume loops
- Pre and post-bronchodilator testing
2. Body Plethysmography
- Measures lung volumes: TLC, RV, FRC
- Airways resistance (Raw)
- Specific airways conductance (sGaw)
3. Diffusion Capacity (DLCO)
- Measures gas transfer
- Usually performed in children >8-10 years
4. Infant Pulmonary Function Tests
- Tidal breathing measurements
- Forced expiratory maneuvers
- Requires sedation
Indications for PFT
Diagnostic Purposes
- Asthma evaluation and monitoring
- Cystic fibrosis
- Bronchiectasis
- Interstitial lung disease
- Bronchiolitis obliterans
- Vocal cord dysfunction
Monitoring
- Disease progression
- Treatment response
- Medication adjustments
- Pre-operative assessment
Technique & Procedure
Pre-Test Requirements
- Proper calibration of equipment
- Height and weight measurement
- Medical history review
- Medication documentation
Testing Protocol
- Patient education and demonstration
- Proper positioning
- Nose clip application
- Multiple maneuvers (minimum 3)
- Quality control assessment
Special Considerations
- Use of pediatric incentive displays
- Proper coaching techniques
- Recognition of fatigue
- Age-appropriate encouragement
Interpretation of Results
Normal Values
- FEV1: ≥80% predicted
- FVC: ≥80% predicted
- FEV1/FVC: >0.85 in children
- TLC: 80-120% predicted
Pattern Recognition
| Pattern | Characteristics |
|---|---|
| Obstructive |
|
| Restrictive |
|
| Mixed |
|
Limitations & Considerations
Age-Related Challenges
- Limited cooperation in young children
- Variable effort and technique
- Need for repeated attempts
Technical Considerations
- Equipment calibration requirements
- Environmental factors
- Time constraints
- Staff expertise needed
Contraindications
- Severe respiratory distress
- Recent surgery
- Hemoptysis
- Pneumothorax
- Active infection
