Respiratory Muscle Ultrasound
Overview
Respiratory muscle ultrasound is a non-invasive imaging technique for assessing diaphragm and accessory respiratory muscle structure and function in pediatric patients.
Key Points
- Real-time visualization of respiratory muscle movement
- Non-invasive and radiation-free
- Can be performed bedside
- Requires minimal patient cooperation
- Valuable for both diagnosis and monitoring
Sonographic Anatomy
Diaphragm Anatomy
- Normal Sonographic Appearance
- Three-layer structure
- Pleural and peritoneal lines
- Muscle thickness variations
- Zone of apposition
- Key Anatomical Landmarks
- Costal margin
- Intercostal spaces
- Liver/spleen window
- Pleural line identification
Accessory Muscles
- Intercostal muscles
- Scalene muscles
- Sternocleidomastoid
- Parasternal muscles
Scanning Technique
Equipment Setup
- Probe Selection
- Linear probe (7-12 MHz)
- Curvilinear probe (3-5 MHz) for deeper structures
- Settings optimization
- Patient Positioning
- Supine position for thickness measurement
- Semi-recumbent for excursion
- Age-specific considerations
Scanning Approaches
- Zone of Apposition View
- Probe placement between ribs
- B-mode imaging
- Thickness measurements
- Subcostal View
- M-mode assessment
- Excursion measurement
- Movement pattern analysis
- Anterior Approach
- Intercostal visualization
- Pleural sliding assessment
Clinical Assessment
Qualitative Assessment
- Movement Pattern Analysis
- Symmetry evaluation
- Paradoxical movement
- Coordination assessment
- Muscle Echogenicity
- Normal patterns
- Pathological changes
- Atrophy signs
Quantitative Measurements
- Thickness Measurements
- End-expiration
- End-inspiration
- Thickening fraction
- Excursion Assessment
- Normal breathing
- Deep breathing
- Sniff maneuver
Measurement Parameters
Normal Values
- Age-Specific References
- Neonatal values
- Infant measurements
- Pediatric ranges
- Key Parameters
- Resting thickness: 0.2-0.3 cm
- Thickening ratio: >20%
- Excursion: 0.5-1.5 cm
- Movement velocity
Pathological Changes
- Thickness Abnormalities
- Atrophy patterns
- Hypertrophy
- Asymmetry
- Movement Disorders
- Paralysis
- Weakness
- Coordination problems
Clinical Applications
Diagnostic Uses
- Neuromuscular Disorders
- Muscular dystrophy
- Spinal muscular atrophy
- Neuropathies
- Critical Care
- Mechanical ventilation weaning
- Diaphragmatic dysfunction
- Post-surgical assessment
- Chronic Conditions
- Chronic lung disease
- Congenital abnormalities
- Chest wall deformities
Monitoring Applications
- Disease Progression
- Serial measurements
- Treatment response
- Recovery assessment
- Rehabilitation
- Exercise training
- Respiratory therapy
- Outcome assessment
