The appearance of retractions is a highly visible sign of respiratory distress in infants, indicating they are working harder than usual to breathe. These visible indentations in the soft tissues of the chest wall are a physical manifestation of a struggle to move air effectively into the lungs. Recognizing these visual cues is important, as they provide an early warning that an infant requires medical attention.
Understanding the Mechanism of Retractions
Normal breathing primarily uses the diaphragm, a dome-shaped muscle beneath the lungs, which pulls downward to create negative pressure and draw air in. When an infant’s airways are narrowed or the lungs are stiff, the body must generate a much stronger negative pressure to overcome this resistance and pull sufficient air inside. To achieve this increased effort, the infant recruits accessory muscles located in the chest and neck that are not typically involved in quiet respiration.
The chest wall of an infant is significantly more pliable and less rigid than that of an older child or adult. This flexibility means that when the powerful suction of the diaphragm and accessory muscles intensifies, the soft tissues between the ribs and around the sternum are pulled inward. This inward pulling, or “retraction,” occurs with every inhalation, directly correlating to the degree of difficulty the infant is experiencing.
Identifying Specific Types of Retractions
Observing an infant’s chest while they are calm and unclothed is the best way to identify retractions, which are categorized by their location. The location of the retraction can offer clues about the severity of the respiratory effort, often progressing from lower to higher areas as the distress worsens.
Subcostal Retractions
These are typically the first retractions to appear and involve the skin and muscle pulling inward just below the rib cage, at the junction of the chest and abdomen. The soft tissue here sinks into the body with each intake of breath, often making the lower edge of the ribs more prominent. This type of pulling is directly related to the powerful downward pull of the diaphragm trying to expand the lungs.
Intercostal Retractions
These appear as a visible indentation in the spaces between the ribs, where the intercostal muscles are located. When the accessory muscles between the ribs contract forcefully to assist inhalation, the skin over these spaces is drawn deeply inward.
Sternal and Substernal Retractions
Sternal retractions involve the entire breastbone (sternum) being pulled inward toward the spine, while substernal retractions occur just beneath the breastbone. When the respiratory distress is moderate to severe, the pliable cartilage of the sternum can visibly move inward with each breath.
Supraclavicular and Suprasternal Retractions
These retractions are typically the last to appear and indicate the most severe level of respiratory distress. Suprasternal retractions are a deep indentation in the soft tissue of the neck, directly above the top of the sternum. Supraclavicular retractions are visible pulling in the areas just above the collarbones (clavicles).
Common Causes of Infant Respiratory Distress
Retractions are a symptom, not a diagnosis, and they point to a variety of underlying conditions that restrict airflow or lung expansion. Respiratory Syncytial Virus (RSV) is a frequent cause, leading to bronchiolitis, which involves inflammation and blockage of the small airways in the lungs. Similarly, bacterial or viral pneumonia can cause retractions by filling the lung tissue with fluid or pus, making the lungs stiff and difficult to inflate.
Another common cause, especially in newborns, is Respiratory Distress Syndrome (RDS), which occurs when premature infants lack sufficient surfactant, a substance that prevents the air sacs from collapsing. Transient tachypnea of the newborn (TTN) is a temporary, less severe condition often seen after birth, caused by fluid remaining in the lungs. Conditions such as croup, which causes swelling in the upper airway, or asthma, which leads to airway narrowing, can also trigger retractions due to the increased effort required to draw air past the constriction.
When to Seek Immediate Medical Help
Any observation of retractions, regardless of their location, is a sign that an infant’s breathing effort is abnormal and requires immediate medical evaluation. Retractions signify that the body is already compensating for a lack of oxygen or a breathing obstruction, and this increased effort can lead to exhaustion. Parents should not wait for the retractions to become more severe before seeking help.
Other visual and auditory signs that accompany retractions also signal a medical emergency:
- Nasal flaring, where the nostrils widen with each breath, is the body’s attempt to reduce resistance in the upper airway.
- An audible grunting sound, which occurs when the infant tries to exhale against a partially closed airway, helps to keep the air sacs open.
- A rapid breathing rate, or tachypnea (defined as over 60 breaths per minute in a newborn), suggests the body is trying to compensate by increasing ventilation.
- A change in skin color, such as a bluish tint around the lips or face (cyanosis), is a serious, late-stage sign of insufficient oxygen.
If retractions are accompanied by lethargy, an inability to feed, or an overall look of distress, immediate emergency services should be contacted.