Overview

Diagnosing respiratory distress in neonates is an emergency and critical aspect of neonatal care. Respiratory distress, characterised by difficulty in breathing, is a common and potentially serious condition in newborns, especially preterm babies. Fifteen percent of term infants and 29% of late preterm infants admitted to the neonatal intensive care unit develop significant respiratory illness; this is even higher for infants born before 34 weeks of pregnancy.

Risk factors that increase the likelihood of neonatal respiratory disease include prematurity, meconium-stained amniotic fluid (MSAF), Cesarean section delivery, gestational diabetes, maternal chorioamnionitis, or prenatal ultrasonographic findings, such as oligohydramnios or structural lung abnormalities.¹ Prompt and accurate diagnosis ensures timely intervention and reduces morbidity (disease) and mortality (death) risk. 

The causes of respiratory distress in neonates are diverse, ranging from transient conditions like transient tachypnea of the Newborn(TTN) to more severe disorders such as respiratory distress syndrome (RDS), congenital diaphragmatic hernia or infections like pneumonia and sepsis.

Diagnosis involves a thorough clinical assessment, which includes the observation of respiratory rate, breathing work, and oxygen saturation, as confirmed by radiographic imaging and laboratory tests. Understanding the underlying cause is essential for setting up appropriate treatment strategies and improving outcomes for affected neonates.

What is a neonate?

According to the World Health Organization(WHO), a neonate is a newborn child, typically an infant in the first 28 days of life. This period is critical for the baby's development and adaptation to life outside the womb. During this time, newborns undergo significant physiological changes and, therefore, require close monitoring and care to ensure they are healthy and thriving.²

Respiratory distress in neonates

Respiratory distress in neonates is a condition where a newborn has difficulty breathing. This can manifest as rapid breathing, grunting, flaring of the nostrils, retractions (where the chest pulls in with each breath), and cyanosis (blue or grey skin).

Immediate assessment and treatment are crucial, as severe respiratory distress can lead to hypoxaemia and acidosis (excessive acidity in the blood), which can be life-threatening if not managed promptly. Treatment may involve supplemental oxygen, mechanical ventilation, medications, or other supportive measures, depending on the underlying cause.¹

Causes of respiratory distress in neonates

Some of the most common causes include:

• Transient Tachypnea of the Newborn (TTN): Often seen in full-term or late preterm infants, TTN is caused by delayed clearance of fetal lung fluid
• Respiratory Distress Syndrome (RDS): Primarily affects preterm infants due to surfactant deficiency
• Meconium Aspiration Syndrome (MAS): Occurs when a newborn inhales a mixture of meconium (the first stool, usually dark green to almost black) and amniotic fluid into the lungs around the time of delivery, leading to airway obstruction and inflammation
• Neonatal Pneumonia: Can be acquired either in utero, during delivery, or postnatally
• Congenital Diaphragmatic Hernia (CDH): A birth defect with a hole in the diaphragm
• Persistent Pulmonary Hypertension of the Newborn (PPHN): Caused by the failure of the normal circulatory transition that occurs after birth
• Pneumothorax: A condition where air gets into the gap between the lung and chest wall
• Congenital Heart Disease: Certain heart defects due to poor oxygenation and circulation
• Bronchopulmonary Dysplasia (BPD): Typically occurs in preterm infants who have received prolonged mechanical ventilation
• Airway Obstructions: Conditions like choanal atresia (blockage of the nasal passage), laryngeal webs, or tracheomalacia (softening of the trachea)
• Maternal Conditions: Maternal diabetes, chorioamnionitis, or opioid use during pregnancy
• Metabolic and Hematologic Disorders: Conditions such as hypoglycemia, anaemia, or erythrocytosis

Signs and symptoms of respiratory distress in neonates 

Respiratory distress often includes several key signs and symptoms that indicate difficulty in breathing. These are:

• Tachypnea: Rapid breathing, typically defined as a respiratory rate greater than 60 breaths per minute
• Grunting: A sound made by the infant when exhaling, which helps keep the airways open
• Nasal flaring: Widening of the nostrils with each breath, indicating increased effort to breathe
• Retractions: Visible pulling in of the chest wall (intercostal, subcostal, or suprasternal areas) during inhalation, indicating increased effort to breathe
• Cyanosis: Bluish discolouration of the skin, especially around the lips and fingers, indicating low oxygen levels
• Poor feeding: Difficulty feeding or inability to suck effectively due to respiratory distress
• Lethargy or irritability: Decreased activity level or increased irritability, which can be signs of hypoxia or hypercapnia
• Apnea: Episodes of paused breathing that last more than 20 seconds
• Abnormal breath sounds: Such as crackles, wheezing, or stridor heard on auscultation

Severity assessment of respiratory distress in neonates 

Assessing how severe the respiratory distress is in neonates is crucial for timely and effective management. The following scoring systems are usually used to assess and monitor respiratory distress in newborns:

Silverman-Andersen Retraction Score:

This assesses the severity of respiratory distress based on five criteria:

1. Chest retractions (intercostal)
2. Xiphoid retractions
3. Nasal flaring
4. Grunting
5. Synchrony of chest and abdominal movement

Each factor is scored between 0 to 2:

0: No symptoms

1: Mild symptoms

2: Severe symptoms

A total score of 0 indicates no distress, while a total score 10 indicates severe respiratory distress.

Downes’ score:

Downes' score is another commonly used scoring system based on the following criteria:

1. Respiratory rate
2. Cyanosis
3. Air entry
4. Retractions
5. Grunting

Each factor is scored between 0 and 2, with higher scores indicating greater severity:

0: Normal

1: Mild symptoms

2: Severe symptoms

Diagnosis of respiratory distress in neonates 

When faced with respiratory distress in neonates, it is crucial to consider common and rare causes. Here is a structured approach:

• Assessment: This begins with a thorough clinical evaluation, which includes vital signs, general appearance, respiratory rate, effort, and oxygen saturation
• History: Gathering information on prenatal, perinatal, and postnatal factors, including maternal history (e.g., prenatal infections, drug exposure), delivery details (e.g., gestational age, mode of delivery, Apgar scores), and neonatal history (e.g., feeding, bowel movements, symptoms progression)
• Physical examination: Performing a comprehensive physical exam focusing on respiratory, cardiovascular, and neurological systems. Looking for signs of cyanosis, retractions, grunting, nasal flaring, and abnormal breath sounds⁴

Diagnostic tests

In neonates experiencing respiratory distress, additional diagnostic tools may include:

• Chest X-ray: To assess for conditions like pneumonia, pneumothorax, or congenital anomalies
• Blood gas analysis: To evaluate oxygen, carbon dioxide levels, and acid-base balance
• Pulse oximetry: Measures oxygen saturation levels in the blood
• Complete Blood Count (CBC): To check for signs of infection or anaemia
• Blood cultures: If infection is suspected, blood cultures may be taken to identify the causative organism
• Ultrasound: Can be used to assess lung and heart function, as well as detect any fluid accumulation
• Echocardiography: To evaluate cardiac function and assess for any structural abnormalities
• Nasopharyngeal aspirate: To test for respiratory viruses, which can be a common cause of respiratory distress in neonates
• Capnography: For real-time monitoring of carbon dioxide levels in exhaled breath, showing the rate of ventilation and perfusion

Differential diagnosis for respiratory distress in neonates 

Respiratory distress in neonates can be confused with other respiratory issues in newborns, like cardiogenic edema and cardiovascular diseases. A detailed history and physical examination should focus beyond the lungs to identify non-pulmonary causes, such as airway obstruction, chest wall abnormalities, cardiovascular disease, or neuromuscular disease, that may initially present as respiratory distress in a newborn. 

Radiographic and laboratory findings will aid in the differential diagnosis. Therefore, when diagnosing respiratory distress in neonates, it is important to pay special attention to the underlying causes and signs & symptoms.⁹ They are grouped into respiratory causes and non-respiratory causes in the table below.

Management and treatment of respiratory distress in neonates 

Respiratory distress in neonates requires prompt assessment and management to prevent complications.

• Assessment: Evaluate the severity of distress using clinical signs, respiratory rate, heart rate, oxygen saturation, and chest X-ray findings
• Oxygen therapy: Administer supplemental oxygen to maintain oxygen saturation levels above 90%. Use a nasal cannula, oxygen hood, or mechanical ventilation as needed
• Ventilation support: For severe distress, provide ventilatory support using non-invasive techniques like continuous positive airway pressure (CPAP) or invasive methods such as mechanical ventilation
• Surfactant replacement therapy: Administer exogenous surfactant to premature neonates with respiratory distress syndrome (RDS) to improve lung compliance and oxygenation
• Fluid management: Ensure appropriate fluid administration to maintain adequate perfusion and prevent volume overload, which can worsen respiratory function
• Infection management: Treat underlying infections promptly with antibiotics if suspected, based on clinical presentation and laboratory findings
• Maintaining thermoregulation: Prevent heat loss and maintain normal temperature to reduce metabolic demand and respiratory distress
• Nutritional support: Ensure adequate nutrition to support growth and development, which can improve respiratory function and overall outcomes
• Monitoring and supportive care: Continuously monitor respiratory and cardiovascular status, electrolyte balance, and blood gas parameters. Provide supportive care such as suctioning, positioning, and gentle handling to optimise respiratory effort
• Multidisciplinary approach: Involve a multidisciplinary team including neonatologists, paediatricians, respiratory therapists, and nurses to optimise management and decision-making
• Follow-up and long-term care: Ensure appropriate follow-up after discharge to monitor respiratory status, growth, and development. Address any ongoing respiratory issues and provide supportive care as needed
• Family support and education: Educate parents about the condition, treatment options, and potential complications. Offer emotional support and involve them in the decision-making process⁷

Individualised management is based on the underlying cause of respiratory distress and the neonate's clinical condition, gestational age, and comorbidities. Regular reassessment and adjustment of treatment are essential for optimal outcomes.⁸

Prognosis, outcomes and complications of respiratory distress in neonates 

Respiratory distress in neonates can have various prognoses, outcomes, and complications depending on the underlying cause and how promptly it is addressed. Common outcomes include full recovery with appropriate treatment, while severe cases can lead to respiratory failure or long-term respiratory issues like chronic lung disease. 

Complications may include pneumonia, bronchopulmonary dysplasia, and neurodevelopmental problems if oxygen deprivation occurs. Early diagnosis and intervention are crucial for improving outcomes and reducing complications.⁵

Summary

• Diagnosing respiratory distress in neonates is crucial for timely treatment. Common indicators include tachypnea, retractions, nasal flaring, grunting, and cyanosis
• Physical examination, chest X-rays, blood gases, and pulse oximetry help in diagnosis
• Causes range from transient tachypnea of the newborn to more severe conditions like meconium aspiration syndrome or congenital pneumonia
• Treatment depends on the underlying cause and may involve oxygen therapy, mechanical ventilation, or medications
• Early recognition and management improve outcomes for neonates with respiratory distress