Neonatal respiratory distress

You are the paediatric registrar on shift overnight, and your phone rings. “It’s Mary in the birth suite. Can you please review a term baby in room 1? Born one hour ago via vaginal delivery… They’re tachypnoeic.

Respiratory distress is common and affects 7% of term infants. It is the most common reason term babies are admitted to special and intensive care nurseries. Several factors increase the likelihood of respiratory distress occurring in a term neonate: meconium exposure, maternal gestational diabetes, chorioamnionitis, oligohydramnios and delivery by caesarean section.

Common causes of respiratory distress include:

• Transient tachypnea of the newborn (aka retained fetal lung fluid)
• Respiratory distress syndrome (aka hyaline membrane disease)
• Persistent pulmonary hypertension
• Pneumothorax
• Meconium aspiration
• Sepsis

What are the less common ones that we don’t want to miss?

• Congenital pneumonia
• Congenital pulmonary airway malformation
• Pleural effusion
• Congenital cardiac disease
• Oesophageal atresia with/out trans oesophageal fistula
• Congenital diaphragmatic hernia
• Metabolic problems: hypothermia, hypoglycemia
• Airway obstruction: choanal atresia, micrognathia, macroglossia, tracheomalacia, subglottic stenosis, airway haemangioma
• Bony abnormalities: skeletal dysplasia
• Hypoxic- ischaemic encephalopathy
• Neuromuscular causes: congenital myotonic dystrophy, spinal muscular atrophy, congenital myopathies, seizures

So what should we be looking for on examination?

• Is the newborn pink or blue? What are the oxygen saturations? Pre-ductal (taken on the right hand) and post-ductal (taken on one of the feet)
• Is the infant distressed? What is their respiratory effort? Subcostal and intercostal recessions, head bob, and tracheal tug are often difficult to spot in newborns because of their large head/lack of neck. Is the baby grunting?
• What is the respiratory rate? Is it >60?
• What are the other vital signs, heart rate and temperature?
• Chest wall movement: is the chest moving adequately and symmetrically?
• Air entry: is it equal? Are there added sounds? Are there bowel sounds in the chest?

Upon your arrival, the infant is on the resuscitaire. She is receiving CPAP of 8cm via mask. She has increased work of breathing with subcostal and intercostal recessions, grunting, and remains tachypnoeic with a respiratory rate of 80. You continue to administer CPAP of 8cm.

What else needs to be done in the birth suite?

• Keep the infant warm: ensure the heater is on and the infant is on the portion of the resuscitaire that the radiant heater covers. Is she wearing a beanie? Has she been dried off? Is she on warm and dry wraps?
• Is her position ideal: neutral airway position
• Does she require oxygen? What are the oxygen saturations?
• Are you getting adequate pressure: is the CPAP maintaining 8cm? Is the mask an appropriate size? Is the flow correct? Is the upper airway obstructed? Does she need to be suctioned?

You take the baby to the nursery for further assessment and treatment. What do you need to do to get prepared for the move?

Most resuscitaires cannot maintain enough power to adjust the cot height or provide heat while transferring. Consider if you have enough warm wraps, enough oxygen and air in the cylinders and appropriate monitoring.

The newborn is admitted to the nursery for ongoing respiratory distress. CPAP is continued at 8cm in 30% oxygen.

What investigations should you do?  

• FBC and Blood culture: respiratory distress can be the first sign of sepsis.
• Blood glucose
• Consider a gas: arterial blood gas is most accurate but difficult to obtain without intra-arterial access. Venous or capillary gases are more practical. Capillary gases are more prone to error in poorly perfused infants but are quick and easy to obtain.
• CXR: With a nasogastric tube in situ, this helps identify oesophageal atresia.

Why do infants get respiratory distress?

The aetiology of respiratory distress is as varied as the causes. Many infants struggle with the transition from birth to neonatal life. Whatever the underlying pathology, surfactant deficiency, meconium aspiration or persistent pulmonary hypertension, these cause atelectasis and ventilation-perfusion (V/Q) mismatch. This leads to hypoxemia and hypercarbia and, ultimately, respiratory acidosis. Tissues then become poorly perfused, leading to metabolic acidosis, which further increases pulmonary vasoconstriction and causes endothelial and epithelial injury and respiratory distress syndrome.

What next?

• Keep the infant warm.
• Positioning of the infant: place in an isolette to monitor respiratory distress; keep the head in a neutral position; consider prone.
• Respiratory support:
  • Start with CPAP 8cm in the oxygen required to maintain saturations >/= 90%
  • Indications for intubation are: FiO₂ >40%, extreme prematurity, recurrent apnoea that requires stimulation or apnoea requiring resuscitation, respiratory failure (pCO₂ > 70 and pH < 7.2)
• IV antibiotics to cover sepsis: use broad-spectrum antibiotics. Your hospital will have a policy. Amoxicillin and gentamicin are a good starting point. Remember to cover for the common pathogens: Group B streptococcus and Escherichia coli.
• Nutrition: A term baby with significant respiratory distress will find it difficult to suck feed. Consider starting IV dextrose and small amounts of enteral feeds via a nasogastric tube when expressed breast milk is available.
• Decompress the stomach with a nasogastric tube.

Just remember there are a few contraindications to CPAP

• Bilateral choanal atresia and tracheoesophageal fistula; upper airway anomalies can make CPAP unsafe or ineffective
• Unrepaired gastroschisis
• Unrepaired congenital diaphragmatic hernia.  CPAP can cause gastric distension and affect thoracic organs.

What is the bottom line?

Respiratory distress can be the first sign of sepsis

Manage respiratory distress early so it does not progress. Start CPAP at 8cm in the oxygen required to maintain saturation.

CPAP has been shown to reduce the need and duration of mechanical ventilation

Selected resources

Reuter S, Moser C, Baack M. Respiratory distress in the newborn. Pediatrics in review. 2014 Oct;35(10):417.

Queensland health clinical guideline Neonatal respiratory distress including CPAP