Respiratory complications of preterm birth

Introduction

Respiratory complications of preterm birth are an important cause of infant mortality and morbidity. This article looks at how advances in perinatal care have improved outcomes for preterm infants with respiratory distress syndrome and chronic lung disease.

Respiratory distress syndrome

Respiratory distress syndrome of prematurity is a major cause of morbidity and mortality in preterm infants. Primarily, respiratory distress syndrome is caused by deficiency of pulmonary surfactant. Surfactant is a complex mixture of phospholipids and proteins that reduces alveolar surface tension and maintains alveolar stability. As most alveolar surfactant is produced after about 30-32 weeks' gestation, preterm infants born before then will probably develop respiratory distress syndrome. In addition to short gestation, several other clinical risk factors have been identified.

Pathogenesis of respiratory distress syndrome is a “vicious cycle”

Preterm infants with respiratory distress syndrome present immediately or soon after birth with worsening respiratory distress. The presenting features include tachypnoea (respiratory rate > 60 breaths per minute); intercostal, subcostal, and sternal recession; expiratory grunting; cyanosis; and diminished breath sounds.

If untreated, infants may become fatigued, apnoeic, and hypoxic. They may progress to respiratory failure and will need assisted ventilation. High airway pressures may be required to ventilate the stiff, non-compliant lungs, thereby increasing the risk of acute respiratory complications, such as pneumothorax, pneumomediastinum, and pulmonary interstitial emphysema.

Endotracheal intubation and ventilation: intercostal drain for pneumothorax

Over the past 20-30 years, two major advances in perinatal management—the use of antenatal corticosteroids and exogenous surfactant replacement—have greatly improved clinical outcomes for preterm infants with respiratory distress syndrome.