Introduction
At birth the lungs must change in seconds from fluid-filled organs to air-filled ones: the fluid is absorbed, the alveoli open and pulmonary blood flow rises eight-fold. Breathing problems in the newborn come from failure of this change, from immaturity, or from malformations.
Signs of respiratory distress in a newborn
Tachypnoea over 60/min, nasal flaring, grunting (breathing out against a partly closed glottis to keep the alveoli open), intercostal and subcostal recession, see-saw breathing, cyanosis, apnoea. Severity is scored with the Silverman–Andersen or Downes score.
Persistent pulmonary hypertension of the newborn (PPHN)
Pulmonary vascular resistance stays high after birth, so blood bypasses the lungs right-to-left through the foramen ovale and ductus. Seen with meconium aspiration, asphyxia, sepsis, diaphragmatic hernia or alone. Severe cyanosis, with pre-ductal (right hand) saturation higher than post-ductal (foot). Echo confirms. Treatment: oxygen, ventilation, inhaled nitric oxide, support the blood pressure, ECMO if all fails.
Apnoea of prematurity
Pauses in breathing of 20 seconds or more (or shorter with bradycardia or desaturation) from an immature respiratory centre, in babies under 34 weeks. Exclude sepsis, hypoglycaemia, seizures, anaemia. Treatment: gentle stimulation, caffeine citrate, CPAP.