Understanding the respiratory consequences of preterm birth

Bronchopulmonary dysplasia is the most common long-term respiratory complication after preterm birth. Shift of the oxyhaemoglobin saturation versus inspired oxygen pressure curve provides an index of pulmonary gas exchange and should be considered as a key variable of a new physiology-based classification of bronchopulmonary dysplasia. Increased efficiency and reduced diaphragmatic work in infants with bronchopulmonary dysplasia could result from the rigid chest wall in these infants. However, the compound contribution of the diaphragm and the chest wall to the breathing disorder present in infants with bronchopulmonary dysplasia appears to be minimal when assessed at 36 weeks' postmenstrual age.