Understanding and treating apnoea of prematurity (AOP)

Abstract □ 1

AOP occurs in 80% of infants born at less than 30 wk gestation. Aspects not usually thought of when trying to understand AOP include (i) indications that diaphragmatic energy failure may be involved, (ii) the fact that lung volume is reduced during apnoea and only restored by a sigh, resulting in a greater instability of oxygenation, and (iii) a persistence of the fetal response to even slight reductions in PAO₂, namely an inhibition of breathing, well into the second month of life. These aspects regarding the pathophysiology of AOP may be directly translated into therapy. AOP can be reduced by placing the infant prone with the head elevated by 15, by removing nasogastric feeding tubes (thereby reducing upper airway resistance) and by maintaining oxygen levels in the upper half of the safety range, e.g. at 70-80 mmHg. Measures that stabilise oxygenation by increasing lung volume, e.g. nasal CPAP, are also highly effective in preventing AOP. Drug treatments that reduce energy failure are currently under investigation.