The impact of neonatal intensive care practices on the developing brain

We reviewed some characteristics of the developing brain and its susceptibility to several frequently used neonatal practices. The combination of some practices, used simultaneously or consecutively in the NICU, could lead to an adverse effect on the developing brain in ELBW infants and may be one of the multiple factors associated with abnormal neurodevelopmental outcome, particularly so if predisposing conditions existed during prenatal life. Several confounding factors need to be considered when trying to understand the role of neonatal practices on the developing brain. Our review found differences in PVL and CP rates for different centers and countries. Although intercenter variability could be partly because of the combination of different practices in NICUs, geographic factors, genetic predisposition, socioeconomic level, obstetric follow-up, and delivery circumstances must also be taken into account before concluding that a specific practice should be modified. However, the past has taught us that careful comparison of outcomes and practices between different centers can lead to substantial benefits for the health of premature infants. The results obtained from experimental animal models are not a sufficient basis for making changes in clinical practice. However, together with the already available human studies, they raise concerns and questions for clinical practice. We believe that changing some clinical practices, such as the use of postnatal steroids and midazolam for example, will improve outcomes. Other practices, like HFV, hypercarbia, analgesia, and the administration of dopamine and xanthines should be carefully evaluated for each individual infant, balancing the possible benefits with the potential for adverse long-term outcomes. Possible potentiating effects of other associated therapies or predisposing events need to be considered. Other practices that may have undesirable consequences, such as transient but repeated exposure to wide variations in oxygen and carbon dioxide levels, are not easily documented in NICU care. Their effect on the developing brain is therefore difficult to evaluate. It seems prudent to avoid these events. Some of the unsolved questions could be addressed by future studies that include long-term follow-up of neurologic outcome. Until that time, it seems that what we do not know is more important than what we currently know.