Drug utilisation in term and preterm neonates (i.e. < 28 days of age) has been investigated prospectively in 4 clinical studies during the past 10 years. 3880 neonates with a mean gestational age of 34.5 weeks (corresponding birthweight 2280g) were enrolled in these studies. An overview indicates a high prevalence of antibiotic treatment throughout the studies, ranging from 69% to virtually 100%. The highest prevalence was observed in studies enroling only preterm neonates (gestational age <30 weeks) with need for mechanical ventilation. A further high prevalence of parenteral nutrition (84 to 100%), transfusion of blood products (91 to 100%) and vitamin use (16 to 78%) was described. Higher degrees of immaturity and rates of complications were associated with an increased drug usage up to a mean of 17 different drugs in very preterm (i.e. ≤ 30 weeks gestation) neonates with severe respiratory disorders and related complications. The high prevalence of antibiotic usage may be explained by the fact that clinical symptoms of neonatal bacterial infections are usually variable, and laboratory tests initially are not highly specific. Respiratory disorders in neonates are often associated with or caused by infections. Nosocomial infections in neonatal intensive care units further prompt administration of antimicrobial agents.
Six prospective controlled clinical trials during the past 10 years have investigated treatment with dexamethasone of bronchopulmonary dysplasia, a chronic lung disease secondary to mechanical ventilation of surfactant-deficient lungs in very preterm neonates. Dexamethasone improved lung function and facilitated weaning from the ventilator of ventilator-dependent neonates; however, the long term safety of this approach still has to be demonstrated in follow-up studies. A new therapeutic approach for the treatment of respiratory distress syndrome has been introduced into neonatal intensive care since the beginning of the 1990s, after natural and synthetic surfactant preparations were shown to be effective in improving neonatal outcome.
Transfusion of blood products is an essential part of neonatal intensive care. About 300 000 neonates per year receive blood products in the US. Strict adherence to transfusion guidelines is mandatory to avoid associated risks, e.g. transmittal of viral illness.
Iatrogenic intrauterine drug exposure mainly concerns promotion of fetal lung maturity by means of corticosteroids, which were effective in several randomised, controlled clinical trials in cases of anticipated prematurity. Cost-effectiveness calculations from The Netherlands indicate that prenatal steroid pretreatment is superior to postnatal surfactant administration in preterm neonates less than 30 weeks gestation. From the clinical point of view, both therapies should be combined, since synergism could be demonstrated to improve survival in very preterm neonates.