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Premature birth is a major public health problem in the United States and internationally. Infants born at or before 32 weeks' gestation (2% of all births in the United States in 2007) are at extremely high risk for death in the neonatal period or for pulmonary, visual, and neurodevelopmental morbidities with lifelong consequences including bronchopulmonary dysplasia, retinopathy of prematurity, and brain injury. Risks for adverse outcomes increase with decreasing gestational age. The economic costs to care for these infants are also substantial (estimated at $26 billion in 2005 in the United States). It is clear that the need for strategies to improve outcomes for this high-risk population is great, and this need has prompted testing of new therapies with the potential to decrease pulmonary and other complications of prematurity. Inhaled nitric oxide (iNO) emerged as one such therapy. To provide health care professionals, families, and the general public with a responsible assessment of currently available data regarding the benefits and risks of iNO in premature infants, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Heart, Lung, and Blood Institute, and the Office of Medical Applications of Research of the National Institutes of Health convened a consensus-development conference. Findings from a substantial body of experimental work in developing animals and other model systems suggest that nitric oxide may enhance lung growth and reduce lung inflammation independently of its effects on blood vessel resistance. Although this work demonstrates biological plausibility and the results of randomized controlled trials in term and near-term infants were positive, combined evidence from the 14 randomized controlled trials of iNO treatment in premature infants of ≤ 34 weeks' gestation shows equivocal effects on pulmonary outcomes, survival, and neurodevelopmental outcomes.

Objective: To provide healthcare providers, patients, and the general public with a responsible assessment of currently available data on the use of inhaled nitric oxide in early routine, early rescue, or later rescue regimens in the care of premature infants <34 weeks gestation who require respiratory support., Participants: A non-Department of Health and Human Services, nonadvocate 16-member panel representing the fields of biostatistics, child psychology, clinical trials, ethics, family-centered care, neonatology, neurodevelopmental follow-up, nursing, pediatric epidemiology, neurobehavior, neurological surgery, neurology, and pulmonology, perinatology, and research methodology. In addition, 18 experts from pertinent fields presented data to the panel and conference audience., Evidence: Presentations by experts and a systematic review of the literature prepared by the Johns Hopkins University Evidence-based Practice Center, through the Agency for Healthcare Research and Quality. Scientific evidence was given precedence over anecdotal experience., Conference Process: The panel drafted its statement based on scientific evidence presented in open forum and on published scientific literature. The draft statement was presented on the final day of the conference and circulated to the audience for comment. The panel released a revised statement later that day at http://consensus.nih.gov. This statement is a report of the panel and is not a policy statement of the NIH or the Federal Government., Conclusions: (1) Taken as a whole, the available evidence does not support use of inhaled nitric oxide in early routine, early rescue, or later rescue regimens in the care of premature infants <34 weeks gestation who require respiratory support. (2) There are rare clinical situations, including pulmonary hypertension or hypoplasia, that have been inadequately studied in which inhaled nitric oxide may have benefit in infants <34 weeks gestation. In such situations, clinicians should communicate with families regarding the current evidence on its risks and benefits as well as remaining uncertainties. (3) Basic research and animal studies have contributed to important understandings of inhaled nitric oxide benefits on lung development and function in infants at high risk of bronchopulmonary dysplasia. These promising results have only partly been realized in clinical trials of inhaled nitric oxide treatment in premature infants. Future research should seek to understand this gap. (4) Predefined subgroup and post hoc analyses of previous trials showing potential benefit of inhaled nitric oxide have generated hypotheses for future research for clinical trials. Prior strategies shown to be ineffective are discouraged unless new evidence emerges. The positive results of one multicenter trial, which was characterized by later timing, higher dose, and longer duration of treatment, require confirmation. Future trials should attempt to quantify the individual effects of each of these treatment-related variables (timing, dose, and duration), ideally by randomizing them separately. (5) Based on assessment of currently available data, hospitals, clinicians, and the pharmaceutical industry should avoid marketing inhaled nitric oxide for premature infants <34 weeks gestation.