Inhaled nitric oxide for respiratory failure in preterm infants
Abstract
Background
Inhaled nitric oxide (iNO) is effective in term infants with hypoxic respiratory failure. The pathophysiology of respiratory failure and the potential risks of iNO differ substantially in preterm infants, necessitating study in this population.
Objectives
To determine the effect of treatment with iNO on death, bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), and neurodevelopmental disability in preterm newborn infants with respiratory disease.
Search methods
Standard methods of the Cochrane Neonatal Review Group were used. MEDLINE, EMBASE, Healthstar and the Cochrane Central Register of Controlled Trials (The Cochrane Library) were searched covering the years from 1985 to 2010. In addition, the abstracts of the Pediatric Academic Societies were also searched.
Selection criteria
Randomized and quasi‐randomized studies in preterm infants with respiratory disease that compared the effects of iNO gas to control, with or without placebo were eligible.
Data collection and analysis
Standard methods of the Cochrane Neonatal Review Group were used.
Main results
Fourteen randomized controlled trials of inhaled nitric oxide therapy in preterm infants were found. The trials have been grouped post hoc into three categories depending on entry criteria; entry in the first three days of life based on oxygenation criteria, routine use in preterm babies with pulmonary disease, and later enrolment based on an increased risk of BPD. No overall analyses were performed.
Nine trials of early rescue treatment of infants based on oxygenation criteria demonstrated no significant effect of iNO on mortality or BPD. Three studies with routine use of iNO in infants with pulmonary disease also demonstrated no significant reduction in death or BPD [typical RR 0.93 (95% CI 0.86 to 1.01)] although this small effect approached significance. Later treatment with iNO based on the risk of BPD (two trials) demonstrated no significant benefit for this outcome in analyses which are possible using summary data.
There is no clear effect of iNO on the frequency of all grades of IVH or of severe IVH. Early rescue treatment was associated with a non‐significant 20% increase in severe IVH.
No effect on the incidence of neurodevelopmental impairment was found.
Authors' conclusions
iNO as rescue therapy for the very ill preterm infant does not appear to be effective. Early routine use of iNO in preterm infants with respiratory disease does not affect serious brain injury or improve survival without BPD. Later use of iNO to prevent BPD might be effective, but requires further study.
PICOs
Plain language summary
Inhaled nitric oxide for respiratory failure in preterm infants
The use of inhaled nitric oxide (iNO) may help reduce breathing failure in preterm babies. Breathing failure in premature newborn babies may be complicated by raised pressure within the vessels that carry blood to the lung (pulmonary hypertension). Medications that cause sedation or muscle relaxation and mechanically assisted breathing (mechanical or assisted ventilation) are used to treat pulmonary hypertension. Nitric oxide is believed to help regulate muscle tone in the arteries of the lungs and, thereby lessen pulmonary hypertension; however, iNO may also cause excessive bleeding (hemorrhage). This review of studies found that nitric oxide therapy does not appear to improve the chances of the baby having an improved outcome. When given to babies who were very ill, iNO did not seem to help, and may have contributed to an increase in intracranial hemorrhage.
