Feasibility of nitric oxide administration by neonatal helmet-CPAP: A bench study

Background: Inhaled nitric oxide (NO) may have a role in the treatment of preterm infants with respiratory failure. We evaluated the feasibility of administering NO therapy by a new continuous positive airway pressure (CPAP) system (neonatal helmet-CPAP). Methods: While maintaining a constant total flow of 8, 10, and 12 l·min-1, NO concentrations were progressively increased to 5, 10, 20, and 40 p.p.m. in the neonatal helmet-CPAP pressure chamber (5 cmH2O). NO, NO2, and O2 concentrations were measured in the pressure chamber and the immediate external environment. Results: In the chamber, NO2 levels remained low (≤0.8 p.p.m.) at inhaled therapeutic NO concentrations (5, 10, 20, and 40 p.p.m.). The lower O2 concentrations were 95% at 40 p.p.m. NO levels. Leakage of NO and NO2 to the surrounding environment was negligible. Conclusions: NO administration is safe and feasible using the neonatal helmet-CPAP system. This method allows the delivery of accurate NO levels and high O2 concentrations avoiding NO2 accumulation. Further experimental and clinical studies are needed. © 2007 The Authors.