Jet nebulization of prostaglandin E 1 during neonatal mechanical ventilation: Stability, emitted dose and aerosol particle size

Abstract

Background We have previously reported the safety of aerosolized PGE 1 in neonatal hypoxemic respiratory failure. The aim of this study is to characterize the physicochemical properties of PGE 1 solution, stability, emitted dose and the aerodynamic particle size distribution (APSD) of PGE 1 aerosol in a neonatal ventilator circuit. Methods PGE 1 was diluted in normal saline and physicochemical properties of the solution characterized. Chemical stability and emitted dose were evaluated during jet nebulization in a neonatal conventional (CMV) or high frequency (HFV) ventilator circuit by a high performance liquid chromatography–mass spectrometry method. The APSD of the PGE 1 aerosol was evaluated with a 6-stage cascade impactor during CMV. Results PGE 1 solution in normal saline had a low viscosity (0.9818 cP) and surface tension (60.8 mN/m) making it suitable for aerosolization. Little or no degradation of PGE 1 was observed in samples from aerosol condensates, the PGE 1 solution infused over 24 h, or the residual solution in the nebulizer. The emitted dose of PGE 1 following jet nebulization was 32–40% during CMV and 0.1% during HFV. The PGE 1 aerosol had a mass median aerodynamic diameter of 1.4 μm and geometric S.D. of 2.9 with 90% of particles being <4.0 μm in size. Conclusion Nebulization of PGE 1 during neonatal CMV or HFV is efficient and results in rapid nebulization without altering the chemical structure. On the basis of the physicochemical properties of PGE 1 solution and the APSD of the PGE 1 aerosol, one can predict predominantly alveolar deposition of aerosolized PGE 1.