Hypertonic saline jet nebulization breathing treatments produce a predictable quantity of aerosolized sodium chloride for inhalation.

PURPOSE: The amount of sodium chloride (NaCl) that escapes a nebulizer cup, intended for patient inhalation, during a 5-min hypertonic saline jet nebulization (HSJN) breathing treatment is apparently unknown in the pure and applied scientific literature. This study aimed to address this void by focusing on NaCl mass changes prior to and after a typical HSJN breathing treatment using an ordinary household, medical-grade air compressor. RESEARCH METHODS: Saline solutions of varying concentrations were nebulized to room air for 5 min. Pre- and post-nebulization NaCl concentrations were determined from measured conductivities via calibration curve. The resulting data were used to quantify NaCl mass changed from the beginning and end of a typical HSJN breathing treatment. MAIN FINDINGS: Conductivity was a reliable metric in NaCl concentrations ranging from 2.10 × 10-1 to 8.16 × 10-3 M. Pre- and post-nebulization NaCl mass differences of 19-114 mg linearly correlated with saline concentration (wt%). The resulting trendline data reasonably predict how much NaCl is available for patient inhalation during a typical HSJN breathing treatment. Linearity in the data suggests that factors such as colligative properties (e.g., osmolarity) have a minimal influence on the amount of NaCl that escapes the nebulizer cup. CONCLUSIONS: These results are the first to quantify how much NaCl escapes a nebulizer cup during a typical HSJN breathing treatment. Furthermore, the results represent a key starting point upon which future studies can be built to explore additional airflow rates, kinetics, and temperature effects. Collectively, these findings will play a critical role in ascertaining the mechanism of action in hypertonic saline breathing treatments.

Cis/Trans Energetics in Epoxide, Thiirane, Aziridine and Phosphirane Containing Cyclopentanols: Effects of Intramolecular OH⋯O, S, N and P Contacts.

A recent computational analysis of the stabilizing intramolecular OH⋯O contact in 1,2-dialkyl-2,3-epoxycyclopentanol diastereomers has been extended to thiiriane, aziridine and phosphirane analogues. Density functional theory (DFT), second-order Møller-Plesset perturbation theory (MP2) and CCSD(T) coupled-cluster computations with simple methyl and ethyl substituents indicate that electronic energies of the c i s isomers are lowered by roughly 3 to 4 kcal mol-1 when the OH group of these cyclopentanol systems forms an intramolecular contact with the O, S, N or P atom on the adjacent carbon. The results also suggest that S and P can participate in these stabilizing intramolecular interactions as effectively as O and N in constrained molecular environments. The stabilizing intramolecular OH⋯O, OH⋯S, OH⋯N and OH⋯P contacts also increase the covalent OH bond length and significantly decrease the OH stretching vibrational frequency in every system with shifts typically on the order of -41 cm-1.