Drug delivery through high-flow nasal cannula (HFNC) systems has become ubiquitous in acute care management of respiratory conditions that concurrently require respiratory support and administration of inhaled medications.1 Administration of continuous albuterol is frequently used in the treatment of severe asthma exacerbations.2 Due to the high cost of inhaled nitric oxide, practitioners have resorted to use nebulized pulmonary vasodilators in an off-label fashion.3 Nebulized continuous albuterol dosing is given at the flat portion of the dose-response curve, thus not needing a robust delivery system able to provide dose titration. Conversely, delivery of inhaled pulmonary vasodilators requires titration to avoid under-dosing the patient, thus not optimizing care or over-dosing the patient and resulting in adverse effects. Most in vivo and in vitro studies of drug delivery through HFNC systems have utilized a vibrating mesh nebulizer placed on the dry side of the humidifier.4 This technology does not incorporate additional flow into the system, which makes it appealing for its use in low-flow conditions (< 10 L/min). However, this feature is less important for cannulas delivering flows typically used in adults (30–50 L/min). An infusion pump connected to the nebulizer allows for dose titration by modifying the infusion rate. One limitation of the vibrating mesh technology is its associated cost. In addition, there are also conflicting reports regarding its failure rate.5–6
This issue of Respiratory Care offers the readership of the Journal two manuscripts from the Stony Brook …
Correspondence: Ariel Berlinski MD FAARC, 1 Children's Way, Slot 512–17, Little Rock, AR 72202. E-mail: berlinskiariel{at}uams.edu