Pulmonary Delivery of Therapeutic and Diagnostic Gases

Abstract

The 21st Congress for the International Society for Aerosols in Medicine included, for the first time, a session on Pulmonary Delivery of Therapeutic and Diagnostic Gases. The rationale for such a session within ISAM is that the pulmonary delivery of gaseous drugs in many cases targets the same therapeutic areas as aerosol drug delivery, and is in many scientific and technical aspects similar to aerosol drug delivery. This article serves as a report on the recent ISAM congress session providing a synopsis of each of the presentations. The topics covered are the conception, testing, and development of the use of nitric oxide to treat pulmonary hypertension; the use of realistic adult nasal replicas to evaluate the performance of pulsed oxygen delivery devices; an overview of several diagnostic gas modalities; and the use of inhaled oxygen as a proton magnetic resonance imaging (MRI) contrast agent for imaging temporal changes in the distribution of specific ventilation during recovery from bronchoconstriction. Themes common to these diverse applications of inhaled gases in medicine are discussed, along with future perspectives on development of therapeutic and diagnostic gases.

Quantitative Mapping of Specific Ventilation in the Human Lung using Proton Magnetic Resonance Imaging and Oxygen as a Contrast Agent

“…The technique is, in general, versatile and different acquisition compromises are possible, each optimal for different applications. For example, in a study of dynamic recovery from an asthma event 25 , SVI data was analyzed at a higher temporal resolution (~7 min vs. ~18 min) and the same spatial resolution, at the cost of a ~ 30% increase in uncertainty of specific ventilation (estimated from Monte Carlo simulations). A recent modeling study 26 sought to quantify the impact of several minor limitations of the SVI technique, namely 1) that the imaged volume does not encompass the entire right lung, 2) that small misalignments between successive images may exist even after registration, and 3) that pulmonary veins, by transporting blood from elsewhere in the lung into an imaged region, may add confounding signal that reflects ventilation in the region where that blood was originally oxygenated and not in the region in which it is being imaged.…”

Biomedically-relevant metal organic framework-hydrogel composites

“…NO, O 2 , CO, H 2 S, Xe) to elicit beneficial biological responses for disease treatment is gaining popularity in recent years. 112 For example, nitric oxide (NO) plays important roles in human biology, such as being neurotransmitters and neuromodulators in the human central nervous system, [113][114][115] and is now accepted as a treatment for pulmonary hypertension due to its ability to relax vascular smooth muscle. 116 Like NO, carbon monoxide (CO) is a gasotransmitter, as well as possessing antiinflammatory and anti-apoptotic properties.…”

Nasally Inhaled Nitric Oxide for Sudden Right-Sided Heart Failure in the Intensive Care Unit: NO Time Like the Present

“…1 Inhaled NO is approved by the US Food and Drug Administration for use in persistent pulmonary hypertension of the newborn, but commonly is used off label in critically ill adult patients worldwide to reduce increased pulmonary vascular resistance (PVR) for afterload reduction during acute right-sided heart failure (RHF) 2 or to treat hypoxic pulmonary vasoconstriction. 2,3 These indications are most common in the subset of adult patients undergoing cardiovascular or thoracic surgery. The agent is initiated either in the operating room or in the intensive care unit (ICU) before or after surgery.…”