Liquid ventilation: clinical experiences

Liquid breathing has been in the medical literature for nearly 80 years and has been proposed as a means of improving gas exchange in patients with acute respiratory failure since the 1970s. There are many potential clinical applications of perfluorochemical (PFC) liquids that span many specialties in medicine. The ability to lower surface tension directed the initial clinical focus on neonatal therapy in the treatment of respiratory distress syndrome. The first clinical trial of PFC ventilation was performed in neonates in 1989. Additional trials using LiquiVent, a medical-grade PFC liquid, were initiated in 1993 in infants, children, and adults with severe respiratory distress. Based on the results of several studies during this time, it was concluded that the technique of liquid ventilation seemed to be safe, improve lung function, and recruit lung volume in patients from these various populations. More than 100 patients from preterm neonates to elderly patients with respiratory distress have been studied. In general, patients experience improvement in lung function and oxygenation, without adverse events. The results of such trials are encouraging and suggest the feasibility of this technique in the neonate with severe respiratory failure requiring respiratory support. Limitations of the technique include a limited understanding of how it works and its effectiveness in different patient populations. It has also become evident that there is a need for additional diagnostic and therapeutic instrumentation to expedite its implementation in the intensive care environment. This article discusses clinical experiences with liquid ventilation and highlights the technical needs to facilitate its implementation in respiratory care management.