Liquid Ventilation: Current Status

Abstract

1. Thomas H. Shaffer, PhD* 2. Marla R. Wolfson, PhD† 3. Jay S. Greenspan, MD‡ 1. 2. *Professor of Physiology and Pediatrics; Director, Respiratory Physiology Section, Temple University School of Medicine, Philadelphia, PA. 3. 4. †Associate Professor of Physiology and Pediatrics, Temple University School of Medicine, Philadelphia, PA. 5. ‡Professor of Pediatrics; Director, Section of Neonatology, Thomas Jefferson University, Philadelphia, PA. After reading this article, the reader should be able to: 1. List the potential medical applications of liquid-assisted ventilation (LAV). 2. Describe the properties of perfluorochemical liquids that are important for their use in liquid ventilation. 3. Describe the potential benefits of LAV in respiratory distress syndrome, congenital diaphragmatic hernia, acute respiratory distress syndrome, and aspiration syndromes. 4. Delineate specific nonrespiratory applications of LAV. With the advent of modern technology and the evolution of intensive care units, the ability to treat respiratory problems has improved remarkably. This accomplishment is particularly remarkable with respect to the 40,000 preterm infants born each year of whom thousands have severe respiratory problems. Fortunately, the number of smaller and more immature infants who are treated, survive respiratory distress, and recover uneventfully is increasing. However, the overall success of treating neonatal respiratory distress remains limited by the inherent problems of surfactant deficiency and structural immaturity of the lung. Consequently, infants delivered preterm who have respiratory insufficiency experience diminished lung distensibility that results in progressive atelectasis and respiratory failure requiring mechanical ventilation. Currently, many of these infants improve over time when their ventilation is supported mechanically and surfactant is introduced into their lungs. However, as many as 37% of these severely impaired infants are left with bronchopulmonary dysplasia related to damage of pulmonary tissues and structures from conventional mechanical ventilation (CMV). Of equal importance, acute respiratory distress syndrome (ARDS) due to trauma, aspiration, or infection strikes more than 100,000 adults in the United States annually. Despite aggressive therapeutic procedures, 60% to 70% of these patients die, and as in infants, many suffer complications associated with CMV. Although structural damage in adults or immaturity in infants cannot be altered acutely, current advances, such as exogenous surfactant replacement therapy to reduce alveolar interfacial surface tension and subsequent inflation pressures, have allowed clinical improvement …