Liquid ventilation

Research on using liquid ventilation to provide artificial respiration in mammals has been ongoing since the 1960s. The development of inert perfluorocarbon (PFC) liquids with high oxygen and carbon dioxide solubility has made gas exchange with liquid ventilation possible. In 1991 the technique of partial liquid ventilation was introduced where PFC are instilled into the lungs whilst continuing with conventional mechanical ventilation. Partial liquid ventilation has been shown to improve gas exchange and lung function with decreased secondary lung injury, in animal models of acute lung injury and surfactant deficiency. It has been used in uncontrolled trials in preterm neonates, and preliminary results are available from a randomized controlled trial of partial liquid ventilation in paediatric acute respiratory distress syndrome. Perfluorocarbons can also be used to deliver drugs to the lungs, to lavage inflammatory exudate and debris from the lungs, and as an intrapulmonary X-ray contrast medium. Many questions about partial liquid ventilation remain unanswered particularly with regard to the dose of PFC required, its ideal method of administration and the long-term effects. Partial liquid ventilation promises to be an exciting new therapy for infants and children with a variety of respiratory problems. The technique requires ongoing research and experimentation.