Gaseous Exchange and Acid-Base Balance in Premature Lambs during Liquid Ventilation since Birth

Abstract

Extractnot only difficult to ventilate, but also hard to k e e~ alive. TheNine distressed premature lambs were studied before, during, and after ventilation with fluorocarbon liquid . It was found that premature lambs, delivered by cesarean section, could be adequately ventilated with oxygenated liquid for periods up to 3 hr. Using fluarocarbon liquid in conjunction with the described liquid breathing system, it was possible to maintain remarkably good pulmonary gas exchange and acid-base balance during normothermic conditions. In addition. ~e a k intratracheal Dressures measured during recovery from li&id ventilation wer; significantly reduced ( P < 0.001) as compared with preliquid ventilation values.This improvement in lung function is in direct contrast to the deterioration in that of the adult animal following liquid ventilation as reported previously. SpeculationAlthough an enormous amount of studies remain to be performed, at this time it is appealing to speculate about the possibilities of this therapeutic modality in the preterm human neonate with respiratory distress. We cannot help but think that this method of therapy serves a twofold purpose: ( 1 ) maintenance of infants with lungs too stiff to ventilate with gas, and (2) a treatment for reducing surface-active forces in infants with marginal lung stability.Liquid ventilation in mammalian species has been studied by various intestigators since 1958 (12). More recently, fluorocarbon liquids capable of dissolving larger volumes of respiratory gases at atmospheric pressure (3,10,14,17,22,24) were recognized as useful media for conducting oxygen-carbon dioxide transport studies. In particular, one of these liquids, FX-80, has been successfully emplqyed to ventilate the lungs of various adult species for periods of up to 8 hr (14). The effect of fluorocarbon liquid ventilation on pulmonary gas exchange (10, 17), surfaceactive properties (15), function (10,21,24,27), and structure (19) has been studied previously. In addition, in order to pave the way for clinical applications, long term experiments have been conducted looking for residual fluorocarbon as well as morphologic, biochemical, and/or histologic evidence of toxicity after ventilation with fluorocarbon liquid (I I, 16).The premature lamb has been employed by,various investigators as a model for studying many physiologic functions related to the human newborn (4,5,18,28). Measurements of pulmonary mechanics and acid-base balance in this animal (26) during the first few hours of life indicate decreased lung compliance, increased respiratory rate, vascular shunting, and increased work of breathing similar to the preterm human neonate with respiratory distress (I). Because of pulmonary immaturity, these animals were purposi of the present study was to evaluate the feasibility and efficacy of liquid ventilation as a therapeutic method In this animal model. Pulmonary gas exchange, acid-base balance, and inflation pressures were measured in these animals during the first few hours of life (a critical t...

Pulmonary Administration of Gentamicin During Liquid Ventilation in a Newborn Lamb Lung Injury Model

“…[15][16][17][18] Animals were ventilated with a breathing frequency of 5, tidal volumes of 25 to 30 mL/kg, inspiratory to expiratory ratio of 1:3, and Fio 2 ϭ 1.0.…”

Liquid ventilation

“…7 It has also been shown to improve gas exchange and lung function in animal models of respiratory distress. [8][9][10][11] In 1991, Fuhrman et al 12 introduced the technique of using functional residual capacity (FRC) volumes of PFC with conventional gas ventilation -PFC associated gas exchange (PAGE). This technique has become known as partial liquid ventilation (PLV) and it is this technique which has the most promise for practical clinical application.…”

Partial Liquid Ventilation in the Extremely Preterm Infant: Potential Benefits and Harms

“…(Wolfson, 1990) It has also been shown to improve lung function and gas exchange in experimental animal models of respiratory distress. (Shaffer, 1976;Shaffer, 1984;Shaffer, 1983; In 1991 Fuhrman et al (Fuhrman, 1991) introduced the method of perfluorocarbon associated gas exchange using functional residual capacity volumes of perfluorocarbon with conventional gas ventilation. This technique is now best known as partial liquid ventilation and it is this technique which is most promising for practical clinical application.…”