Hernan L J, Fuhrman B P, Kaiser R E, Penfil S, Foley C, Papo M C, Leach C L
Division of Pediatric Critical Care, Children's Hospital of Buffalo, NY 14222, USA.
Crit Care Med. 1996 Mar;24(3):475-81. doi: 10.1097/00003246-199603000-00018.
We hypothesized that a) perfluorocarbon-associated gas exchange could be accomplished in normal large sheep; b) the determinants of gas exchange would be similar during perfluorocarbon-associated gas exchange and conventional gas ventilation; c)in large animals with lung injury, perfluorocarbon-associated gas exchange could be used to enhance gas exchange without adverse effects on hemodynamics; and d) the large animal with lung injury could be supported with an FIO2 of <1.0 during perfluorocarbon-associated gas exchange.
Prospective, observational animal study and prospective randomized, controlled animal study.
An animal laboratory in a university setting.
Thirty adult ewes.
Five normal ewes (61.0 +/- 4.0 kg) underwent perfluorocarbon-associated gas exchange to ascertain the effects of tidal volume, end-inspiratory pressure, and positive end-expiratory pressure (PEEP) on oxygenation. Respiratory rate, tidal volume, and minute ventilation were studied to determine their effects on CO2 clearance. Sheep, weighing 58.9 +/- 8.3 kg, had lung injury induced by instilling 2 mL/kg of 0.05 Normal hydrochloric acid into the trachea. Five minutes after injury, PEEP was increased to 10 cm H2O. Ten minutes after injury, sheep with Pao2 values of <100 torr (<13.3 kPa) were randomized to continue gas ventilation (control, n=9) or to institute perfluorocarbon-associated gas exchange (n=9) by instilling 1.6 L of unoxygenated perflubron into the trachea and resuming gas ventilation. Blood gas and hemodynamic measurements were obtained throughout the 4-hr study. Both tidal volume and end-inspiratory pressure influenced oxygenation in normal sheep during perfluorocarbon-associated gas exchange. Minute ventilation determined CO2 clearance during perfluorocarbon-associated gas exchange in normal sheep. After acid aspiration lung injury, perfluorocarbon-associated gas exchange increased PaO2 and reduced intrapulmonary shunt fraction. Hypoxia and intrapulmonary shunting were unabated after injury in control animals. Hemodynamics were not influenced by the institution of perfluorocarbon-associated gas exchange.
Tidal volume and end-inspiratory pressure directly influence oxygenation during perfluorocarbon-associated gas exchange in large animals. Minute ventilation influences clearance of CO2. In adult sheep with acid aspiration lung injury, perfluorocarbon-associated gas exchange at an FIO2 of <1.0 supports oxygenation and improves intrapulmonary shunting, without adverse hemodynamic effects, when compared with conventional gas ventilation.
我们假设：a）全氟化碳相关气体交换可在正常大型绵羊中实现；b）全氟化碳相关气体交换和传统气体通气过程中气体交换的决定因素相似；c）在患有肺损伤的大型动物中，全氟化碳相关气体交换可用于增强气体交换且对血流动力学无不良影响；d）在全氟化碳相关气体交换过程中，患有肺损伤的大型动物可在吸入氧分数<1.0的情况下得到支持。
前瞻性观察性动物研究和前瞻性随机对照动物研究。
大学环境中的动物实验室。
30只成年母羊。
5只正常母羊（61.0±4.0千克）进行全氟化碳相关气体交换，以确定潮气量、吸气末压力和呼气末正压（PEEP）对氧合的影响。研究呼吸频率、潮气量和分钟通气量以确定它们对二氧化碳清除的影响。给体重58.9±8.3千克的绵羊气管内注入2毫升/千克的0.05当量盐酸诱导肺损伤。损伤后5分钟，将PEEP增加到10厘米水柱。损伤后10分钟，动脉血氧分压（Pao2）值<100托（<13.3千帕）的绵羊被随机分组，继续进行气体通气（对照组，n = 9）或通过向气管内注入1.6升未氧合的全氟辛溴烷并恢复气体通气来进行全氟化碳相关气体交换（n = 9）。在整个4小时的研究过程中进行血气和血流动力学测量。在全氟化碳相关气体交换过程中，潮气量和吸气末压力均影响正常绵羊的氧合。分钟通气量决定正常绵羊在全氟化碳相关气体交换过程中的二氧化碳清除。酸吸入性肺损伤后，全氟化碳相关气体交换增加了动脉血氧分压（PaO2）并降低了肺内分流分数。对照组动物损伤后低氧血症和肺内分流未减轻。全氟化碳相关气体交换的实施对血流动力学无影响。
在大型动物全氟化碳相关气体交换过程中，潮气量和吸气末压力直接影响氧合。分钟通气量影响二氧化碳清除。与传统气体通气相比，在成年酸吸入性肺损伤绵羊中，吸入氧分数<1.0的全氟化碳相关气体交换可支持氧合并改善肺内分流，且无不良血流动力学影响。
