RESUMEN
BACKGROUND: The purpose of this study was to evaluate canine lungs obtained from non-heart-beating donors after unilateral lung transplantation subjected to partial liquid ventilation with perfluorodecalin. METHODS: Twelve donor dogs were killed and kept under mechanical ventilation for 3 hours. Heart-lung blocks were harvested after retrograde pulmonary hypothermic flush with Perfadex. Left lung grafts were randomly transplanted into 12 weight-matched recipient animals. Animals were divided into 2 groups: control (standard mechanical ventilation, n = 6) and PLV (partial liquid ventilation, n = 6). Forty-five minutes after transplantation, the animals in the PLV group received perfluorodecalin (15 ml/kg) via orotracheal tube. All animals received volume-controlled ventilation (FIO2) 1.0, PEEP 5 cm H(2)O) over 6 consecutive hours. Thereafter, blood-gas analysis, ventilatory mechanics and hemodynamics were registered at 30-minute intervals. After 6 hours of reperfusion the animals were killed and the transplanted lungs were extracted to obtain the wet/dry weight ratio. RESULTS: There were significant differences in pulmonary arterial pressure, which were higher in control group animals (p < 0.009). The control animals also showed higher arterial PaO(2) than those in the PLV group (p < 0.00001), but lower PaCO(2) (p < 0.008). The peak and plateau pressures were higher in the PLV group (p < 0.00001). Neither static compliance nor wet/dry weight ratios were different in between groups. CONCLUSIONS: PLV with perfluorodecalin yields functional results compatible with life in this model. Nonetheless, pulmonary gas exchange and mechanics were superior after reperfusion in animals given conventional mechanical ventilation up to 6 hours after left lung allotransplantation.
Asunto(s)
Sustitutos Sanguíneos , Fluorocarburos , Ventilación Liquida , Trasplante de Pulmón , Animales , Estudios de Casos y Controles , Perros , Ventilación Liquida/métodos , Trasplante de Pulmón/fisiología , Intercambio Gaseoso Pulmonar , Respiración Artificial , Mecánica Respiratoria , Donantes de Tejidos , Trasplante HomólogoRESUMEN
Atualmente, novas alternativas de ventilação têm sido estudadas em quadros de insuficiência respiratória, com o objetivo de melhorar a oxigenação e minimizar a agressão ao parênquima pulmonar. A utilização de perfluorocarbonos líquidos administrados diretamente na via aérea vem sendo ostensivamente estudada em modelos de lesão pulmonar e em alguns ensaios clínicos, demonstrando bons resultados com relação à troca gasosa, mecânica ventilatória e propriedades antiinflamatórias. Os PFCs são substâncias que possuem baixa tensão superficial, alta densidade, são insolúveis em água, além de permitirem alta difusão de oxigênio e gás carbônico. Esses compostos atuam recrutando alvéolos colapsados, melhorando a oxigenação, protegendo a arquitetura pulmonar e atuando como carreadores de impurezas, limpando a superfície alveolar de resíduos da degradação celular. Neste artigo de revisão são apresentadas as diferentes modalidades ventilatórias com perfluorocarbonos e fornecidas informações sobre a utilização e o estado atual da ventilação líquida