Partial Liquid Ventilation (PLV) combined with Proportional Assist Ventilation (PAV) in spontaneously breathing animals

Abstract 88

Background/Aim: PLV has been shown to improve gas exchange in paralyzed animals and humans with lung disease. This study tests the hypothesis that PLV combined with PAV results in stable ventilation and gas exchange in spontaneously breathing animals. Subjects: Ten adult anesthetized, intubated rabbits were ventilated using PAV (FiO₂ = 1.0; PEEP = 6 [4-6] cmH₂O). Intervention/Measurements: Expiratory minute ventilation(V_E), respiratory rate (RR), esophageal pressure (Pe) and blood pressure (ABP) were recorded continuously during PAV for 1 h. Then 30 ml/kg Pertfluorocarbon was instilled into the endotracheal tube with a rate of 0.5ml/kg/min. Thereafter data were recorded again for 1 h. Arterial blood gases were obtained at the end of each period. Variability of V_E, tidal volume (Vt), RR and peak Pe was assessed by calculating coefficients of variation using data obtained each minute. Table Coefficients of variation for V_E, Vt, RR and peak Pe were similar for both ventilatory modes. Conclusion: The results suggest a larger dead space ventilation and diffusion barrier during PLV + PAV compared to PAV alone. However, stable ventilation and gas exchange was achieved during PLV + PAV in these spontaneously breathing animals without lung disease. We speculate, that PLV combined with PAV may help to recruit lung volume and improve gas exchange in spontaneously breathing animals with lung disease.

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