Delayed partial liquid ventilation shows no efficacy in the treatment of smoke inhalation injury in swine

In an earlier neonatal porcine model of smoke inhalation injury (SII), imme diate postinjury application of partial liquid ventilation (PLV) had dramat ic beneficial effects on lung compliance, oxygenation, and survival over a 24-h period. To explore the efficacy of PLV following SII, we treated anima ls at 2 and 6 h after SII and followed them for 72 h. Pigs weighing 8-12 kg were sedated and pharmacologically paralyzed, given a SII, and placed on v olume-cycled, pressure-limited ventilation. Animals were randomized to thre e groups: group I (+SII, no PLV, n = 8), group II (+SII, PLV at 2 h, n = 6) , and group III (+SII, PLV at 6 h, n = 7). Ventilatory parameters and arter ial blood gasses were obtained at scheduled intervals. The PLV animals (gro ups II and III) followed a worse course than group I (no PLV); PLV groups h ad higher peak and mean airway pressures, oxygenation index, and rate-press ure product (a barotrauma index) and lower lung compliance and arterial par tial pressure of oxygen-to-inspired oxygen fraction ratio (all P < 0.05). P LV conferred no survival advantage. The reported beneficial effects of PLV with other models of acute lung injury do not appear to extend to the treat ment of SII when PLV is instituted in a delayed manner. This study was not able to validate the previously reported beneficial effects of PLV in SII a nd actually found deleterious effects, perhaps reflecting the predominance of airway over alveolar disease in SII.