The combination of partial liquid ventilation and inhaled nitric oxide in the severe oleic acid lung injury model

Study objectives: To elucidate the efficacy of the combination of inhaled nitric oxide (NO) and partial liquid ventilation (PLV) in ARDS. Design: Prospective, randomized, controlled study, Setting: A research laboratory at a university medical center. Subjects: Thirty-two rabbits. Interventions: Animals were anesthetized and ventilated via tracheostomy (tidal volume=40 mt; respiratory rate=25 breaths/min; fraction of inspired oxygen=0.99). After 0.08 mL/kg (0.071 g/kg) oleic acid was administered via the central venous route, animals were randomly divided into the following four groups depending on, the ventilatory mode: (1) Gas ventilation (GV)control group: GV was continued throughout the study; (2) GV-NO group: NO inhalation (10 ppm) was performed under GV; (3) PLV-control group: PLV using perflubron (15 mL/kg) was continued until the end of the study; and (4) PLV-NO group: NO inhalation (10 ppm) was performed under PLV. Measurements and results: NO inhalation improved PaO2 in the PLV-NO group (from 133+/-20 to 167+/-23 mm Hg; p=0.0008), but not in the GV-NO group (from 67+/-6 to 63+/-9 mm Hg), although pulmonary vascular resistance decreased both in the GV-NO (from 4,604+/-328 to 4,337+/-322 dyne.s.cm(-5); p=0.0116) and the PLV-NO group (from 4,727+/-665 to 4,112+/-560 dyne.s.cm(-5); p=0.0036). (Data were expressed as mean+/-SEM.) Conclusion: PLV augmented the effect of inhaled NO on pulmonary gas exchange. The combination of PLV and NO inhalation could be effective in severe ARDs.