Effects of combined high-dose partial liquid ventilation and almitrine on pulmonary gas exchange and hemodynamics in an animal model of acute lung injury

Objectives: To determine possible additive effects of combined high-dose partial liquid ventilation (PLV) and almitrine bismesylate (ALM) on pulmonary gas exchange and hemodynamics in an animal model of acute lung injury (ALI). Design and setting: Prospective, controlled animal study in an animal research facility of a university hospital. Interventions: ALI was induced in 12 anesthetized and mechanically ventilated pigs by repeated wash-out of surfactant. After initiation of PLV with 30 ml/kg perfluorocarbon the animals were randomly assigned to receive either accumulating doses of ALM (0.5, 1.0, 2.0, 4.0, 8.0, and 16.0 mug/kg per minute) for 30 min each (n= 6) or the solvent malic acid (n = 6). Measurement and results: Pulmonary gas exchange and hemodynamics were measured at the end of each infusion period. Compared to ALI, PLV alone significantly increased arterial oxygen partial pressure (PaO2) and decreased venous admixture (Q(VA)/Q(T)) and mean pulmonary artery pressure (MPAP). Administration of ALM did not result in a further improvement in PaO2, Q(VA)/Q(T) or MPAP compared to PLV alone but decreased PaO2 and increased Q(VA)/Q(T) and MPAP when 16 mug/kg per min ALM was compared to PLV alone. Conclusions: In an animal model of surfactant depiction induced ALI the combined treatment of PLV and ALM induced no significant improvement in pulmonary gas exchange or hemodynamics when compared to PLV alone. Moreover, high-dose ALM significantly impaired gas exchange and pulmonary hemodynamics.