The dynamics of PFC liquid inventory during partial liquid ventilation(PLV) and subsequent recovery to gas ventilation is not clearly understood and has not been objectively quantitated previously. The objective of this study was to evaluate the distribution, uptake and elimination profile of LiquiVent® during PLV through recovery to spontaneous breathing. Twelve New Zealand White rabbits were randomized to a 24 hr (n = 6) or 7 day (n = 6) study group, intubated, received 17 ml/kg of LiquiVent® (Alliance Pharm Corp, San Diego, CA), and ventilated for 4 hrs at a constant frequency (30 bpm), tidal volume (9.3 ± 0.3 SE ml/kg), end expiratory pressure (4 cm H2O), and inspiratory time (0.3 sec). Following completion of the acute study, animals were extubated and monitored for successful transition to spontaneous breathing. PFC loss (ml/kg/hr) and distribution were assessed by thermal detection and chest radiographs (anterior/posterior and cross table lateral), respectively, during the acute protocol and at the end the protocol. Radiographic assessment demonstrated a time dependent migration of LiquiVent® to dependent regions of the lung during the acute protocol. Thermal detector analysis of PFC in the expired gas demonstrated a significant(p< 0.05) non-linear decrement in the rate of PFC elimination with time (1 hrs:1.19 ± 0.11 SE; 4 hrs: 0.26 ± 0.04 SE; 24 hrs and 7 days:<0.10). Arterial PFC blood levels (μg PFC/gm blood) were 3.71± 0.89 at 4 hrs post fill followed by a significant decrease (p < 0.05) at 24 hrs (2.09 ± 0.47 SE) and 7 days (2.04 ± 0.87 SE). At 24 hrs and 7 days post fill, no PFC liquid was evident in the respiratory system as assessed by thermal detection or chest radiograph. These data characterize a relatively rapid rate of elimination and minimal uptake of LiquiVent® during PLV and subsequent recovery to spontaneous breathing.

(Supp in part and consultation from Alliance Pharm Corp, Hoechst Marion Roussel, Inc.)