Abstract 1923 Poster Session I, Saturday, 5/1 (poster 44)

While PFC elimination from the lungs is in part dependent on ventilation strategy, PFC vapor pressure, and initial dose, questions exist regarding the role of repositioning on replacement dosing. We hypothesized that PFC evaporative loss EL profile over time is dependent upon repositioning. To test this hypothesis, perflubron (LiquiVent®) was instilled endotracheally over 3-5 minutes using an initial low dose (6 ml/kg) in 2 groups of juvenile rabbits (wt =2.2 ±0.2 SE kg; n=8) while repositioning to optimize distribution. The animals were then divided into groups: GR I-constant supine position and GR II- continuous repositioning (supine, prone, rt. decubitus, It. decubitus; rotations every 10 min). Rabbits were ventilated using a constant ventilator strategy: frequency: 30 br/min, tidal volume = 10.7±1.3 ml/kg, Vm=281±4.2 ml/min/kg. A previously described thermal detector device for measuring PFC content in expired gas was used to determine EL profile [loss rate C'PFC (ml/kg/hr), LPFC cumulative PFC loss as % of initial dose] up to 4 hrs after initial dosing. EL data expressed as (Mean±SE). (Table)

Table 1 No caption available

In this study, there was a significant group, time and group-time interaction such that EL profile was dependent on repositioning after fill (p<0.01). We conclude that EL profile is dependent upon repositioning and time after dosing. Thus, patient repositioning should be considered with replacement perflubron dosing in addition to ventilation strategy and initial dosing.

[Funded in part by Alliance Pharmaceutical Corp]