Differential impact of perfluorochemical physical properties on the physiologic, histologic, and inflammatory profile in acute lung injury.
OBJECTIVE
To evaluate the differential effects of physical properties of combinational perfluorochemical liquids (PFC) during partial liquid ventilation (PLV) on inflammatory indexes in the injured lung.


METHODS
: Interventional laboratory study.


METHODS
Academic medical research laboratory.


METHODS
Seventeen saline lavage-injured juvenile rabbits.


METHODS
Rabbits were anesthetized, ventilated, saline lavage-injured, and randomized into groups: group 1 (conventional mechanical ventilation alone-no PFC), group 2 (PLV: lowest viscosity, highest vapor pressure), group 3 (PLV: mid-viscosity, mid-vapor pressure), group 4 (PLV: highest viscosity, lowest vapor pressure).


RESULTS
Arterial blood chemistry and pulmonary mechanics were monitored throughout the protocol. Following 4 hrs, lung tissue was harvested for interleukin-8, myeloperoxidase, and histologic analyses. Oxygenation (Pao2), ventilation (ventilation efficiency index), and respiratory compliance were not significantly different between groups before or following injury. Pao2 increased significantly following treatment in groups 3 and 4. Oxygenation index was significantly lower and respiratory compliance and ventilation efficiency index were significantly higher for group 4 following 4 hrs than all other groups. Total lung tissue interleukin-8 was significantly lower in groups 3 and 4 than groups 1 and 2, and lung myeloperoxidase was significantly lower in all PLV-treated groups than CMV alone. Histologic examination showed increased recruitment of the dependent lung in groups 3 and 4, with significantly greater lung expansion index, than groups 1 and 2.


CONCLUSIONS
PLV, with a single dose of higher viscosity and lower vapor pressure PFC, resulted in significantly improved gas exchange and lung mechanics with significant reduction in lung inflammation compared with conventional mechanical ventilation alone and PLV with lower viscosity and higher vapor pressure liquid. Since PFC evaporative loss and redistribution are minimized by lower VP and higher viscosity, these data suggest that greater mechanoprotection and cytoprotection of the lung are conferred during PLV with PFC liquids that remain distributed throughout the entire lung for a longer duration.
Shashikant
Beth N
BN
Department of Physiology, Temple University School of Medicine, Philadelphia, PA, USA.
Miller
Thomas L
TL
Jeng
Mei-Jy
MJ
Davis
Jonathan
J
Shaffer
Thomas H
TH
Wolfson
Marla R
MR
D000818:Animals; D005466:Fluorocarbons / Q000008:administration & dosage / Q000627:therapeutic use*; D016209:Interleukin-8 / Q000378:metabolism; D021061:Liquid Ventilation / Q000379:methods*; D009195:Peroxidase / Q000378:metabolism; D011817:Rabbits; D012128:Respiratory Distress Syndrome / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D013329:Structure-Activity Relationship
D005466:Fluorocarbons; D016209:Interleukin-8; D009195:Peroxidase