Neutrophil accumulation is reduced during partial liquid ventilation.
OBJECTIVE
This study evaluates the ability of perflubron to inhibit pulmonary neutrophil accumulation during partial liquid ventilation (PLV) in the setting of acute lung injury.


METHODS
Randomized, controlled, nonblinded study.


METHODS
Research laboratory at a university.


METHODS
Male, Sprague-Dawley rats (n = 120, 506 +/- 42 g).


METHODS
Animals were divided into eight groups (n = 15 in each group, of which n = 12 for myeloperoxidase content and n = 3 for histologic neutrophil counting): a) GV-CVF group, animals received gas ventilation (GV) with the induction of lung injury using cobra venom factor (CVF); b) PLV-CVF group, animals received partial liquid ventilation before the induction of lung injury; c) PEEP-CVF group, animals received positive end-expiratory pressure (PEEP) before the administration of cobra venom factor; d) CVF-PLV group, animals received partial liquid ventilation after cobra venom factor; e) CVF-PEEP group, animals received PEEP after cobra venom factor; f) PLV only group, animals received partial liquid ventilation only; g) GV only group, animals received gas ventilation only; and h) NVSBA group, nonventilated spontaneous breathing animals.


RESULTS
After the experimental period, total lung myeloperoxidase content was significantly decreased in the PLV-CVF (0.29 +/- 0.08, p = .02) and PEEP-CVF (0.34 +/- 0.04, p = .01) groups when compared with the GV-CVF group (0.62 +/- 0.07). When compared with the GV-CVF group, a trend toward a reduction in myeloperoxidase was observed in the CVF-PLV (0.42 +/- 0.05, p = .07) and the CVF-PEEP (0.39 +/- 0.06, p = .07) groups. When compared with the cobra venom factor only group (GV-CVF 47 +/- 2 neutrophils/high-power field), reductions in neutrophil count were observed in all groups (neutrophils/high-power field): PLV-CVF (20 +/- 2, p = .009); PEEP-CVF (24 +/- 1, p = .01); CVF-PLV (30 +/- 2, p = .03); and CVF-PEEP (37 +/- 1, p = .04).


CONCLUSIONS
These data suggest that both partial liquid ventilation and PEEP result in a reduction in neutrophil accumulation in the setting of acute lung injury.
Department of Surgery, University of Michigan Medical Center, Ann Arbor 48109-0245, USA.
D M
DM
Colton
G O
GO
Till
K J
KJ
Johnson
S B
SB
Dean
R H
RH
Bartlett
R B
RB
Hirschl
D000818:Animals; D001784:Blood Gas Analysis; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004546:Elapid Venoms; D005466:Fluorocarbons / Q000627:therapeutic use*; D006842:Hydrocarbons, Brominated; D007322:Instillation, Drug; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils / Q000276:immunology*; D009195:Peroxidase / Q000032:analysis; D011175:Positive-Pressure Respiration / Q000379:methods*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*
D004546:Elapid Venoms; D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; D009195:Peroxidase; C003072:perflubron