Exogenous surfactant reduces ventilator-induced decompartmentalization of tumor necrosis factor alpha in absence of positive end-expiratory pressure.
OBJECTIVE
To determine the effect of pretreatment with exogenous surfactant on ventilator-induced decompartmentalization of TNF-alpha.


METHODS
Prospective, randomized, animal study in the experimental laboratory of a university.


METHODS
Male Sprague-Dawley rats (n=102) received lipopolysaccharide either intratracheally or intraperitoneally to stimulate TNF-alpha production; one-half of the animals were pretreated with surfactant. Animals were ventilated for 20 min with a peak inspiratory pressure/positive end-expiratory pressure (PEEP) ratio of either 45/0 or 45/10 (frequency 30 bpm, I/E ratio 1:2, FIO(2)=1).


RESULTS
Blood gas tension and arterial pressures were recorded 1, 10, and 20 min after the start of mechanical ventilation. After the animals were killed pressure-volume curves were recorded, and bronchoalveolar lavage was performed for assessment of protein content and the small/large surfactant aggregate ratio. TNF-alpha was determined in serum and bronchoalveolar lavage. Pretreatment with surfactant decreased decompartmentalization of TNF-alpha during 45/0 ventilation. Addition of a PEEP level of 10 cm H(2)O reduced decompartmentalization even further. In addition, surfactant prevented deterioration in oxygenation and decreased accumulation of protein in the bronchoalveolar lavage in the zero-PEEP group.


CONCLUSIONS
An excess of active surfactant decreases transfer of cytokines across the alveolar-capillary membrane similar to PEEP. The combination of PEEP and surfactant reduces decompartmentalization of TNF-alpha even further.
Department of Anesthesiology, Erasmus University Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
Jack J
JJ
Haitsma
Stefan
S
Uhlig
Ulrike
U
Lachmann
Serge J
SJ
Verbrugge
Davey L H
DL
Poelma
Burkhard
B
Lachmann
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005858:Germany; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008297:Male; D011175:Positive-Pressure Respiration; D011663:Pulmonary Surfactants / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism*
D008070:Lipopolysaccharides; D011663:Pulmonary Surfactants; D014409:Tumor Necrosis Factor-alpha