Leukocyte sequestration in isolated guinea pig lungs during extracorporealcirculation: Effects on microvascular function

Neutrophils accumulate in patient lungs during clinical hemodialysis and in isolated blood-perfused guinea pig lungs due to the contact between blood and extracorporeal system. However, it is unclear how these sequestered and partly activated neutrophils affect the lung microvasculature. We, therefo re, studied pulmonary vascular resistance, vascular permeability, gas excha nge, and oxygen free radical production in isolated guinea pig lungs during perfusion with whole blood containing partly 'activated' neutrophils in co mparison with perfusions using leukopenic blood. We also connected a Cuprop han hemodialysis membrane to the whole-blood perfusion system in order to i nvestigate whether a dialyzer, which may further activate leukocytes, affec ts lung microvascular permeability, vascular resistances, and reactive oxyg en species production. The sequestered neutrophils did not seem to markedly affect the lung microvascular function, since neither the leukocyte-free p erfusion nor the hemodialysis membrane altered any of the measured variable s as compared with whole-blood perfusion in a system without a dialyzer. We conclude that neutrophils, whether activated by a perfusion system or by a dialysis membrane, can accumulate in isolated lungs without adversely affe cting the microvascular function. Copyright (C) 2000 S. Karger AG, Basel.