What evidence indicates biotrauma may be a mechanism of ventilator-induced lung injury (VILI)?

A. the presence of increased tumor necrosis factor-? in the serum of animals receiving low lung volumes and PEEP
B. the presence of increase neutrophils and alveolar macrophages in the mucus of animals ventilated with low lung volumes and high pressures
C. the increased incidence of alveolar-capillary permeability in animals ventilated with high lung volumes and no PEEP
D. the presence of increased inflammatory mediators in broncho-alveolar lavage in animals receiving high lung volumes and no PEEP

?ANS: D
A. Incorrect response: Chiumello et al found higher levels of tumor necrosis factor-α (TNF-α) and macrophage inflammatory protein-2 (MIP-2) in the serum of animals that developed lung injury while receiving high tidal volumes and no PEEP.
B. Incorrect response: Haitsma et al found results similar to Chiumello and colleagues regarding TNF-α in a model of lipopolysaccharide-induced lung injury.
C. Incorrect response: The demonstration of an increased incidence of alveolar-capillary permeability in animals ventilated with high lung volumes and no PEEP is evidence of volutrauma, not biotrauma.
D. Correct response: A number of studies have provided evidence that an increase in bronchoalveolar lavage and serum concentrations of inflammatory cytokines and chemokines indicate a strong relationship between biotrauma and VILI in animals ventilated with high lung volumes.