Consequences of vascular flow on lung injury induced by mechanical ventilation.
To investigate whether the magnitude of blood flow contributes to ventilator-induced lung injury, 14 sets of isolated rabbit lungs were randomized for perfusion at either 300 (Group A: n = 7) or 900 ml/ min (Group B: n = 7) while ventilated with 30 cm H2O peak static pressure. Control lungs (Group C: n = 7) were ventilated with lower peak static pressure (15 cm H2O) and perfused at 500 ml/min. Weight gain, changes in the ultrafiltration coefficient (DeltaKf) and lung static compliance (CL), and extent of hemorrhage (scored by histology) were compared. Group B had a larger decrease in CL (-13 +/- 11%) than Groups A (2 +/- 6%) and C (5 +/- 5%) (p < 0.05). Group B had more hemorrhage and gained more weight (16.2 +/- 9.5 g) than Groups A (8.7 +/- 3.4 g) and C (1.6 +/- 1.0 g) (p < 0.05 for each pairwise comparison between groups). Finally, Kf (g . min-1 . cm H2O-1 . 100 g-1) increased the most in Group B (DeltaKf = 0.26 +/- 0. 20 versus 0.17 +/- 0.10 in Group A and 0.05 +/- 0.04 in Group C; p < 0.05 for B versus C). We conclude that the intensity of lung perfusion contributes to ventilator- induced lung injury in this model.
Broccard
A F
AF
Division of Pulmonary and Critical Care Medicine, University of Minnesota, Minneapolis/St. Paul, MN, USA.
Hotchkiss
J R
JR
Kuwayama
N
N
Olson
D A
DA
Jamal
S
S
Wangensteen
D O
DO
Marini
J J
JJ
D000818:Animals; D001794:Blood Pressure; D006439:Hemodynamics; D006470:Hemorrhage / Q000209:etiology / Q000473:pathology; D008168:Lung / Q000473:pathology; D009929:Organ Size; D018467:Positive-Pressure Respiration, Intrinsic; D011652:Pulmonary Circulation; D011817:Rabbits; D012121:Respiration, Artificial / Q000009:adverse effects*; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*