Contributions of vascular flow and pulmonary capillary pressure to ventilator-induced lung injury.
OBJECTIVE
To evaluate the influence of vascular flow on ventilator-induced lung injury independent of vascular pressures.


METHODS
Laboratory study.


METHODS
Hospital laboratory.


METHODS
Thirty-two New Zealand White rabbits.


METHODS
Thirty-two isolated perfused rabbit lungs were allocated into four groups: low flow/low pulmonary capillary pressure; high flow/high pulmonary capillary pressure; low flow/high pulmonary capillary pressure, and high flow/low pulmonary capillary pressure. All lungs were ventilated with peak airway pressure 30 cm H2O and positive end-expiratory pressure 5 cm H2O for 30 mins.


RESULTS
Outcome measures included frequency of gross structural failure (pulmonary rupture), pulmonary hemorrhage, edema formation, changes in lung compliance, pulmonary vascular resistance, and pulmonary ultrafiltration coefficient. Lungs exposed to high pulmonary vascular flow ruptured more frequently, displayed more hemorrhage, developed more edema, suffered larger decreases in compliance, and had larger increases in vascular resistance than lungs exposed to low vascular flows (p < .05 for each pairwise comparison between groups).


CONCLUSIONS
These findings suggest that high pulmonary vascular flows might exacerbate ventilator-induced lung injury independent of their effects on pulmonary vascular pressures.
Critical Care Center, Hospital de Sabadell, Institut Universitari Parc Taulí, Universitat Autónoma de Barcelona, Esfera UAB, Spain.
Josefina
J
López-Aguilar
Enrique
E
Piacentini
Ana
A
Villagrá
Gastón
G
Murias
Sara
S
Pascotto
Alicia
A
Saenz-Valiente
Pilar
P
Fernández-Segoviano
John R
JR
Hotchkiss
Lluis
L
Blanch
D000818:Animals; D001794:Blood Pressure; D002196:Capillaries / Q000503:physiopathology; D008171:Lung Diseases / Q000209:etiology* / Q000503:physiopathology*; D011817:Rabbits; D012039:Regional Blood Flow; D012121:Respiration, Artificial / Q000009:adverse effects*