Systemic inflammation induced by cardiopulmonary bypass: a review of pathogenesis and treatment.
The acute respiratory distress syndrome (ARDS) is a severe alteration in lung structure and function that develops secondary to a traumatic stimulus. When ARDS develops following cardiopulmonary bypass (CPB) it is know as postpump syndrome (PPS). ARDS can be caused by a single massive insult ("hit"); however, sequential minor insults ("hits") are more common clinically. The concept of multiple sequential insults causing ARDS has been termed the "two-hit" model of ARDS. The purpose of this article is to summarize our studies testing the hypothesis that PPS is caused by multiple sequential insults. To confirm our hypothesis, we developed a porcine model of "two-hit" PPS. Our model was composed of sequential benign insults, with CPB as the "first hit" and low dose of endotoxin as the "second-hit." It is our hypothesis that the mechanism of PPS is CPB-induced priming of polymorphonuclear leukocytes (PMNs) ("first-hit") with subsequent PMN activation by a second insult ("second-hit") such as endotoxin. Our model confirms this clinically relevant postulate, and we provide strategies to disrupt the inflammatory cascade leading to PPS.
Nieman
G
G
SUNY Health Science Center at Syracuse, Department of Surgery 13210, USA.
Searles
B
B
Carney
D
D
McCann
U
U
Schiller
H
H
Lutz
C
C
Finck
C
C
Gatto
L A
LA
Hodell
M
M
Picone
A
A
D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D006801:Humans; D012128:Respiratory Distress Syndrome / Q000209:etiology* / Q000628:therapy*