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.
SUNY Health Science Center at Syracuse, Department of Surgery 13210, USA.
G
G
Nieman
B
B
Searles
D
D
Carney
U
U
McCann
H
H
Schiller
C
C
Lutz
C
C
Finck
L A
LA
Gatto
M
M
Hodell
A
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Picone
D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D006801:Humans; D012128:Respiratory Distress Syndrome / Q000209:etiology* / Q000628:therapy*