Cardiopulmonary bypass in man: role of the intestine in a self-limiting inflammatory response with demonstrable bacterial translocation.
BACKGROUND
Cardiopulmonary bypass provokes a systemic inflammatory reaction that, in 1% to 2% of all cases, leads to multiorgan disfunction. The aim of this study was to evaluate the possible role of the intestine in the pathogenesis and development of this reaction.


METHODS
Eleven selected patients scheduled for elective coronary artery bypass graft surgery were enrolled in a open, prospective clinical study. Gastric tonometry, chromium-labeled test and double sugar intestinal absorption tests, polymerase chain reaction microbial DNA test, and measurement of cytokines and transcriptional factor (nuclear factor kappaB) activation were performed.


RESULTS
During the postoperative period, gastric pH remained stable (range,7.2 to 7.3). The partial pressure for carbon dioxide gradient between the gastric mucosa and arterial blood increased significantly (from 1 to 23 mm Hg), peaking in the sixth postoperative hour. Interleukin 6 increased significantly over basal levels, peaking 3 hours after cardiopulmonary bypass (96.3 versus 24 pg/mL). Nuclear factor kappaB never reached levels higher than those observed after lipopolysaccharide stimulation. Escherichia coli translocation was documented in 10 patients: in eight cases from removal of aortic cross-clamps and in two cases from the first postoperative hour. With respect to basal value (6.4%), the urine collection revealed a significant increase in excretion of the radioisotope during the first 24 hours after surgery (39.1%), although there were no significant variations with the double sugar test.


CONCLUSIONS
The results obtained showed a correlation between the damage of the gastrointestinal mucosa, subsequent increased permeability, E coli bacteremia, and the activation of a self-limited inflammatory response in the absence of significant macrocirculatory changes and postoperative complications.
Rossi
Marco
M
Department of Anesthesia, Unit of Cardiac Anesthesia, Università Cattolica del Sacro Cuore, Policlinico "A. Gemelli,", Rome, Italy. cardioanucsc@rm.unicatt.it
Sganga
Gabriele
G
Mazzone
Marinella
M
Valenza
Venanzio
V
Guarneri
Sergio
S
Portale
Grazia
G
Carbone
Luigi
L
Gatta
Lucia
L
Pioli
Claudio
C
Sanguinetti
Maurizio
M
Montalto
Massimo
M
Glieca
Franco
F
Fadda
Giovanni
G
Schiavello
Rocco
R
Silveri
Nicolò G
NG
D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000276:immunology; D018988:Bacterial Translocation / Q000276:immunology*; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000276:immunology / Q000601:surgery*; D016207:Cytokines / Q000097:blood; D004926:Escherichia coli / Q000276:immunology; D004927:Escherichia coli Infections / Q000276:immunology; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology; D006801:Humans; D007408:Intestinal Absorption / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000097:blood; D011183:Postoperative Complications / Q000276:immunology*; D011446:Prospective Studies; D012307:Risk Factors; D018746:Systemic Inflammatory Response Syndrome / Q000276:immunology*
D016207:Cytokines; D016328:NF-kappa B