No effect of preoperative selective gut decontamination on endotoxemia and cytokine activation during cardiopulmonary bypass: a randomized, placebo-controlled study.
BACKGROUND
Cardiopulmonary bypass predisposes the splanchnic region to inadequate perfusion and increases in gut permeability. Related to these changes, circulating endotoxin has been shown to rise during cardiac surgery, and may contribute to cytokine activation, high oxygen consumption, and fever ("postperfusion syndrome"). To a large extent, free endotoxin in the gut is a product of the proliferation of aerobic gram-negative bacteria and may be reduced by nonabsorbable antibiotics.


OBJECTIVE
To evaluate the effect of preoperative selective gut decontamination (SGD) on the incidence of endotoxemia and cytokine activation in patients undergoing open heart surgery.


METHODS
Prospective, randomized, placebo-controlled double-blind trial.


METHODS
Tertiary-care university teaching hospital.


METHODS
Preoperative administration for 5 to 7 days of oral nonabsorbable antibiotics (polymyxin B and neomycin) vs. placebo. The efficacy of SGD was assessed by culture of rectal swabs.


METHODS
Forty-four patients (median age 65 yrs, 29 males) were included in a pilot study to establish the sampling points of perioperative measurements. Seventy-eight consecutive patients (median age 65 yrs, 55 males) were enrolled for the prospective study; of these, 51 were randomly allocated to take SGD (n = 24) or placebo (n = 27); 27 were included in a control group (no medication).


RESULTS
SGD but not placebo effectively reduced the number of rectal swabs that grew aerobic gram-negative bacteria (27% vs. 93%, respectively; p < .001). SGD did not affect the occurrence of perioperative endotoxemia, nor did it reduce the tumor necrosis factor-alpha, interleukin-10, or interleukin-6 concentrations (p > .20), as determined before surgery, upon aorta declamping, 30 mins into reperfusion, or 2 hrs after surgery. Also, SGD did not alter the incidence of postoperative fever or clinical outcome measures such as duration of artificial ventilation and intensive care unit and hospital stay.


CONCLUSIONS
SGD effectively reduces the aerobic gram-negative bowel flora in cardiac surgery patients but fails to affect the incidence of perioperative endotoxemia and cytokine activation during cardiopulmonary bypass and the occurrence of a postperfusion syndrome.
Bouter
Hens
H
Department of Infectious Diseases, Leiden University Medical Center, The Netherlands.
Schippers
Emile F
EF
Luelmo
Saskia A C
SA
Versteegh
Michael I M
MI
Ros
Peter
P
Guiot
Henri F L
HF
Frölich
Marijke
M
van Dissel
Jaap T
JT
D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis; D002315:Cardiopulmonary Bypass; D016207:Cytokines / Q000097:blood*; D003666:Decontamination; D004311:Double-Blind Method; D019446:Endotoxemia / Q000517:prevention & control*; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007422:Intestines / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009355:Neomycin / Q000008:administration & dosage; D010865:Pilot Projects; D011112:Polymyxin B / Q000008:administration & dosage; D011300:Preoperative Care; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D000900:Anti-Bacterial Agents; D016207:Cytokines; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D009355:Neomycin; D011112:Polymyxin B