The microbiology of multiple organ failure. The proximal gastrointestinal tract as an occult reservoir of pathogens
J. C. Marshall, N. V. Christou, R. Horn and J. L. Meakins
Department of Surgery, Royal Victoria Hospital, Montreal, Canada.
The microbiology of infection acquired in the intensive care unit (ICU) was
studied prospectively in 205 consecutive patients admitted to a surgical
intensive care unit. A multiple organ failure (MOF) score was calculated
for each admission. Susceptibility to ICU-acquired infection increased with
increasing MOF scores. While Escherichia coli, Bacteroides fragilis, and
enterococci were the most common isolates from infections present at the
time of ICU admission, Staphylococcus epidermidis, Candida, and Pseudomonas
dominated infections occurring in patients with high MOF scores. Mortality
correlated highly with infection due to S epidermidis or Candida and only
poorly with infection due to Pseudomonas or E coli; significant foci of
invasive infection were frequently absent at autopsy. Quantitative cultures
of proximal gastrointestinal fluid in 16 of these patients showed Candida,
S epidermidis, and Pseudomonas to be the most common isolates, and all but
one patient colonized with these organisms had invasive infection with the
same organism. The proximal gastrointestinal tract appears to be an
important occult reservoir of the predominant pathogens in MOF.