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Urosepsis in Critical Care
Burke A. Cunha
Infectious Disease Division, Winthrop-University Hospital, Mineola, New York, and
State University of New York School of Medicine, Stony Brook, New York, U.S.A.OVERVIEW
The most common cause of sepsis in patients admitted to the hospital is urosepsis. Urosepsis is
bacteremia from a urinary tract source, which is diagnosed by culturing the same organism
from urine and blood. It may be community or nosocomially acquired. Community-acquired
urosepsis occurs in non-leukopenic compromised hosts, those with preexisting renal disease,
or those with anatomical abnormalities of the urinary tract. Nosocomial urosepsis may occur
in normal as well as abnormal hosts due to the presence of stones, stents, or nephrostomy
tubes (1–5).
COMMUNITY-ACQUIRED UROSEPSIS
The organisms causing community-acquired urinary tract infections (UTI), i.e.,Escherichia coli,
Proteus mirabilis, Klebsiella pneumoniae, enterococci,Enterococcus faecalis[vancomycin-susceptible
enterococci (VSE)], group B streptococci, are the organisms isolated from blood as well as from
urine in urosepsis. Clinical scenarios that predispose to community-acquired urosepsis include
cystitis in non-leukopenic compromised hosts [diabetes mellitus, systemic lupus erythematosus
(SLE), alcoholism, multiple myeloma, steroid therapy, etc.), acute pyelonephritis, those with
partial/total urinary tract obstruction, preexisting renal disease, or renal/bladder calculi
(Table 1).
Urosepsis is accompanied by bacteremia with systemic symptoms with or without
hypotension (6–8). Excluding multiple myeloma and chronic lymphatic leukemia (CLL),
urosepsis is relatively uncommon in leukopenic compromised hosts (e.g., cancer patients
receiving chemotherapy). Immune defects related to malignancy and/or chemotherapy do not
diminish mucosal defenses, e.g., secretory IgA that prevent bacterial adherence to uroepithelial
cells (4,5).
UROSEPSIS: NOSOCOMIAL
Nosocomial urosepsis is caused by urinary tract catheterization/instrumentation in non-
leukopenic hosts. Catheter-associated bacteriuria in the hospital does not result in urosepsis in
normal hosts. Bacteriuria will not result in bacteremia unless the patient has structural
abnormalities of the GU tract, i.e., congenital abnormalities of the collecting system, stone
disease, or unilateral/bilateral obstruction due to intrinsic/extrinsic causes. Urologic instru-
mentation/procedures done in the presence of a UTI may result in bacteremia with systemic
symptoms/hypotension. Urosepsis from urologic instrumentation/procedures may occur in
normal or abnormal hosts (4,5,9–12) (Table 2).
Uropathogens associated with nosocomial urosepsis are aerobic gram-negative bacilli
(GNB) orE. faecalis.The most common nosocomial uropathogens areE. coli, K. pneumoniae,
E. faecalis(VSE), andE. faecium[vancomycin-resistant enterococci (VRE)]. Less commonly,
Serratia marcesens,Enterobacter sp., Providencia sp.,Citrobacter sp., Stenotrophomonas maltophilia,
Burkholderia cepacia,orPseudomonas aeruginosa, are nosocomialAcinetobacteruropathogens.
Because the uropathogens causing community-acquired versus nosocomially acquired
urosepsis are dissimilar, different therapeutic approaches are required for community-
acquired and nosocomially acquired urosepsis (5,9,11) (Table 3).