Prevalence and risk factors for colonisation with gram-negative bacteria in an intensive care unit.
OBJECTIVE
To investigate prevalence and determine risk factors for colonisation with Gram-negative bacteria in ICU patients.


METHODS
Prospective, surveillance study.


METHODS
26-bed surgical and paediatric ICU.


METHODS
159 patients--whereof 22 infants--admitted to the surgical/paediatric ICU over a two-month period.


METHODS
In all patients routine microbiological monitoring was performed by thrice weekly oral swabs, urine sampling and, additionally, tracheal aspirates in patients on mechanical ventilation (MV) and by anal swabs once weekly.


RESULTS
Population characteristics: Mean age of the adult population was 51.1 +/- 17.6 year. Mean age of the paediatric population was 6.3 +/- 5.3 year. The mean APACHE II-score was 18 +/- 9.1. The mean PRISM-score was 9.7 +/- 5.4. The mean ICU stay was 7.5 +/- 11.4 days. 43.4 percent of patients received mechanical ventilation (MV). The mean number of mechanical ventilation days was 11.1 +/- 14.7 days. 32.1% of patients experienced colonisation with Gram-negative bacteria. Prevalence of colonisation increased with length of ICU stay. The probability of colonisation was 24% after an ICU stay of 3 days (= median ICU stay). Time to colonisation was not different between the controlled sites (p > 0.05). 47% of colonizations were due to multiresistant strains. Higher APACHE II-scores and MV were associated with a higher prevalence of colonisation (p < 0.01). The ICU mortality was 8% among adult and 4% among paediatric patients.


CONCLUSIONS
Patients with high APACHE II-scores, on mechanical ventilation and with an ICU stay of more than 3 days are most at risk for colonisation with Gram-negative bacteria. These patients should be cared with the optimal precautions in the prevention of colonisation and infection.
Blot
S
S
Department of Intensive Care, Ghent University Hospital, Belgium. icu@rug.ac.be
Vandewoude
K
K
Blot
K
K
Colardyn
F
F
D018806:APACHE; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000382:microbiology; D001437:Bacteriuria / Q000382:microbiology; D002648:Child; D003422:Critical Care / Q000706:statistics & numerical data*; D003428:Cross Infection / Q000453:epidemiology* / Q000517:prevention & control; D004352:Drug Resistance, Microbial; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007902:Length of Stay; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology; D011159:Population Surveillance; D015995:Prevalence; D011446:Prospective Studies; D012121:Respiration, Artificial; D012307:Risk Factors; D013997:Time Factors; D014132:Trachea / Q000382:microbiology