Diagnostic accuracy of urinary dipstick to exclude catheter-associated urinary tract infection in ICU patients: a reappraisal

• Published in: Infection Vol. 42; no. 4; pp. 661 - 668
• Main Authors: Coman, T., Troché, G., Semoun, O., Pangon, B., Mignon, F., Jacq, G., Merceron, S., Abbosh, N., Laurent, V., Guezennec, P., Henry-Lagarrigue, M., Revault-d’Allonnes, L., Ben-Mokhtar, H., Audibert, J., Bruneel, F., Resche-Rigon, M., Bedos, J.-P., Legriel, S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2014; Springer Nature B.V
• Subjects: Adult; Carboxylic Ester Hydrolases - analysis; Catheter-Related Infections - diagnosis; Clinical and Epidemiological Study; Cohort Studies; Family Medicine; Female; Fever of Unknown Origin - etiology; General Practice; Humans; Hypothermia; Hypothermia - etiology; Infectious Diseases; Intensive Care Units; Internal Medicine; Male; Medical instruments; Medicine; Medicine & Public Health; Microbiological Techniques; Middle Aged; Nitrites - analysis; Observational studies; Point-of-Care Systems; Prospective Studies; Urinary Tract Infections - diagnosis; Urine - chemistry; Urine - microbiology; Urine; Urinary tract infection; Dipstick; Urinalysis; Critically ill; Diagnostic accuracy; Catheter
• ISSN: 0300-8126; 1439-0973
• DOI: 10.1007/s15010-014-0612-6

Objectives
We wanted to assess the diagnostic accuracy of urinary dipstick testing in excluding catheter-associated urinary tract infection (CAUTI) in intensive care unit (ICU) patients with fever or hypothermia.
Methods
This was a prospective observational cohort study in a medical-surgical ICU. Patients with new-onset fever >38.3 °C or hypothermia <36 °C at least 48 h after urinary catheter insertion were included over a 2-year period. At each episode, a urinary dipstick test and a urine culture were performed as the criterion standard. Extensive microbiological investigations for extra-urinary infections were performed also. The performances of various urinary dipstick result combinations in ruling out CAUTI were compared based on the likelihood ratios (LR+ and LR−).
Results
Symptomatic CAUTI was diagnosed in 31 (24.4 %) of the 127 included patients (195 episodes of fever or hypothermia). LR+ was best for combined leukocyte esterase-positive and nitrite-positive dipstick results (overall population: 14.91; 95 % confidence interval [95 % CI], 5.53–40.19; patients without urinary symptoms: 15.63; 95 % CI, 5.76–42.39). LR− was best for either leukocyte esterase-positive or nitrite-positive dipstick results (overall population: 0.41; 95 % CI, 0.57–0.65; patients without urinary symptoms, 0.36; 95 % CI, 0.21–0.60).
Conclusions
Urinary dipstick testing at the bedside does not help to rule out symptomatic CAUTI in medical or surgical ICU patients with fever or hypothermia.