title: Impact of round-the-clock CSF Gram stain on empirical therapy for suspected central nervous system infections.
abstract: The impact of round-the-clock cerebrospinal fluid (CSF) Gram stain on overnight empirical therapy for suspected central nervous system (CNS) infections was investigated. All consecutive overnight CSF Gram stains between 2006 and 2011 were included. The impact of a positive or a negative test on empirical therapy was evaluated and compared to other clinical and biological indications based on institutional guidelines. Bacterial CNS infection was documented in 51/241 suspected cases. Overnight CSF Gram stain was positive in 24/51. Upon validation, there were two false-positive and one false-negative results. The sensitivity and specificity were 41 and 99 %, respectively. All patients but one had other indications for empirical therapy than Gram stain alone. Upon obtaining the Gram result, empirical therapy was modified in 7/24, including the addition of an appropriate agent (1), addition of unnecessary agents (3) and simplification of unnecessary combination therapy (3/11). Among 74 cases with a negative CSF Gram stain and without formal indication for empirical therapy, antibiotics were withheld in only 29. Round-the-clock CSF Gram stain had a low impact on overnight empirical therapy for suspected CNS infections and was associated with several misinterpretation errors. Clinicians showed little confidence in CSF direct examination for simplifying or withholding therapy before definite microbiological results.
authors.affiliation: Infectious Diseases Service, Department of Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, rue du Bugnon 46, 1011, Lausanne, Switzerland, frederic.tissot@chuv.ch.
authors.forename: F
authors.initials: F
authors.lastname: Tissot
authors.forename: G
authors.initials: G
authors.lastname: Prod'hom
authors.forename: O
authors.initials: O
authors.lastname: Manuel
authors.forename: G
authors.initials: G
authors.lastname: Greub
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002555:Cerebrospinal Fluid / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000382:microbiology; D003428:Cross Infection / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D005840:Gentian Violet; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016920:Meningitis, Bacterial / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D008875:Middle Aged; D010619:Phenazines; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods; D062606:Tertiary Care Centers; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; C035863:Gram's stain; D010619:Phenazines; D005840:Gentian Violet