Literature Update - December, 2004
Compiled by Dr Deb Friedman, VICNISS ID Physician
Ventilator-Associated Pneumonia
Much controversy surrounds the diagnosis of ventilator-associated pneumonia (VAP). Many believe that invasive procedures
such as bronchoscopy are more precise than an endotracheal aspirate (EA).
A new study (Elatrous S et al. Intensive Care Med 2004;30:853-8) has compared EA with blind sampling via a plugged
telescoping catheter (PTC). In this study EA was always performed before PTC, and specimens were processed in the laboratory
within 15 minutes of collection.
In 75% of the episodes of VAP, a pathogen was isolated, and the EA and PTC correlated well for bacterial counts. If a
diagnostic threshold of 10 4 colony-forming units is used, the EA was 92% sensitive, and 85% specific at determining the
pathogens causing VAP.
This study adds to the evidence that EA specimens are adequate for determining the pathogens causing VAP.
Linezolid is a Short-lived Success
Linezolid was released in 2000 as a treatment for infections caused by multidrug-resistant enterococci. Now researchers
have tested vancomycin-resistant E. faecium isolates from 1996-2002 in Houston to determine
their susceptibility to linezolid (Raad II et al, Antimicrob Agents Chemother 2004;48:3583-5).
Of the E. faecium isolates obtained from the era prior to linezolid use, 100% were
susceptible to linezolid. After this agent was used for >6 months, the susceptibility to linezolid was 83%.
This data is indicative of the rapid emergence of resistance to linezolid, and is concerning for the future utility of this drug.
CVC Removal in Catheter-Related Bacteraemia
Investigators have conducted a retrospective study to assess the role of CVC removal in relapse of cases of gram-negative
bacteraemia (Hanna H et al. Infect Control Hosp Epidemiol 2004;25:646-9).
Among 72 patients with gram-negative catheter-related bloodstream infection (CRBSI), 93% had their CVC removed.
Relapse of infection occurred in 2 of 67 patients who had the CVC removed, compared with all 5 patients who retained
their device.
CVC removal within 72 hours after CRBSI onset was the sole independent protective factor against relapse.
This study, although retrospective, indicates the importance of prompt CVC removal in cases of CRBSI.
Handwashing in Healthcare Workers: Accessibility of Sink Location does not Improve Compliance
A group from Brisbane studied whether or not relocation of a large hospital to a new building affected handwashing
compliance (Whitby M, J Hosp Infection 2004;58(4):247-253). In the new building, no clinical activity was >5 metres
from a sink, compared with approximately 30 metres in the old building.
After performing covert observations of healthcare workers both before and after the relocation, they found that
there was a brief period 1-month after relocation in which handwashing after-patient contact increased. However, this
improvement was not sustained at 9 months. These results are in keeping with other studies which have illustrated that
increasing the sink:bed ratio did not lead to more frequent handwashing.
For reasons which are not stated, the hospital featured in this study does not use alcohol-based handrub, and thus
there is complete reliance on the positioning of sinks for improving hand hygiene.