Literature Update - October, 2007
Compiled by Dr Leon Worth, ID Physician
Needle-free Intravascular Devices & Risk for Catheter-related Bloodstream Infection
Previously, both increased and decreased rates of infection have been reported in association with needle-free valves for vascular devices.
At a single Spanish centre, Estave et al (J Hosp Infect 2007; 67:30-34) prospectively compared the use of a needle-free valve connection
system (NFVCS) with a three-way stop-cock connector (3WSC). ICU patients were randomly assigned to each study arm. Catheter-related
bloodstream infection was defined as the presence of the same micro-organism in both peripheral blood and catheter tip, with clinical
signs of sepsis not related to another source.
Of 799 studied patients, 404 were assigned to NFVCS, and 395 to 3WSC, and groups were comparable with regard to length of ICU admission
and SAP II score. In total, 90 episodes of arterial catheter or CVC-related bloodstream infection were diagnosed: 47 in the NFVCS
group, and 43 in the 3WSC group. Rates of infection were 4.61 per 1000 catheter days and 4.11 per 1000 catheter days,
respectively (p=0.59). For CVC-associated bloodstream infection, the rates of infection were 4.26 and 5.27 per 1000 CVC days
for NFVCS and 3WSC groups, respectively (p=0.4). Colonisation rates were also compared, and were not significantly different in the 2 groups.
This study did not demonstrate a significant difference in infection and colonisation rates when NFVCS and 3WSC devices were compared.
The composite endpoint of ‘all catheters’ (i.e. arterial and CVC) is not a standardised approach, and it is not clear if this is a valid or
meaningful measure of device-related infection. Further study of arterial catheters is required – for example, specific process
measures may be related to these catheters, but not CVCs. Furthermore, since 6/47 infections in the NFVCS group were due to
Acinetobacter baumannii, it would be relevant to know if an inter-current nosocomial outbreak contributed
to the incidence of infections during the study period.
Voice Prompts to Enhance Hand Hygiene
The use of voice prompts to improve hand hygiene was prospectively evaluated in a surgical unit in Baltimore
(Swoboda SM, et al. Am J Infect Control 2007; 35:470-6). The study design included 3 phases: (I) baseline evaluation, including
electronic monitoring system, (II) intervention phase - voice prompt delivered if hand hygiene did not occur (“Please wash
your hands”), (III) hand hygiene compliance monitored without voice prompts. Patients were identified for isolation by the hospital
epidemiology and infection control department, surgical or nursing staff. Nosocomial infection was defined as any infection that
occurred 48 hours after admission to the studied ward.
During each of the 3 study phases (15 month study period), the isolation status of patients remained constant (24-29%).
In isolation patient rooms, compliance with hand hygiene improved in phases II and III, compared to baseline (OR 1.49, p=0.03).
Also, compliance was greater in isolation vs. non-isolation rooms throughout the study period (OR 1.49, p=0.0006). A greater number
of patients in isolation rooms developed nosocomial infection, compared to non-isolation rooms (OR 1.46, p=0.07).
This study suggests that hand hygiene compliance can be enhanced by use of isolation rooms, and that this can be further improved
by the novel intervention of voice prompting. The failure to demonstrate a decrease in nosocomial infection rate in association
with isolation rooms and voice prompting is likely to have been confounded by other risk factors for infection (e.g. patients known to be
colonised, or already commenced antibiotics for infection). Additional studies are required to further address this question, before
considering broader implementation.