Development of a Surveillance System for External Ventricular Shunt-Associated Meningitis/Ventriculitis in Intensive Care Units

Background:  

External ventricular shunts are common devices especially in some kinds of intensive care units (ICU). The most significant complication resulting from intracranial ventricular shunt is infection.

Objective:  

To establish a surveillance system in ICU for nosocomial meningitis/ventriculits associated to external ventricular shunts as an element of internal quality management.

Methods:  

The German nosocomial surveillance system (KISS) provides ICU the possibility to perform surveillance of meningitis/ventriculits since January 2008. All ICU patients have to be observed for signs and symptoms of meningitis/ventriculitis. The diagnosis of meningitis/ventriculits is based on CDC definitions. All meningitis/ventriculitis in which an external ventricular shunt (VS) was in place at the time of, or within 48 hours before, onset of the event is classified as VS-associated. The VS-associated meningitis/ventriculitis (VAM) rate per 1000 VS-days is calculated for each ICU. The VS utilization ratio is calculated by dividing the number of VS days by the number of patient days.

Results:  

53 ICU in Germany performed surveillance for VAM until June 2010. Most of the ICU were surgical (n=14) and medical/surgical (n=13) followed by neurosurgical (n=10) and neurologic ICU (n=6). The mean utilization ratio was 10.8 VS-days/100 patient days. 193 VAM were observed during 40,615 VS-days, resulting in a VAM rate of 4.8/1000 VS-days (interquartile range: 0.0 to 3.3). Table 1 shows utilization ratio, VAM rate and other device-associated infection rates stratified by type of ICU. 156 pathogens accounted for 145 cases of VAM. The most common species were coagulase negative staphylococci (n=70), enterococci (n=24) and S. aureus (n=13). In 25% no pathogen could be isolated. Patients with VAM differ from patients with other types of device-associated infections in ICU: Patients with VAM were younger (mean 55 years) compared with patients affected by other types of device-associated infections (mean age for CLABSI 58, VAP 60, CAUTI 62 years). In contrast to VAP and CLABSI with a portion of only one third females in infected patients, nearly half of the patients with VAM were female.

Table 1 VS utilization ratio and device-associated infection rates stratified by type of ICU

ICU type	VS utilization ratio (mean)	device-associated-infection rates (mean)
		VAM	VAP	CLABSI	CAUTI
surgical	8.7	5.1	5.7	1.3	3.9
medical/surgical	6.8	6.2	4.2	1.3	2.7
neurosurgical	23.3	5.0	8.9	1.9	5.3
neurologic	12.6	3.0	8.6	1.1	3.8

VAP= ventilator associated pneumonia, CLABSI= central line associated bloodstream infection, CAUTI= catheter associated urinary tract infection

Conclusions:

The device-associated infection rate for meningitis/ventriculitis is comparably high to other devices-associated infections in ICU. Therefore, surveillance of VS-associated meningitis/ventriculitis is most worthwhile.