The effect of ICU design on the incidence of vancomycin resistant enterococci

Introduction: The threat of multiple resistant organisms is a growing concern in intensive care units (ICU), particularly since many populations are aging and invasive procedures are used with increasing frequency. Methicillin resistant Staphylococcus aureas has been endemic in our ICU for many years. However, in January 1995, the first vancomycin resistant enterococcal (VRE) isolate in our hospital was discovered in a urine sample from a patient in the surgical intensive care unit (SICU). Rectal swabs obtained from all other patients in this unit identified three additional patients who were colonized with VRE. DNA fingerprinting confirmed that all four isolates were the same strain and, additionally, 20/23 isolates hospital-wide were the identical strain. The percentage of nosocomial VRE increased from 0.3 to 7.9% in ate US from 1989 - '93. We evaluated the effect of a new ICU design on the incidence of VRE. Methods: The SICU relocated to a new unit in August 1997. Prior to, and during the evaluation period, rectal swabs for VRE were obtained on all patients upon admission to the SICU, weekly, and at SICU discharge. All colonized patients were placed on contact isolation. After March 1998 routine surveillance for VRE colonization was discontinued. VRE colonization rates for a 6 month period (Oct 97 to Mar 98) in the new SICU were compared to an equivalent time period (Oct 96 to Mar 97) in the old SICU. The colonization rates were compared using a z-test. Infection control measures implemented in 1995 were constant throughout the study period. In addition to increasing square footage, sinks were strategically located in the new ICU to optimize hand washing and each room had its own waste disposal system rather than a single system in the dirty utility room. The table below lists some major differences between the ICUs: Total Size(sq ft) Room Size (sq ft) Sinks Isolation Rms # of Rms Old SICU 4414 120-145 7 None 8 New SICU 7700 220-250 25 4 12 Results: The rate of VRE colonization decreased from 6.6 cases per 1000 patient days in the old SICU to 1.7 cases per 1000 patient in the new SICU (p = 0.025). Conclusions: Unit structure and design, including private rooms and increased accessibility of handwashing facilities, can make a significant difference controlling the spread of multiple resistant organisms.