Of the cases of VRE bacteremia in the current study, 38% were due to documented catheter-related infections, and in the remaining 62% the catheter tip was not cultured, suggesting that the rate of catheter-related VRE bacteremias could have been higher. Beezhold et al demonstrated that VRE could colonize the inguinal and antecubital skin in 86% of patients with VRE bacteremia, suggesting that VRE may be an important cause of catheter-related bacteremia in hospitalized patients. In addition, Bassetti et al demonstrated a correlation between zones of inhibition and the in vivo efficacy of AICs. Since most of the VRE isolates in our unit prior to the introduction of the AICs were susceptible to either minocycline or rifampin, and since the AICs had zones of inhibition against most of the VRE isolates, it is possible that the AIC significantly decreased the risk of catheter-related VRE bacteremia in our ICUs, resulting in a significant decrease in this type of infection.
Several investigators have demonstrated that the use of the AIC in the ICU was associated with a significant decrease in the cost of medical care through the prevention of CR-BSIs. Pittet et al estimated the extra cost of a single episode of nosocomial BSI to be $40,890 (in 1994 dollars). This could be converted to $44,864 per nosocomial BSI in 1999. The introduction of AICs into our adult ICU resulted in the prevention of at least 33 episodes of nosocomial BSI. This resulted in a cost saving of $1,480,512 for FY 1999. The added cost related to the AIC is $46 per catheter, which would result in a total of $21,528 for the purchase of the 468 AICs used in FY 1999. The net savings for FY 1999 would have been $1,458,984. However, it should be noted that this cost saving estimation did not differentiate between primary BSIs and CR-BSIs.
In conclusion, the introduction of AICs to the adult MICU and SICU was associated with a significant decrease in nosocomial primary Gram-positive and Gram-negative bacteremia. This reduction of nosocomial bacteremia was associated with a significant decrease in catheter-related infections and cases of nosocomial multidrug-resistant VRE bacteremia, as well as a significant decrease in the length of hospital and ICU stay. This significant decrease in nosocomial BSIs resulted in a net savings of at least $1,450,000 during FY 1999.