Impact of a change in antibiotic prophylaxis on total antibiotic use in a surgical intensive care unit

OBJECTIVE

The aim of this study was to evaluate the impact of reducing the length of antibiotic prophylaxis for cerebro spinal shunts on total antibiotic use and key resistant pathogens.

METHODS

In January 2004, the use of antibiotic prophylaxis was reduced to a single shot dose with cefuroxime in an intensive care unit (ICU). Prior to this intervention, prophylaxis with second-generation cephalosporins was administered during the entire period of external cerebro spinal fluid (CSF) drainage. The effect on the antibiotic use density (AD: DDD [defined daily doses] per 1,000 patient-days[pd]) was calculated prior to (January 2002-December 2003) and following implementation of the intervention(January 2004-December 2006) by segmented regression analysis of an interrupted time series. Resistance proportions(RP) and resistance densities (RD), defined as resistant pathogen/1,000 pd of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis or E. faecium, third-generation-resistant (3GC) Escherichia coli and Klebsiella pneumoniae, and imipenem-resistant Pseudomonus aeruginosa, were compared by the Fisher's exact test before and after the intervention.

RESULTS

Total antibiotic use by 147 DDD/1,000 pd decreased after the intervention when pre-operative prophylaxis was changed into single shot prophylaxis, from an estimated mean of 1,036 DDD/1,000 pd before the intervention to 887DDD/1,000 pd post-intervention. This decrease was primarily due to a significant reduction in the amount of cefuroxime used for prophylaxis. The reduction in total antibiotic consumption was sustainable, and it did not increase again during the next 36 months. The RR and RD of third-generation cephalosporin-resistant E. coli increased after January 2004, whereas the percentage of MRSA significantly decreased.

CONCLUSION

Change to single shot prophylaxis along with an ongoing antibiotic stewardship program resulted in a cut-back in total antibiotic use amounting to as much as 15%. It would therefore appear that targeting interventions aimed at reducing antibiotic prophylaxis in surgical ICUs may be very worthwhile.

Regulation of actin assembly by SCAR/WAVE proteins

Actin reorganization is a tightly regulated process that co-ordinates complex cellular events, such as cell migration, chemotaxis, phagocytosis and adhesion, but the molecular mechanisms that underlie these processes are not well understood. SCAR (suppressor of cAMP receptor)/WAVE [WASP (Wiskott-Aldrich syndrome protein)-family verprolin homology protein] proteins are members of the conserved WASP family of cytoskeletal regulators, which play a critical role in actin dynamics by triggering Arp2/3 (actin-related protein 2/3)-dependent actin nucleation. SCAR/WAVEs are thought to be regulated by a pentameric complex which also contains Abi (Abl-interactor), Nap (Nck-associated protein), PIR121 (p53-inducible mRNA 121) and HSPC300 (haematopoietic stem progenitor cell 300), but the structural organization of the complex and the contribution of its individual components to the regulation of SCAR/WAVE function remain unclear. Additional features of SCAR/WAVE regulation are highlighted by the discovery of other interactors and distinct complexes. It is likely that the combinatorial assembly of different components of SCAR/WAVE complexes will prove to be vital for their roles at the centre of dynamic actin reorganization.