Effect of antimicrobial locks for tunneled hemodialysis catheters on bloodstream infection and bacterial resistance: a quality improvement report.
BACKGROUND
Catheter-restricted antimicrobial lock (AML) use reduces catheter-associated bloodstream infection (CA-BSI) in clinical trial settings, but may not be as effective in clinical settings and may increase bacterial resistance.


METHODS
Quality improvement report analyzed using a cross-sectional time series (unbalanced panel) design.


METHODS
The study cohort comprised all prevalent adults treated with hemodialysis through a tunneled catheter for any, but not necessarily all, of the time from January 1, 2003, to June 30, 2006, in Manukau City, New Zealand (135,346 catheter-days, 404 tunneled catheters, 320 patients).


METHODS
Catheter-restricted AMLs (heparin plus gentamicin) for all tunneled catheters from July 1, 2004.


METHODS
Repeated observations of CA-BSI, hospitalization, tunneled catheter removal, and death from CA-BSI analyzed by using generalized estimating equations with a single level of clustering for each tunneled catheter and patterns of bacterial resistance analyzed by using simple descriptive statistics.


RESULTS
AML use was associated with reductions in rates of CA-BSI and hospitalization for CA-BSI by 52% and 69% for patients with tunneled catheters locked continuously with AMLs since their insertion compared with those with tunneled catheters that were not, respectively. AML exposure also was associated with a trend to increased gentamicin resistance amongst coagulase-negative staphylococci isolates, a pattern similar to that observed for BSIs in our general hemodialysis population in which tunneled catheters were not the source of BSI, but different from that in the general non-end-stage renal disease population in the region.


CONCLUSIONS
This is an uncontrolled observational study and cannot prove causality. The follow-up period of 18 months is longer than for other studies, but still too short to definitely answer whether AML use drives bacterial resistance.


CONCLUSIONS
A change to use of AMLs may improve clinical outcomes; however, additional study of associated bacterial resistance is needed before AML use becomes standard care.
Abbas
Saib A
SA
Department of Renal Medicine, Middlemore Hospital, Counties-Manukau District Health Board, Manukau, New Zealand.
Haloob
Imad A
IA
Taylor
Susan L
SL
Curry
Elizabeth M
EM
King
Bruce B
BB
Van der Merwe
Walter M
WM
Marshall
Mark R
MR
D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D055499:Catheter-Related Infections / Q000517:prevention & control*; D002408:Catheters, Indwelling; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D004867:Equipment Design; D005260:Female; D005839:Gentamicins / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D018805:Sepsis / Q000517:prevention & control*
D000900:Anti-Bacterial Agents; D005839:Gentamicins