Reducing dialysis associated bacteraemia, and recommendations for surveillance in the United Kingdom: prospective study

Editor – In support of George et al(1) we too believe that dialysis
associated bacteraemia is a significant contributor to morbidity,
mortality and antibiotic usage. We have undertaken formal line infection
surveillance by recording episodes of line infection and bacteraemia for
the last three years and regularly perform clinical audit and review of
practice.

George et al present a decline in the rate of dialysis associated
bacteraemia using two quarters (June to September 2002 and September to
December 2004). The data bears closer scrutiny.

Our own data shows a seasonal variation in dialysis related
bacteraemia with bacteraemia rates for any given year being consistently
higher in the June to September quarter and significantly different to the
September to December quarter of the same year. In George et al’s study
the crude rate for access related bacteraemia would appear to have almost
halved however it would be interesting to know whether the results are
less impressive if shown comparing June to September 2002 with the same
period in 2004.

In our unit the dialysis associated bacteraemia rate was 6.75 per 100
patient months in June to September 2003 and 2.41 per 100 patient months
in the subsequent quarter (Chi square test p<0.01). In June to
September 2005 the bacteraemia rate was also 2.41 per 100 patient months
and the rate in the subsequent quarter was 1.71. Seasonal variation in
dialysis related bacteraemia could be presented as showing a large
reduction between June to September 2003 and September to December 2005
(6.75 per 100 patient months to 1.71 per 100 patient months) or a small
reduction between June to September 2003 and June to September 2005 (2.41
per 100 patient months to 1.71 per 100 patient months), without any overt
change in clinical practice except an increased use of thrombolytic agents
to preserve line patency (Alteplase).

Seasonal variations in bacteraemia rate could be expected to
translate in to seasonal variations in the rates of admission to hospital
and rates of antibiotic usage. A longer period of observation with a
sustained reduction in bacteraemia rates is required across several
quarters to confirm the results of George’s intervention.

The authors raise two important points. Firstly that there are likely
to be significantly higher rates of bacteraemia related mortality,
morbidity and cost in units employing a high proportion of semi permanent
dialysis catheters. Secondly that there is no standardized method of
surveillance in the United Kingdom and to this end it is unfortunate that
there is not, as yet, a Renal Association Standard(2) for haemodialysis
related bacteraemia as there is for peritoneal dialysis related infection.

References:

1. George A et al Reducing dialysis associated bacteraemia, and
recommendations for surveillance in the United Kingdom: prospective study.
BMJ 332:1435

2. The Renal Association: Treatment of adults and children with renal
failure. Standards and audit measures. 3rd Edition (2002). Royal College
of Physicians.

Competing interests:
None declared