Stop Sepsis - start with Best Practices in blood culturing.

B esides volume and number of

blood culture sets, timing of blood cultures

also plays an important role in detecting

significant bacteremia. Many physicians’

orders for blood cultures often specify that

blood specimens be collected at or around

the time of a temperature elevation,

presumably as a means of enhancing the

likehood of detecting significant

bacteremia. Experimental data have shown

that an influx of bacteria into the

bloodstream is followed by a lag of

approximately one hour before chills and

fever develop.1

Routinely it’s a common and

conventional practice to obtain blood

specimens at or around the time of a

temperature elevation as a means of

enhancing the likehood of documenting

bacteremia. This practice is based on the

principle that the presence of organisms in

the intravascular space leads to the

elaboration of cytokines, which in turn

causes body temperatures to rise.2

Figure 1 below shows the relation

between bacteremia level, temperature

and timing of blood culture collection.

Newsletter

Best Practices in Blood Culture Collection

March 2013 03/2013

Timing of Blood Culture Collection

Figure 1: Relation between bacteremia level, temperature and blood culture collection.

I t’s also highly recommended to

obtain blood cultures before administration

of antibiotic. For these reasons, the clinical

status of the patient should be the primary

guide to the timing of blood cultures. In

urgent situations where prompt

administration of antimicrobial therapy is

mandated, blood cultures should be obtained

simultaneously or over a short time frame

(e.g. less than 1 hour). In less urgent

situations in which patient is relatively

stable, drawing blood at spaced intervals,

such as 1 to 2 hours apart, may be indicated.

This is helpful for clinicians whom wishes to

document continuous bacteremia in patients

with suspected endovascular infections or

other endovascular (e.g., catheter-related)

bacteremia.3

See below a table adapted from

Cumitech 1C (Cumulative Techniques and

Procedures in Clinical Microbiology)

Blood Cultures IV (page 5)3 which shows

the recommendations for the timing of blood

cultures.

In summary, timing of blood cultures

is very much dependent on the patient’s

clinical status. It is BEST to collect blood

cultures as close as possible to chill and fever

and when collecting multiple blood culture

sets, simultaneous collection (or over a short

timeframe) is recommended.

Timing of Blood Culture Collection

Towards-Better-Lives

BMS DIAGNOSTICS (M) SDN BHD (485573-V) 19, Jalan 4/62A, Bandar Menjalara, Kepong, 52200 Kuala Lumpur, Malaysia. Website: www.bmsd.com.my Email: info@bmsd.com.my Tel: +603- 6272 0236 Fax: +603- 6277 0750

This table above taken directly from Cumitech 1C: Blood Cultures IV

References:

1. Principles and Procedures for Blood Cultures; Approved Guideline M47-A

2. Timing of Specimen Collection for Blood Cultures from Febrile Patients with Bacteremia, Riedel et al,

JCM 2008 : 1381 – 1385

3. Cumulative Techniques and Procedures in Clinical Microbiology (CUMITECH) 1C, Blood Culture IV