Handling and Bacteriologic Work-up of Blood Components
Below are recommendations that have been proposed by the BaCon Study Group for handling and bacteriologic work-up of blood components suspected to be bacterially contaminated. However, in addition to these recommendations, personnel are urged, as always, to follow standard operating procedures for their institution.
A blood component bag suspected of being bacterially contaminated should be handled in an aseptic manner. The first priority is to create a closed system by sealing the transfusion tubing. Options for sealing include heat seal, clamping, or if these are not available, placement of a tight slip knot in the tubing, (i.e., tighten until the tubing in the knot is a white color). The bag should be refrigerated as soon as possible until bacteriologic testing can be performed.
Use a sampling site coupler (e.g., Fenwal [Baxter Healthcare*]) to obtain a sample for culture. On the blood component bag there should be a number of outlet ports. Aseptically remove the plastic sheath over the spike from the coupler, and with a twisting motion, insert the spike completely into one of the outlet ports of the blood bag. Disinfect the rubber septum on the surface of the sampling site and use a syringe and needle (using a needle gauge sufficiently large enough to allow easy drawback of blood product into the syringe) to remove a sample from the blood component bag. Do not remove the sampling site coupler from the unit once it is in place.
*Use of trade names and commercial sources is for identification only and does not imply endorsement by the Public Health Service or the Department of Health and Human Services.
In instances where the whole component has been administered, the empty unit can be cultured using the following procedure.
- Attach a sampling site coupler and disinfect as described above.
- Using 0.9% sodium chloride for irrigation, (USP grade; non bacteriostatic) aseptically inject 20 ml of sterile saline into the unit through the sampling site coupler.
- Rotate the bag so that the saline comes into contact with all the interior surfaces of the unit and withdraw as much of the saline from the unit as possible.
- A sample can then be obtained from the unit for culture as described above.
After being obtained, the blood product sample should be inoculated directly into blood culture bottles for qualitative culture; it is also recommended that, if possible, samples be serially inoculated into dilution blanks (e.g., undiluted, 1:10 , 1:1,000, 1:100,000) of sterile 0.9% saline so that spread plate (e.g., chocolate agar) quantitative cultures can be performed. Dilution methods are preferred for quantitative culture, but if they are not available, then semi-quantitative methods may be used.
Plates and cultures should be incubated at 35-37°C. Colony counts should be performed at 48 hours; if the organism is suspected to be psychrophilic, e.g., Yersinia enterocolitica, (and may not grow well at standard incubation temperatures), the cultures should be incubated for an additional 72 hours at ambient room temperature. Gram staining also can be done but the sample should be cultured regardless of the direct Gram stain result.