Test Includes

Culture for aerobic and anaerobic bacteria
If systemic fungal or Mycobacterial infection is suspected, please contact the Microbiology Department (ext. 3557) for advice

Request Form 

Microbiology form (Green)

Availability

On request BUT only take blood for culture when there is a clinical need to do so and not as routine. Blood cultures are taken to identify patients with bacteraemia. There are many signs and symptoms in a patient which may suggest bacteraemia and clinical judgement is required, but the following indicators should be taken into account when assessing a patient for signs of bacteraemia or sepsis:  core temperature out of normal range; focal signs of infection;  tachycardia, hypotension or respiratory rate (raised); chills or rigors; raised or very low white blood cell count; and new or worsening confusion. NB: Signs of sepsis may be minimal or absent in the very young and the elderly. Blood cultures should be taken after identification of possible bacteraemia or sepsis and before the administration of antibiotics. If a patient is on antibiotics, blood cultures should ideally be taken immediately before the next dose, with the exception of paediatric patients. All blood cultures should be documented in the patient’s notes, including date, time, site and indications.

Specific Criteria

Please give detailed clinical information, including date of onset/contact with the suspected infection, including any current, or intended, antibiotic therapy

Patient Preparation

It is vital that an aseptic technique is used when collecting blood cultures. Always make a fresh stab In patients with suspected bacteraemia, it is generally recommended that two sets of cultures be taken at separate times from separate sites. Do not use existing peripheral lines/cannulae or sites immediately above peripheral lines. (If a central line is present, blood may be taken from this and from a separate peripheral site when investigating potential infection related to the central line; the peripheral vein sample should be collected first.) Identify a suitable venepuncture site before disinfecting the skin. Avoid femoral vein puncture because of the difficulty in adequate skin cleansing and disinfection.

ENDOCARDITIS: If endocarditis [SBE] is suspected, it is STRONGLY recommended that a minimum of 3 sets of blood cultures be taken before antibiotic therapy is commenced. Each set must be taken at different times from different sites and sent to the laboratory with a separate request form for each set stating the date, time and site of collection.

Step one: Kit preparation Label bottles with appropriate patient information. Ensure that barcodes on the bottles are not covered by additional labels and that any tear-off barcode labels are not removed. Please note: The rubber seals on blood culture bottles are NOT sterile and MUST be cleaned before inoculating the bottles. Clean the tops of culture bottles with a 70% isopropyl alcohol impregnated swab and allow to dry.
Step two: Skin preparation - Wash your hands with soap and water then dry. Clean any visibly soiled skin on the patient with soap and water then dry. Apply a disposable tourniquet (if applicable) and palpate to identify vein. Clean skin with a 70% isopropyl alcohol impregnated swab and allow to dry. If a culture is being collected from a central venous catheter, disinfect the access port with a 70% isopropyl alcohol impregnated swab. Once disinfected, don’t touch the skin again To avoid cross-contamination from the collector’s fingers (even when gloved), it is vitally important not to palpate the site again once it has been disinfected
Step Three: Sample collection – use method as outlined below
WINGED BLOOD COLLECTION METHOD - Wash and dry your hands again or use alcohol hand rub and apply clean examination gloves (sterile gloves are not necessary). Attach winged blood collection set to blood collection adapter cap. Insert needle into prepared site. Do not palpate again after cleaning. Place adapter cap over blood collection bottle and pierce septum. Hold bottle upright and use bottle graduation lines to accurately gauge sample volume and collect sample. If blood is being collected for other tests, always collect the blood culture first. Cover the puncture site with an appropriate dressing. Discard winged blood collection set in a sharps container. Wash hands after removing gloves. Record the procedure with indication for culture, time, site of venepuncture and any complications in the patient’s record

Turnaround Time

Cultures are incubated for up to 5 days (10 days if sub-acute bacterial endocarditis [SBE] is suspected) before reporting as negative

Specimen

Whole blood

Volume

ADULT ROUTINE: A routine blood culture set consists of two bottles: aerobic - blue top and anaerobic - purple top

Each bottle should be inoculated with 5-10 ml of blood

It is imperative that no more than 10 ml of blood is introduced into each bottle 

PAEDIATRIC ROUTINE: A single bottle (yellow top) set is used, requiring the inoculation of up to 4 ml of blood

ENDOCARDITIS: If endocarditis [SBE] is suspected, it is STRONGLY recommended that a minimum of 3 sets of blood cultures be taken before antibiotic therapy is commenced

Each set must be  taken at different times from different sites and sent to the laboratory with a separate request form for each set stating the date, time and site of collection

Container

Blood culture bottles

Collection

Samples should be transported to laboratory immediately.  Outside normal working hours the culture bottles must be sent to the Pathology Laboratory, Basildon Hospital and marked "please place in the pathology incubator"

Lab. Handling

Incubate on arrival

Causes for Rejection

Unlabelled sample

Results Reporting

All positive results will be telephoned and all results are also available on the results reporting system