Taking a blood culture involves taking blood in an aseptic technique for the purposes of checking for bacteria of fungi in the patient's blood (septicaemia) . This is often an important aspect of doing a septic screen on a patient that is pyrexial. The procedure shown below is only a reference and please refer to local policies as your guide.
If the patient has a central, arterial or femoral line in – best to take one set of cultures from the line and also to do peripheral cultures as well.
It can take a few days for cultures to grow an organism and a further 24‐48 hours to determine antibiotic sensitivities.
Wash your hands using the Ayliffe technique
Introduce yourself and give your name and grade
“Hi, my name is Teddy Daniels and I am a 4th year medical student”
Explain what examination you are performing and what this involves
“Today I will be taking some blood from your arm, it shouldn’t be very painful but may feel like a sharp scratch”
“Would this be okay with you?”
Blood culture bottles ( anaerobic and aerobic)
3x chlorhexadine wipes
Sterile Gloves + apron
Green needle (21G) and syringe 20mls / vacutainer system
Let the patient know you have finished examining them and thank them for their time.
“That’s the end of the procedure. Thank you for your time.”
Label bloods at bed side – including the site of the blood cultures were taken from. Also some blood culture packs contain stickers to sign and put in the notes.
Once you have cleaned the skin, do not re-palpate the skin as this increase contamination rates
If the patient has a central line – clean the ports with chlorexadine wipes and discard the first 10mls of blood. Remember to flush with 10 ml saline and place new ports.
Insufficient blood in the bottles could lead to false negative results.
Do not change needles after obtaining the blood as this increases the risk of needlestick injuries
Fill the aerobic bottle first as the needle is initially filled with air, and that air will be drawn into the tube along with the blood.
Choose another vein, or switch arms if struggling.
Consider look for veins in the feet or legs – warn the patient it’s more painful.
Best to get senior help if unsuccessful after 2-3 attempts.
Consider a femoral stab if you are unable to get blood from peripheral veins