Blood Taking
This
is quite often tested in OSCEs using plastic arms. You get marks
for all the little things like washing your hands and putting on
gloves,
not actual technique. Nevertheless technique is very important as a
house officer as on some patients venepuncture can be very difficult!
Therefore we have provided some tips alongside the methods.
Need
Gloves, needle, syringe/vacutainer, tourniquet, alcohol swab,
blood sample tubes, cotton wool, tape, sharps bin
Method with Vacutainers:
-
Prepare the equipment.
-
Explain the procedure.
-
Place a towel under patent's arm
-
Palpate the vein. The antecubital fossa is usually the
best site
to start, if not then try more distal. Once found wipe with a alcohol
steret. It may be useful to leave the steret on the patient with a
corner pointing towards the vein if the vein is hard to see.
-
Put on gloves.
-
Apply a tourniquet
-
The skin is rendered tense with the other hand (prevents
vein
moving when needle enters)
-
Say, "sharp scratch"
-
Enter the vein with the needle at 15 degrees. You may feel
a
loss of resistance when in. Apply the blood tube to the vacutainer
system.
-
Remove the tourniqut then the needle.
-
Apply pressure to the needle site and tape on some cotton
wool.
Bottles
-
Purple: FBC, blood film, ESR
-
Orange (sometimes red with yellow rim): U+Es, CRP
-
Tall pink: Group and save/crossmatch
-
Blue: Clotting
Tips:
-
The
easiest site is the veins in the antecubital fossa. Other good sites
are the veins on the radial side of the arm at the wrist and on the
back of the hand. Note veins on the back of the hand are delicate and
are more likely to leave a nasty bruise.
-
Make the skin taught by straightening the arm (or wrist)
and by
using your other fingers to pull the skin flat. This helps prevent the
vein moving when you enter the skin.
-
Although
vacutainer is most likely to be tested in exams, taking with a needle
is often easier because you get a "flashback" when it enters the vein.
The advantage of vacutainer is that it is less likely to haemolyse.
-
Using
a blue (smaller) needle makes it easier to get in to small veins,
however the blood is more likely to haemolyse. Many people also find
"butterfly" needles easier to use than needles.
-
Using a smaller syringe makes the vein less likely to
collapse.
A 5mm syringe can fill two standard bottles of blood.
