process of accessing intravenous flow for the purpose of therapy or obtaining venous blood for sampling
Patient to make a fist, but not pump hands:
make a fist for veins to be more prominent
not pumping to prevent hemoconcentration
Tourniquet:
makes vein easier to feel or palpate
3-4 inchesabove intended puncture site
must notbeapplied more than 1 minute
the patient should be either lying down or sitting in a special phlebotomy chair
phlebotomy chair
has a movable arm support that helps in positioning the patient's arm
Never attempt phlebotomy when a patient is standing
If only armless chair is available, place patient arm on the his or her thigh for proper support
Supine position is the most common phlebotomy position in inpatient in hospital beds
H pattern
~70% of the population
median cubital vein
near center
cephalic vein
lateral aspect of the af
basilic vein
medial aspect of the af
m pattern
forms when cephalic and basilic veins divide into two branches forming v-shape
median vein
at the very center of the pattern
median cephalic vein
branches from the median vein to the lateral aspect of the arm
median basilic vein
branches from the median vein to the medial aspect of the arm
tourniquet application
position the tourniquet under the arm while grasping the ends above the arm and venipuncture area. the tourniquet should bet 3-4 inchesabove the site.
cross the left and over the right end and apply a small amount of tension to the tourniquet.
using the right middle finger or index finger, tuck the left and under the right end.
a loose end of the tourniquet will be pointing toward the shoulder and the loop will be pointed toward the hand.
palpating the venipuncture site
Determine size, depth, and direction of the vein
Palpate using the tip of the index finger
Select vein that is large, and does not roll from side-to-side or move easily
An appropriate vein for venipuncture will bounce and have resilience to it
Avoid veins that exhibit sclerosis, or feels hard and cordlike
petechiae
small, nonraised redspots in the skin due to a minute hemorrhage, can result if tourniquet is left on toolong
choking precautions
patients should not be drinking, eating, or chewing gum during phlebotomy
hematoma
mass of blood caused by leakage of blood into the tissues (tourniquet is left too long, or left after needle is taken out; bevel went through and through the vein)
hemoconcentration
rapid increase in the ration of blood components to plasma
specimen considerations: Avoid the following sites for venipuncture:
edematous or full of swelling, iv site, mastectomy site (lyphostasis)
Special considerations for various population groups:
children, geriatric, patients with hiv or hepatitis, psychiatric patients