Hematoma
A collection/pouch of blood, under the skin, which escaped from a vessel into a space or tissue. May be caused by blood escaping out from the “hole” made by the needle.
Preventing Hematomas
- do not tie tourniquet too close to the veni site (8-10 cm above)
- only use major veins (not superficial surface veins)
- only puncture uppermost wall of vein & ensure needle fully penetrates this wall (partial penetration may allow blood to leak into soft tissue surrounding vein)
- apply direct pressure to stop bleeding
Bruise
An escape of blood into the tissues in a shallow area under the skin. Usually oval or round, blood will diffuse through the layers of tissue.
Hemolysis
The rupture of erythrocytes with the release of the cell contents into the plasma.
Diseases that may cause IN VIVO hemolysis
Hemolytic anemia, some liver diseases, hemolytic transfusion reactions, & severe trauma.
Causes of IN VITRO hemolysis during blood collection
- using too small a needle to the amount of vacuum in tube
- shaking the tube/not filling the tube completely
- taking blood from a hematoma
- probing/traumatic venipuncture
- incorrect ratio of blood to anticoagulant
Possible Complications When Performing Venipunctues
- dizziness
- fainting (loses consciousness)
- nausea
- vomitting
- seizures
Petechiae
Small red spots on patient’s skin indicating small amounts of blood have escaped the blood vessels. May be caused by platelet defects (patient may bleed excessively) or by the tourniquet.
An obese patient’s veins may be more difficult to feel…
- tie tourniquet tighter
- use a warm towel
- do not go in blindly
- microcollection may be an option
Avoid b/c sites are hard to penetrate & test results will be erroneous
- sclerosed (hardened) veins
- thrombosed (clotted) or scarred veins
- infections
- burns
Hemoconcentration
When plasma filters out of blood & into tissues causing an increase in concentration of larger molecules & formed elements.
- prolonged tourniquet application
- squeezing or probing a site
- long term IV therapy
- sclerosed veins
- pumping fist before blood collection
Basal State
The resting metabolic state of the body early in the morning after fasting for a minimum of 12 hours (ideal state for obtaining the best test results).
Factors that Influence the Basal State I
- exercise (pH, PCO2, Ck, LDH, glucose)
- diet (excessive fluid intake decreases Hgb levels & alters electrolyte balance)
- diurnal/nocturnal variations (time of day - FSH, cortisol, Fe)
- posture (plasma aldosterone, renin, protein, K)
- emotional stress (fear, anxiety, trauma may cause elevations in WBCs; stress can decrease serum iron & increase cortisol)
Factors that Influence the Basal State II
- age & gender (RBC, WBC, CrCl)
- geographic location (oxygen levels decrease at higher altitudes –> body produces more RBCs to compensate; RBC counts have higher normal ranges at higher elevations)
- drug levels
- smoking
- fever, jaundice
- pregnancy
Fasting State
Occurs when there is abstention from food (includes candies, gum, & fluids other than water)
Fasting Period
length of fast varies:
a) specific test ordered
cholesterol: 12-14 hour fast & glucose: 8-10 hour fast
b) purpose of test ordered
Fistula vs. Shunt
Surgical passage between an artery & a vein, medical team can then attach a dialysis unit (must develop for 4-6 weeks after surgery before it can be used for dialysis).
vs.
A plastic tube connecting the vein to the artery, also for dialysis.
IV’s
- do not take blood if there is an IV running in patient’s arm (erroneous test results) –> choose alternate site
- ask nurse to stop IV (min. 2 min) & collect BELOW the IV site, NEVER ABOVE
Avoid collecting from alternate sites:
Poor circulation & prone to infection:
- diabetics
- coronary insufficiency
Unconscious/Unresponsive Patients
- make sure nurse identifies patient
- ask nurse to hold patient’s arm (pain reflex)
- communicate with patient (may still be able to hear)
Psychiatric Patients
- check with nurse
- leave your tray at nurse’s station (only bring necessary equipment)
- do not attempt to take blood or calm violent patients by yourself
