Risk Factors Associated with Hemolysis of a Blood Specimen

Cause

Rationale

Solution

contamination of sample with alcohol or other skin preparation solution

some disinfectants act by disrupting membranes

let skin preparation solutions dry first

bacterial contamination

usually from skin contaminants

clean skin carefully, transport immediately and refrigerate

traumatic venipuncture of fragile veins

difficult collections result in turbulence and clotting

handle small, fragile blood vessels with care

aspiration of hematoma or extravasated blood

blood already breaking down

avoid these areas

phlebotomy needle too small or too large

usually in combination with too much pressure or vacuum

match the needle, patient and vein size

sample collected through IV tubing and catheters

multiple connections allow for pressure gradients

minimize distance between vein and collection container; draw slowly to keep vacuum low

hypotonic infusion solution

osmotic rupture of red blood cells

do not collect blood from IV lines running hypotonic solutions

excess chemical preservative

underfilled tubes results in excess preservative

fill tubes completely

blood clots during collection

combination of taking too much time with too much turbulence

if blood clots perform a new venipuncture; mix blood with anticoagulant; transfer blood from syringe to tubes immediately

excess pressure when emptying a syringe

excessive turbulence can shear red blood cells

do not force the plunger

excessive vacuum (needle too large, too much suction on syringe)

excessive turbulence can shear red blood cells

avoid large needles, do not use large syringes, and limit the amount of suction applied

loose connection between needle and collecting container

air may be drawn into sample, causing bubbles

make sure all connections are tight

shaking or agitating tubes

generate bubbles and create turbulence

do not shake or agitate tubes excessively

specimen allowed to freeze or overheat during transport

extremes of temperature can disrupt red blood cell membranes

do not specimen freeze or become exposed to heat