ESR – Sources of Error - 1
Increased amount of anticoagulant:
Decreased
ESR
Sodium or
potassium oxalate used as anticoagulant:
Causes
RBCs to shrink resulting in elevated ESR
ESR
increased as cells slide down side of tube
Cells
swell inhibiting rouleaux thus decreasing ESR
Tube tilted
more than 2% from vertical:
Specimen old
(>4 hrs @ RT or > 12hrs @refrig temp:
Bubbles in
tube:
Test
result invalid