Testing Situations When Capillary Blood Collection is Not Appropriate

How to Subscribe
MLS & MLT Comprehensive CE Package
Includes 176 CE courses, most popular
$109Add to cart
Pick Your Courses
Up to 8 CE hours
$55Add to cart
Phlebotomy CE Package$59Add to cart
Individual course$25Add to cart
Need multiple seats for your university or lab? Get a quote
The page below is a sample from the LabCE course Pre-analytical Challenges Encountered with Capillary Blood Collection and Testing. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Pre-analytical Challenges Encountered with Capillary Blood Collection and Testing (online CE course)
Testing Situations When Capillary Blood Collection is Not Appropriate

Capillary collection should not be performed on adult patients if adequate veins are available and the patient is willing to allow their use. Also, capillary collection should be avoided if the patient is dehydrated, has edema, or presents with poor circulation to the extremities. Blood collected from an edematous (swollen) site will be contaminated with tissue fluid. Dehydration and poor circulation would also interfere with capillary blood flow, and patients presenting with one of these conditions would not be good candidates for capillary blood collection.
Certain tests cannot be performed on capillary blood due to the large volume they require or the possibility of contamination. These include the following:
  • Westergren erythrocyte sedimentation rate (ESR) test due to large blood volume required.
  • Coagulation studies that require large plasma specimens due to contamination with interstitial fluid, which promotes clotting.
  • Blood cultures, due to the large volume of blood required and the possibility of skin flora contamination.