lesson 7 - capillary puncture equipment and procedure

• capillary puncture or skin puncture -  a method that uses a lancet to make a small incision into the capillary bed of the skin to obtain small volume of blood specimen
• equipment used for capillary collection:

  1. lancet/incision lancets
  2. laser lancet
  3. microcollection container
  4. microhematocrit tubes and sealants
  5. microscope slides
  6. warming devices
  7. capillary blood gas (CBG) equipment
• lancet/incision devices - sterile, sharp instruments that are intended forone-time use only. They are designed for use in making cuts in the skin forfinger or heel puncture.
• Laser lancet - this type of lancet produces a small hole in the skin by vaporizing water in the skin; there are two types: finger puncture lancetand heel puncture lancet
• Micro collection container - also known as microtube, this is a small plastic tube used to hold blood speciments collected in the capillary puncture
• Microhematocrit tubes and sealants - narrow bore tubes made ofeither plastic or glass typically used for hematocrit determinations
• Microscope slides - these are used for blood films for hematology determinations
• Warming devices - used to increase the blood flow seven-fold by warming the puncture site.
• Capillary blood gas (CBG) equipment - special equipment for collecting CBG; contains CBG collection tubes, stirrers, magnet, and plastic caps.

   
• capillary blood specimen - is a mixture of different blood and fluids
• capillary blood specimen includes:

  • arterial blood
  • venous blood
  • capillary blood
  • interstitial fluid
  • intracellular fluid
• arterial blood - Bright red blood (oxygenated) . found in the pulmonary vein, left chamber of the heart, and arteries 
• Venous blood - Blood that travels from the peripheral veins passing through the venous . Dark red (deoxygenated) 
• Capillary blood - Preferred specimen for infants, young children, elderly, and patients with severe burns. Extracted from venules and arterioles found in the capillary bed 
• Interstitial fluid - Fills the spaces around the cells. Filtered from the blood capillaries. Drained away as lymph  
• Intracellular fluid - Found inside the cells. Facilitates the movement of fluid in the membrane and blocks the entrance of unwanted materials 
• capillary reference values - may vary from the venous values
• The concentration of the glucose in the blood is higher while the total protein (TP), calcium, and potassium concentrations are lower