How to Determine Packed Cell Volume

Packed cell volume, or hematocrit, reflects the volume of red blood cells in a given volume of blood. The red blood cells are separated from the blood sample via centrifugation, measured, and reported as a percentage of the original blood sample. Results show the average amount of circulating red blood cells, which is useful in monitoring conditions such as anemia, bleeding, dehydration and leukemia. Average hematocrit amounts vary from male to female, but are within the same range of 40 percent to 50 percent. Usually part of a CBC, or complete blood count, a hematocrit is only performed by licensed and trained health care practitioners, usually lab technicians and depending on the methodology, may be referred to as a microhematocrit.

Things You'll Need

• Absorbent paper and/or wipes
• Gloves
• Venous or capillary blood sample
• Anti-coagulated capillary tubes
• Sealing clay block
• Centrifuge
• Reading device

Show More

Instructions

Preparation

• 1

  Cover work area with absorbent paper, securing edges if necessary.

• 2

  Organize capillary tubes and absorbent wipes for easy reach. Place rack containing blood specimen on work area.

• 3

  Put on gloves.

Filling the Tube

• 4

  Open lid on blood specimen tube.

• 5

  Insert capillary tube tip into the top portion of the blood specimen. Fill capillary tube to approximately 3/4 full, using capillary action.

• 6

  Place the dry end of the capillary tube into the sealing clay at a 90 degree angle.

Centrifugation

• 7

  Remove capillary tube from sealing clay.

• 8

  Place capillary tube into the centrifuge, sealed end out. Close top of centrifuge, tightening cover.

• 9

  Centrifuge for five minutes at 10,000 to 15,000 rpm.

• 10

  Remove capillary tube from centrifuge and take to reading device.

Determining Result

• 11

  Place capillary tube on reader, positioning so the bottom of the tube containing the red cells is within the measuring area.

• 12

  Measure packed red cells against numbers or chart on the reader.

• 13

  Report percentage, rounded to the nearest whole number.