For cartridge testing of blood gases, electrolytes, chemistries, and hematocrits, draw the patient’s blood as described below.

Blood Draw

Completely fill a plain syringe, blood gas heparinized syringe (in the CCATT allowance standard), or a syringe with the minimum volume of heparin to prevent clotting (10 U/mL of blood). Mix a heparinized syringe by rolling it between the palms for at least 5 seconds in two directions, then invert the syringe repeatedly for at least 5 seconds. For best results, test the blood immediately. For samples measuring pH, PCO2, PO2, TCO2, and ionized calcium, sample processing within 10 minutes of blood draw is acceptable; other analytes can be processed within 30 minutes of blood draw if a heparinized syringe was used. If a tourniquet is used for a venous stick, do not leave it on for more than 1 minute; do not draw blood proximal to an IV site.

Criteria for Specimen Rejection

  1.  There is evidence of specimen 
  2. Specimens were collected in vacuum tubes with anticoagulants other than lithium or sodium
  3. Syringe for pH, PCO2, PO2, or TCO2 has air bubbles in An air bubble stuck only on the plunger will not affect the results.

 Precautions: Avoid the Following Circumstances

 Cartridge Preparation for Loading Blood Sample