If a dialysis patient has a cannula inserted, this should be your primary site for draws.

• A. True
• B. Sometimes
• C. False
• D. Only if cannula is functioning

Answer: (C)

Don’t use a dialysis cannula as the primary site for routine blood draws. A cannula used for dialysis is a critical access point and drawing from it can dilute or contaminate the sample with saline or heparin and can interfere with dialysis and test accuracy. The safer, standard approach is to obtain the blood from a peripheral vein by venipuncture whenever possible. If a catheter-based draw is absolutely necessary, use the catheter’s designated sampling port and follow the facility’s protocol, not the main cannula lumen. That’s why the statement is false.