A critical care nurse is tasked with obtaining a blood specimen for a complete blood count (CBC) from a client's multi-lumen central venous catheter (CVC). A continuous infusion of total parenteral nutrition (TPN) is currently infusing through the medial lumen. Place the following steps for obtaining the blood sample in the correct sequential order. (Arrange the steps from first to last).
- 1Pause the continuous total parenteral nutrition (TPN) infusion running through the medial lumen.
- 2Scrub the needleless connector of the selected lumen with an antiseptic swab.
- 3Flush the selected lumen with 10 mL of 0.9% sodium chloride.
- 4Aspirate and discard 5 mL of blood from the catheter.
- 5Withdraw the required volume of blood into a new syringe for the laboratory specimen.
- 6Flush the catheter lumen with 20 mL of 0.9% sodium chloride using a pulsatile technique.
Answer
The correct sequence is: Pause the TPN, scrub the connector, flush with 10 mL of normal saline, discard the first 5 mL of blood, withdraw the sample, and finally flush with 20 mL of normal saline.
When obtaining blood from a CVC, the nurse must first pause any active infusions to avoid sample contamination. Aseptic technique is initiated by scrubbing the hub. A 10 mL normal saline flush confirms patency and clears the line. The discard method (removing 4 to 5 mL of blood) ensures the subsequent sample is undiluted. Finally, a larger volume flush (10 to 20 mL) using a push-pause technique clears the line of blood, reducing the risk of thrombosis.
Step-by-Step Solution
Key Concept
The discard method is the standard of practice for obtaining blood samples from a central venous catheter to ensure accurate laboratory results and maintain catheter patency.