Examkin

Question

Difficulty: MediumPharmacological and Parenteral Therapies

A registered nurse is preparing to collect a routine laboratory blood specimen from a client's multi-lumen central venous catheter (CVC). Arrange the steps for this procedure in the correct chronological order from first to last.

  1. 1Pause any active continuous intravenous infusions and wait at least 1 minute.
  2. 2Scrub the needleless connector and flush the selected lumen with 0.9% sodium chloride.
  3. 3Aspirate and discard an initial waste sample of blood from the catheter.
  4. 4Withdraw the required blood volume for the laboratory specimens.
  5. 5Flush the lumen thoroughly with 10 to 20 mL of 0.9% sodium chloride.

Answer

The correct sequence is: pause active infusions, flush the line to verify patency, discard a waste sample of blood, collect the required specimen, and perform a final thorough flush.
Obtaining blood from a central venous catheter requires a strict sequence to ensure accurate laboratory results and maintain line patency. Infusions must be stopped first to prevent sample contamination. The line is then flushed to confirm patency. A waste sample must be discarded to clear the line's dead space of flush solution. After the true sample is collected, a vigorous final flush is mandatory to clear all blood from the lumen and prevent catheter clotting.

Step-by-Step Solution

1
Pause continuous IV infusions.
Prevents medication or fluids from mixing with the blood sample.
Drawing blood while fluids are actively infusing will yield falsely elevated or altered laboratory results corresponding to the infused substances.
2
Clean the hub and flush with normal saline.
Ensures catheter patency.
Confirming the line is open and functioning prevents complications during the blood draw process and maintains sterility.
3
Draw and discard a waste blood sample.
Removes the saline flush and any residual medication from the catheter.
The 'dead space' in the catheter contains fluid that would dilute or alter the laboratory specimen if not discarded first.
4
Collect the blood specimen.
Obtains pure, undiluted blood for testing.
This sample accurately reflects the client's true systemic blood values.
5
Perform a final flush with 10 to 20 mL of normal saline.
Clears all blood from the catheter lumen.
Blood left sitting in the catheter can quickly clot, leading to partial or complete occlusion of the central line.

Key Concept

Central Venous Catheter Blood Specimen Collection
Rate this question

Topics

Pharmacological and Parenteral Therapies

More questions from this topic