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Difficulty: HardPharmacological and Parenteral Therapies

A nurse is preparing to obtain a blood specimen for laboratory testing from a client's multi-lumen central venous catheter (CVC). The selected lumen currently has a continuous infusion of 0.9% sodium chloride. Arrange the following steps for obtaining the blood sample in the correct clinical sequence.

  1. 1Pause the continuous intravenous infusion.
  2. 2Scrub the needleless connector hub with an appropriate antiseptic.
  3. 3Attach a syringe and withdraw the initial blood sample to discard.
  4. 4Attach a new sterile syringe and withdraw the blood sample for the laboratory test.
  5. 5Flush the catheter lumen with sterile 0.9% sodium chloride.

Answer

The correct clinical sequence is to first pause the infusion, disinfect the hub, withdraw a discard sample, obtain the diagnostic blood sample, and finally flush the line to maintain patency.
Obtaining a blood specimen from a central venous catheter requires a strict sequence to ensure infection control and sample accuracy. The infusion must first be paused to prevent hemodilution. Next, the hub must be scrubbed with an antiseptic to prevent a central line-associated bloodstream infection (CLABSI). A discard volume of blood must then be withdrawn to clear the dead space of the catheter. After the discard, the diagnostic sample is drawn using a new syringe. Finally, the catheter must be flushed immediately with 0.9% sodium chloride to prevent blood from clotting within the lumen.

Step-by-Step Solution

1
Pause the continuous intravenous infusion.
The flow of IV fluid is halted.
Prevents hemodilution of the blood sample with the infusing saline, which would cause false laboratory values.
2
Scrub the needleless connector hub with an appropriate antiseptic.
The access point is disinfected.
Prevents the introduction of external pathogens into the central circulation, minimizing the risk of infection.
3
Attach a syringe and withdraw the initial blood sample to discard.
The catheter's dead space is cleared.
Removes residual IV fluids from the catheter lumen so the final sample reflects the client's actual circulating blood levels.
4
Attach a new sterile syringe and withdraw the blood sample for the laboratory test.
An unadulterated diagnostic sample is obtained.
Provides an accurate specimen for laboratory analysis.
5
Flush the catheter lumen with sterile 0.9% sodium chloride.
The catheter is cleared of whole blood.
Maintains catheter patency by preventing red blood cells from clotting within the lumen.

Key Concept

Central Venous Catheter (CVC) Blood Sampling Procedure
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Topics

Pharmacological and Parenteral Therapies

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