Obtaining an Arterial Blood Sample From an Arterial Line – Stopcock System

Goal: A specimen is obtained without compromise to the patency of the arterial line.

1. Gather all equipment and bring it to the bedside.

2. Perform hand hygiene.

3. Check the patient’s identification. Compare the specimen label with the patient’s identification. Explain the procedure to the patient. Close curtains around bed and close door to room if possible.

4. If bed is adjustable, raise it to a comfortable working height.

5. Perform hand hygiene and put on gloves and goggles.

6. Turn off or temporarily silence the arterial pressure alarms, depending on your facility’s policy (some facilities require that alarms be left on).

7. Locate the stopcock nearest the arterial line insertion site. Use the alcohol swab or chlorhexidine to scrub the sampling port on the stopcock. Allow to air dry.

8. Attach a 5-mL syringe into the sampling port on the stopcock to obtain the discard volume. Turn the stopcock off to the flush solution. Aspirate slowly until blood enters the syringe. Stop aspirating. Note the volume in the syringe, which is the dead-space volume. Continue to aspirate until the dead-space volume has been withdrawn a total of 3 times. For example, if the dead-space volume is 0.8 mL, aspirate 2.4 mL of blood.

9. Turn the stopcock to the halfway position between the flush solution and the sampling port to close the system in all directions.

10. Remove the discard syringe and dispose of appropriately.

11. Place the syringe for the laboratory sample or the Vacutainer in the sampling port of the stopcock. Turn the stopcock off to the flush solution, and slowly withdraw the required amount of blood. For each additional sample required, repeat this procedure. If the physician has ordered coagulation tests, obtain blood for this sample from the final syringe.

12. Turn the stopcock to the halfway position between the flush solution and the sampling port to close the system in all directions. Remove the syringe or Vacutainer. Apply the rubber cap to the ABG syringe hub, if necessary.

13. Insert a 5-mL syringe into the sampling port of the stopcock. Turn the stopcock off to the patient. Activate the in-line flushing device. Flush through the sampling port into the syringe to clear the stopcock and sampling port of any residual blood.

14. Turn off the stopcock to the sampling port; remove the syringe. Remove sampling port cap and replace with new sterile one. Intermittently flush the arterial catheter with the in-line flushing device until the tubing is clear of blood.

15. Reactivate the monitor alarms. Attach needles to the filled syringes and transfer the blood samples to the appropriate containers, if necessary. Record date and time the samples were obtained on the labels, as well as the required information to identify the person obtaining the samples. If ABG was collected, record oxygen flow rate (or room air) on label. Apply labels to the specimens, according to facility policy. Place in biohazard bags; place ABG sample in bag with ice.

16. Check the monitor for return of the arterial waveform and pressure reading.

17. Return the patient to a comfortable position. Lower bed height and adjust head of bed to a comfortable position.

18. Remove any remaining equipment. Perform hand hygiene. Send specimens to the lab immediately.