PROCEDURE FOR DRAWING ARTERIAL BLOOD
GASES FROM AN INDWELLING LINE


Equipment Required:

  1- heparinized blood gas syringe (premixed, powdered heparin)
  1 -syringe or vacutainer with red top tube for discharge sample
  1- unsterile gauze square
  1-Chlorhexidine 2% and 70% alcohol swab

  1- PPE-non-sterile gloves, assess risk for need of face shield. 

  1-bag of ice.
  1- functional arterial line.
 

Procedure
 Rationale
1. Proceed to withdraw a discard sample as per procedure for withdrawing blood samples from an indwelling line. 1. The heparinized saline needs to be removed from catheter deadspace to avoid dilution of the sample.
2. Ensure that stopcock is turned to 45o between syringe changes. 2. Forty five degrees is off in all 3 directions.  This will prevent any heparinized saline from entering the tubing between the stopcock and the patient catheter between syringe changes.
3. Observe the patients SpO2 reading. 3. To compare the SpO2 to the SaO2 when the blood gas results are back from the lab.
4. Slowly withdraw 1-2 mL using the heparinzed syringe.  Ensure that the syringe is securely attached to the stopcock. 4.
  • A heparinized syringe is required to prevent clotting of the specimen.
  • To prevent air bubbles from entering the sample.  The PaO2 of room air is 140 mmHg; air bubbles will falsely increase the PaO2.
5. Hold sample upright at a STRICT 90o angle with gauze square over top to catch blood.  Gently tap any air bubbles to the top and expel into the gauze and cap syringe.

Do not draw air into the syringe (as you might when drawing up a medication). 

 5.
  • If the syringe is slightly tilted, the air bubbles will be trapped in the syringe hub.  By holding the syringe upright, the air will be expelled out of the syringe and into the gauze.
  • Drawing air into the syringe can falsely elevate the PaO2.
6. Label the syringe and place on ice. Either take sample to the point of care testing machine (GEM) or send sample on ice to the lab in a biohazardous bag. 6. Ice stops the cells from metabolizing.  If there is a delay before the sample is tested, a sample that is left at room temperature may have a false increase in carbon dioxide, decreased pH or lowered PaO2 due to continued cell metabolism.
7.

Flush the catheter, stopcock and clearlink cap of blood and replace cap as per blood drawing protocol.

 7. To maintain catheter patency and reduce potential for bacterial colonization.

 

8.

Remove non-sterile gloves and perform hand hygiene.

8.

In accordance with the MoHLTC 4 moments of hand hygiene and LHSC infection control policies in an effort to reduce risk of transmission of microorganisms and secretions.

LHSC Hand Hygiene Policy

LHSC Routine Practices Policy

LHSC Donning and Doffing Policy
9.

Ensure that lab requisition includes FiO2, PEEP, AC/SIMV, PS, Vt, minute volume and temperature if sending sample to the lab.

For the point of care testing machine (GEM),FiO2, PEEP, minute volume and temperature are required to be inputed into the GEM. See GEM policy: http://www.lhsc.on.ca/Health_Professionals/CCTC/home/gemPolicy.pdf

 9.
  • In order to interpret blood gases (adequacy of breathing and oxygenation) in light of ventilatory support.
  • Blood gases are corrected to body temperature.
10. Document results in the graphic record and communicate any significant findings to the physician and respiratory therapist. 10. To ensure appropriate interventions are made.

November, 1988
Last Update: March 23, 2010.
Brenda Morgan, Clinical Educator, CCTC

LHSCHealth Professionals

Last Updated January 4, 2011 | © 2007, LHSC, London Ontario Canada