Medical-surgical Nursing Demystified

CHAPTER 2 Respiratory System^137

HOW DOES THE TEST WORK?

Three to five milliliters of blood is sampled from an artery in a heparinized
syringe. If the sample cannot be analyzed right away, it should be placed on ice.

• The normal results are:
  
  
  • pH 7.35–7.45
  
  
  • PaO 2 80–100 mmHg
  
  
  • PaCO 2 35–45 mmHg
  
  
  • HCO 3 22–26 mEq/L
  
  
  
  

WHAT TO DO?

• Before the test:
  
  
  • Provide the lab with information on whether or not the patient is receiv-
    ing supplemental oxygen or mechanical ventilation as well as the amount
    of oxygen received or the setting of the ventilator. Oxygen supplementa-
    tion at the time of testing will be reported with the results.
  
  
  • Note the patient’s temperature. Alteration in temperature may alter the
    results of the test.
  
  
  
  


• After the test:
  
  
  • Apply mechanical pressure to puncture site for 5 minutes.
  
  
  • Apply pressure dressing to puncture site for 30 minutes once bleeding has
    stopped.
  
  
  • Monitor the puncture site for bleeding.
  
  
  
  

Ventilation-Perfusion Scan

(V/Q scan)

WHY IS IT DONE?

Enables visualization of the flow of blood in the lungs to determine if lung tissue
is adequately perfused.