Final answer:
VBG and ABG are blood tests used to measure oxygen, carbon dioxide, and other gases in the blood. VBG is less invasive and obtained from a vein, while ABG requires a sample from an artery. ABG may be preferred in specific medical situations for more accurate measurements.
Step-by-step explanation:
A VBG (venous blood gas) or ABG (arterial blood gas) is ordered to measure the levels of oxygen, carbon dioxide, and other gases in the blood. Both tests are used to assess the function of the respiratory system and diagnose respiratory disorders or acid-base imbalances.
A VBG is commonly ordered as a less invasive alternative to an ABG. It is obtained by drawing blood from a vein, usually from the arm. On the other hand, an ABG requires a blood sample to be taken from an artery, typically from the wrist or groin.
In certain medical situations, an ABG may be preferred over a VBG for more accurate measurements, such as when assessing the severity of respiratory failure, evaluating patients with suspected lung disease, or monitoring patients on mechanical ventilation.