Arterial Blood Gas (ABG) vs Venous Blood Gas (VBG)

From UpToDate:

Correlation with arterial blood gases — Although arterial blood gas analysis is more accurate than venous analysis for the assessment of oxygenation, measurement of PCO2, pH, and HCO3 are similar with some minor adjustments (table 1) [5-17]:

●The central venous pH is usually 0.03 to 0.05 pH units lower than the arterial pH and the PCO2 is usually 4 to 5 mmHg higher, with little or no increase in HCO3 [5,6,16]. Mixed venous blood (ie, SvO2 drawn from a pulmonary artery catheter) gives results similar to central venous blood (ie, ScvO2 drawn from a central venous catheter) [7-9].
●The peripheral venous pH is approximately 0.02 to 0.04 pH units lower than the arterial pH, the venous serum HCO3 concentration is approximately 1 to 2 meq/L higher, and the venous PCO2 is approximately 3 to 8 mmHg higher [10-15].

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s