Question about ScVo2 and I-STAT

[nurs1ng]

When drawing from a central line or PICC, is this considered 'venous' or 'mixed venous' on an I-STAT? I've seen co workers input central line-obtained blood as 'mixed venous' on an I-STAT. I thought that you can only obtain mixed venous via a PA catheter..

Also, is ScVo2 the same as SO2 (is this equivalent to SaO2?) on the I-STAT?

Thanks for any help!!

[vanilla bean]

I've never used an ISTAT, so can't speak to your question as it relates to ISTAT use, but found a website that you may find helpful in terms of line placement and values of venous gases:

venousgases

[MunoRN, RN]

"Mixed" refers to a sample that contains venous blood from the entire body, which you usually can't really get from a typical PICC or central line since the tip should be above where blood from the lower body empties into the RA. So you are correct, typically a mixed SvO2 must come from the PA port (or a central line tip that is too far in). The difference between the two is fairly small and usually treatment protocols are guided by ScVO2 because there is no established advantage to using mixed venous gasses.

From what I remember with I-stats, an SaO2 would be the SO2 if you've used arterial blood, and if you've used venous blood then the SO2 would be an SvO2 (or ScvO2).