In er w/ numb cheek+ arm, pallor. cbc + ekg normal.oximeter showed 99% sat. but venous gas blood o2 saturation low at 0.34 (ref. range 0.5-0.8). why?

Extraction or anemia: The oximeter only shows the amt of oxygen binding of the existing hemoglobin in the ARTERIES. JUST BECAUSE UR SATS R FINE DOESN'T MEAN EVERYTHING IS FINE. This is a common mistake even docs make. In ur case, the VENOUS blood has lower O2 content. It cd mean the body is using up more O2 (more extraction) d/t infx,, vascular probs, smoking, etc. Or u cd be anemic. Less Hgb = lower O2 content. TTYD!