What's in a Blood Gas? VBG vs ABG BOTTOM LINE: VBG is less painful, more easily obtained than ABG, pH correlates very well, and PvCO2 >45mmHg has a 100% sensitivity & 100% NPV in predicting arterial hypercarbia. #EBM #Diagnosis #ABG #VBG #Differences #Versus #Comparison #PH #PCO2 #Studies #Conversion #Correlation