It's a VBG stupid

We had a patient present with tachycardia. He underwent a chest CT which showed a small subsegmental pulmonary embolism. During my review of his labs, I noticed his PaO2 was 50. Of course! I thought. That surely goes along with a PE.  Well, if I had paid closer attention I would have realized that it was a VBG (venous blood gas), not an ABG. Pay attention. It's a VBG stupid. Hope not to make that mistake again.