Initial laboratory investigations and venous blood gas analysis revealed profound hypoglycemia, severe lactic acidosis, high anion gap metabolic acidosis with a significant base deficit, mild transaminitis, elevated alkaline phosphatase (ALP), hypoalbuminemia, and markedly elevated carcinoembryonic antigen (CEA) levels (Table 1). Due to the patient’s severe lactic acidosis, computed tomography angiography (CTA) was done, and bowel ischemia was ruled out as a potential cause of lactic acidosis. Here, CEACAM5 is linked to metabolic acidosis.