This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2019, Subject name: Medicine
A patient of CKD has presented with protracted vomiting. ABG shows pH = 7.40, pCO2 = 40 mm Hg, HCO3 = 25 mEq, Na=145 mEq/L, Chloride = 100 mEq/L, HCO3 = 24 mEq/L. What is the observation? 
Select and explain. 
A. Normal anion gap metabolic acidosis, B. High anion gap metabolic acidosis, C. No acid base abnormality, D. High anion gap metabolic acidosis and metabolic alkalosis
D: High anion gap metabolic acidosis and metabolic alkalosis
Answer: D: High anion gap metabolic acidosis and metabolic alkalosis 
Explanation: AG(Anion Gap)= Na+ - (Cl- + HCO3-) = 145-124 = 21 meq Normal 8-10meq Rules out option a. - CKD is condition where patient experiences impaired ability to excrete H+ - Vomiting contributes to metabolic alkalosis - Two processes simultaneously occurring So answer is High anion gap metabolic acidosis and metabolic alkalosis.