An elderly diabetic female has presented with multiple episodes of vomiting within a few hours of consuming food from outside. On admission, BP is low and ABG shows pH = 7.5 pCO2 = 45 mm Hg and HCO3 = 30 mEq. Na = 130, K = 3.5 and chloride = 90 mEq/L. Comment on the etiology of these findings.