A new technologist on a weekend shift in the core laboratory has seen low glucose levels before, but never one as low as the 23 mg/dL (reference interval 70-100 mg/dL) she has encountered. She repeats the glucose analysis and obtains the same result. She notes that all other tests results within the CHEM 7 profile are within the reference intervals, although the potassium is at the upper reference limit of 5.3 mEq/L (reference interval 3.5 - 5.3 mEq/L). No previous results are available for this presurgical outpatient.
Being a Saturday afternoon, she is somewhat limited as to what she could investigate, but what should her investigation include?