A 12-year-old boy with no past medical history accidentally ingested a soda can tab 2.5 hours prior to arrival. He is asymptomatic at present, feels well, and is able to tolerate secretions without difficulty. On exam, the patient is alert, acyanotic, and non-stridulous. Breath sounds are clear to auscultation bilaterally, and his abdomen is nontender. What evaluation is necessary, and what is the appropriate management?