you are called to a private home where a 92-year-old man is experiencing severe squeezing chest pain on the left side that radiates to his left jaw and shoulder. he is prescribed nitroglycerin but has not taken any. he is also on a daily aspirin regimen, which he just took with his morning medications. his pulse is 90, bp is 88/64, respirations are 26, and his skin is pink, warm, and dry. after giving oxygen therapy, performing a focused physical assessment, and obtaining opqrst and sample history, what should you do next?