A patient returns from the recovery room at 9 AM alert and oriented, with an IV infusing. His pulse is 82, blood pressure is 120 and 80, respirations are 20, and all are within normal range. At 10 am and at 11 am, his vital signs are stable. At noon, however, his pulse rate is 94, blood pressure is 116 and 74, and respirations are 24. What nursing action is most appropriate?