A patient's admission vital signs are temperature 37.6° C, heart rate 96 beats/min, respirations 22 breaths/min, and blood pressure 140/90 mm Hg. Later, the patient requests pain medication, and the nurse records vital signs before administering codeine 15 mg with acetaminophen 300 mg (Tylenol 2) two tablets by mouth. Before administering the medication, which patient assessment is the nurse's priority?

Codeine is an opioid analgesic that carries a significant risk of respiratory depression. A respiratory rate of 10 breaths per minute is already below the normal range of 12–20 breaths per minute and represents a critical finding that must be addressed before administering any opioid. Administering codeine to a patient with a respiratory rate of 10 could further suppress respiratory drive and lead to hypoxia, respiratory arrest, or death. This makes the low respiratory rate the highest-priority assessment finding. The nurse should withhold the medication and notify the prescriber. A heart rate of 110 is mildly elevated (tachycardia) but does not contraindicate opioid administration and is not an immediate danger in this context. A temperature of 38.0°C is only slightly above the admission temperature of 37.6°C and represents a low-grade elevation that is not an urgent contraindication. A blood pressure of 160/86 mm Hg is elevated but is not dramatically different from the admission value of 140/90 mm Hg, and while it warrants monitoring, it does not preclude opioid use in the same way that severe respiratory depression does. Safety before opioid administration always centers on ensuring the respiratory rate is within an acceptable threshold, typically at least 12 breaths per minute, making option A the correct priority assessment.