Final answer:
A respiratory rate of 7 breaths per minute after opioid administration is a sign of opioid-induced respiratory depression and is a concerning adverse reaction that requires immediate attention.
Step-by-step explanation:
A nurse administers an opioid to a postoperative adult patient, and we want to identify which vital sign might indicate an adverse reaction to the medication. Among the given options, a respiratory rate of 7 breaths per minute is a clear indicator of opioid-induced respiratory depression, which is a serious side effect of opioids.
This is significantly lower than the normal breathing rate of 12-18 breaths per minute and requires immediate medical attention. On the other hand, a blood pressure of 100/60, while on the lower end, is not necessarily indicative of an adverse reaction, providing the patient is stable. A heart rate of 60 bpm is within the normal range of 60-100 beats per minute. Lastly, a temperature of 102 degrees Fahrenheit indicates fever, which isn't a typical side effect of opioids and may suggest an infection or another issue.