The nurse is caring for a client with rib fractures and a pneumothorax who reports a pain score of 8/10. The nurse administered prescribed hydromorphone IV push and reassesses the client in 30 minutes. What data indicates that the treatment is effective?

A. The primary goal of administering hydromorphone IV is to relieve severe pain. A decrease in the pain score from 8/10 to 3/10 indicates that the analgesic intervention has been effective, allowing improved comfort and potentially better respiratory effort. B. While reduced anxiety may occur as a secondary effect of pain relief, it is not a direct measure of the effectiveness of the opioid analgesic. Anxiety reduction alone does not confirm pain control. C. Although maintaining a normal respiratory rate is important, opioids can depress respirations. The rate of 16 may reflect adequate breathing, but it does not directly measure pain relief. The client could still be in pain despite a normal respiratory rate. D. Improvement in oxygenation may occur as a result of better ventilation after pain control, but it is an indirect indicator. PaO2 can be influenced by factors other than pain, such as the pneumothorax or underlying lung injury, so it does not confirm analgesic effectiveness.