一位病人術後使用靜脈注射嗎啡。下列何種評估結果顯示最嚴重的副作用？

嗎啡（Morphine）是阿片類止痛藥，其最嚴重的副作用是呼吸抑制（Respiratory depression）。護理師在給藥前必須評估呼吸頻率，給藥後需持續監測呼吸狀態、鎮靜評分（Sedation scale）及氧氣飽和度。若呼吸頻率過慢，需立即停止給藥並視情況給予解毒劑（如 Naloxone）。

Morphine is an opioid analgesic, and its most serious adverse effect is respiratory depression. Before administering, the nurse must assess the respiratory rate; after administration, the nurse must continuously monitor respiratory status, sedation score, and oxygen saturation. If the respiratory rate becomes too slow, the drug must be stopped immediately and an antidote (such as naloxone) given as indicated.