A client has been administered lorazepam for acute seizure control. Which clinical manifestation is the nurse's priority to monitor for immediately following the administration?

A. Respiratory depression: Lorazepam is a benzodiazepine that enhances the effect of gamma-aminobutyric acid (GABA), producing CNS depression to control seizures. A major adverse effect is respiratory depression due to suppression of the brainstem respiratory centers. Immediate monitoring of respiratory rate, depth, and oxygen saturation is critical. B. Confusion: Benzodiazepines can cause CNS effects such as confusion or altered mental status, particularly in elderly clients. While important to monitor, confusion is less acutely dangerous than respiratory compromise and does not require immediate life-saving intervention. C. Sedation: Sedation is an expected pharmacologic effect of lorazepam. It indicates the drug is taking effect but is not the highest-priority concern unless it progresses to hypoventilation or airway compromise. Monitoring for sedation is secondary to respiratory status. D. Dizziness: Dizziness may occur as a side effect, especially with ambulation or position changes. It increases fall risk but is not an immediate threat to life, unlike respiratory depression, which requires urgent assessment and intervention.