A nurse is caring for a client who is postoperative and has a PCA pump. Which of the following assessments should the nurse make in the first 24 hr following initiation of the PСА?

A. Check the client's pulse oximetry level every 6 hr: Pulse oximetry provides valuable information on oxygen saturation, but checking only every 6 hours may not detect early respiratory depression caused by opioid PCA therapy. B. Check the client's blood pressure every 4 hr: Blood pressure monitoring is important postoperatively, but opioid-induced respiratory depression is a more immediate risk in the first 24 hours of PCA use, so respirations take priority. C. Check the client's respirations every 2 hr: Opioids administered via PCA can cause respiratory depression, especially in the first 24 hours. Monitoring respiratory rate frequently allows for early detection and intervention if hypoventilation occurs. D. Assess the client's apical heart rate every 8 hr: While cardiac monitoring may be indicated for some clients, the apical heart rate is not the most critical assessment for PCA therapy. Respiratory function is the priority for detecting opioid-related complications.