The nurse is instructing the client on the correct way to take nitroglycerin as needed for chest pain:

Choice A reason: Encouraging family members to press the PCA button for the client is not recommended. The PCA device is designed to be used by the patient to manage their own pain. Allowing someone other than the patient to administer the medication can lead to over-sedation or respiratory depression. The patient must have control over the PCA device to ensure that they are receiving the medication based on their pain level and not someone else's perception of their pain.

Choice B reason: Monitoring the client's respiratory status every 4 hours is important but may not be sufficient for a patient receiving morphine via a PCA device. According to clinical guidelines, respiratory rate, sedation, and pain scores must be recorded more frequently after the initiation of PCA therapy—typically every 15 minutes for the first hour, then every 30 minutes for the next 2 hours, and hourly until 24 hours post-operation. This is to ensure early detection of any adverse effects such as respiratory depression, which is a risk with opioid administration.

Choice C reason: Teaching the client how to self-medicate using the PCA device is the correct action. Patient education is crucial for the effective use of PCA. The patient should be instructed on how to use the device, including when to press the button and the importance of only the patient controlling the button. This empowers the patient to manage their pain effectively and safely, ensuring that they receive the medication when needed and reducing the risk of over-sedation or under-medication.

Choice D reason: Administering an oral opioid for breakthrough pain may be necessary if the PCA does not adequately control the patient's pain. However, this should be done cautiously and typically under the guidance of a pain management team or physician. Breakthrough pain medication is usually reserved for instances where the PCA is not providing sufficient pain relief, and the patient's pain is assessed to be higher than what can be managed by the PCA alone.

Choice A reason: Administering aspirin is one of the first interventions for a client experiencing acute angina because aspirin has antiplatelet properties that help prevent blood clots, which can reduce the risk of a heart attack.

Choice B reason: Measuring blood pressure is important but not the first action to take. It provides valuable information about the cardiovascular status of the client and can influence further treatment decisions.

Choice C reason: Administering nitroglycerin is a priority action for acute angina as it helps to dilate the coronary arteries and relieve chest pain. However, it is typically administered after aspirin unless contraindicated.

Choice D reason: Initiating IV access is an important step in the management of acute angina, as it allows for the administration of medications and fluids if needed. However, it is not the first action to take during an acute angina episode.