A nurse is caring for a client who is receiving morphine via a PCA pump. The nurse should monitor for which of the following as adverse effects of this medication? Select all that apply

Morphine is an opioid agonist that binds to mu-opioid receptors in the central nervous system to provide potent analgesia. Beyond pain relief, it exerts a depressant effect on the respiratory center and the autonomic nervous system, necessitating continuous monitoring of the patient's level of consciousness and hemodynamic stability. Rationale: A. Tachycardia is not a typical adverse effect of morphine; in fact, opioids tend to cause a decrease in heart rate or have no significant effect on it. Morphine reduces sympathetic outflow, which is more likely to result in bradycardia or a stable heart rate. The presence of tachycardia in a patient on a PCA pump might actually indicate inadequately controlled pain or a different underlying complication. B. Sedation is a common and significant adverse effect of morphine that often precedes respiratory depression in patients using a PCA pump. The nurse must use a standardized scale to assess the client's arousal level, as excessive sleepiness indicates the drug is accumulating to potentially toxic levels. Monitoring for sedation allows the nurse to intervene early by adjusting the dose before life-threatening complications occur. C. Hypotension occurs with morphine administration due to peripheral vasodilation and the release of histamine, which lowers systemic vascular resistance. This is particularly common when the drug is administered intravenously or in large doses via a PCA pump. The nurse must monitor blood pressure regularly and instruct the client to change positions slowly to prevent orthostatic hypotension and potential falls during therapy. D. Hyperthermia is not an adverse effect associated with opioid analgesics like morphine. Morphine does not interfere with the thermoregulatory center in the hypothalamus in a way that would cause an elevated body temperature. If a patient receiving morphine develops a fever, the nurse should investigate other causes, such as an underlying infection or an inflammatory process, rather than attributing it to the medication. E. Bradypnea, or an abnormally slow respiratory rate, is one of the most dangerous adverse effects of morphine because it directly depresses the brainstem respiratory centers. The nurse must count the client's respirations frequently and be prepared to administer naloxone if the rate falls below 8 to 10 breaths per minute. Bradypnea can lead to hypercapnia and respiratory arrest, making it a critical focus of PCA monitoring.