Which of the following is a sign of respiratory depression in an opioid overdose patient?

Unresponsiveness is a key sign of respiratory depression in a patient who has experienced an opioid overdose. Opioids can significantly suppress the central nervous system, leading to decreased levels of consciousness and responsiveness. This occurs because opioids bind to specific receptors in the brain that regulate not just pain perception, but also alertness and respiratory drive. When respiratory function is compromised due to overdose, the patient may become unresponsive, indicating that their body is not adequately responding to stimuli or maintaining adequate oxygen levels.

In the context of the other options, increased heart rate is typically a response to stress or pain rather than a direct sign of respiratory depression. Excessive sweating may occur in various conditions, including anxiety or pain but is not specifically indicative of respiratory depression itself. Elevated blood pressure may also occur due to pain or stress reactions, rather than directly signifying respiratory issues following opioid use. Therefore, unresponsiveness stands out as a direct consequence of reduced respiratory function caused by opioid overdose.