Which of the following is a sign of possible anesthesia overdose?

Unresponsiveness and shallow breathing are critical indicators of possible anesthesia overdose. This condition arises when the dosage of anesthetic exceeds the body's safe threshold, leading to a significant suppression of the central nervous system. As a result, the patient may become unresponsive, indicating that they are unable to react to external stimuli. Shallow breathing suggests that the respiratory drive is compromised, which can further lead to inadequate oxygenation and potential respiratory failure.

In contrast, while symptoms like increased heart rate, severe agitation, and excessive sweating could be associated with various medical conditions or reactions to anesthesia, they do not specifically indicate overdose. Increased heart rate might be an indication of anxiety or pain, severe agitation could be a sign of undesirable reactions or emergence delirium, and excessive sweating could relate to stress or other factors, rather than directly pointing toward an overdose scenario. Therefore, unresponsiveness and shallow breathing are the most direct signs to monitor for potential overdose in a patient undergoing anesthesia.