What action should the EMT perform after administering naloxone to a patient who sustained a fentanyl overdose?

Monitoring blood pressure after administering naloxone to a patient who has sustained a fentanyl overdose is crucial because naloxone is an opioid antagonist that reverses the effects of opioids, including respiratory depression and sedation. Administering naloxone can lead to a rebound effect where the patient experiences withdrawal symptoms or a return of respiratory depression, which may influence their hemodynamics. Blood pressure is an important vital sign to assess, as significant fluctuations may indicate the patient is in distress or that naloxone is effectively reversing the opioid effects.

It is also important to observe the patient closely for potential complications that may arise from the reversal of opioid effects, including changes in cardiovascular status. This could involve a rapid increase in heart rate and blood pressure as the patient's breathing improves. Regular monitoring enables the EMT to intervene promptly if the patient shows signs of instability.

Other options, such as obtaining oral temperature, administering antiemetics, or assessing for tremors, do not address the immediate and most critical needs of a patient recovering from opioid toxicity, making blood pressure monitoring the most relevant and vital action to perform at this stage.