In which scenario would it be inappropriate to use a vasoconstrictor with local anesthesia?

Using a vasoconstrictor with local anesthesia in a patient with hypertension can pose risks due to how vasoconstrictors work. These agents function by narrowing blood vessels, which can increase blood pressure and potentially lead to cardiovascular complications in individuals who already have elevated blood pressure. Therefore, in such patients, the risk of inducing an adverse cardiovascular event, such as elevated heart rate or stroke, outweighs the benefits of using a vasoconstrictor.

In contrast, using vasoconstrictors in healthy patients, pediatric patients, or those with dental infections is generally considered safe and often beneficial. Healthy patients can tolerate vasoconstrictors without significant risk, and in pediatric patients, appropriate dosing is key, but they can receive local anesthesia with vasoconstrictors safely. Additionally, in the presence of a dental infection, the use of vasoconstrictors can help control bleeding and improve the field of vision during procedures. Thus, the most appropriate scenario where using a vasoconstrictor would be inappropriate is in a patient with hypertension.