Which of the following is NOT a contraindication for N2O use?

Nitrous oxide (N2O) is a commonly used anesthetic and analgesic agent in dentistry, but there are specific contraindications that practitioners need to be aware of when considering its use. Hypertension is not considered a contraindication for the use of nitrous oxide, which is why this choice is correct.

N2O primarily acts as a sedative that can help to alleviate anxiety and discomfort during dental procedures. While patients with uncontrolled hypertension should be managed carefully, stable hypertension itself typically does not preclude the use of nitrous oxide.

In contrast, chronic obstructive pulmonary disease (COPD), pregnancy, and a history of substance abuse present more direct concerns for its use. COPD can lead to difficulties in oxygenation and ventilation, pregnancy raises concerns about potential effects on the fetus, and individuals with a history of substance abuse may be more prone to adverse reactions or misuse of sedative agents.

Understanding these distinctions helps dental professionals to make informed decisions about patient management and the safe use of nitrous oxide in clinical settings.