Which local anesthetic should be used for at least 5 hours of anesthesia?

Bupivacaine is the appropriate choice for achieving at least 5 hours of anesthesia. It is a long-acting local anesthetic that is particularly favored in various clinical settings, such as in surgical procedures and pain management, where prolonged anesthesia is required. Bupivacaine typically has a duration of action of 4 to 8 hours, making it ideal for situations where extended pain relief is necessary.

In contrast, other local anesthetics like Lidocaine, Prilocaine, and Mepivacaine generally have shorter durations of action. Lidocaine usually offers effective anesthesia for about 1 to 2 hours, Prilocaine has a similar duration, and Mepivacaine also typically provides anesthesia for around 1.5 to 3 hours. Therefore, while they each serve important roles in specific situations, none of these alternatives provides the extended duration of anesthesia that Bupivacaine does, making it the superior option for this clinical requirement.