A patient has several open sores on their arm that haven't healed despite taking antibiotics. What should you do?

The best course of action in this scenario is to don gloves and gown immediately in order to prevent the transmission of any potential infectious agents, especially considering the presence of open sores that have not healed despite antibiotic treatment. This suggests a risk of infection that could be contagious or pose a risk to healthcare personnel and others.

By wearing personal protective equipment, including gloves and a gown, you help protect yourself and others from any potential bloodborne pathogens or bodily fluids that may come into contact with the sores. This is especially important in a medical setting to maintain a sterile environment and to follow infection control protocols.

Other choices, while they may seem relevant, do not directly address the immediate need for infection control. Using a surgical mask would be inappropriate unless there is a risk of droplet transmission, administering oxygen via nasal cannula does not relate to the management of the sores, and applying a sterile dressing or bandage, while important for wound care, does not provide the necessary protection for the caregiver in this context.