A nurse on the night shift is making client rounds. When the nurse checks a client who is 97 years old and has successfully been treated for heart failure, he notes that the client is not breathing. If the client does not have a do-not-resuscitate (DNR) order, the nurse should take which action?

Administering cardiopulmonary resuscitation (CPR) is the appropriate action when a client is not breathing and does not have a do-not-resuscitate (DNR) order. CPR is considered an emergency treatment that can be provided without client consent in life-threatening situations. Calling the health care provider or nursing supervisor for directions, as well as administering oxygen without addressing the lack of breathing, would delay critical life-saving interventions. Therefore, administering CPR is the most urgent and necessary action to perform in this scenario.