Final answer:
A DNR order may be suspended in the preoperative period and CPR performed if a cardiac arrest is due to a drug reaction, as this is considered a reversible condition.
Step-by-step explanation:
A Do Not Resuscitate (DNR) order is a legal document stipulating that no resuscitative procedures should be performed on a patient experiencing cardiac arrest. However, there may be circumstances where a DNR might be suspended, such as during the preoperative period. If a patient with a DNR experiences a cardiac arrest due to a reversible cause like a drug reaction while preparing for surgery, it may be deemed appropriate to perform CPR to reverse the effects of the medication and proceed with the planned surgery. This is because the drug reaction is considered a temporary and reversible condition, unlike cases like advanced cancer or sepsis, which might reflect the patient's underlying terminal state.