What procedure should not be performed on a patient with a valid Do Not Resuscitate (DNR) order?

Intubation is an advanced life support procedure that is typically associated with aggressive resuscitative efforts. A patient with a valid Do Not Resuscitate (DNR) order has clearly expressed their wishes against resuscitative measures in the event of cardiac or respiratory arrest. Therefore, proceeding with intubation, which requires invasive intervention, would go against the intent of the DNR.

The DNR specifically indicates that the patient does not want certain life-sustaining measures. In the context of the other options, basic life support techniques might be acceptable as they include measures like airway maintenance and chest compressions. Providing comfort measures is entirely appropriate as it aligns with respecting the patient's end-of-life wishes. Though some medications may be given for symptom relief in a palliative context, these do not constitute resuscitative measures and would not violate the DNR principles as long as they align with comfort care.