A client with multiple sclerosis (MS) has a living will and a do not resuscitate (DNR) prescription in the medical record. Currently the client's oxygen saturation is 86% on room air and the client is anxious and requesting oxygen. Which intervention should the nurse implement first?

Choice A reason: Applying a nonrebreather mask with 100% oxygen is the immediate priority because the client’s oxygen saturation is critically low at 86%. Providing oxygen addresses hypoxemia and relieves anxiety caused by dyspnea. A DNR order does not mean withholding basic comfort measures such as oxygen therapy; it only applies to resuscitation in the event of cardiac or respiratory arrest. Choice B reason: Reviewing DNR instructions is important for understanding limitations of care, but it should not delay immediate intervention. The client is requesting oxygen, and providing it is consistent with supportive care even under a DNR order. Choice C reason: Calling the rapid response team may be necessary if the client’s condition does not improve with oxygen therapy, but the first step is to administer oxygen. Rapid response is reserved for acute deterioration after initial supportive measures have been attempted. Choice D reason: Administering a sedative would not address hypoxemia and could worsen respiratory depression. Sedation is inappropriate when oxygen saturation is already critically low. The priority is correcting oxygenation, not suppressing symptoms.