A client with chronic obstructive pulmonary disease (COPD) is receiving oxygen at 4 liters per minute via nasal cannula. The client becomes lethargic and confused. What action should the nurse take first?

In this scenario, the priority action for the nurse is to decrease the oxygen flow rate. Clients with COPD are sensitive to high levels of oxygen and can develop oxygen toxicity, leading to symptoms like lethargy and confusion. Decreasing the oxygen flow rate helps prevent this complication. Increasing the oxygen flow rate would worsen the client's condition. Encouraging coughing and deep breathing may not address the immediate issue of oxygen toxicity. While monitoring the client's oxygen saturation level is important, taking action to address the oxygen toxicity by decreasing the flow rate is the priority in this situation.