Final answer:
The nurse should instruct the client to notify their provider if they experience weakness.
Step-by-step explanation:
The nurse should include the following statement in the DC instructions for a client who has COPD and experienced a pneumothorax: "Notify your provider if you experience weakness."
This is important because weakness can be a sign of complications or worsening of the condition. It is crucial for the healthcare provider to be notified in order to assess and address any potential issues.
Some of the other options are not directly related to the client's condition. For example, returning to work in 1 week would depend on the individual's recovery progress and the advice of their healthcare provider. Wearing a mask in crowded areas is generally recommended during respiratory illness outbreaks, but may not be specific to the client's case. Lastly, a productive cough is a common symptom of COPD and may not warrant immediate notification unless it is accompanied by other concerning symptoms.