What initial action should a nurse take for a client diagnosed with deep vein thrombosis who reports severe chest pain and shortness of breath?

In the context of a client diagnosed with deep vein thrombosis (DVT) who is reporting severe chest pain and shortness of breath, the priority action is to apply supplemental oxygen via nasal cannula. This is critical because these symptoms may indicate a potential complication of DVT, such as a pulmonary embolism, where a blood clot travels to the lungs, potentially leading to respiratory distress or hypoxia.

Administering supplemental oxygen ensures that the client receives adequate oxygenation, which is vital in managing shortness of breath. It can help prevent further complications and stabilize the patient's condition while further assessment and treatment are initiated.

In contrast, merely encouraging the client to rest does not address the urgent nature of their symptoms; while resting is important, it does not provide immediate relief or treatment for potentially life-threatening respiratory distress. Preparing for immediate discharge is inappropriate at this point, as the client is exhibiting concerning symptoms that require further evaluation and care. Ignoring the client's complaints would be negligent, as they are critical indicators that warrant immediate medical intervention. Thus, the choice to apply supplemental oxygen aligns with the best practices for managing acute respiratory symptoms in a patient with DVT.