Final answer:
Mid-sternal chest pain requires immediate intervention by the nurse in a client with tachycardia.
Step-by-step explanation:
Out of the manifestations listed, mid-sternal chest pain requires immediate intervention by the nurse in a client with tachycardia. Chest pain can be indicative of a myocardial infarction (heart attack), which is a serious medical emergency that requires immediate medical attention. Prompt intervention can help prevent further damage to the heart and improve the client's prognosis.