Final answer:
When fundal massage is ineffective in achieving uterine firmness, it is critical to immediately notify the healthcare provider to address the potential risk of postpartum hemorrhage.
Step-by-step explanation:
If the fundus does not respond to fundal massage, the correct action to take is to notify the healthcare provider immediately. Fundal massage is performed to stimulate contractions and prevent postpartum hemorrhage by ensuring that the uterus remains firm after childbirth. If the uterus does not contract properly, it can lead to significant bleeding and is considered a medical emergency. Increasing the massage pressure may cause further pain or damage without resolving the underlying issue. Administering pain medication would not address the lack of uterine firmness, and encouraging the client to walk is not appropriate at this stage due to the risk of hemorrhage.