Final answer:
When a postpartum hemorrhage is detected, immediate nursing interventions should include massaging the fundus, administering oxytocin, and monitoring vital signs.
Step-by-step explanation:
When a postpartum hemorrhage is detected, immediate nursing interventions should include massaging the fundus to help the uterus contract, administering oxytocin to further stimulate uterine contractions, and monitoring vital signs to assess the patient's condition. These interventions help control bleeding and prevent further complications. Administering diuretics or anticoagulants would not be appropriate in this situation, and withholding fluids could lead to dehydration and worsen the patient's condition.