What intervention is crucial for a postpartum woman experiencing heavy vaginal bleeding?

In the context of a postpartum woman experiencing heavy vaginal bleeding, performing a uterine massage is crucial because it directly addresses one of the most common causes of postpartum hemorrhage, which is uterine atony. Uterine atony occurs when the uterine muscles do not contract effectively after delivery, leading to significant blood loss.

By performing a uterine massage, the nurse stimulates contractions of the uterus, which can help to reduce or stop the bleeding. This intervention is often the first step in managing postpartum hemorrhage and can be immediately effective in stabilizing the patient's condition.

While increasing intravenous fluids and checking vital signs frequently are important components of overall care for a woman experiencing heavy bleeding, they do not address the primary cause of the bleeding as specifically or effectively as uterine massage does. Administering pain relief, while important for patient comfort, does not contribute to the management of the bleeding itself. Thus, performing a uterine massage is the most appropriate and effective intervention in this situation.