After a cardiac catheterization, what is the nurse's first priority action when noticing a large puddle of blood under the client?

In the scenario after a cardiac catheterization, the nurse's first priority action when identifying a large puddle of blood under the client is to assess the groin site. This is crucial because the groin is the access site commonly used for catheterization procedures in the cardiovascular system.

By assessing the groin site, the nurse can determine if there is active bleeding, where the source might be, and if any complications, such as hematoma formation or vessel injury, are occurring. This initial assessment is vital to prioritize interventions and ensure patient safety. Identifying the nature and extent of the bleeding will guide the next steps, such as applying pressure to control bleeding, notifying the physician, or preparing for further interventions if necessary.

Prioritizing the assessment of the groin site over actions like calling for help, obtaining vital signs, or asking the client to "lift up" is aligned with the nursing process of assessing before intervening. It allows the nurse to gather critical information that can influence immediate care decisions.