Final answer:
The nursing action that is done immediately after the client is pronounced dead is to contact the organ procurement organization (OPO).
Step-by-step explanation:
After the client is pronounced dead, the nursing action that is done immediately is to contact the organ procurement organization (OPO). The OPO is responsible for coordinating the process of organ donation, including evaluating the suitability of organs, contacting potential recipients, and overseeing the retrieval and transplantation of organs.