Final answer:
The nurse should first place the fallen internal cervical radiation implant in a lead-lined container before calling for assistance. Documentation of the incident in the client's medical chart should follow.
Step-by-step explanation:
If a nurse discovers that an internal cervical radiation implant has fallen out, the first action the nurse should take is to place the implant in a lead-lined container. This is important to protect anyone in the vicinity from unnecessary exposure to radiation. Once the implant is secured, the nurse should then call for assistance from a medical professional who is trained to handle such incidents. Following these actions, it is crucial to document the event in the client's medical chart, including the time of the incident, the actions taken, and any observations or communications with the client.