Final answer:
The nurse should notify the physician immediately due to the potential severity of the symptoms suggesting impaired circulation or nerve compression, which could lead to serious complications.
Step-by-step explanation:
The symptoms described by the client, such as numbness, tingling, pallor, coolness, and swelling in the fingers distal to a new arm cast, are indicative of impaired circulation or nerve compression, which can be a medical emergency. Given the severity of these symptoms and the potential for serious complications such as compartment syndrome, the nurse should notify the physician immediately. It is important not to delay treatment as doing so could result in permanent damage. While elevation of the affected limb can sometimes alleviate swelling, and loosening the cast might relieve pressure if it is too tight, these steps should only be taken after consulting with a physician. It is not recommended for the nurse to massage the affected area as this could exacerbate the condition.