A 65-year-old post-operative patient presents with a sudden opening of their surgical abdominal wound. What is the most appropriate immediate nursing action to take for this patient experiencing wound dehiscence?

Instruct the patient to cough and deep breathe to prevent atelectasis.

Apply a sterile saline dressing and notify the surgeon immediately.

Increase the patient's oral fluid intake to promote healing.

Apply pressure to the wound to stop any bleeding.