Final answer:
The nurse should notify the surgeon immediately when a client who had a laparotomy has drained 300 ml of dark red fluids from the nasogastric tube. This could indicate internal bleeding and requires immediate medical attention.
Step-by-step explanation:
The nurse should take the action to notify the surgeon immediately first when assessing a client who had a laparotomy and has drained 300 ml of dark red fluids from the nasogastric tube in the last hour. This could indicate internal bleeding and requires immediate medical attention. The nurse should then proceed to assess the client's vital signs, level of pain, and monitor urinary output to provide comprehensive care to the client.