Final answer:
The most important nursing intervention after a liver biopsy is to evaluate the patient's vital signs every 10 to 20 minutes for 2 hours post-procedure to monitor for potential complications.
Step-by-step explanation:
After a liver biopsy is performed, the registered nurse's (RN) most important intervention is to evaluate vital signs every 10 to 20 minutes for 2 hours after the procedure. This practice is crucial for monitoring the patient for signs of bleeding or other complications following the biopsy. It is part of the direct supervision and care that a nurse provides to ensure patient safety and to quickly identify and manage any adverse reactions.