The nurse knows the best intervention for preventing a postoperative infection is

  1. wearing gown, gloves, and mask in the client’s room.
  2. administering a prophylactic antibiotic.
  3. placing the client in a private room.
  4. following hand hygiene protocols.
Number 4 is correct.
Rationale: Hand washing is the most effective intervention for breaking the chain of infection. While barriers such as a gown, gloves, and mask might help in preventing transmission, hand washing is the first and most effective step to medical asepsis. Unless the patient is compromised or undergoing certain procedures, antibiotics are generally not indicated and may cause long-term resistance to antibiotics. A private room is not always feasible and hand washing is still indicated.