A nurse is caring for a client who has an endotracheal tube and is receiving mechanical ventilation. Which of the following actions should the nurse take to reduce the risk of ventilator-associated pneumonia?

The correct answer is B: Brush the client's teeth with a suction toothbrush every 12 hours. This action helps reduce the risk of ventilator-associated pneumonia by preventing the buildup of bacteria in the oral cavity that could be aspirated into the lungs. Ventilator-associated pneumonia is often caused by bacteria from the oral cavity entering the respiratory system. Regular oral care, including brushing the teeth, helps to reduce the bacterial load in the mouth. Turning the client every 4 hours (choice A) helps prevent pressure ulcers but does not directly reduce the risk of ventilator-associated pneumonia. Providing humidity in the ventilator tubing (choice C) is important for maintaining airway moisture but does not specifically target pneumonia prevention. Positioning the head of the client's bed flat (choice D) is important for proper ventilation but does not address oral care and bacterial buildup.