Final answer:
To address severe pain after negative suction wound therapy for pressure ulcers, the immediate nursing action should be to reduce the suction.
Step-by-step explanation:
After receiving negative suction wound therapy for pressure ulcers, if the patient complains of severe pain, the immediate nursing action should be to reduce the suction. Severe pain can indicate that the suction setting is too high, causing discomfort and potentially damaging the wound. By reducing the suction, the patient's pain can be alleviated, promoting their comfort and well-being.