A 78-year-old man with advanced dementia resides in a care home. He has stopped eating and drinking over the last 48 hours and is now minimally responsive. The care home staff are asking about the appropriateness of inserting a nasogastric tube for feeding. He has an advance decision to refuse treatment (ADRT) made 3 years ago when he had capacity, which states he refuses artificial nutrition and hydration if he loses capacity and has a life-limiting illness with no prospect of recovery. What is the most appropriate course of action?