Hi, I went through your query and can understand your concern. Severe alcohol withdrawal state can lead to delirium tremens. Generally, mild withdrawal causes only anxiety, insomnia, palpitations, tremors. But when severe, it can also lead to seizures and later on delirium. A visit to ER is definitely warranted in case the patient seizes; there is a very high probability that he may develop delirium. Look out for his orientation, any suggestion of visual or auditory hallucinations. As a psychiatrist, I will advice medications started as a prophylactic measure as he also has history of severe withdrawal and its better to control before things get out of hands. Wish you all the best.