Incidence of dehydration encephalopathy among patients with disturbed consciousness at a hospital emergency unit

Systemic dehydration and diffuse central nervous system signs without any other illness is referred to as dehydration encephalopathy (DE). However, the incidence of DE at emergency units remains uncertain. We investigated the incidence of DE among persons with disturbed consciousness who visited the emergency unit. We reviewed the medical case records of the emergency unit at our university hospital during a 6-month period. Among them, 132 patients presented with disturbed consciousness as the sole initial manifestation on arrival. They were 75 men, 47 women; mean age 68 years (16–95 years). After carefully excluding other etiologies, the incidence of DE was 2% among all persons in the emergency unit and 4% among persons older than 68 years. In conclusion, the incidence of DE in our emergency unit was not common. Nevertheless, recognition of DE is extremely important in order to avoid unnecessary medication in elderly subjects.