Excited delirium syndrome

Abstract

Mental health calls make up a large proportion of ambulance workloads, with paramedics responding to a wide range of presentations such as anxiety, depression, bipolar disorder, schizophrenia, and excited delirium syndrome. Excited delirium syndrome is an increasingly common presentation, characterised by extreme agitation and aggression in a patient with an altered mental status. Excited delirium is a potentially life-threatening condition, with generally non-specific symptoms. Common triggers of excited delirium syndrome are acute drug use, psychiatric illness, or abrupt cessation of antipsychotic medication. It occurs when there is excessive dopamine stimulation in the striatum, combined with acute exposure to catecholaminergic psychoactive substances. A history of schizophrenia, or bipolar disorder are known risk factors for excited delirium syndrome. While agitation and aggression, concomitant with an altered mental status are the hallmark of excited delirium, other medical conditions such as hypoxia, head trauma, hypoglycaemia, hyperglycaemia, and infection can produce similar symptoms, and need to be ruled out as causes. Safety is paramount in the management of excited delirium, with the use of physical and chemical restraint being commonplace. Rhabdomyolysis often occurs when the patient is able to exercise extreme exertion against the restraints and this should be minimised to prevent the risk of cardiac arrest.