Hypoactive delirium

#### What you need to know Hypoactive delirium tends to capture less clinical attention than hyperactive delirium. Like all delirium, it can occur in a variety of patients and settings and will consequently be encountered by many groups of doctors. It can be more difficult to recognise, and is associated with worse outcomes, than hyperactive delirium. This article outlines when to suspect, assess, and appropriately manage patients with hypoactive delirium. Hypoactive delirium is dominated by symptoms of drowsiness and inactivity, whereas hyperactive delirium is characterised by restlessness and agitation (see infographic).1 Some people experience a mix of these subtypes.2 All forms of delirium are a syndrome characterised by acute changes from baseline in a patient’s ability to maintain attention and awareness, accompanied by other disturbances in cognition that develop over a short period of time (hours to days) and tend to fluctuate in severity over the course of a day (see box 1).3 It can arise as a physiological consequence of a medical condition, substance withdrawal or intoxication state, exposure to toxins, or a combination of these. #### Box 1: DSM 5 classification of delirium and techniques for diagnosis3 In order for a patient to be diagnosed with delirium they must display all of the following: 1. Disturbance in attention (reduced ability to direct, focus, sustain, and shift attention) and awareness (reduced orientation to the environment).