Research Abstract: Free Paper - Poster Presentation Only Australian and New Zealand Society for Geriatric Medicine Annual Scientific Meeting 2023

Aims Delirium has conventionally been considered a disorder of consciousness and we explore possible measures.

Methods First, a critique of the delirium diagnostic criteria and review of the historical context with respect to consciousness is considered. Second, a review of consciousness measures used in routine clinical assessment is conducted. Third, an opportunity for consideration of an expanded view of consciousness is undertaken.

Results Thin measures of consciousness, comprising alertness and arousal, are most commonly used in delirium assessment used but are not representative of the multidimensionality of consciousness (see table 1). Access consciousness, involving attention and working memory, are already well represented within existing delirium screening tools. Phenomenal consciousness, or the 'what its like' of subjective experience provides a more multidimensional measure of consciousness that is not currently used in delirium diagnosis. Three candidate dimensions of consciousness are identified as the pre-reflective state, phenomenal experience and reflective thought.

Conclusions Pre-reflective state, phenomenal experience and reflective thought are promising dimensions of phenomenal consciousness that could be applied to the diagnosis of delirium.  

Table 1 showing examples of the ten most commonly cited screening tools in delirium and incorporation of measures of consciousness