Abstract
AIM: This study aimed to evaluate the phenomenology of delirium in patients admitted in a Respiratory Intensive Care Unit (RICU). METHODS: Consecutive patients admitted to RICU were screened for delirium using Richmond Agitation-Sedation Scale (RASS), Confusion Assessment Method for ICU (CAM-ICU) assessment tool and those found positive for delirium were evaluated by a psychiatrist to confirm the diagnosis. Those with a diagnosis of delirium as per the psychiatrist were evaluated on Delirium Rating Scale-Revised-98 (DRS-R-98) to study phenomenology. RESULTS: All the 75 patients fulfilled the criteria of "acute onset of symptoms" and "presence of an underlying physical disorder" as per the DRS-R-98. Commonly seen symptoms of delirium included disturbances in attention (100%), thought process abnormality (100%), fluctuation in symptoms (97.33%) disturbance in, sleep-wake cycle, language disturbance (94.7%), disorientation (81.33%), and short-term memory impairments (73.33%). No patient had delusions and very few (5.3%) reported perceptual disturbances. According to RASS subtyping, hypoactive delirium was the most common subtype (n = 34; 45.33%), followed by hyperactive subtype (n = 28; 37.33%) and a few patients had mixed subtype of delirium (n = 13; 17.33%). Factor structure of DRS-R-98 symptoms yielded 3 factors (Factor-1: cognitive factor; Factor-2: motoric factor; Factor-3; thought, language, and fluctuation factor). CONCLUSION: The phenomenology of delirium in ICU patients is similar to non-ICU patients, but hypoactive delirium is the most common subtype.