Stability of Postoperative Delirium Psychomotor Subtypes in Individuals with Hip Fracture

ObjectivesTo determine the stability of psychomotor subtypes of delirium over time and identify characteristics associated with delirium psychomotor subtypes in individuals undergoing surgical repair of hip fracture. DesignProspective cohort study. SettingThe Transfusion Trigger Trial for Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair Cognitive Ancillary Study was conducted at 13 participating sites from 2008 to 2009. ParticipantsIndividuals who had undergone surgical repair of hip fracture (N=139). MeasurementsDelirium was assessed up to four times postoperatively using the Confusion Assessment Method (CAM) and the Memorial Delirium Assessment Scale. Psychomotor subtypes of delirium were categorized as hypoactive, hyperactive, mixed, and normal psychomotor activity. ResultsIncidence of postoperative delirium was 41% (n=57). Of 90 CAM-positive (CAM+) observations, 56% were hypoactive, 10% were hyperactive, 21% were mixed, and 14% had normal psychomotor symptoms. Of 26 participants with more than one CAM+ assessment, 50% maintained subtype stability over time. Participants with hypoactive or normal psychomotor symptoms (n=31) were less likely to have chart documentation of delirium than participants with any hyperactive symptoms (n=19) (22% vs 58%, P=.009). ConclusionPsychomotor subtypes of delirium often fluctuate from assessment to assessment, rather than representing fixed categories of delirium. Hypoactive delirium is the most common presentation of delirium but is the least likely to be documented by healthcare providers.