Subtle attentional deficits in the absence of dementia are associated with an increased risk of post-operative delirium.
BACKGROUND
Previously, key studies of the risk profile for post-surgical delirium have focused on general medical and non-elective patients, few have examined elective cohorts. Accurate prediction is imperative for clinical trials and prevention strategies.


OBJECTIVE
Our hypothesis was that subtle pre-operative impairments of attention will be associated with risk of post-operative delirium.


METHODS
A prospective study evaluating pre- and post-operative neuropsychological performance in older (> or =70) consecutive elective admissions for orthopaedic surgery, and free of dementia (n = 100) was initiated in a general medical hospital.


RESULTS
Pre-operative attentional deficits were closely associated with delirium. Patients who developed post-surgical delirium had significantly slower mean reaction times (p < or = 0.011) and greater variability of reaction time (p = 0.017). A 4- to 5-fold increased risk of delirium was observed for people one standard deviation above the sample means on these variables.


CONCLUSIONS
The present study describes a measurement of attentional performance which could form the basis of a neuropsychological marker of delirium.
Lowery
David P
DP
University of Newcastle upon Tyne, Newcastle upon Tyne, UK. d_lowery_home@yahoo.co.uk
Wesnes
Keith
K
Ballard
Clive G
CG
D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications* / Q000175:diagnosis; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000150:complications* / Q000175:diagnosis; D003693:Delirium / Q000209:etiology* / Q000523:psychology; D017558:Elective Surgical Procedures / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000209:etiology* / Q000523:psychology; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology; D012307:Risk Factors; D018709:Statistics, Nonparametric