PURPOSE: To determine if elderly patients undergoing hip surgery became 
delirious postoperatively and, if so, whether age and/or time of day were 
related to delirium.
DESIGN: Repeated measures.
SAMPLE: A convenience sample of 70 hip surgery patients 60 years of age and 
older at a large Midwestern teaching hospital were studied. Patients were 
excluded who were unconscious, unable to hear, see, and/or verbally communicate 
in English. Patients were also excluded who had a known history of dementia, 
Alzheimer's dementia, addiction to alcohol and/or sedative hypnotics, functional 
psychosis, or any other psychiatric diagnosis. Of the 70 patients, 37 were 
female and 33 were male. Mean age of the patients was 72.9 years (S.D. = 8.13). 
Patients were placed into one of three groups: Group 1--age 60 to 69 years (n = 
25); Group 2--age 70 to 79 years (n = 25); or Group 3--80 years and older (n = 
20). The most common procedure for all groups was total hip replacement (n = 
48).
METHOD: Data were collected primarily by both objective and subjective 
assessment of the patients. Both the Folstein's Mini Mental Status Exam (MMSE) 
and the NEECHAM Confusion Tool were used to collect data. Chart reviews provided 
additional data. Patients were assessed preoperatively to obtain baseline 
assessment and screen out patients with preexisting confusion. Assessments were 
then done once in the morning and once in the evening for 5 days following 
surgery.
MAIN RESEARCH CLASSIFICATIONS: Delirium, sundowning, sundown syndrome.
FINDINGS: The MMSE and NEECHAM were found to be highly correlated: Morning 
NEECHAM vs morning MMSE (Correlation Coefficient = .6515; p = .000), evening 
NEECHAM vs evening MMSE (Correlation Coefficient = .8301; p = .000). A test of 
repeated measures was used to examine the data. The Within factor was time, the 
Between factor was age, and the interaction effect was age by time of day. 
Dependent variables were total NEECHAM scores and total MMSE scores, in addition 
to total scores of these tests' subsections. An alpha level of .05 was used for 
all statistical tests. Age had a significant main effect on the NEECHAM (F = 
7.44; p = .001) and MMSE (F = 6.04; p = .004). Time did not have a significant 
effect on either the MMSE (F = .00; p = .953) or the NEECHAM (F = .43; p = 
.513). There was no statistically significant interaction between age and time 
of day (NEECHAM, F = .97, p = .384 and MMSE (F = .19, p = .826). No subjects 
were assessed as demented per the MMSE. Only 12 episodes of acute confusion were 
noted using the NEECHAM.
CONCLUSION: Patients in this population rarely, if ever, became confused. The 
older the individual, the more likely he/she was to have confusion. Time of day 
was neither significant in development of delirium nor on mental status 
assessment scores in this population.
IMPLICATIONS FOR NURSING RESEARCH: Current research literature notes that 10% to 
50% of elderly postoperative patients experience delirium. Patients who have had 
femoral neck fractures can experience delirium three times more than patients 
having nonorthopaedic surgery. This study found that delirium in hip surgery 
patients is rare. A study of the more subtle components of delirium such as 
attention and memory might reveal less obvious changes in mental status 
following surgery. Type of orthopaedic surgery also might impact incidence of 
delirium. A comparative study between elderly total knee and total hip 
replacement patients would be interesting. Studying patients who have emergency 
hip surgery related to fracture in comparison to patients having elective hip 
surgery for degenerative conditions might identify other etiologies for delirium 
following hip surgery. Fatigue rather than time of day might be studied to 
observe whether it has a significant impact on mental status or delirium scores.