Person:

Fong, Tamara

Objectives: To examine the effect of hospital readmission on functional recovery after elective surgery in older adults.

Design: Prospective cohort of individuals aged 70 and older undergoing elective surgery, enrolled from June 2010 to August 2013.

Setting: Two academic medical centers.

Participants: Community-dwelling older adults (N = 566; mean age ± standard deviation 77 ± 5) undergoing major elective surgery and expected to be admitted for at least 3 days.

Measurements: Readmission was assessed in multiple interviews with participants and family members over 18 months and validated against medical record review. Physical function was assessed according to ability to perform instrumental activities of daily living (IADLs) and activities of daily living (ADL), Medical Outcomes Study 12-item Short-Form Survey Physical Component Summary score, and a standardized functional composite.

Results: Two hundred fifty-five (45%) participants experienced 503 readmissions. Readmissions were associated with delays in functional recovery in all measures of physical function. Having two or more readmissions over 18 months was associated with persistent and significantly greater risk of IADL dependence (relative risk (RR) = 1.8, 95% confidence interval (CI) = 1.5-2.3) and ADL dependence (RR = 3.3, 95% CI = 1.7-6.4). Degree of functional impairment increased progressively with number of readmissions. Readmissions within 2 months resulted in delayed functional recovery to baseline by 18 months, and readmissions between 12 and 18 months after surgery resulted in loss of functional recovery previously achieved.

Conclusion: Readmission after elective surgery may contribute to delays in functional recovery and persistent functional deficits in older adults.

Background Cognitive and brain reserve theories suggest that aspects of neural architecture or cognitive processes modify the impact of neuropathological processes on cognitive outcomes. While frequently studied in the context of dementia, reserve in delirium is relatively understudied.

Methods We examined the association of three markers of brain reserve (head circumference, MRI-derived brain volume, and leisure time physical activity) and five markers of cognitive reserve (education, vocabulary, cognitive activities, cognitive demand of lifetime occupation, and interpersonal demand of lifetime occupation) and the risk of postoperative delirium in a prospective observational study of 566 older adults free of dementia undergoing scheduled surgery.

Findings Twenty four percent of patients (135/566) developed delirium during the postoperative hospitalization period. Of the reserve markers examined, only the Wechsler Test of Adult Reading (WTAR) was significantly associated with the risk of delirium. A one-half standard deviation better performance on the WTAR was associated with a 38% reduction in delirium risk (P = 0·01); adjusted relative risk of 0·62, 95% confidence interval 0·45–0·85.

Interpretation In this relatively large and well-designed study, most markers of reserve fail to predict delirium risk. The exception to this is the WTAR. Our findings suggest that the reserve markers that are important for delirium may be different from those considered to be important for dementia.

Purpose This study is to investigate whether measurement of arterial transit time (ATT) can improve the accuracy of Arterial Spin Labeling (ASL) cerebral blood flow (CBF) quantification in an elderly cohort due to the potentially prolonged ATT in the cohort.

Methods We employed a 1 minute, low resolution (12 mm in plane), sequential multi-delay ATT measurement (both with and without vessel suppression) approach to characterize and correct ATT errors in CBF imaging of an elderly, clinical cohort. 140 non-demented subjects greater than 70 years old were imaged at 3 Tesla with a single delay, volumetric continuous ASL sequence and also with the fast ATT measurement method. 9 healthy young subjects (28 ± 6 years old) were also imaged.

Results ATT’s measured without vessel suppression (superior frontal: 1.51 ± 0.27s) in the elderly were significantly shorter than those with suppression (p<0.0001). Correction of CBF for ATT significantly increased average CBF in multiple brain regions where ATT was longer than the post-labeling delay (p < 0.01) and decreased inter-subject variability of CBF in frontal, parietal, and occipital regions (p <10−8). Measured ATT with vessel suppression was significantly longer in the elderly subjects (e.g. superior frontal: 1.76 ± 0.25s) compared to the younger adults (superior frontal: 1.59 ± 0.19s) in basal ganglia and frontal cortical regions (p < 0.05).

Conclusions The ATT measurement is beneficial for imaging of elderly clinical populations. If ATT mapping is not feasible or available, post-labeling delays of 2–2.3s should be used for elderly populations based on longest measured regional ATTs.

Background Cognitive impairment is a well-recognized risk factor for delirium. Our goal was to determine if the level of cognitive performance across the non-demented cognitive ability spectrum is correlated with delirium risk, and to gauge the importance of cognition relative to other known risk factors for delirium.

Methods The SAGES (Successful Aging after Elective Surgery) study enrolled 566 adults age ≥ 70 years scheduled for major surgery. Patients were assessed preoperatively and daily during hospitalization for the occurrence of delirium using the Confusion Assessment Method. Cognitive function was assessed preoperatively with an 11-test neuropsychological battery combined into a composite score for general cognitive performance (GCP). We examined the risk for delirium attributable to GCP, as well as demographic factors, vocabulary ability, and informant-rated cognitive decline, and compared the strength of association to risk factors identified in a previously published delirium prediction rule for delirium.

Results Delirium occurred in 135 (24%) patients. Lower GCP score was strongly and linearly predictive of delirium risk (RR = 2.0 per each half standard deviation difference in GCP score, 95% confidence interval, 1.5, 2.5). This effect was not attenuated by statistical adjustment for demographics, vocabulary ability, and informant-rated cognitive decline. The effect was stronger than, and largely independent from, both standard delirium risk factors and comorbidity.

Conclusions Risk of delirium is linearly and strongly related to presurgical cognitive performance level even at levels above the population median, which would be considered unimpaired.