Diabetes, but Not Hypertension and Obesity, Is Associated with Postoperative Cognitive Dysfunction.

BACKGROUND/AIMS: Older people undergoing surgery are at risk of developing postoperative cognitive dysfunction (POCD), but little is known of risk factors predisposing patients to POCD. Our objective was to estimate the risk of POCD associated with exposure to preoperative diabetes, hypertension, and obesity. METHODS: Original data from 3 randomised controlled trials (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis on diabetes, hypertension, baseline blood pressure, obesity (BMI ≥30 kg/m2), and BMI as risk factors for POCD in multiple logistic regression models. Risk estimates were pooled across the 3 studies. RESULTS: Analyses totalled 1,034 patients. POCD occurred in 5.2% of patients in DECS, in 9.4% in SuDoCo, and in 32.1% of patients in OCTOPUS. After adjustment for age, sex, surgery type, randomisation, obesity, and hypertension, diabetes was associated with a 1.84-fold increased risk of POCD (OR 1.84; 95% CI 1.14, 2.97; p = 0.01). Obesity, BMI, hypertension, and baseline blood pressure were each not associated with POCD in fully adjusted models (all p > 0.05). CONCLUSION: Diabetes, but not obesity or hypertension, is associated with increased POCD risk. Consideration of diabetes status may be helpful for risk assessment of surgical patients.

Association of obesity, diabetes and hypertension with cognitive impairment in older age.

BACKGROUND: Age-related cognitive impairment is rising in prevalence but is not yet fully characterized in terms of its epidemiology. Here, we aimed to elucidate the role of obesity, diabetes and hypertension as candidate risk factors. METHODS: Original baseline data from 3 studies (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis of cross-sectional associations of diabetes, hypertension, blood pressure, obesity (body mass index [BMI] ≥30 kg/m2) and BMI with presence of cognitive impairment in log-binomial regression analyses. Cognitive impairment was defined as scoring more than 2 standard deviations below controls on at least one of 5-11 cognitive tests. Underweight participants (BMI<18.5 kg/m2) were excluded. Results were pooled across studies in fixed-effects inverse variance models. RESULTS: Analyses totaled 1545 participants with a mean age of 61 years (OCTOPUS) to 70 years (SuDoCo). Cognitive impairment was found in 29.0% of participants in DECS, 8.2% in SuDoCo and 45.6% in OCTOPUS. In pooled analyses, after adjustment for age, sex, diabetes and hypertension, obesity was associated with a 1.29-fold increased prevalence of cognitive impairment (risk ratio [RR] 1.29; 95% CI 0.98, 1.72). Each 1 kg/m2 increment in BMI was associated with 3% increased prevalence (RR 1.03; 95% CI 1.00, 1.06). None of the remaining risk factors were associated with impairment. CONCLUSION: Our results show that older people who are obese have higher prevalence of cognitive impairment compared with normal weight and overweight individuals, and independently of co-morbid hypertension or diabetes. Prospective studies are needed to investigate the temporal relationship of the association.

Effects of dexamethasone on cognitive decline after cardiac surgery: a randomized clinical trial.

BACKGROUND: Cardiac surgery can be complicated by postoperative cognitive decline (POCD), which is characterized by impaired memory function and intellectual ability. The systemic inflammatory response that is induced by major surgery and cardiopulmonary bypass may play an important role in the etiology of POCD. Prophylactic corticosteroids to attenuate the inflammatory response may therefore reduce the risk of POCD. The authors investigated the effect of intraoperative high-dose dexamethasone on the incidence of POCD at 1 month and 12 months after cardiac surgery. METHODS: This multicenter, randomized, double-blind, placebo-controlled trial is a preplanned substudy of the DExamethasone for Cardiac Surgery trial. A total of 291 adult patients undergoing cardiac surgery with cardiopulmonary bypass were recruited in three hospitals and randomized to receive dexamethasone 1 mg/kg (n = 145) or placebo (n = 146). The main outcome measures were incidence of POCD at 1- and 12-month follow-up, defined as a decline in neuropsychological test performance beyond natural variability, as measured in a control group. RESULTS: At 1-month follow-up, 19 of 140 patients in the dexamethasone group (13.6%) and 10 of 138 patients in the placebo group (7.2%) fulfilled the diagnostic criteria for POCD (relative risk, 1.87; 95% CI, 0.90 to 3.88; P = 0.09). At 12-month follow-up, 8 of 115 patients in the dexamethasone group (7.0%) and 4 of 114 patients (3.5%) in the placebo group had POCD (relative risk, 1.98; 95% CI, 0.61 to 6.40; P = 0.24). CONCLUSION: Intraoperative high-dose dexamethasone did not reduce the risk of POCD after cardiac surgery.

Intraoperative dexamethasone and delirium after cardiac surgery: a randomized clinical trial.

BACKGROUND: Delirium is common after cardiac surgery and may be partly related to the systemic inflammatory response triggered by the surgery and the use of cardiopulmonary bypass. We hypothesized that intraoperative administration of high-dose dexamethasone, a drug with potent anti-inflammatory effects, would reduce the incidence of delirium at any time point during the first 4 postoperative days after cardiac surgery. METHODS: This was a single-center substudy within a larger, multicenter placebo-controlled randomized clinical trial, the Dexamethasone for Cardiac Surgery (DECS) trial that randomized patients ≥18 years, undergoing cardiac surgery with cardiopulmonary bypass, to receive, in a double-blind fashion, either dexamethasone 1 mg/kg or placebo at the induction of anesthesia. Over the first 4 postoperative days, we compared between groups the incidence of delirium (based on the Confusion Assessment Method adapted for the intensive care unit, or after intensive care unit discharge, by the Confusion Assessment Method, accompanied by chart review), restraint use, and administered haloperidol, benzodiazepines, and opioids. Data were analyzed according to the intention-to-treat principle. The proportion of patients with delirium in the dexamethasone versus the placebo group was compared using the odds ratio (OR) with a 95% confidence interval (CI). The proportion also was compared using logistic regression to adjust for common baseline variables that might confound the presence of delirium between the 2 groups. RESULTS: Of 768 eligible patients, 737 subjects (96.0%) had complete data. The incidence of delirium was similar between the dexamethasone (14.2%) and placebo (14.9%) groups (crude OR = 0.95, 95% CI, 0.63-1.43; adjusted OR = 0.85, 95% CI, 0.55-1.31). Among patients who developed delirium, the median (interquartile range) duration of delirium was similar between the dexamethasone and placebo groups (2 [1-3] vs 2 [1-2] days, respectively, P = 0.45; WMWodds 0.98, 95% CI, 0.83-1.17). Restraint use and the administration of haloperidol, benzodiazepines, and opioids were also similar between the 2 groups. CONCLUSIONS: The intraoperative administration of dexamethasone did not reduce the incidence or duration of delirium in the first 4 days after cardiac surgery.

Cognitive outcomes 7.5 years after angioplasty compared with off-pump coronary bypass surgery.

BACKGROUND: Off-pump coronary artery bypass grafting and percutaneous coronary intervention are both associated with cognitive decline, but limited data are available on long-term outcomes. This study compared long-term cognitive outcomes between patients managed with percutaneous coronary intervention and off-pump coronary artery bypass grafting. METHODS: A multicenter trial in the Netherlands randomized 280 patients to percutaneous coronary intervention or off-pump coronary artery bypass grafting. Cognitive performance 7.5 years after randomization was assessed through a battery of 9 neuropsychologic tests and summarized into a combined Z-score. RESULTS: After 7.5 years, cognitive assessment could be performed in 81% of the 249 surviving patients. Better cognitive performance was observed in the off-pump coronary artery bypass grafting group (combined Z-score 0.11 for off-pump coronary artery bypass grafting versus -0.17 for percutaneous coronary intervention; difference 0.28, 95% confidence interval 0.08 to 0.47, p < 0.01). However, this difference became nonsignificant (Z-score difference 0.14, 95% confidence interval -0.01 to 0.29, p = 0.08) after multivariable adjustment for potential confounders. CONCLUSIONS: At 7.5 years follow-up, off-pump coronary artery bypass grafting patients had a similar or perhaps even better cognitive performance compared with percutaneous coronary intervention patients.

Postoperative cognitive decline.

Memory loss and lack of concentration are symptoms that frequently occur in patients who have undergone a surgical procedure. Although cognitive function can be assessed using neuropsychological tests, reliable diagnosis of postoperative cognitive decline (POCD) appears to be difficult. Therefore, the true incidence of POCD is unknown. Severe POCD, which is apparent even without neuropsychological testing, is reported most frequently after cardiac and hip-replacement surgery. In these cases, POCD probably reflects microembolic brain injury. Apart from the nature of the surgical procedure, advanced age is the most important risk factor for POCD. The anesthetic technique is not a determinant of POCD: the risk of POCD appears to be similar after both general and regional anesthesia.

Presence of coronary collaterals is associated with a decreased incidence of cognitive decline after coronary artery bypass surgery.

OBJECTIVE: Coronary artery bypass grafting (CABG) is associated with significant cerebral morbidity, usually manifested as cognitive decline or stroke. The underlying mechanism leading to cognitive decline is still unclear. Presence of coronary collateral arteries, which may reflect an overall better cardiovascular condition, recently appeared to relate to a better cardiac outcome after CABG. In this study, we investigated the hypothesis that presence of coronary collaterals is associated with less cognitive decline after coronary artery bypass grafting. METHODS: Data from 281 patients undergoing first-time coronary artery bypass grafting were used. Presence of coronary collaterals was determined on the preoperative angiogram. Cognitive function was evaluated before the operation, at 3 and 12 months and 5 years thereafter by standardised neuropsychological assessment. Cognitive decline in individuals was determined by calculating the reliable change score, a cognitive change score corrected for natural testing variability and practice effects. RESULTS: Cognitive decline was found in 19 (8%) patients at 3 months, in 31 (12%) patients at 12 months and in 82 (34%) at 5 years follow-up. Presence of coronary collaterals was independently associated with a better cognitive outcome at both 3 months (odds ratio (OR) 0.30; 95% confidence interval (CI) 0.09-0.95; p=0.04) and 12 months (OR 0.42; 95% CI 0.18-0.97; p=0.04) after coronary artery bypass grafting. At 5 years, the OR was 0.57 (95% CI 0.31-1.05; p=0.07). CONCLUSIONS: In patients undergoing first-time coronary artery bypass grafting, presence of coronary collaterals is associated with a decreased risk of cognitive decline at both 3 and 12 months of follow-up. This trend persists at 5-year follow-up. Preoperative differences in the cardiac vascular condition may therefore predict cognitive outcome in patients undergoing coronary artery bypass grafting.