Postoperative cognitive disorders in the elderly

TWO DISTINCT CATEGORIES: Postoperative cognitive disorders include delirium and long-term cognitive dysfunction. DELERIUM: Delirium is an acute state occurring early during the postoperative period. It may be considered as an acute cerebral insufficiency which may be consecutive both to the negative effects of aging and chronic illness on cognitive function, and to the cerebral impact of operative stress. In addition, precipitating postoperative medical factors may facilitate cerebral failure. Only a few studies have been devoted to prevention programs aimed at reducing the risk of postoperative delirium. Nevertheless, we can hypothesize that a preoperative gerontology assessment would be effective in determining risk factors of delirium in old patients and thus enable proposing individual postoperative management. LONG-TERM COGNITIVE DYSFUNCTION: The definition of this clinical picture is less precise than delirium. Long-term cognitive dysfunction corresponds to a loss of cognitive performance in the weeks and months after anesthesia. The IPOCD1 study conducted in a large cohort of elderly patients has shown that postoperative cognitive dysfunction was present in 25.8% of patients 1 week after surgery and in 9.9% 3 months after surgery. One to two years after surgery, cognitive dysfunction was observed in 10.4% of patients compared with 10.6% in a control population of non-operated patients. We would suggest that in many cases, postoperative cognitive dysfunction may result from preoperative dementia unmasked by surgery.     

Higher tacrolimus trough levels on days 2–5 post-renal transplant are associated with reduced rates of acute rejection

Abstract:  We analyzed the association between whole-blood trough tacrolimus (TAC) levels in the first days post-kidney transplant and acute cellular rejection (ACR) rates. Four hundred and sixty-four consecutive, deceased-donor kidney transplant recipients were included. All were treated with a combination of TAC, mycophenolate mofetil and prednisolone. Patients were analyzed in four groups based on quartiles of the mean TAC on days 2 and 5 post-transplant: Group 1: median TAC 11 ng/mL (n = 122, range 2–13.5 ng/mL), Group 2: median 17 ng/mL (n = 123, range 14–20 ng/mL), Group 3: median 24 ng/mL (n = 108, range 20.5–27 ng/mL) and Group 4: median 33.5 ng/mL (n = 116, range 27.5–77.5 ng/mL). A graded reduction in the rates of ACR was observed for each incremental days 2–5 TAC. The one-yr ACR rate was 24.03% (95% CI 17.26–32.88), 22.20% (95% CI 15.78–30.70), 13.41% (95% CI 8.15–21.63) and 8.69% (95% CI 4.77–15.55) for Groups 1–4, respectively (p = 0.003). This study suggests that higher early TACs are associated with reduced rates of ACR at one yr.     

A prospective cohort study evaluating associations among delirium, postoperative cognitive dysfunction, and apolipoprotein E genotype following open aortic repair

Background

Patients undergoing major vascular surgery are at high risk of postoperative delirium and postoperative cognitive dysfunction (POCD). Apolipoprotein E (APOE) is involved in central acetylcholine synthesis, and patients bearing the ε4 genotype (APOE-ε4) are at increased risk of both vascular dementia and peripheral vascular disease. The purpose of this study was to evaluate the associations among delirium, POCD, and APOE-ε4 in patients undergoing open aortic repair.

Methods

Following Research Ethics Board approval and written informed consent, we recruited a cohort of patients ≥ 60 yr of age undergoing open aortic repair. Apolipoprotein E genotyping and a battery of nine neuropsychometric (NP) tests were performed prior to surgery. Delirium was assessed on postoperative days two, four, and discharge using the Confusion Assessment Method. Neuropsychometric testing was repeated at discharge and again three months following surgery. A group of non-surgical patients was used to adjust NP scores using reliable change index methodology. Logistic regression was used to evaluate independent predictors of both delirium and POCD.

Results

Eighty-eight patients underwent surgery, 78 completed NP testing on discharge, and sixty-nine completed NP testing at three months. Delirium was noted in 36% of patients after surgery, while POCD was noted in 62% at discharge and 6% at three months. Delirium predicted POCD at discharge (odds ratio 2.86; 95% confidence intervals 0.99 to 8.27) but not at three months. Apolipoprotein E-ε4 genotype was not associated with either delirium or POCD following adjustment for covariates.

Conclusion

Both delirium and POCD are common following open aortic repair; however, the APOE genotype did not predict either condition. This trial has been registered with ClinicalTrials.gov (NCT00911677).     

Optimal interval and duration of CAM-ICU assessments for delirium detection after cardiac surgery

Study objectiveOur goal was to determine when postoperative delirium first occurs, and to assess evaluation strategies that reliably detect delirium with lowest frequency of testing’.DesignThis was a retrospective study that used a database from a five-center randomized trial.SettingPostoperative cardiothoracic ICU and surgical wards.ParticipantAdults scheduled for elective coronary artery bypass and/or valve surgery.Intervention and measurementsPostoperative delirium was assessed using CAM-ICU questionnaires twice daily for 5 days or until hospital discharge. Data were analyzed using frequency tables and Kaplan-Meier time-to-event estimators, the latter being used to summarize time to first positive CAM-ICU over POD1–5 for all patients for various evaluation strategies, including all assessments, only morning assessment, and only afternoon assessments. Sensitivity for various strategies were compared using McNemar's test for paired proportions.Main resultsA total of 95 of 788 patients (12% [95% CI, 10% to 15%]) had at least 1 episode of delirium within the first 5 postoperative days. Among all patients with delirium, 65% were identified by the end of the first postoperative day. Delirium was detected more often in the mornings (10% of patients) than evenings (7% of patients). Compared to delirium assessments twice daily for five days, we found that twice daily assessments for 4 days detected an estimated 97% (95% CI 91%, 99%) of delirium. Measurements twice daily for three days detected 90% (82%, 95%) of delirium.ConclusionsPostoperative delirium is common, and CAM-ICU assessments twice daily for 4 days, versus 5 days, detects nearly all delirium with 20% fewer assessments. Four days of assessment may usually be sufficient for clinical and research purposes.     

The clock drawing test is a poor screening tool for postoperative delirium and cognitive dysfunction after aortic repair

Background

The Clock Drawing Test (CDT) is a screening tool for dementia that tests a variety of cognitive domains. The CDT takes a maximum of two minutes to complete and might be helpful in identifying postoperative cognitive disorders at the bedside. The objective of this study was to evaluate the accuracy of the CDT in a population at high risk for postoperative cognitive disorders

Methods

In this prospective observational cohort study, patients were recruited who were ≥ 60 yr of age and scheduled for elective open repair of the abdominal aorta. Delirium was assessed using the Confusion Assessment Method (CAM) on postoperative days (POD) 2 and 4 and at discharge. Cognitive function was assessed with neuropsychometric tests before surgery and at discharge. Postoperative cognitive dysfunction (POCD) was determined using the Reliable Change Index. Clock Drawing Tests were administered at all time points. Agreement between the CDT and test for delirium or POCD was assessed with Cohen’s Kappa statistic.

Results

Delirium was noted in 30 of 83 patients (36%; 95% confidence interval [CI] 26 to 46%) during their hospital stay, while POCD was noted in 48 of 78 patients (60%; 95% CI 51 to 72%) at discharge. Agreement between the CDT and CAM was poor at three intervals (Kappa 0.06 to 0.29), as was POCD at discharge (Kappa 0.46). Sensitivity of the CDT was <0.71 for both delirium and POCD at all intervals. False positives and negatives were common.

Conclusion

Agreement between CDT and tests for delirium and POCD was poor; sensitivity was inadequate for a screening test. (ClinicalTrials.gov number, NCT00911677).     

Association between perioperative hypotension and postoperative delirium and atrial fibrillation after cardiac surgery: A post-hoc analysis of the DECADE trial

Study objectiveTo test the hypotheses that in adults having cardiac surgery with cardio-pulmonary bypass, perioperative hypotension increases the risk of delirium and atrial fibrillation during the initial five postoperative days.DesignSub-analysis of the DECADE multi-center randomized trial.SettingPatients who had cardiac surgery with cardiopulmonary bypass at the Cleveland Clinic.InterventionsIn the underlying trial, patients were randomly assigned 1:1 to dexmedetomidine or normal saline placebo.MeasurementsIntraoperative mean arterial pressures were recorded at 1-min intervals from arterial catheters or at 1–5-min intervals oscillometrically. Postoperative blood pressures were recorded every half-hour or more often. The co-primary outcomes were atrial fibrillation and delirium occurring between intensive care unit admission and the earlier of postoperative day 5 or hospital discharge. Delirium was assessed twice daily during the initial 5 postoperative days while patients remained hospitalized with the Confusion Assessment Method for the intensive care unit. Assessments were made by trained research fellows who were blinded to the dexmedetomidine administration.Main resultsThere was no significant association between intraoperative hypotension and delirium, with an adjusted odds ratio of 0.94 (95% CI: 0.81, 1.09; P = 0.419) for a doubling in AUC of mean arterial pressure (MAP) <60 mmHg. An increase in intraoperative AUC of MAP <60 mmHg was not significantly associated with the odds of atrial fibrillation (adjusted odds ratio = 0.99; 95% CI: 0.87, 1.11; P = 0.819). Postoperative MAP <70 mmHg per hour 1.14 (97.5% CI: 1.04,1.26; P = 0.002) and MAP <80 mmHg per hour 1.05 (97.5%: 1.01, 1.10; P = 0.010) were significantly associated with atrial fibrillation.ConclusionsIn patients having cardiac surgery with cardio-pulmonary bypass, neither intraoperative nor postoperative hypotension were associated with delirium. Postoperative hypotension was associated with atrial fibrillation, although intraoperative hypotension was not.     

Cerebral blood flow and cognitive dysfunction after coronary surgery

BACKGROUND: Postoperative cognitive dysfunction after cardiac surgery has been attributed both to embolic events and periods with reduced cerebral perfusion. We investigated whether cognitive dysfunction after coronary surgery is associated with changes in regional cerebral blood flow (CBF) using single photon emission computed tomography. METHODS: Before surgery and at discharge, 15 coronary surgery patients were studied. Global and regional CBF were measured using a brain-dedicated single photon emission computed tomography scanner, and neuropsychological testing with seven subtests was performed. Postoperative cognitive dysfunction was defined as a Z score above 2. Normative single photon emission computed tomography data were available from 26 healthy age-matched controls. RESULTS: Preoperative global CBF was significantly lower in patients compared with controls (53.7 versus 46.1 mL/100 g/min, p = 0.006). After surgery, global CBF significantly decreased in the patient group (46.1 versus 38.6 mL/100 g/min, p = 0.0001). No significant differences were detected in regional CBF. Cognitive dysfunction was identified in 4 of the 15 patients (26.7%, 95% CI 7.8% to 55.1%). No correlation was found between the neuropsychological Z score and global or regional CBF. CONCLUSIONS: The significant decrease in CBF after coronary surgery was uniformly distributed and was not correlated to postoperative cognitive dysfunction.     

Association of postoperative delirium with cognitive outcomes: A meta-analysis

Study objectiveTo determine the association between postoperative delirium (POD) and cognitive outcomes at least 1 month after surgery in elderly patients, and synthesize the dynamic risk trajectory of cognition impairment after POD.DesignMeta-analysis searching PubMed, Cochrane and EMBASE from inception to November 1, 2020. The terms postoperative delirium, delirium after surgery, postsurgical delirium, postoperative cogniti*, postoperative cognitive dysfunction, postoperative cognition decline, cognitive decline, cognitive impair* and dement* were searched alone or in combination.MeasurementsInclusion criteria were prospective cohort studies investigating the association between POD and cognitive outcomes in patients aged ≥60 years underwent surgery. The primary outcome was the association between POD and cognitive outcomes at 1 or more months after surgery. We considered cognitive outcomes measured up to 12 months after surgery as short-term and beyond 12 months as long-term. Two authors performed the study screening, data extraction and quality assessments. Effect sizes were calculated as Hedges g or Odds ratio (OR) based on random- and fixed-effects models. Meta-regression was conducted to analyze the role of potential contributors to heterogeneity.Main resultsEighteen studies were included. Our result showed a significant and medium association between POD and cognitive outcomes after at least 1 month postoperatively (g = 0.61 95% CI 0.43–0.79; I² = 65.1%), indicating that patients with POD were associated with worse cognitive outcomes. The association of POD with short- and long-term cognitive impairment were also both significant (short-term: g = 0.46 95% CI 0.24–0.68; I² = 53.1%; and long-term: g = 0.82 95% CI 0.57–1.06; I² = 57.1%). A multivariate meta-regression suggested that age and measure of delirium were significant sources of heterogeneity. POD was also associated with the significant risk for dementia (OR = 6.08 95% CI 3.80–9.72; I² = 0) as well as attention (OR = 1.74 95% CI 1.13–2.68; I² = 0), executive (OR = 1.33 95% CI 1.00–1.80; I² = 0) and memory impairment (OR = 1.59 95% CI 1.20–2.10; I² = 43.0%). Additionally, our results showed that the risk trajectory for cognitive decline associated with POD within five years after surgery revealed exponential growth.ConclusionsThis is the first meta-analysis quantifying the association between POD and cognitive outcomes. Our results showed that POD was significantly associated with worse cognitive outcomes, including short- and long-term cognitive outcomes following surgery.     

Cognitive dysfunction 1-2 years after non-cardiac surgery in the elderly. ISPOCD group. International Study of Post-Operative Cognitive Dysfunction

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a well-recognised complication of cardiac surgery, but evidence of POCD after general surgery has been lacking. We recently showed that POCD was present in 9.9% of elderly patients 3 months after major non-cardiac surgery. The aim of the present study was to investigate whether POCD persists for 1-2 years after operation. METHODS: A total of 336 elderly patients (median age 69 years, range 60-86) was studied after major surgery under general anesthesia. Psychometric testing was performed before surgery and at a median of 7, 98 and 532 days postoperatively using a neuropsychological test battery with 7 subtests. A control group of 47 non-hospitalised volunteers of similar age were tested with the test battery at the same intervals. RESULTS: 1-2 years after surgery, 35 out of 336 patients (10.4%, CI: 7.2-13.7%) had cognitive dysfunction. Three patients had POCD at all three postoperative test sessions (0.9%). From our definition of POCD, there is only a 1:64000 likelihood that a single subject would have POCD at all three test points by chance. Logistic regression analysis identified age, early POCD, and infection within the first three postoperative months as significant risk factors for long-term cognitive dysfunction. Five of 47 normal controls fulfilled the criteria for cognitive dysfunction 1-2 years after initial testing (10.6%, CI: 1.8-19.4%), i.e. a similar incidence of age-related cognitive impairment as among patients. CONCLUSION: POCD is a reversible condition in the majority of cases but may persist in approximately 1% of patients.     

Postoperative cognitive dysfunction in middle-aged patients

BACKGROUND: Postoperative cognitive dysfunction (POCD) after noncardiac surgery is strongly associated with increasing age in elderly patients; middle-aged patients (aged 40-60 yr) may be expected to have a lower incidence, although subjective complaints are frequent. METHODS: The authors compared the changes in neuropsychological test results at 1 week and 3 months in patients aged 40-60 yr, using a battery of neuropsychological tests, with those of age-matched control subjects using Z-score analysis. They assessed risk factors and associations of POCD with measures of subjective cognitive function, depression, and activities of daily living. RESULTS: At 7 days, cognitive dysfunction as defined was present in 19.2% (confidence interval [CI], 15.7-23.1) of the patients and in 4.0% (CI, 1.6-8.0) of control subjects (P < 0.001). After 3 months, the incidence was 6.2% (CI, 4.1-8.9) in patients and 4.1% (CI, 1.7-8.4) in control subjects (not significant). POCD at 7 days was associated with supplementary epidural analgesia and reported avoidance of alcohol consumption. At 3 months, 29% of patients had subjective symptoms of POCD, and this finding was associated with depression. Early POCD was associated with reports of lower activity scores at 3 months. CONCLUSIONS: Postoperative cognitive dysfunction occurs frequently but resolves by 3 months after surgery. It may be associated with decreased activity during this period. Subjective report overestimates the incidence of POCD. Patients may be helped by recognition that the problem is genuine and reassured that it is likely to be transient.     

Can we identify risk factors for postoperative delirium in cardiac coronary patients? Our experience

Introduction: Delirium is a temporary mental disorder that frequently occurs among elderly hospitalized patients. Patients who undergo cardiac operations have an increased risk of postoperative delirium, which is associated with higher mortality and morbidity rates, a prolonged hospital stay, and reduced cognitive and functional recovery.Patients and Methods: In our prospective study, we included 370 consecutive adult patients who underwent on-pump coronary artery surgery between January 1, 2011, and July 1, 2011. We selected 21 potential risk factors and divided them into preoperative, intraoperative, and postoperative groups. Delirium was diagnosed with the Confusion Assessment Method.Results: Postoperative delirium was diagnosed in 74 patients (20%). Four predictive factors were associated with postoperative delirium: diabetes mellitus, cerebrovascular disease, peripheral vascular disease, and prolonged intubation (P < .05).Conclusion: Three of the four predictive factors significantly associated with delirium are preoperative. They are relatively easy to measure and can be used to identify patients at higher risk. Fast extubation of these patients and preventive interventions can be taken to prevent negative consequences of this postoperative complication.     

Postoperative delirium: the importance of pain and pain management

Postoperative delirium is common in geriatric patients. Few studies have examined events in the postoperative period that may contribute to the occurrence of postoperative delirium. We hypothesized that postoperative delirium is related to postoperative pain and/or pain management strategy. Patients aged > or =65 years who were scheduled for major noncardiac surgery were studied. A structured interview was conducted preoperatively and for the first 3 postoperative days to determine the presence of delirium using the Confusion Assessment Method. The method of postoperative pain management, as well as pre- and postoperative medications for the first 3 days, was collected. Pre- and postoperative pain at rest and with movement was recorded using the Visual Analog Scale. Three hundred thirty-three patients, with a mean age of 74 +/- 6 years, were studied. After surgery, 46% of patients developed postoperative delirium. By multivariate logistic regression, age (odds ratio [OR], 2.5; 95% confidence interval [CI] 1.5 to 4.2), moderate (OR, 2.2; 95% CI 1.2 to 4.0) and severe (OR, 3.7; 95% CI 1.5 to 9.0) preoperative resting pain, and increase in level of pain from baseline to postoperative day one (OR, 1.1; 95% CI 1.01 to 1.2) were independently associated with a greater risk for the development of postoperative delirium. In contrast, patients who used oral opioid analgesics as their sole means of postoperative pain control were at decreased risk of developing delirium in comparison with those who used opioid analgesics via IV patient-controlled analgesia technique (OR, 0.4; 95% CI 0.2 to 0.7). These results validate our hypothesis that pain and pain management strategies are important factors related to the development of postoperative delirium in elderly patients.     

Risk factors and prevalence of perioperative cognitive dysfunction in abdominal aneurysm patients

BACKGROUND: Perioperative delirium is common in high-risk surgery and is associated with age, education, preoperative cognitive functioning, pre-existing medical conditions, and postoperative complications. We investigated these factors as well as lifestyle and demographic variables by using cognitive measures that were more sensitive than those used in previous studies. METHODS: Extensive medical and demographic data were collected on 102 patients between 41 and 88 years of age to identify comorbidities and lifestyle considerations preoperatively. Elective abdominal aortic aneurysm surgery was performed under combined general/epidural anesthesia with postoperative epidural analgesia. A battery of sensitive, cognitive measures was administered preoperatively, at the time of discharge from hospital, and 3 months postoperatively. Symptoms of delirium were assessed during the first 6 postoperative days using Diagnostic and Statistical Manual of Mental Disorders-4th Edition criteria. Intraoperative and postoperative data, including medications, vital signs, conduct of the surgery and anesthesia, complications, and details of pain control, were collected. RESULTS: Delirium occurred in 33% of the patients during the first 6 days after surgery. Longer duration of delirium was related to lower education, preoperative depression, and greater preoperative psychoactive medication use. Characteristics of the surgery and hospital stay were unrelated to the development of delirium. Patients who were diagnosed with delirium had lower cognitive scores during each of the three assessment periods, even when controlling for age and education. Logistic regression analysis indicated that the most powerful preoperative predictors of delirium were number of pack years smoked (P = .001), mental status scores (P = .003), and number of psychoactive medications (P = .005). CONCLUSION: A significant proportion of patients undergoing elective abdominal aortic aneurysm repair are susceptible to the development of delirium and are at risk for cognitive dysfunction after surgery. Our findings have implications for promoting long-term lifestyle changes, including smoking cessation and improved management of mental health as risk-reduction strategies.     

The effect of delirium preventive measures on the occurrence of postoperative cognitive dysfunction in older adults undergoing cardiovascular surgery. The DelPOCD randomised controlled trial

Study objectiveThis trial examines the effect of delirium preventive measures on the incidence of postoperative cognitive dysfunction in older adults.DesignIn a randomised approach, a delirium prevention and a standard care group were compared regarding manifestation of postoperative cognitive dysfunction at seven days, three and twelve months postoperatively (primary outcome). To correct for practice effects and age-depended cognitive decline, a control group of age-matched healthy subjects was included.SettingThe trial was conducted at the University Medical Centre Hamburg between 2014 and 2018, data assessment took place in the Anaesthesia Outpatient Clinic and on the surgical ward.PatientsA total of 609 patients ≥60 years scheduled for cardiovascular surgery were enrolled, allocated treatment was received by 284 patients in the delirium prevention and 274 patients in the standard care group.InterventionThe intervention consisted of a delirium prevention bundle including reorientation measures, sleeping aids and early mobilisation. Measurements: Cognitive functions were assessed via neuropsychological testing of attention, executive functions including word fluency, and verbal memory utilizing a computerised test of attentional performance, the trail making test, the digit span subtest from the Wechsler Adult Intelligence Scale-IV, the verbal learning and memory test, and the Regensburg Word Fluency Test. Assessments were performed preoperatively and at three time points postoperatively (one week, three months and 12 months).Main resultsPostoperative cognitive dysfunction was defined as a clinically meaningful decline in at least two out of nine chosen test parameters compared to the preoperative level (reliable change index ≤ − 1.96). The rates of postoperative cognitive dysfunction were 25.9% (delirium prevention group, n = 284) vs. 28.1% (standard care group, n = 274) [X²(1,n = 433) = 0.245;p = 0.621] at postoperative day seven and declined to 7.8% vs. 6.8% [X²(1,n = 219) = 0.081;p = 0.775] and 1.3% vs. 5.6% (p = 0.215, Fisher's exact test) at three and 12 months following surgery, respectively. The postoperative delirium rates did not differ between the two groups (delirium prevention group: 13.4% vs. standard care group: 17.3%). Attentional performance was impaired shortly after surgery, whereas verbal delayed recall was most frequently affected over the whole postoperative period.ConclusionThese findings suggest that an intervention combining specific measures extracted from established postoperative delirium prevention programs did not reduce the rate of postoperative cognitive dysfunction in older adults.     

Postoperative cognitive dysfunction: true deterioration versus random variation

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common complication, especially in the elderly. The aim of this study was to describe how variability in neuropsychological testing could lead to the detection of cognitive improvement and poor consistency of POCD between postoperative test sessions. METHODS: In four published studies performed by the ISPOCD group, we included 2536 patients and 359 healthy controls. Cognitive function was assessed using neuropsychological tests preoperatively and at 7 days and 3 months thereafter, comparing the changes between those at baseline with those after surgery. Postoperative cognitive dysfunction was defined as a Z score greater than 2, and we also defined a corresponding improvement as a Z score less than -2. Consistency of POCD between postoperative test sessions was analyzed and we also assessed test-retest variability using data from healthy control subjects. RESULTS: Improvement in cognitive function was found in 4.2-8.7% of patients after 1 week and in 5.0-7.8% after 3 months. The ratio between incidence of dysfunction and improvement varied in patients between 3.3 and 6.2 early after major surgery. Of those patients who displayed POCD at the 3-month test, 30-48% also had POCD at the previous test at 1 week. The test-retest reliability was between 0.56 and 0.90, except for the error score in Concept Shifting Test, where the values were 0.20 and 0.37. CONCLUSION: Variability in neuropsychological test data contributes to a low consistency between postoperative test sessions but it does not explain the detection of cognitive dysfunction after major surgery.     

A prospective,observational study of cerebrovascular autoregulation and its association with delirium following cardiac surgery

This aim of this prospective observational cohort study was to evaluate any association between postoperatively impaired cerebrovascular autoregulation and the onset of delirium following cardiac surgery. Previous studies have shown that impaired intra-operative cerebrovascular autoregulation during cardiopulmonary bypass is associated with delirium. However, postoperative changes in cerebrovascular autoregulation and its association with delirium have not been investigated. One-hundred and eight consecutive adult cardiac surgical patients without baseline cognitive dysfunction or aphasia were included in the study. Cerebrovascular autoregulation was assessed by the Pearson correlation between near-infrared spectroscopy-derived cerebral tissue oxygen saturation and mean arterial pressure to derive the tissue oximetry index. Cerebrovascular autoregulation was monitored for a minimum of 90 min on postoperative day 0 and postoperative day 1. Delirium was assessed throughout intensive care unit admission using the confusion assessment method for the intensive care unit. We observed delirium in 24 of the 108 patients studied. The mean (SD) tissue oximetry index was higher in delirious patients on postoperative day 0 compared with non-delirious patients; 0.270 (0.199) vs. 0.180 (0.142), p = 0.044, but not on postoperative day 1; 0.130 (0.160) vs. 0.150 (0.130), p = 0.543. All patients showed improvement in tissue oximetry index on postoperative day 1 compared with postoperative day 0. Logistic regression analysis demonstrated tissue oximetry index on postoperative day 0 to be independently associated with delirium; odds ratio 1.05 (95%CI 1.01–1.10), p = 0.043. In conclusion, we found an association between impaired cerebrovascular autoregulation, measured by near-infrared spectroscopy, and delirium in the early postoperative period.     

The influence of anesthetic techniques on postoperative cognitive function in elderly patients undergoing hip fracture surgery: General vs spinal anesthesia

BackgroundHip fracture is common and morbid in elderly patients. Postoperative cognitive dysfunction (POCD) is also very common in these subjects undergoing surgery with an incidence which exceeds 40% in some reports. To date, the evidence is ambiguous as to whether anesthetic technique may affect the patients’ outcome as far as postoperative cognitive function is concerned.ObjectiveThe aim of this study was to compare the effect of general and subarachnoid (spinal) anesthesia on the development of POCD up to 30 days after surgery in elderly patients undergoing hip fracture surgery.Methods Subjects over 65 years with hip fracture undergoing surgery were recruited for this study. They were enrolled and randomized to receive either general anesthesia (GA group) or subarachnoid (spinal) anesthesia (S group). Cognitive function was assessed using a battery of neuropsychological tests undertaken preoperatively and at 30 days postoperatively. The incidence of delirium was examined during the same period and their functional status, in terms of activities of daily living was also recorded.ResultsA total of seventy patients, 33 men and 37 females, mean age of 76 years were analyzed. Thirty-three patients received general anesthesia (GA group) and 37 subarachnoid (spinal) anesthesia (S group). The two groups of patients were similar with respect to baseline characteristics, comorbidities and perioperative data. The results of neuropsychological testing showed that there were no significant differences between the groups in eight out of ten neurocognitive tests at baseline and 30 days after surgery. There was a statistically significant decline of the Instrumental Activities of Daily Living Scale score in S group compared with group GA on the 30th postoperative day (p = 0.043). A significant decline was also present in Color-Word Task test in S group compared with group GA at baseline (p = 0.014) and 30 days postoperatively (p = 0.003). Postoperative delirium was present in four patients (12%) for the GA group, and in 10 patients (27%) for the group receiving subarachnoid anesthesia.ConclusionWe concluded that the choice of anesthesia modality does not appear to influence the emergence of postoperative cognitive dysfunction in elderly patients undergoing hip fracture surgery.     

Risk factors and effect of postoperative delirium on adverse surgical outcomes in older adults after elective abdominal cancer surgery in Taiwan

BackgroundPostoperative delirium (POD) is a common complication in older adults, with unknown epidemiology and effects on surgical outcomes in Asian geriatric cancer patients. This study evaluated incidence, risk factors, and association between adverse surgical outcomes and POD after intra-abdominal cancer surgery in Taiwan.MethodsOverall, 345 patients aged ≥65 years who underwent elective abdominal cancer surgery at a medical center in Taiwan were prospectively enrolled. Delirium was assessed daily using the Confusion Assessment Method. Univariate and multivariate logistic regression analyses investigated risk factors for POD occurrence and estimated the association with adverse surgical outcomes.ResultsPOD occurred in 19 (5.5%) of the 345 patients. Age ≥73 years, Charlson comorbidity index ≥3, and operative time >428 min were independent predictors for POD occurrence. Patients presenting with one, two, and three risk factors had 4.1-fold (95% confidence interval [CI], 0.4–35.8, p = 0.20), 17.4-fold (95% CI, 2.2–138, p = 0.007), and 30.8-fold likelihood (95% CI, 2.9–321, p = 0.004) for POD occurrence, respectively. Patients with POD had a higher probability of prolonged hospital stay (adjusted odds ratio [OR] 2.8; 95% CI, 1.0–8.1; p = 0.037), intensive care stay (adjusted OR: 3.9; 95% CI, 1.5–10.5; p = 0.008), 30-day readmission (adjusted OR 3.1; 95% CI, 1.1–9.7; p = 0.039), and 90-day postoperative death (adjusted OR: 4.2; 95% CI, 1.0–17.7; p = 0.041).ConclusionPOD occurrence was significantly associated with adverse surgical outcomes in geriatric patients undergoing elective abdominal cancer surgery, highlighting the importance of early POD identification in geriatric patients to improve postoperative care quality.     

Incidence and precipitating factors of delirium after coronary artery bypass grafting

OBJECTIVE: To analyze large contemporary patient population, undergoing on-pump coronary artery bypass grafting at our institution, and identify the prevalence and precipitating factors of delirium development. DESIGN: Baseline demographics, operative data and postoperative outcomes of 1367 consecutive patients were recorded prospectively and analysed using multivariate logistic regression analysis, to determine independent predictors of postoperative delirium development. RESULTS: Delirium was detected in 42 (3.07%) patients. Eight factors: age more than 65 years, peripheral vascular disease, Euroscore>/=5, preoperative IABP support, postoperative blood product usage and postoperative low cardiac output syndrome were independently predicting delirium development after coronary artery bypass procedures. Postoperative delirium was associated with significantly higher mortality rate (16.6% vs. 3.9%, p=0.013), prolonged mechanical ventilation time (9.2+/-3.1 vs. 5.05+/-7.6, p=0.04) and increased length of intensive care unit stay (6.8+/-4.9 vs. 2.0+/-2.7 days, p=0.001). CONCLUSIONS: Delirium is a dangerous complication, prolonging intensive care unit stay and postoperative mortality. Factors associated with delirium development are advanced age, peripheral vascular disease, diminished cardiac function and blood product usage.     

Postoperative Cognitive Dysfunction in Middle-aged Patients

Background: Postoperative cognitive dysfunction (POCD) after noncardiac surgery is strongly associated with increasing age in elderly patients; middle-aged patients (aged 40-60 yr) may be expected to have a lower incidence, although subjective complaints are frequent.

Methods: The authors compared the changes in neuropsychological test results at 1 week and 3 months in patients aged 40-60 yr, using a battery of neuropsychological tests, with those of age-matched control subjects using Z-score analysis. They assessed risk factors and associations of POCD with measures of subjective cognitive function, depression, and activities of daily living.

Results: At 7 days, cognitive dysfunction as defined was present in 19.2% (confidence interval [CI], 15.7-23.1) of the patients and in 4.0% (CI, 1.6-8.0) of control subjects (P < 0.001). After 3 months, the incidence was 6.2% (CI, 4.1-8.9) in patients and 4.1% (CI, 1.7-8.4) in control subjects (not significant). POCD at 7 days was associated with supplementary epidural analgesia and reported avoidance of alcohol consumption. At 3 months, 29% of patients had subjective symptoms of POCD, and this finding was associated with depression. Early POCD was associated with reports of lower activity scores at 3 months.