Postoperative Delirium In Older Patients Research Articles

The Effect of Preoperative Methylprednisolone on Postoperative Delirium in Older Patients Undergoing Gastrointestinal Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial.

Preoperative administration of methylprednisolone reduced circulating markers of endothelial activation. This randomized, double-blind, placebo-controlled trial was to evaluate whether a single preoperative dose of methylprednisolone reduced the rate of postoperative delirium (POD) in older patients undergoing gastrointestinal surgery and its association with the shedding of endothelial glycocalyx markers. About 168 patients, aged 65-80 years and scheduled for laparoscopic gastrointestinal surgery, were randomized to 2 mg/kg methylprednisolone (Group M, n = 84) or equivalent dose of placebo (Group C, n = 84). The primary outcome was the incidence of delirium during the first 5 days after surgery, assessed by the Confusion Assessment Method (CAM). POD severity was rated daily using CAM-Severity (CAM-S). Levels of syndecan-1, heparan sulfate, tumor necrosis factor-α (TNF-α), and brain-derived neurotrophic factor (BDNF) were measured at baseline, 1 day, and 3 days after surgery. Compared with placebo, methylprednisolone greatly reduced the incidence of delirium at 72 hours following surgery (9 [10.7%] vs 20 [23.8%], p = .03, OR = 2.22 [95% CI 1.05-4.59]). No between-group difference was found in the cumulative CAM-S score (p = .14). The levels of heparan sulfate, syndecan-1, and TNF-α in Group M were lower than that in Group C (p < .05 and p < .01), while the level of BDNF in Group M was higher than that in Group C (p < .01). Preoperative administration of methylprednisolone does not reduce the severity of POD, but may reduce the incidence of delirium after gastrointestinal surgery in older patients, which may be related to a reduction in circulating markers of endothelial degradation, followed by the increase of BDNF level. Chinese Clinical Trial.gov, ChiCTR2000028792. Registered January 4, 2020. http://www.chictr.org.cn/showproj.aspx?proj=47807.

One-Year Medicare Costs Associated With Delirium in Older Patients Undergoing Major Elective Surgery

Delirium is a common, serious, and potentially preventable problem for older adults, associated with adverse outcomes. Coupled with its preventable nature, these adverse sequelae make delirium a significant public health concern; understanding its economic costs is important for policy makers and health care leaders to prioritize care. To evaluate current 1-year health care costs attributable to postoperative delirium in older patients undergoing elective surgery. This prospective cohort study included 497 patients from the Successful Aging after Elective Surgery (SAGES) study, an ongoing cohort study of older adults undergoing major elective surgery. Patients were enrolled from June 18, 2010, to August 8, 2013. Eligible patients were 70 years or older, English-speaking, able to communicate verbally, and scheduled to undergo major surgery at 1 of 2 Harvard-affiliated hospitals with an anticipated length of stay of at least 3 days. Eligible surgical procedures included total hip or knee replacement; lumbar, cervical, or sacral laminectomy; lower extremity arterial bypass surgery; open abdominal aortic aneurysm repair; and open or laparoscopic colectomy. Data were analyzed from October 15, 2019, to September 15, 2020. Major elective surgery and hospitalization. Cumulative and period-specific costs (index hospitalization, 30-day, 90-day, and 1-year follow-up) were examined using Medicare claims and extensive clinical data. Total inflation-adjusted health care costs were determined using data from Medicare administrative claims files for the 2010 to 2014 period. Delirium was rated using the Confusion Assessment Method. We also examined whether increasing delirium severity was associated with higher cumulative and period-specific costs. Delirium severity was measured with the Confusion Assessment Method-Severity long form. Regression models were used to determine costs associated with delirium after adjusting for patient demographic and clinical characteristics. Of the 566 patients who were eligible for the study, a total of 497 patients (mean [SD] age, 76.8 [5.1] years; 281 women [57%]; 461 White participants [93%]) were enrolled after exclusion criteria were applied. During the index hospitalization, 122 patients (25%) developed postoperative delirium, whereas 375 (75%) did not. Patients with delirium had significantly higher unadjusted health care costs than patients without delirium (mean [SD] cost, $146 358 [$140 469] vs $94 609 [$80 648]). After adjusting for relevant confounders, the cumulative health care costs attributable to delirium were $44 291 (95% CI, $34 554-$56 673) per patient per year, with the majority of costs coming from the first 90 days: index hospitalization ($20 327), subsequent rehospitalizations ($27 797), and postacute rehabilitation stays ($2803). Health care costs increased directly and significantly with level of delirium severity (none-mild, $83 534; moderate, $99 756; severe, $140 008), suggesting an exposure-response relationship. The adjusted mean cumulative costs attributable to severe delirium were $56 474 (95% CI, $40 927-$77 440) per patient per year. Extrapolating nationally, the health care costs attributable to postoperative delirium were estimated at $32.9 billion (95% CI, $25.7 billion-$42.2 billion) per year. These findings suggest that the economic outcomes of delirium and severe delirium after elective surgery are substantial, rivaling costs associated with cardiovascular disease and diabetes. These results highlight the need for policy imperatives to address delirium as a large-scale public health issue.

Propofol plus low-dose dexmedetomidine infusion and postoperative delirium in older patients undergoing cardiac surgery

BackgroundPostoperative delirium (POD) is a frequent complication in older patients. Dexmedetomidine might be effective in decreasing the incidence of POD. We hypothesised that adding low-dose rate dexmedetomidine infusion to a propofol sedation regimen would have fewer side-effects and would counteract the possible delirium producing properties of propofol, resulting in a lower risk of POD than propofol with placebo. MethodsIn this double-blind placebo-controlled trial, patients ≥60 yr old undergoing on-pump cardiac surgery were randomised 1:1 to the following postoperative sedative regimens: a propofol infusion and dexmedetomidine (0.4 μg kg−1 h−1) or a propofol infusion and saline 0.9% (placebo group). The study drug was started at chest closure and continued for 10 h. The primary endpoint was in-hospital POD, assessed using the Confusion Assessment Method and chart review method. ResultsPOD over the course of hospital stay occurred in 31/177 (18%) and 33/172 (19%) patients in the dexmedetomidine and placebo arm, respectively (P=0.687; odds ratio=0.89; 95% confidence interval, 0.52–1.54). The incidence of POD in the intensive care alone, or on the ward alone, was also not significantly different between the groups. Subjects in the dexmedetomidine group spent less median time in a delirious state (P=0.026). Median administered postoperative norepinephrine was significantly higher in the dexmedetomidine group (P<0.001). One patient in the dexmedetomidine group and 10 patients in the placebo group died in the hospital. ConclusionsAdding low-dose rate dexmedetomidine to a sedative regimen based on propofol did not result in a different risk of in-hospital delirium in older patients undergoing cardiac surgery. With a suggestion of both harm and benefit in secondary outcomes, supplementing postoperative propofol with dexmedetomidine cannot be recommended based on this study. Clinical trial registrationNCT03388541.

Is preoperative anxiety associated with postoperative delirium in older persons undergoing cardiac surgery? Secondary data analysis of a randomized controlled trial

BackgroundAlthough many studies have reported numerous risk factors for postoperative delirium, data are scarce about preoperative anxiety as a risk factor. The study aimed to investigate the association between preoperative anxiety and postoperative delirium in older patients undergoing cardiac surgery.MethodsSecondary data analysis of a randomized, observer-blind, controlled trial. A total of 190 patients 65 years or older and admitted to the intensive care unit and cardiac surgery unit of a university hospital scheduled for elective on-pump cardiac surgery were included. State anxiety was measured preoperatively using the Amsterdam Preoperative Anxiety and Information Scale and the Visual Analogue Scale for anxiety. Incidence of delirium was measured during the first 5 postoperative days using the Confusion Assessment Method for Intensive Care Unit (when ventilated), or the 3 Minute Diagnostic Interview for Confusion Assessment Method (when extubated) and by daily chart review.ResultsPreoperative state anxiety was reported by 31% of the patients and 41% had postoperative delirium. A multiple step logistic regression analyses revealed no association between preoperative anxiety and postoperative delirium. Significant risk factors for postoperative delirium were age (OR = 1.10, 95% CI (1.03–1.18)), activities of daily living (0.69, 95% CI (0.50–0.96)), diabetes mellitus (OR = 3.15, 95% CI (1.42–7.00)) and time on cardiopulmonary bypass (OR = 1.01, 95% CI (1.00 to 1.02)).ConclusionsNo relationship could be found between preoperative anxiety and postoperative delirium.

A survey about postoperative delirium in older patients among nurses and anaesthetists: implications for future practice and policy.

Postoperative delirium is a major complication associated with anaesthesia and surgery, more commonly seen in older people. The aims of this study were to explore the knowledge and understanding of anaesthetists and nurses involved in anaesthesia through their responses to two case scenarios of postoperative delirium experienced by older people. A 30-item online survey was sent to 500 potential respondents. Two hundred and twenty-six practitioners from Australia, New Zealand and Scotland responded. Most had no workplace protocols for anaesthesia planning in older people. There was substantial variability in practice in relation to postoperative delirium screening, detection, prevention and management. Improvements in education and awareness, together with a more coherent approach, for example, as recommended in the European Society of Anaesthesiology Guidelines, could help to reduce the impact of postoperative delirium in older people. This should be combined with ongoing research into perioperative optimisation of detection, prevention and management of postoperative delirium.

Commentary: A survey about postoperative delirium in older patients among nurses and anaesthetists: implications for future practice and policy.

Commentary: A survey about postoperative delirium in older patients among nurses and anaesthetists: implications for future practice and policy.

The Effects of Propofol and Sevoflurane on Postoperative Delirium in Older Patients: A Randomized Clinical Trial Study.

Postoperative delirium is associated with adverse postoperative outcomes. However, whether intravenous and inhalation anesthetics are associated with different risks of postoperative delirium remains unknown. We set up to determine the incidence and duration of postoperative delirium in older patients who had surgery under the intravenous anesthetic propofol or the inhalational anesthetic sevoflurane. Participants were patients who had total hip/knee replacements and were randomized to propofol (N = 106) or sevoflurane (N = 103) anesthesia group. The Confusion Assessment Method was employed by investigators who were blinded to the anesthesia regimen to assess the incidence and duration (days of postoperative delirium per person) of postoperative delirium on postoperative days 1, 2, and 3. A total of 209 participants (71.2±6.7 years old, 29.2% male) were included in the final data analysis. The incidence of postoperative delirium was 33.0% with propofol anesthesia and 23.3% with sevoflurane anesthesia (p = 0.119, Chi-square test), and we estimated that we would need 316 participants in each arm to detect a potential statistically significant difference. Days of postoperative delirium per person were higher in the propofol (0.5±0.8) anesthesia group compared to the sevoflurane anesthesia group (0.3±0.5, p = 0.049, Student's t-test). This pilot study established a system to compare effects of different anesthetics and generated a hypothesis that propofol trended to have a higher incidence and had longer duration of postoperative delirium than sevoflurane. Additional studies with a larger sample size are needed to test this hypothesis.

Incidence and risk factors for acute delirium in older patients with a hip fracture: A retrospective cohort study

This retrospective cohort study aimed to determine the incidence, and preoperative, intraoperative, and postoperative risk factors for postoperative delirium in older patients undergoing surgical fixation of a hip fracture. Electronic medical records were examined of 260 patients who underwent a surgical fixation of a hip fracture between June 2017 and October 2018 at a university-affiliated tertiary care hospital in Victoria, Australia. Demographic, clinical, and perioperative data were examined for potential risk factors for postoperative delirium. Of the 260 patients, 63 patients (24.2%) developed delirium postoperatively. Univariate logistic regression analysis indicated that advanced age, comorbidity, cognitive impairment, dementia, American Society of Anesthesiologists score, and antipsychotic usage were significant risk factors for delirium, while doses of paracetamol, fentanyl, and diazepam showed complex associations. Multivariate logistic regression analysis determined comorbidity and cognitive impairment as independent risk factors for the development of delirium. This study demonstrates the importance of evaluation of medications prescribed in the perioperative period as modifiable risk factors, in order to identify patients at high risk of delirium and enable targeted monitoring and treatment during patients' hospitalization.

Post-operative delirium in older patients following cancer related and other high-risk surgeries.

e24024 Background: Older adults are at increased risk for postoperative delirium (POD). This risk might be higher in patients with cancer as underlying malignancy and its complications predispose individuals to develop delirium. Therefore, it is important to evaluate the onset of delirium in this patient population especially as POD is associated with increased risk of rehospitalization, decline in cognitive function, morbidity and mortality. Methods: We performed a retrospective review of patients aged ≥ 70 years admitted January 2017 through July 2019 to a tertiary care referral center for a high-risk surgery, defined as associated with a mortality risk greater than 1%. Cancer related surgeries (CRS) were identified through cross matching with Cancer Registry. Patients who had delirium assessment in the postoperative setting using the Confusion Assessment Method (CAM) were included. Chi-square tests of proportion, Wilcoxon Ranked Sum and multivariate logistic regression analyses were conducted. Results: A total of 2340 patients were included in this analysis, 315 of whom had (CRS). Overall, the age (median, IQR) of patients at surgery was 76 years (72-80) and the length of stay (LOS) was 7 (4-11) days. Patients receiving CRS were younger (75, 72-79) than those with non-CRS (76, 72-81) (p = 0.022); had a shorter post-operative LOS (4, 2-7 vs. 5, 3-8; p &gt; 0.001), and were less likely to develop POD (7.6% vs. 16.1%; p &lt; 0.001). Among patients receiving CSR, those who developed POD were older (78 vs. 74; p = 0.008) and had longer post-operative LOS (14.0 vs. 4.0; p &lt; 0.001). Those having experienced radiotherapy (RT) for cancer within the year before the surgery, were more likely to develop POD (40.0% vs. 6.6% p. &lt; 0.001). Chemotherapy in the year prior to surgery did not increase the risk of POD (6.1% vs. 7.8%; p = 0.721). Among those having non-CRS, a cancer diagnosis did not affect POD. A logistic regression predicting POD indicated that the lower likelihood of POD following CRS was independent of age or gender (OR = 0.40; p &lt; .001); RT within one year prior was independent predictor of higher POD (OR = 5.48; p = 0.003). Our data presentation will include further analysis of POD risk factors. Conclusions: Although older adults receiving CRS were significantly less likely to develop delirium than patients with other high-risk surgeries, it is still important to evaluate POD in this population due to its impact of patients’ outcomes. Further understanding of POD risk factors, such as preoperative RT, would allow the development of targeted interventions that might lessen the risk.

Effects of Ramelteon on the Prevention of Postoperative Delirium in Older Patients Undergoing Orthopedic Surgery: The RECOVER Randomized Controlled Trial

Postoperative delirium, associated with negative consequences including longer hospital stays and worse cognitive and physical outcomes, is frequently accompanied by sleep-wake disturbance. Our objective was to evaluate the efficacy and short-term safety of ramelteon, a melatonin receptor agonist, for the prevention of postoperative delirium in older patients undergoing orthopedic surgery. A quadruple-masked randomized placebo-controlled trial (Clinical Trials.gov NCT02324153) conducted from March 2017 to June 2019. Tertiary academic medical center. Patients aged 65 years or older, undergoing elective primary or revision hip or knee replacement. Ramelteon (8 mg) or placebo MEASUREMENTS: Eighty participants were randomized to an oral gel cap of ramelteon or placebo for 3 consecutive nights starting the night before surgery. Trained research staff conducted delirium assessments for 3 consecutive days starting on postoperative day (POD) 0, after recovery from anesthesia, and on to POD2. A delirium diagnosis was based upon DSM-5 criteria determined by expert panel consensus. Of 80 participants, five withdrew consent (one placebo, four ramelteon) and four were excluded (four ramelteon) after randomization. Delirium incidence during the 2 days following surgery was 7% (5 of 71) with no difference between the ramelteon versus placebo: 9% (3 of 33) and 5% (2 of 38), respectively. The adjusted odds ratio for postoperative delirium as a function of assignment to the ramelteon treatment arm was 1.28 (95% confidence interval: 0.21-7.93; z-value 0.27; p-value = 0.79). Adverse events were similar between the two groups. In older patients undergoing elective primary or revision hip or knee replacement, ramelteon was not efficacious in preventing postoperative delirium.

Relation of serum melatonin levels to postoperative delirium in older patients undergoing major abdominal surgery.

ObjectivePostoperative delirium (POD) is a perennial and distressing complication in older patients, and it may be caused by various factors. This study aimed to determine whether serum melatonin levels are associated with POD in older patients who undergo major abdominal surgery.MethodsWe collected serum samples from patients undergoing major abdominal surgery. Melatonin was measured by enzyme-linked immunosorbent assay and delirium was assessed by the Confusion Assessment Method after surgery. We classified the patients into the POD group and non-POD group.ResultsA total of 120 patients met the inclusion criteria and 104 patients were included in the analysis. Postoperative serum melatonin levels were significantly lower than preoperative levels. Multivariate analyses showed that a longer duration of anesthesia (odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.02–1.64), advanced age (OR = 3.36, 95% CI = 1.37–8.22), and lower postoperative levels of melatonin (OR = 0.50, 95% CI = 0.25–1.00) were associated with POD.ConclusionsSerum melatonin levels significantly decline after surgery and anesthesia. Significantly decreased serum melatonin concentrations postoperatively may be a biomarker for predicting POD in older patients undergoing major abdominal surgery with general anesthesia.

Intraoperative hypotension and delirium in patients with hip fracture

Postoperative delirium is common after hip fracture surgery in elderly patients and is associated with poor outcome (higher risk of mortality, institutionalization and length of stay). The relationship between modifiable intra-operative risk factors, such as intra-operative hypotension, and postoperative delirium is unclear. The main objective of this study was to evaluate the association between intra-operative hypotension and the development of a postoperative delirium in older patients with hip fracture. A secondary aim was to assess the impact of other pre- and intra-operative predisposing factors (anaesthetic approaches or specific anaesthetic drugs, surgery duration, timing of surgery, type of implants used as primary treatment, intra-operative blood loss) on developing postoperative delirium in this elderly population. This retrospective monocentric study included 100 consecutive hip fracture patients, aged 75 years and older, admitted to a dedicated ortho-geriatric unit. All patients were screened for post-operative delirium using the confusion assessment method performed by a geriatrician. Intra-operative hypotension was defined as a decrease of more than 30% below the preoperative baseline for systolic blood pressure or a decrease in mean arterial pressure (MAP) below 60 mmHg. Post-operative delirium (n = 37; 37.8%) and intra-operative hypotension (n = 80; 81.6%) are both common in old patients but we did not demonstrate a significant association regardless of the chosen definition. The following risk factors were significantly associated with postoperative delirium: surgical delay (OR 1.47[1.01-2.02]; p = 0.02), institutionalisation (OR 2.25[1.33-3.8]; p = 0.02) and postoperative acute kidney injury (OR 2.34[1.32-4.15]; p = 0.02). Postoperative delirium is common in old patients with hip fracture and is associated with postoperative complications, institutionalisation and surgical delay but not with intra-operative risk factors.

Registration of attentional function as a predictor of incident delirium (the RAPID study).

IntroductionOlder adults undergoing elective surgery have a high risk of developing postoperative delirium (POD). Validated models predicting POD are scarce. This study investigated whether preoperative impairment of attentional function predicts POD in older adults without previously diagnosed cognitive impairment.MethodsIn this prospective cohort study we recruited patients aged ≥70 years preceding major elective surgery. Preoperatively a visual vigilance test was administered to determine intra‐individual reaction‐time variability. Postoperatively, presence of delirium was screened daily.ResultsWe recruited 152 patients, 25 (16.4%) developed POD. Intra‐individual reaction‐time variability was not significantly different between patients with or without POD (0.18 ± 0.08 ms vs 0.22 ± 0.11 ms; P = 0.087). Receiver operating characteristic analyses indicated a poor accuracy for POD (area under the curve 0.609 ± 0.63). Except for surgery duration, no clinically significant between‐group differences were found for secondary outcome parameters.DiscussionPreoperative intra‐individual reaction time variability does not predict the incidence of POD in older patients undergoing major elective surgery.

Association between postoperative delirium and postoperative cerebral oxygen desaturation in older patients after cardiac surgery

BackgroundNear-infrared spectroscopy non-invasively measures regional cerebral oxygen saturation. Intraoperative cerebral desaturations have been associated with worse neurological outcomes. We investigated whether perioperative cerebral desaturations are associated with postoperative delirium in older patients after cardiac surgery. MethodsPatients aged 70 yr and older scheduled for on-pump cardiac surgery were included between 2015 and 2017 in a single-centre, prospective, observational study. Baseline cerebral oxygen saturation was measured 1 day before surgery. Throughout surgery and after ICU admission, cerebral oxygen saturation was monitored continuously up to 72 h after operation. The presence of delirium was assessed using the confusion assessment method for the ICU. Association with delirium was evaluated with unadjusted analyses and multivariable logistic regression. ResultsNinety-six of 103 patients were included, and 29 (30%) became delirious. Intraoperative cerebral oxygen saturation was not significantly associated with postoperative delirium. The lowest postoperative cerebral oxygen saturation was lower in patients who became delirious (P=0.001). The absolute and relative postoperative cerebral oxygen saturation decreases were more marked in patients with delirium (13 [6]% and 19 [9]%, respectively) compared with patients without delirium (9 [4]% and 14 [5]%; P=0.002 and P=0.001, respectively). These differences in cerebral oxygen saturation were no longer present after excluding cerebral oxygen saturation values after patients became delirious. Older age, previous stroke, higher EuroSCORE II, lower preoperative Mini-Mental Status Examination, and more substantial absolute postoperative cerebral oxygen saturation decreases were independently associated with postoperative delirium incidence. ConclusionsPostoperative delirium in older patients undergoing cardiac surgery is associated with absolute decreases in postoperative cerebral oxygen saturation. These differences appear most detectable after the onset of delirium. Clinical trial registrationNCT02532530.

Physical Activity and Risk of Postoperative Delirium.

Regular physical activity (PA) has been associated with improved cognitive function, but its effect on postoperative delirium (POD) has not been established. Our objectives were to determine the effect of baseline PA on the incidence of POD in older patients undergoing elective orthopedic surgery and to determine whether these effects were independent of cognitive reserve. We hypothesize that PA protects against POD by bolstering physiologic reserve needed to withstand the stressors of surgery. Secondary analysis of a prospective, single-center, cohort study. Urban academic hospital. A total of 132 nondemented, English-speaking adults older than 60 years undergoing elective orthopedic surgery. Subjects were screened for POD and delirium severity using the Confusion Assessment Method and the Memorial Delirium Assessment Scale. Baseline cognitive activities and PAs were assessed with a validated Leisure Activity Scale. Regular PA was categorized as 6 to 7 days per week. The association of regular PA with incidence of POD was assessed using multivariable logistic regression, adjusting for age, sex, Charlson Comorbidity Index, cognitive reserve, and cognitive function. Linear regression was used to assess the association of delirium severity with regular PA. Of 132 patients, 41 (31.1%) developed POD. Regular PA was associated with a 74% lower odds of developing POD (odds ratio [OR] = 0.26; 95% confidence interval [CI] = 0.08-0.82). There was no significant interaction between PA and cognitive reserve (P = .70). Of 85 women, 25 (29.4%), and of 47 men, 16 (34.0%) developed POD. In stratified analysis, women who engaged in regular PA had dramatically lower odds of POD (OR = 0.08; 95% CI = 0.01-0.63) compared with men (OR = 0.93; 95% CI = 0.18-4.97). Regular PA is associated with decreased incidence of POD, especially among women. Future studies should address the basis of sex differences in PA benefits on delirium. J Am Geriatr Soc 67:2260-2266, 2019.

Localization Establishment of an Interdisciplinary Intervention Model to Prevent Post-Operative Delirium in Older Patients Based on 'Hospital Elder Life Program'

Postoperative delirium is a significant complication in elderly patients. The occurrence of delirium may increase the related physical and psychological risks, delay the length of hospital stays, and even lead to death. According to the current evidence-based model, the application of interdisciplinary intervention may effectively prevent delirium, shorten the length of hospital stays, and save costs. To establish a culturally appropriate interdisciplinary intervention model for preventing postoperative delirium in older Chinese patients. The authors adapted the original version of the Hospital Elder Life Program (HELP©) from the Hebrew Senior Life Institute for Aging Research of Harvard University by localizing the content using additional medical resources and translating the modified instrument into Chinese. Furthermore, the final version of this interdisciplinary intervention model for postoperative delirium was developed in accordance with the "guideline of delirium: diagnosis, prevention and management produced by the National Institute for Health and Clinical Excellence in 2010" and the "clinical practice guideline for postoperative delirium in older adults" produced by American geriatrics society in 2014. Finally, the translated instrument was revised and improved using discussions, consultations, and pilot study. The abovementioned procedure generated an interdisciplinary intervention model for preventing postoperative delirium that is applicable to the Chinese medical environment. The content addresses personnel structure and assignment of responsibility; details of interdisciplinary intervention protocols and implementation procedures; and required personnel training. The revised model is expected to decrease the occurrence of post-operative delirium and other complications in elderly patients, to help them maintain and improve their function, to shorten the length of their hospital stays, and to facilitate recovery.

Checking the Brain’s Immune Privilege: Evolving Theories of Brain–Immune Interactions

The mind takes years to develop yet can be undone in a matter of hours. Few experiences can be more frightening than watching a loved one disintegrate in a hospital room, either quietly retreating into themselves or becoming aggressive and agitated, unaware of who or where they are. Delirium is defined clinically as a “disturbance of attention,” ( 1 Maldonado J.R. Neuropathogenesis of delirium: Review of current etiologic theories and common pathways. Am J Geriatr Psychiatry. 2013; 21: 1190-1222 Abstract Full Text Full Text PDF PubMed Scopus (354) Google Scholar ) but in the moment, to the individuals involved, it can seem cataclysmic—a dramatic rending of identity. Higher C-Reactive Protein Levels Predict Postoperative Delirium in Older Patients Undergoing Major Elective Surgery: A Longitudinal Nested Case-Control StudyBiological PsychiatryVol. 81Issue 2PreviewDelirium is a common, morbid, and costly postoperative complication. We aimed to identify blood-based postoperative delirium markers in a nested case-control study of older surgical patients using a proteomics approach followed by enzyme-linked immunosorbent assay (ELISA) validation. Full-Text PDF

Rivastigmine patch reduces the incidence of postoperative delirium in older patients with cognitive impairment.

To date, data regarding the efficacy of acetylcholinesterase inhibitors in preventing postoperative delirium (POD) are inconsistent and conflicting. Older individuals with cognitive dysfunction are thought to show POD more frequently. Our aim was to study the effectiveness of rivastigmine prophylaxis on the incidence, severity, and risk factors for POD in older patients with cognitive impairment undergoing hip fracture surgery. Of 62 older patients with cognitive impairment about to undergo surgery after a hip fracture, 31 were randomly assigned to receive a rivastigmine patch from 3 days before to 7 days after the operation (Group I), and the other 31 did not receive a rivastigmine patch (Group II). The two groups were compared with regard to incidence and severity of delirium on postoperative days 2 or 3 and 7. Multivariate logistic regression analysis was performed to assess factors associated with POD. Postoperative delirium occurred in five Group I patients and 14 Group II patients (p = 0.013). The mean severity of delirium in the two groups as determined by the Delirium Rating Scale was 2.2 and 6.2 respectively (p = 0.033). The odds ratio for POD was 0.259 (95% CI: 0.074-0.905, p = 0.034) after adjusting for American Society of Anesthesiologists score (p = 0.058), age (p = 0.203), and gender (p = 0.560). There were no rivastigmine-related perioperative complications. Perioperative rivastigmine patch application could reduce the occurrence of POD in older patients with low cognitive status. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of Intraoperative Hypotension and Blood Pressure Fluctuations on Early Postoperative Delirium After Non-cardiac Surgery

(Abstracted from Br J Anaesth, 115:418–426, 2015) The role of intraoperative hypotension in postoperative delirium is a subject of controversy. Some studies suggested that it is a major predictor of postoperative delirium, whereas others did not.

Impact of intraoperative hypotension and blood pressure fluctuations on early postoperative delirium after non-cardiac surgery

Postoperative delirium is common in older patients. Despite its prognostic significance, the pathophysiology is incompletely understood. Although many risk factors have been identified, no reversible factors, particularly ones potentially modifiable by anaesthetic management, have been identified. The goal of this prospective cohort study was to investigate whether intraoperative hypotension was associated with postoperative delirium in older patients undergoing major non-cardiac surgery. Study subjects were patients >65 years of age, undergoing major non-cardiac surgery, who were enrolled in an ongoing prospective observational study of the pathophysiology of postoperative delirium. Intraoperative blood pressure was measured and predefined criteria were used to define hypotension. Delirium was measured by the Confusion Assessment Method on the first two postoperative days. Data were analysed using t-tests, two-sample proportion tests and ordered logistic regression multivariable models, including correction for multiple comparisons. Data from 594 patients with a mean age of 73.6 years (sd 6.2) were studied. Of these 178 (30%) developed delirium on day 1 and 176 (30%) on day 2. Patients developing delirium were older, more often female, had lower preoperative cognitive scores, and underwent longer operations. Relative hypotension (decreases by 20, 30, or 40%) or absolute hypotension [mean arterial pressure (MAP)<50 mm Hg] were not significantly associated with postoperative delirium, nor was the duration of hypotension (MAP<50 mm Hg). Conversely, intraoperative blood pressure variance was significantly associated with postoperative delirium. These results showed that increased blood pressure fluctuation, not absolute or relative hypotension, was predictive of postoperative delirium.