Postoperative delirium: age and low functional reserve as independent risk factors

The Association of Preoperative Diabetes With Postoperative Delirium in Older Patients Undergoing Major Orthopedic Surgery: A Prospective Matched Cohort Study

BACKGROUND

Postoperative delirium (POD) is a common form of postoperative brain dysfunction, especially in the elderly. However, its risk factors remain largely to be determined. This study aimed to investigate whether (1) preoperative diabetes is associated with POD after elective orthopedic surgery and (2) intraoperative frontal alpha power is a mediator of the association between preoperative diabetes and POD.

METHODS

This was a prospective matched cohort study of patients aged 60 years or more, with a preoperative diabetes who underwent elective orthopedic surgery. Nondiabetic patients were matched 1:1 to diabetic patients in terms of age, sex, and type of surgery. Primary outcome was occurrence of POD, assessed using the 3-minute Diagnostic Confusion Assessment Method (3D-CAM) once daily from 6 pm to 8 pm during the postoperative days 1-7 or until discharge. Secondary outcome was the severity of POD which was assessed for all participants using the short form of the CAM-Severity. Frontal electroencephalogram (EEG) was recorded starting before induction of anesthesia and lasting until discharge from the operating room. Intraoperative alpha power was calculated using multitaper spectral analyses. Mediation analysis was used to estimate the proportion of the association between preoperative diabetes and POD that could be explained by intraoperative alpha power.

RESULTS

A total of 138 pairs of eligible patients successfully matched 1:1. After enrollment, 6 patients in the diabetes group and 4 patients in the nondiabetes group were excluded due to unavailability of raw EEG data. The final analysis included 132 participants with preoperative diabetes and 134 participants without preoperative diabetes, with a median age of 68 years and 72.6% of patients were female. The incidence of POD was 16.7% (22/132) in patients with preoperative diabetes vs 6.0% (8/134) in patients without preoperative diabetes. Preoperative diabetes was associated with increased odds of POD after adjustment of age, sex, body mass index, education level, hypertension, arrhythmia, coronary heart disease, and history of stroke (odds ratio, 3.2; 95% confidence interval [CI], 1.4-8.0; P = .009). The intraoperative alpha power accounted for an estimated 20% (95% CI, 2.6-60%; P = .021) of the association between diabetes and POD.

CONCLUSIONS

This study suggests that preoperative diabetes is associated with an increased risk of POD in older patients undergoing major orthopedic surgery, and that low intraoperative alpha power partially mediates such association.

Association between intraoperative ketamine and the incidence of emergence delirium in laparoscopic surgeries: an observational study

BACKGROUND

Emergence Delirium (ED) is an essential condition in the immediate postoperative period. Systematic review and meta-analysis of randomized controlled trials have concluded that the effect of ketamine on postoperative delirium remains unclear. The present study sought to evaluate if the intraoperative use of ketamine for postoperative analgesia is associated with postoperative ED in laparoscopic surgeries.

METHODS

A prospective observational study was performed in the PostAnesthetic Care Unit (PACU) to evaluate patients who had undergone laparoscopic surgery under a rigid intraoperative anesthesia protocol from July 2018 to January 2019. Patients submitted to laparoscopic surgery for cholecystectomy, oophorectomy, or salpingectomy with a score ≥1 on the Richmond Assessment Sedation Scale (RASS) or ≥2 on the Nursing Delirium Screening Scale (Nu-DESC) were considered to have ED. t-test, Chi-Square test or Fisher's exact tests were used for comparison.

RESULTS

One hundred and fifteen patients were studied after laparoscopic surgery. Seventeen patients (14.8%) developed ED, and the incidence of ED in patients who received ketamine was not different from that of other patients (18.3% vs. 10.6%, p = 0.262). Patients with ED had more postoperative pain and morphine requirement at the PACU (p = 0.005 and p = 0.025, respectively). Type of surgery (general surgery, OR = 6.4, 95% CI 1.2‒35.2) and postoperative pain (OR = 3.7, 95% CI 1.2‒11.4) were risk factors for ED.

CONCLUSION

In this study, no association was found between ED and intraoperative administration of ketamine in laparoscopic surgeries. Type of surgery and postoperative pain were risk factors for ED.

Risk factors associated with postoperative delirium in elderly patients undergoing hip surgery

Objective

We retrospectively analyzed the occurrence of postoperative delirium following hip surgery and the associated risk factors. The aim was to establish a clinical foundation for preventing postoperative delirium after hip surgery.

Methods

We retrospectively selected elderly patients who had hip surgery at our hospital between January 2022 and August 2022. We included patients who experienced delirium in the observation group and those who did not encounter delirium in the control group. We then proceeded to compare various indicators among these two groups of patients.

Results

We analyzed a total of 97 cases of hip surgery, and among them, 32 cases experienced postoperative delirium, resulting in an incidence rate of 32.9%. Various factors were found to be linked to the development of postoperative delirium, including age, height, gender (male), preoperative erythrocyte sedimentation rate (ESR), postoperative ESR, preoperative lactate levels, pain scores on the first day after surgery, type of surgical procedure, and the occurrence of delirium in the post-anesthesia care unit (PACU delirium). Additionally, it was observed that 75% of patients who had PACU delirium also experienced postoperative delirium.

Conclusion

Postoperative delirium in patients who have hip surgery had an incidence rate of 32.9%. This phenomenon is linked to various factors that pose a risk, such as the patient age, height, gender, preoperative ESR levels, postoperative ESR levels, preoperative lactate levels, pain scores on the day following surgery, and the specific surgical procedure performed. The likelihood of experiencing delirium increases by 12% for every additional 10 years in patient age. Additionally, the occurrence of delirium in the PACU is a strong indicator of the likelihood of experiencing postoperative delirium.

Lipopolysaccharide-Induced Delirium-like Behaviour in a Rat Model of Chronic Cerebral Hypoperfusion Is Associated with Increased Indoleamine 2,3-Dioxygenase Expression and Endotoxin Tolerance

Indoleamine 2,3-dioxygenase (IDO) and the tryptophan-kynurenine pathway (TRP-KP) are upregulated in ageing and could be implicated in the pathogenesis of delirium. This study evaluated the role of IDO/KP in lipopolysaccharide (LPS)-induced delirium in an animal model of chronic cerebral hypoperfusion (CCH), a proposed model for delirium. CCH was induced by a permanent bilateral common carotid artery ligation (BCCAL) in Sprague Dawley rats to trigger chronic neuroinflammation-induced neurodegeneration. Eight weeks after permanent BCCAL, the rats were treated with a single systemic LPS. The rats were divided into three groups: (1) post-BCCAL rats treated with intraperitoneal (i.p.) saline, (2) post-BCCAL rats treated with i.p. LPS 100 μg/kg, and (3) sham-operated rats treated with i.p. LPS 100 μg/kg. Each group consisted of 10 male rats. To elucidate the LPS-induced delirium-like behaviour, natural and learned behaviour changes were assessed by a buried food test (BFT), open field test (OFT), and Y-maze test at 0, 24-, 48-, and 72 h after LPS treatment. Serum was collected after each session of behavioural assessment. The rats were euthanised after the last serum collection, and the hippocampi and cerebral cortex were collected. The TRP-KP neuroactive metabolites were measured in both serum and brain tissues using ELISA. Our data show that LPS treatment in CCH rats was associated with acute, transient, and fluctuated deficits in natural and learned behaviour, consistent with features of delirium. These behaviour deficits were mild compared to the sham-operated rats, which exhibited robust behaviour impairments. Additionally, heightened hippocampal IDO expression in the LPS-treated CCH rats was associated with reduced serum KP activity together with a decrease in the hippocampal quinolinic acid (QA) expression compared to the sham-operated rats, suggested for the presence of endotoxin tolerance through the immunomodulatory activity of IDO in the brain. These data provide new insight into the underlying mechanisms of delirium, and future studies should further explore the role of IDO modulation and its therapeutic potential in delirium.

A predictive scoring system for postoperative delirium in the elderly patients with intertrochanteric fracture

OBJECTIVE

To establish a scoring system to predict the postoperative delirium in elderly patients with intertrochanteric fracture.

MATERIALS AND METHODS

We retrospectively reviewed 159 elderly patients with a diagnosis of intertrochanteric fracture and underwent closed reduction and intramedullary nail fixation, and then divided them into two groups including the delirium group (23 cases) or non-delirium group (136 cases) in our hospital from January 2017 to December 2019. The following clinical characteristics were recorded and analyzed: age, gender, fracture classification, body mass index (BMI), history of diabetes mellitus, history of stroke, preoperative albumin, preoperative hemoglobin (Hb), preoperative arterial partial pressure of oxygen (PaO₂), time between admission and surgery, lower limb thrombosis, American Society of Anesthesiologists (ASA) grade, operative time, operative blood loss, and intraoperative blood transfusion. The prevalence of these clinical characteristics in delirium group was evaluated, and the scoring system was established using logistic regression analysis. The performance of the scoring system was also prospectively validated.

RESULTS

The predictive scoring system was based on five clinical characteristics confirmed as significant predictors of postoperative delirium, namely, age > 75 years, history of stroke, preoperative Hb ≤ 100 g/L, preoperative PaO₂ ≤ 60 mmHg, and time between admission to surgery > 3 days. Delirium group showed a significant higher score than non-delirium (6.26 vs. 2.29, P < 0.001), and the optimal cut-off value for the scoring system was 4 points. The sensitivity and specificity of the scoring system for predicting postoperative delirium were 82.61% and 81.62% in derivation set, respectively, and 72.71% and 75.00% in validation set.

CONCLUSION

The predictive scoring system confirmed with achieve satisfactory sensitivity and specificity in predicting postoperative delirium in the elderly with intertrochanteric fracture. The risk of postoperative delirium in patients with the score of 5 to 11 is high, while the score of 0 to 4 is low.

Postoperative C-Reactive Protein Predicts Postoperative Delirium in Colorectal Cancer Following Surgery

Background

Postoperative delirium (POD) is a common complication in operative patients. Neuroinflammation has been reported to be a potential mechanism associated with the development of POD. Identifying available inflammatory markers such as C-reactive protein (CRP) would aid clinicians in early detection of POD. Previous studies have demonstrated that CRP may be a promising predictive marker for POD. Thus, this study aimed to explore the association between CRP and POD among those elderly colorectal cancer (CRC) patients.

Methods

643 patients with CRC were included in this study. CRP levels were measured before operation and on postoperative day 1. The univariate and multivariate regression analyses were used to identify risk factors for POD.

Results

Of 643 patients with CRC, 112 cases (17.4%) had POD. CRC patients with POD showed older age, higher CRP level on postoperative day 1, and higher percentage of smoking, diabetes mellitus, and chronic obstructive pulmonary disease (COPD) than CRC patients without POD. Preoperative CRP level was not associated with the POD. Univariate and multivariate regression analyses showed that older age (> 70 years), diabetes mellitus, COPD, and higher CRP level on postoperative day 1 (> 48 mg/L) were risk factors for POD in CRC patients.

Conclusion

Postoperative CRP level is an independent indicator for POD among CRC patients, suggesting the predictive role of postoperative CRP levels for POD in elderly CRC patients undergoing surgery.

Preoperative Risk Factors Associated with Increased Incidence of Postoperative Delirium: Systematic Review of Qualified Clinical Studies

Postoperative delirium (POD) is an acute alteration of mental state, characterized by reduced awareness and attention, occurring up to five postoperative days after recovery from anesthesia. Several original studies and reviews have identified possible perioperative POD risk factors; however, there is no comprehensive review of the preoperative risk factors in patients diagnosed with POD using only validated diagnostic scales. The aim of this systematic review was to report the preoperative risk factors associated with an increased incidence of POD in patients undergoing non-cardiac and non-brain surgery. The reviewed studies included original research papers that used at least one validated diagnostic scale to identify POD occurrence for more than 24 h. A total of 6475 references were retrieved from the database search, with only 260 of them being suitable for further review. Out of the 260 reviewed studies, only 165 that used a validated POD scale reported one or more preoperative risk factors. Forty-one risk factors were identified, with various levels of statistical significance. The extracted risk factors could serve as a preoperative POD risk assessment workup. Future studies dedicated to the further evaluation of the specific preoperative risk factors' contributions to POD could help with the development of a weighted screening tool.

Sepsis-Associated Delirium: A Narrative Review

Delirium is characterized by an acutely altered mental status accompanied by reductions in cognitive function and attention. Delirium in septic patients, termed sepsis-associated delirium (SAD), differs in several specific aspects from the other types of delirium that are typically encountered in intensive care units. Since sepsis and delirium are both closely associated with increased morbidity and mortality, it is important to not only prevent but also promptly diagnose and treat SAD. We herein reviewed the etiology, pathogenesis, risk factors, prevention, diagnosis, treatment, and prognosis of SAD, including coronavirus disease 2019 (COVID-19)-related delirium. Delirium by itself not only worsens long-term prognosis, but it is also regarded as an important factor affecting the outcome of post-intensive care syndrome. In COVID-19 patients, the difficulties associated with adequately implementing the ABCDEF bundle (Assess, prevent, and manage pain; Both spontaneous awakening and breathing trials: Choice of analgesia and sedation; Delirium assess, prevent, and manage; Early mobility and exercise; Family engagement/empowerment) and the need for social isolation are issues that require the development of conventional care for SAD.

Association of preoperative prognostic nutritional index with risk of postoperative delirium: A systematic review and meta-analysis

Study objective

To assess the association between prognostic nutritional index (PNI) and risk of postoperative delirium (POD) in adult patients.

Methods

MEDLINE, Google scholar, EMBASE, and Cochrane library databases were searched from inception till April 2022. The primary outcome was the association between PNI and the risk of POD, while the secondary outcomes were correlations of other prognostic factors with POD risk. The correlation between PNI and the incidence of POD was assessed with three approaches: Difference in preoperative PNI between POD and non-POD groups (Model 1) as well as the association of PNI as a continuous parameter (Model 2) or as a binary variable (i.e., low vs. high using a PNI cut-off value of 50) (Model 3) with POD risk.

Results

Analysis of nine observational studies published from 2010 to 2021 recruiting 3,743 patients showed a POD incidence of 6.4-35%. Our meta-analysis demonstrated a lower PNI among patients in the POD group (MD: -3.78, 95% CI: -4.85 to -2.71, p < 0.0001, I ² = 54.2%) compared to the non-POD group (Model 1). Pooled results revealed a negative association between PNI and POD risk for both Model 2 (OR: 0.91, 95% CI: 0.86-0.97, p = 0.002, I ² = 71%) and Model 3 (OR: 1.68, 95% CI: 1.26-2.23, p < 0.0001, I ² = 0%). Besides, while our results supported an age-dependent increase in POD risk, other factors including body-mass index, surgical time, health status, hypertension, diabetes mellitus, and male gender were non-significant predictors of POD.

Conclusion

Our results demonstrated a negative association between PNI and POD, which warrant further large-scale studies for validation.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022323809.

Acceptability of transdermal antipsychotic patches by patients who refuse oral medication and their effectiveness in preventing recurrence of delirium: a retrospective observational study

Injectable antipsychotics had been used for patients who refuse oral medications in delirium practice. The objectives were to investigate acceptability of transdermal antipsychotic patches by patients who refuse oral medications and their effectiveness in preventing recurrence of delirium. In this retrospective observational study, data were collected between October 2019 and December 2021. The sample was represented by patients hospitalized because of acute diseases or elective surgery who had delirium on the night before the consultation and had refused oral therapy after consultation. Delirium has been diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Instead, a transdermal patch of blonanserin, a second-generation antipsychotic drug, was tried. The primary outcome was the rate of patients who accepted it. The secondary outcome was recurrence rates of delirium. As much as 95.1% of patients who refused oral medications (98/103 patients) accepted to receive the transdermal patch. Of these, 24 patients developed delirium again, whereas all five patients who refused it developed delirium again [24.5% (24/98) vs. 100% (5/5); P = 0.0014]. The present findings suggest that transdermal antipsychotic patches are more likely to be accepted by patients who refuse oral medications. Prospective studies are needed.

Preoperative anxiety as an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation

BACKGROUND

Anxiety is common in older patients suffering from lumbar disc herniation. Postoperative delirium is related to poor prognosis. But the relationship between preoperative anxiety and postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation is not clear.

AIMS

The study aimed to investigate if preoperative anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation.

METHODS

The medical records of 1290 patients undergoing elective surgery for lumbar disc herniation at a single institution from 2016 through 2021 were reviewed. Of 863 eligible patients, 225 (26.1%) patients had been diagnosed with anxiety by a board-certified psychiatrist and constituted the Anxiety group; the remaining 638 patients constituted the no-anxiety group. The demographics, baseline, operative variable and postoperative complications were collected and compared between the two groups. The primary outcome of this study was the incidence of delirium, according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition, during a hospital stay after surgery for lumbar disc herniation. The relationship between anxiety and postoperative delirium was determined through multivariate logistic regression analysis.

RESULTS

The demographics and comorbidity were similar between the two groups, except for age, sex, alcohol use and cerebrovascular disease. The operative variables were different between the two groups. The incidence of postoperative complications other than postoperative delirium was also similar between the two groups. In total, 86 patients (9.97%) had an episode of postoperative delirium, with anxiety group patients experiencing approximately a twofold higher rate (15.6% vs 7.99%). In a multivariate logistic regression analysis, anxiety was an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation (OR 2.228, 95% CI 1.494-3.416, p = 0.009).

CONCLUSION

This study suggests that anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation. Preoperative anxiety assessment can help to identify older patients at high risk of postoperative delirium and facilitate perioperative management of older patients undergoing elective surgery for lumbar disc herniation.

Effectiveness of nursing intervention to reduce delirium in adult critically ill - A protocol for a randomized trial

The incidence of delirium in intensive care patients remains high, and its consequences have a high negative impact on patients, their families, health care teams, and society in general. Because delirium can lead to increased hospital stay, increased days on mechanical ventilation, increased risk of adverse events, increased memory loss and even increased mortality. However, some factors that precipitate delirium can be modified to reduce its presence and duration through non-pharmacological measures. Thus, the present protocol seeks to establish the theoretical and methodological background to develop and test nursing interventions to reduce delirium in adult patients hospitalized in the intensive care unit. For this reason, it is based on the theoretical elements of delirium and a nursing theory, called the Dynamic Symptoms Model (DSM), to understand the phenomenon and how nursing knowledge can be used to intervene. Thus, a nursing intervention proposal is proposed based on the DSM and scientific evidence, and a methodological design of a randomized controlled clinical trial type with parallel groups, which allows measuring the effectiveness of the designed interventions, following methodological and ethical rigor and with adequate control of biases.

Postoperative Delirium in Neurosurgical Patients: Recent Insights into the Pathogenesis

Postoperative delirium (POD) is a complication characterized by disturbances in attention, awareness, and cognitive function that occur shortly after surgery or emergence from anesthesia. Since it occurs prevalently in neurosurgical patients and poses great threats to the well-being of patients, much emphasis is placed on POD in neurosurgical units. However, there are intricate theories about its pathogenesis and limited pharmacological interventions for POD. In this study, we review the recent insights into its pathogenesis, mainly based on studies within five years, and the five dominant pathological theories that account for the development of POD, with the intention of furthering our understanding and boosting its clinical management.

Risk factors and a nomogram model for postoperative delirium in elderly gastric cancer patients after laparoscopic gastrectomy

Background

To evaluate the risk factors of postoperative delirium (POD) in elderly gastric cancer (GC) patients after laparoscopic gastrectomy and construct a predictive model.

Methods

Elderly GC patients undergoing laparoscopic gastrectomy were enrolled and grouped based on the status of POD development within postoperative 7 days. Independent risk factors were selected out by univariate and multivariate logistic regression analyses and then enrolled in the nomogram prediction model.

Results

A total of 270 elderly GC patients were enrolled, and POD occurred in 74 (27.4%) patients within postoperative 7 days. The results of multivariate regression analysis indicated that age (OR: 3.30, 95% CI: 1.41–6.85, P < 0.001), sleeping pills (OR: 1.87, 95% CI: 1.12–3.09, P = 0.012), duration of ICU stay (OR: 1.55, 95% CI: 1.02–2.37, P = 0.029), albumin/fibrinogen ratio (AFR) (OR: 1.74, 95% CI: 1.03–2.76, P = 0.019), and neutrophils/lymphocytes ratio (NLR) (OR: 2.12, 95% CI: 1.11–4.01, P = 0.016) were five independent risk factors for POD in elderly GC patients. The AUC of the constructed nomogram model based on these five factors was 0.807.

Conclusions

This study highlighted that age, AFR, NLR, sleeping pills taking, and duration of ICU stay were independent risk factors for POD, and the nomogram model based on these factors could effectively predict POD in elderly GC patients.

Clinical Predictors and Outcomes Associated with Postoperative Delirium Following Infrainguinal Bypass Surgery

OBJECTIVES

Postoperative delirium (POD) is common yet often underdiagnosed following vascular surgery. Elderly patients with advanced peripheral artery disease may be at particular risk for POD yet understanding of the clinical predictors and impact of POD is incomplete. We sought to identify POD predictors and associated resource utilization after infrainguinal lower extremity bypass.

METHODS

This single center retrospective analysis included all infrainguinal bypass cases performed for peripheral arterial disease from 2012-2020. The primary outcome was inpatient post-operative delirium. Delirium sequelae were also evaluated. Key secondary outcomes were length of stay, non-home discharge, readmission, 30-day amputation, postoperative myocardial infarction, mortality, and 2-year survival. Regression analysis was used to evaluate risk factors for delirium in addition to association with 2-year survival and amputation free survival.

RESULTS

Among 420 subjects undergoing infrainguinal lower extremity bypass, 105 (25%) developed POD. Individuals with POD were older and more likely to have non-elective surgery (p<0.05). On multivariable analysis, independent predictors of POD were age 60-89 years old, chronic limb threatening ischemia, female sex, and non-elective procedure. Consultations for POD took place for 25 cases (24%); 13 (52%) were with pharmacists, and only 4 (16%) resulted in recommendations. The average length of stay for those with POD was higher (17 days vs 9 days; p<.001). POD was associated with increased non-home discharge (61.8% vs 22.1%; p<.001), 30-day major amputation (6.7% vs 1.6%; p<0.01), 30-day postoperative myocardial infarction (11.4% vs 4.1%; p<0.01), and 90-day mortality (7.6% vs 2.9%; p=0.03). Survival at 2 years was lower in those with delirium (89% vs 75%; p<.001). In a Cox proportional hazards model, delirium was independently associated with decreased survival (HR=2.0; 95% CI=1.15-3.38; p=0.014) and decreased major-amputation free survival (HR=1.9; 95% CI=1.18-2.96; p=0.007).

CONCLUSIONS

Postoperative delirium is common following infrainguinal lower extremity bypass and is associated with other adverse post-operative outcomes and increased resource utilization, including increased hospital length of stay, non-home discharge, and worse 2-year survival. Future studies should evaluate the role of routine multidisciplinary care for high-risk patients to improve perioperative outcomes for vulnerable older adults undergoing infrainguinal lower extremity bypass.

Instruments to Identify Delirium in Patients Recovering From Anesthesia: A Scoping Review

PURPOSE

To identify the validated instruments used for screening and detecting postoperative delirium (POD) during Post Anesthesia Recovery (PAR) period, and the incidence and associated risk factors with POD.

DESIGN

A scoping review.

METHODS

The study search occurred in May 2021 in the PubMed, Embase, Scopus, CINAHL, Web of Science and LILACS databases. Primary studies that used validated instruments for screening and detecting POD in the PAR period were included.

FINDINGS

A total of 38 articles were included. The most used instruments were CAM-ICU, Nu-DESC, and RASS. The instruments that screened and detected delirium earliest were the Nu-DESC and CAM-ICU. POD incidence was up to 20% in more than half of the included studies. Cardiovascular comorbidities, chronic kidney disease, low functional reserve, chronic obstructive pulmonary disease and postoperative pain were among the primary risk factors.

CONCLUSION

The instrumentsshowing the greatest accuracy for screening and detecting POD in the PAR period were the Nu-DESC and CAM-ICU.

The Relationship Between Suboptimal Social Networks and Postoperative Delirium: The PNDABLE Study

Background

Although it has been proven that social networks are related to cognition, studies are conducted to characterize the correlation between social networks and postoperative delirium (POD).

Objective

We investigated whether suboptimal social networks are a risk factor for POD, and to verify whether different levels of intimacy in the same social relationship can affect the concentration of cerebrospinal fluid (CSF) biomarkers, such as amyloid-β (Aβ42), total tau (T-tau), and phosphorylated tau (P-tau), and the mediating role of CSF biomarkers between social network and POD in middle-aged and elderly Han people.

Methods

Our study recruited 743 participants from The Perioperative Neurocognitive Disorder and Biomarker Lifestyle (PNDABLE) study. Confusion Assessment Method (CAM) was used to evaluate the incidence of POD and its severity was measured using the Memorial Delirium Assessment Scale (MDAS). The social networks were measured using self-reported questionnaires about social ties. Mann–Whitney U test, Logistic Regression and Independent-samples test were used for Statistical Analysis.

Results

The incidence of POD was 20.7%. Mann–Whitney U test showed that the total score of the social network was associated with POD (P < 0.001). Independent-samples test showed that different levels of intimacy in the same social relationship were significantly associated with CSF POD biomarkers, and mediation analyses revealed that the association between suboptimal social networks and POD was partially mediated by T-tau (proportion: 20%), P-tau (proportion: 33%), Aβ42/T-tau (proportion: 14%), and Aβ42/P-tau (proportion: 15%).

Conclusion

Having suboptimal social networks is a risk factor for POD in middle-aged and elderly Han people. CSF POD biomarkers can mediate the correlation between suboptimal social networks and POD, which is mainly mediated by tau protein.

Clinical Trial Registration

www.chictr.org.cn, identifier ChiCTR2000033439.

Influence of Renin-Angiotensin System Inhibitors on Postoperative Delirium in Patients With Pulmonary Arterial Hypertension: A Secondary Analysis of a Retrospective Cohort Study

OBJECTIVE

To investigate the correlation between preoperative use of ACEIs/ARBs and postoperative delirium (POD) in surgical patients with pulmonary arterial hypertension (PAH).

METHODS

The present study is a secondary analysis of a retrospective cohort study conducted at the University of Washington Medical Center from April 2007 to September 2013. Patients with PAH who underwent non-cardiac, non-obstetric surgery were enrolled in the original research. We further excluded stroke, sepsis, and craniotomy patients from interfering with POD evaluation. The univariate regression analysis and multivariate-adjusted model were used to explore the influence of preoperative ACEIs/ARBs use on the occurrence of POD.

RESULTS

A total of 539 patients were included in this study. The incidence of POD in these patients was 3.0%. Following the adjustment of potential confounders (age, BMI, smoking status, pulmonary arterial systolic pressure, length of surgery, vascular surgery, asthma, obstructive sleep apnea, renal failure, atrial fibrillation, coronary artery disease, hydrochlorothiazide, alpha-blocker, calcium channel blocker, antiplatelet, steroids, statin, isoflurane), a negative relationship was found between preoperative use of ACEIs/ARBs and occurrence of POD (OR = 0.15, 95%CI: 0.03 to 0.80, P = 0.0266).

CONCLUSION

Preoperative use of ACEIs/ARBs in patients with PAH reduces the risk of POD. ACEIs/ARBs may be more recommended for patients with PAH in the future.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

Systematic review of clinical evidence on postoperative delirium: literature search of original studies based on validated diagnostic scales

BACKGROUND

Postoperative delirium is a serious complication that can occur within the 5th postoperative day. In 2017, the European Society of Anesthesiologists delivered dedicated guidelines that reported the need for routine monitoring using validated scales.

OBJECTIVE

Aim of this systematic review is to identify clinical studies related to postoperative delirium that included postoperative monitoring with validated scales.

DESIGN

Systematic review METHODS: Searched keywords included the following terms: postoperative, postsurgical, post anesthesia, anesthesia recovery, delirium, and confusion. Two researchers independently screened retrieved studies using a data extraction form.

RESULTS

Literature search led to retrieve 6475 hits; of these, 260 studies (5.6% of the retrieved), published between 1987 and 2021, included in their methods a diagnostic workup with the use of a postoperative delirium validated scale and monitored patients for more than 24 h, therefore are qualified to be included in the present systematic review.

CONCLUSION

In conclusion, available clinical literature on postoperative delirium relies on a limited number of studies, that included a validated diagnostic workup based on validated scales, extracted from a large series of studies that used inconsistent diagnostic criteria. In order to extract indications based on reliable evidence-based criteria, these are the studies that should be selectively considered. The analysis of these studies can also serve to design future projects and to test clinical hypothesis with a more standardized methodological approach.

The influence of age on EEG-based anaesthesia indices

STUDY OBJECTIVE

In the upcoming years there will be a growing number of elderly patients requiring general anaesthesia. As age is an independent risk factor for postoperative delirium (POD) the incidence of POD will increase concordantly. One approach to reduce the risk of POD would be to avoid excessively high doses of anaesthetics by using neuromonitoring to guide anaesthesia titration. Therefore, we evaluated the influence of patient's age on various electroencephalogram (EEG)-based anaesthesia indices.

DESIGN AND PATIENTS

We conducted an analysis of previously published data by replaying single electrode EEG episodes of maintenance of general anaesthesia from 180 patients (18-90 years; ASA I-IV) into the five different commercially available monitoring systems and evaluated their indices. We included the State/Response Entropy, Narcotrend, qCON/qNOX, bispectral index (BIS), and Treaton MGA-06. For a non-commercial comparison, we extracted the spectral edge frequency (SEF) from the BIS. To evaluate the influence of the age we generated linear regression models. We also assessed the correlation between the various indices.

MAIN RESULTS

During anaesthetic maintenance the values of the SEF, State/Response Entropy, qCON/qNOX and BIS all significantly increased (0.05 Hz/0.19-0.26 index points per year) with the patient's age (p < 0.001); whereas the Narcotrend did not change significantly with age (0.06 index points per year; p = 0.28). The index values of the Treaton device significantly decreased with age (-0.09 index points per year; p < 0.001). These findings were independent of the administered dose of anaesthetics.

CONCLUSIONS

Almost all current neuromonitoring devices are influenced by age, with the potential to result in inappropriately high dosage of anaesthetics. Therefore, anaesthesiologists should be aware of this phenomenon, and the next generation of monitors should correct for these changes.

Usefulness of postoperative serum translocator protein as a predictive marker for delirium after breast cancer surgery in elderly women

Objective

Postoperative delirium (POD) has rarely been investigated in breast cancer patients. Herein, we assessed the association between serum levels of the inflammatory biomarker translocator protein (TP) and the occurrence of POD in breast cancer patients.

Methods

In this prospective, observational study, TP levels were detected in preoperative and postoperative serum samples from 152 elderly breast cancer patients, samples from 152 healthy elderly women, and samples from 152 elderly women with benign breast diseases. The relationship between serum TP levels and POD was investigated using multivariate analysis.

Results

TP levels in postoperative patient serum samples were significantly higher than in preoperative patient serum samples and serum from women in the two control groups. Postoperative serum TP levels were independently correlated with serum C-reactive protein levels and the occurrence of POD. Postoperative serum TP levels had a high discriminatory ability for POD under the receiver operating characteristic curve.

Conclusions

Increased postoperative serum TP levels are independently associated with the degree of inflammatory response and the risk of POD in elderly breast cancer patients, substantializing TP as an inflammatory biomarker that can efficiently discriminate POD after breast cancer surgery.

Delirium after Deep Brain Stimulation in Parkinson's Disease

Deep brain stimulation is a primary treatment method that improves motor and motor complications in patients with advanced Parkinson's disease. Delirium is a common and serious complication following deep brain stimulation. However, the clinical attention toward this complication remains insufficient. Advanced age, cognitive decline, and the severity of the disease may all be risk factors for delirium. The presence of delirium may also affect cognitive function and disease prognosis. Neurotransmitters such as acetylcholine and dopamine may be involved in the occurrence of delirium. Furthermore, inflammation, the effects of microlesioning of local nuclei, and brain atrophy may also play roles in the onset of delirium. Nonpharmacological therapy appears to be the primary treatment for postoperative delirium in Parkinson's disease. The current article reviews the pathogenesis, epidemiology, prognosis, and treatment of delirium following deep brain stimulation in Parkinson's disease to help clinicians better understand this common complication and to prevent, identify, and treat it as soon as possible, as well as to provide more accurate treatment for patients.

Analysis of Delirium From the Dynamic Symptoms Model: A Literature Review

Delirium is a manifestation of brain injury or acute and generalized dysfunction of the upper cerebral cortical processes. In this way, it is important to analyze delirium more broadly as a symptom to understand and intervene taking into account that it is manifesting the presence of brain lesions whose consequences are deleterious to the neurological performance of patients. This article is intended to present a comprehensive approach of delirium analyzed from a symptom perspective and from theoretical and conceptual structure, such as the Dynamic Symptoms Model, specific to the nursing practice. A literature review related to delirium and components of Dynamic Symptoms Model was carried out. We searched the MEDLINE, ScienceDirect, SciELO, and Scopus databases using the terms Delirium, Intensive Care Units, Nursing, and Risk Factor. The existing literature provides evidence of the antecedents, experience, interventions, interactions, and consequences of delirium, which are components of the Model. Thus, the analysis from the Dynamic Symptoms Model perspective bears relevance and contributes to the understanding and approach of delirium.

The Effects of Propofol or Dexmedetomidine Sedation on Postoperative Recovery in Elderly Patients Receiving Lower Limb Surgery under Spinal Anesthesia: A Retrospective Propensity Score-Matched Analysis

Propofol and dexmedetomidine are the two most popular intravenous sedatives during anesthesia. However, data comparing the effects of these two sedatives during spinal anesthesia on postoperative recovery are still insufficient. We retrospectively analyzed the medical records of patients aged ≥65 years who underwent orthopedic surgery under spinal anesthesia between March 2012 and February 2017. The patients were allocated into two groups according to the intraoperative sedatives: the propofol group and dexmedetomidine group. We analyzed the incidence of postoperative delirium, analgesic requirement, and rescue anti-emetic treatment. A total of 1045 patients were included in the analysis. After propensity score matching with the propofol group, the dexmedetomidine group showed a lower incidence of postoperative delirium (odds ratio, 0.19; 95% CI, 0.07–0.56; p = 0.011). Postoperative analgesic and anti-emetic requirement were not significantly different between the two groups (p = 0.156 and 0.245, respectively). Multivariate logistic regression analysis revealed that intraoperative sedation, age, preoperative albumin level, and hip surgery were significantly associated with the incidence of postoperative delirium. This study showed that intraoperative dexmedetomidine sedation under spinal anesthesia during lower limb surgery is associated with a lower incidence of postoperative delirium compared with propofol sedation.

Derivation and validation of a novel comorbidity-based delirium risk index to predict postoperative delirium using national administrative healthcare database

OBJECTIVE

To derive and validate a comorbidity-based delirium risk index (DRI) to predict postoperative delirium.

DATA SOURCE/STUDY SETTING

Data of 506 438 hip fracture repair surgeries from 2006 to 2016 were collected to derive DRI and perform internal validation from the Premier Healthcare Database, which provided billing information on 20-25 percent of hospitalizations in the USA. Additionally, data of 1 130 569 knee arthroplasty surgeries were retrieved for external validation.

STUDY DESIGN

Thirty-six commonly seen comorbidities were evaluated by logistic regression with the outcome of postoperative delirium. The hip fracture repair surgery cohort was separated into a training dataset (60 percent) and an internal validation (40 percent) dataset. The least absolute shrinkage and selection operator (LASSO) procedure was applied for variable selection, and weights were assigned to selected comorbidities to quantify corresponding risks. The newly developed DRI was then compared to the Charlson-Deyo Index for goodness-of-fit and predictive ability, using the Akaike information criterion (AIC), Bayesian information criterion (BIC), area under the ROC curve (AUC) for goodness-of-fit, and odds ratios for predictive performance. Additional internal validation was performed by splitting the data by four regions and in 4 randomly selected hospitals. External validation was conducted in patients with knee arthroplasty surgeries.

DATA COLLECTION

Hip fracture repair surgeries, knee arthroplasty surgeries, and comorbidities were identified by using ICD-9 codes. Postoperative delirium was defined by using ICD-9 codes and analyzing billing information for antipsychotics (specifically haloperidol, olanzapine, and quetiapine) typically recommended to treat delirium.

PRINCIPAL FINDINGS

The derived DRI includes 14 comorbidities and assigns comorbidities weights ranging from 1 to 6. The DRI outperformed the Charlson-Deyo Comorbidity Index with better goodness-of-fit and predictive performance.

CONCLUSIONS

Delirium risk index is a valid comorbidity index for covariate adjustment and risk prediction in the context of postoperative delirium. Future work is needed to test its performance in different patient populations and varying definitions of delirium.

Estimates of Geriatric Delirium Frequency in Noncardiac Surgeries and Its Evaluation Across the Years: A Systematic Review and Meta-analysis

OBJECTIVES

Delirium is an acute neuropsychiatric syndrome associated with poor outcomes. Older adults undergoing surgery have a higher risk of manifesting perioperative delirium, particularly those having associated comorbidities. It remains unclear whether delirium frequency varies across surgical settings and if it has remained stable across the years. We conducted a systematic review to (1) determine the overall frequency of delirium in older people undergoing noncardiac surgery; (2) explore factors explaining the variability of the estimates; and (3) determine the changing of the estimates over the past 2 decades.

DESIGN

Systematic review and meta-analysis. Literature search was performed in MEDLINE, PubMed, ISI Web of Science, EBSCO, ISRCTN registry, ScienceDirect, and Embase in January 2020 for studies published from 1995 to 2020.

SETTING

Noncardiac surgical settings.

PARTICIPANTS

Forty-nine studies were included with a total of 26,865 patients screened for delirium.

METHODS

We included observational and controlled trials reporting incidence, prevalence, or proportion of delirium in adults aged ≥60 years undergoing any noncardiac surgery requiring hospitalization. Data extracted included sample size, reported delirium frequencies, surgery type, anesthesia type, delirium diagnosis method, length of hospitalization, and year of assessment. (PROSPERO registration no.: CRD42020160045).

RESULTS

We found an overall pooled frequency of preoperative delirium of 17.9% and postoperative delirium (POD) of 23.8%. The POD estimates increased between 1995 and 2020 at an average rate of 3% per year. Pooled estimates of POD were significantly higher in studies not excluding patients with lower cognitive performance before surgery (28% vs 16%) and when general anesthesia was used in comparison to local, spinal, or epidural anesthesia (28% vs 20%).

CONCLUSIONS AND IMPLICATIONS

Type of anesthesia and preoperative cognitive status were significant moderators of delirium frequency. POD in noncardiac surgery has been increasing across the years, suggesting that more resources should be allocated to delirium prevention and management.

Regional Metabolic Patterns of Abnormal Postoperative Behavioral Performance in Aged Mice Assessed by 1H-NMR Dynamic Mapping Method

Abnormal postoperative neurobehavioral performance (APNP) is a common phenomenon in the early postoperative period. The disturbed homeostatic status of metabolites in the brain after anesthesia and surgery might make a significant contribution to APNP. The dynamic changes of metabolites in different brain regions after anesthesia and surgery, as well as their potential association with APNP are still not well understood. Here, we used a battery of behavioral tests to assess the effects of laparotomy under isoflurane anesthesia in aged mice, and investigated the metabolites in 12 different sub-regions of the brain at different time points using proton nuclear magnetic resonance (1H-NMR) spectroscopy. The abnormal neurobehavioral performance occurred at 6 h and/or 9 h, and recovered at 24 h after anesthesia/surgery. Compared with the control group, the altered metabolite of the model group at 6 h was aspartate (Asp), and the difference was mainly displayed in the cortex; while significant changes at 9 h occurred predominantly in the cortex and hippocampus, and the corresponding metabolites were Asp and glutamate (Glu). All changes returned to baseline at 24 h. The altered metabolic changes could have occurred as a result of the acute APNP, and the metabolites Asp and Glu in the cortex and hippocampus could provide preliminary evidence for understanding the APNP process.

Effectiveness of non-pharmacological strategies for managing delirium in hospitalized postoperative adults: an umbrella review protocol

REVIEW QUESTION/OBJECTIVE

The question of this review: What is the effectiveness of non-pharmacological strategies for the management of delirium in hospitalized adult postoperative patients?The objective of this umbrella review is to determine the effectiveness of non-pharmacological strategies for the management of delirium in adult postoperative patients, 18 years and over, in an acute care hospitalized setting.More specifically, the review aims to identify which non-pharmacological strategy/strategies, provided as a single strategy or combined as two or more strategies, is the most effective for management of delirium in hospitalized postoperative adult patients?

Delirium pathophysiology: An updated hypothesis of the etiology of acute brain failure

BACKGROUND

Delirium is the most common neuropsychiatric syndrome encountered by clinicians dealing with older adults and the medically ill and is best characterized by 5 core domains: cognitive deficits, attentional deficits, circadian rhythm dysregulation, emotional dysregulation, and alteration in psychomotor functioning.

DESIGN

An extensive literature review and consolidation of published data into a novel interpretation of known pathophysiological causes of delirium.

RESULTS

Available data suggest that numerous pathological factors may serve as precipitants for delirium, each having differential effects depending on patient-specific patient physiological characteristics (substrate). On the basis of an extensive literature search, a newly proposed theory, the systems integration failure hypothesis, was developed to bring together the most salient previously described theories, by describing the various contributions from each into a complex web of pathways-highlighting areas of intersection and commonalities and explaining how the variable contribution of these may lead to the development of various cognitive and behavioral dysfunctions characteristic of delirium. The specific cognitive and behavioral manifestations of the specific delirium picture result from a combination of neurotransmitter function and availability, variability in integration and processing of sensory information, motor responses to both external and internal cues, and the degree of breakdown in neuronal network connectivity, hence the term acute brain failure.

CONCLUSIONS

The systems integration failure hypothesis attempts to explain how the various proposed delirium pathophysiologic theories interact with each other, causing various clinically observed delirium phenotypes. A better understanding of the underlying pathophysiology of delirium may eventually assist in designing better prevention and management approaches.

Incidence and risk factors of postoperative delirium in the elderly patients with hip fracture

Background

To investigate the incidence and related risk factors of delirium in elderly patients with hip fracture.

Methods

This is a retrospective study, performed in a medical center from October 2014 to February 2017, which enrolled all subjects aged over 65 years who were admitted for hip surgeries (hip arthroplasty, proximal femoral nail fixation). Univariate and multivariate logistic analysis was used to determine the incidence and risk factors of delirium. Delirium was assessed according to the Confusion Assessment Method (CAM).

Results

Overall, 19.29% of total 306 patients (mean age 81.9 ± 5.4 years) were identified as delirium. The delirium was significantly associated (p < 0.05) with the factors of age, hospitalization, diabetes, preoperative hematocrit (HCT), perioperative protein consumption, transfusion volume, preoperative leukocyte level, albumin level, American Society of Anesthesiologists (NYHA) classification, American Society of Anesthesiologists (ASA) classification, blood loss, coronary heart disease, and cerebral infarction. Multivariate analysis of the variables confirmed that age (> 75 years old), diabetes, and ASA classification (> 2 level) are the independent risk factors of postoperative delirium (POD). In addition, patients in delirium had prolonged hospitalization and high perioperative albumin infusion.

Conclusion

The elderly patients over the age of 75 years with the history of diabetes or ASA classification > 2 level were at higher risk of POD. Delirium is an important postoperative complication, which had prolonged hospitalization and high perioperative albumin infusion.

Level of evidence: III