Pre-operative hemoglobin level and use of sedative-hypnotics are independent risk factors for post-operative delirium following total knee arthroplasty

Establishment and validation of the prediction model for postoperative delirium risk factors in older patients after total knee arthroplasty: A retrospective study

This study aimed to establish an effective predictive model for postoperative delirium (POD) risk assessment after total knee arthroplasty (TKA) in older patients. The clinical data of 446 older patients undergoing TKA in the Orthopedics Department of our University from January to December 2022 were retrospectively analyzed, and the POD risk prediction model of older patients after TKA was established. Finally, 446 patients were included, which were divided into training group (n = 313) and verification group (n = 133). Logistic regression method was used to select meaningful predictors. The prediction model was constructed with nomographs, and the model was evaluated with correction curve and receiver operating characteristic curve. The logistic regression analysis showed that age, educational level, American Society of Anesthesiologists grade, accompaniment of chronic obstructive pulmonary disease, accompaniment of cerebral stroke, postoperative hypoxemia, long operation time, and postoperative pain were independent risk factors for POD after TKA (P < .05). The nomogram prediction model established. The area under receiver operating characteristic curve of the model group and the validation group were 0.954 and 0.931, respectively. The calibration curve of the prediction model has a high consistency between the 2 groups. The occurrence of POD was associated with age, educational level, American Society of Anesthesiologists grade, accompaniment of chronic obstructive pulmonary disease, accompaniment of cerebral stroke, postoperative hypoxemia, long operation time, and postoperative pain in TKA patients.

Assessment and report of individual symptoms in studies of delirium in postoperative populations: a systematic review

OBJECTIVES

Delirium is most often reported as present or absent. Patients with symptoms falling short of the diagnostic criteria for delirium fall into 'no delirium' or 'control' groups. This binary classification neglects individual symptoms and may be hindering identification of the pathophysiology underlying delirium. This systematic review investigates which individual symptoms of delirium are reported by studies of postoperative delirium in adults.

METHODS

Medline, EMBASE and Web of Science databases were searched on 03 June 2021 and 06 April 2023. Two reviewers independently examined titles and abstracts. Each paper was screened in duplicate and conflicting decisions settled by consensus discussion. Data were extracted, qualitatively synthesised and narratively reported. All included studies were quality assessed.

RESULTS

These searches yielded 4,367 results. After title and abstract screening, 694 full-text studies were reviewed, and 62 deemed eligible for inclusion. This review details 11,377 patients including 2,049 patients with delirium. In total, 78 differently described delirium symptoms were reported. The most reported symptoms were inattention (N = 29), disorientation (N = 27), psychomotor agitation/retardation (N = 22), hallucination (N = 22) and memory impairment (N = 18). Notably, psychomotor agitation and hallucinations are not listed in the current Diagnostic and Statistical Manual for Mental Disorders-5-Text Revision delirium definition.

CONCLUSIONS

The 78 symptoms reported in this systematic review cover domains of attention, awareness, disorientation and other cognitive changes. There is a lack of standardisation of terms, and many recorded symptoms are synonyms of each other. This systematic review provides a library of individual delirium symptoms, which may be used to inform future reporting.

Identification of risk factors for postoperative delirium in patients following intraoral reconstruction with microvascular free flaps: a matched-pair analysis

Postoperative delirium (POD) following microvascular head and neck reconstruction negatively impacts patient outcomes, and only a few risk factors have been identified. The aim of this study was to identify additional risk factors for POD after intraoral reconstruction with microvascular free flaps. Data from 377 patients who underwent intraoral microvascular free flap reconstruction between 2011 and 2019 were analysed retrospectively. Preoperative, intraoperative, and postoperative variables were compared between 40 patients with POD and 40 patients without POD who were matched for previously identified risk factors (i.e., sex, age, American Society of Anesthesiologists class, preoperative arterial hypertension, tracheotomy, operation time, and blood transfusion). A multivariable regression analysis was then performed to identify risk factors associated with POD. POD occurred in 50 (13.3%) of the 377 cases studied; the median time of onset was postoperative day 2. Excessive preoperative alcohol consumption (odds ratio 9.22, 95% confidence interval 1.09-77.97; P = 0.041) and postoperative transplant revision (odds ratio 25.72, 95% confidence interval 1.26-525.43; P = 0.035) were identified as risk factors for POD. The identification of patients at high risk of POD based on these two risk factors may allow early adjustment of diagnostic and therapeutic modalities to improve outcomes and reduce healthcare costs.

Machine learning for prediction of delirium in patients with extensive burns after surgery

AIMS

Machine learning-based identification of key variables and prediction of postoperative delirium in patients with extensive burns.

METHODS

Five hundred and eighteen patients with extensive burns who underwent surgery were included and randomly divided into a training set, a validation set, and a testing set. Multifactorial logistic regression analysis was used to screen for significant variables. Nine prediction models were constructed in the training and validation sets (80% of dataset). The testing set (20% of dataset) was used to further evaluate the model. The area under the receiver operating curve (AUROC) was used to compare model performance. SHapley Additive exPlanations (SHAP) was used to interpret the best one and to externally validate it in another large tertiary hospital.

RESULTS

Seven variables were used in the development of nine prediction models: physical restraint, diabetes, sex, preoperative hemoglobin, acute physiological and chronic health assessment, time in the Burn Intensive Care Unit and total body surface area. Random Forest (RF) outperformed the other eight models in terms of predictive performance (ROC:84.00%) When external validation was performed, RF performed well (accuracy: 77.12%, sensitivity: 67.74% and specificity: 80.46%).

CONCLUSION

The first machine learning-based delirium prediction model for patients with extensive burns was successfully developed and validated. High-risk patients for delirium can be effectively identified and targeted interventions can be made to reduce the incidence of delirium.

Alcohol consumption may be associated with postoperative delirium in the elderly: the PNDABLE study

OBJECTIVES

This study aimed to reveal the relationship between alcohol consumption and Postoperative delirium (POD) in the elderly.

METHODS

We selected 252 patients from the Perioperative Neurocognitive Disorder And Biomarker Lifestyle (PNDABLE ) study. Patients in the PNDABLE database have been measured for Alzheimer-related biomarkers in CSF (Aβ40, Aβ42, P-tau, and tau protein). Mini-Mental State Examination (MMSE) was used to assess the preoperative mental status of patients. POD was diagnosed using the Confusion Assessment Method (CAM) and assessed for severity using the Memorial Delirium Assessment Scale (MDAS). Logistic regression analysis was utilized to explore the association of alcohol consumption with POD. Linear regression analysis was used to study the relationship between alcohol consumption and CSF biomarkers. Mediation analyses with 10,000 bootstrapped iterations were used to explore the mediation effects. Finally, we constructed the receiver operating characteristic (ROC) curve and the nomogram model to evaluate the efficacy of alcohol consumption and CSF biomarkers in predicting POD.  RESULT: The incidence of POD was 17.5%. Logistic regression showed that alcohol consumption (OR = 1.016, 95%CI 1.009-1.024, P < 0.001) is a risk factor for POD. What's more, Aβ42 is a protective factor for POD (OR = 0.993, 95%CI 0.989-0.997, P < 0.05), and P-Tau was a risk factor for POD (OR = 1.093, 95%CI 1.022-1.168, P < 0.05). Linear regression analysis revealed that alcohol consumption was negatively associated with CSF Aβ42 (β = -0.638, P < 0.001) in POD patients. Mediation analyses showed that alcohol consumption is likely to partially mediate POD through Aβ42 (proportion:14.21%). ROC curve showed that alcohol consumption (AUC = 0.904; P < 0.001) exhibited a relatively better discriminatory ability in POD prediction compared to Aβ42 (AUC = 0.798; P < 0.001). The calibration curve indicated a good nomogram prediction (P = 0.797).

CONCLUSION

Alcohol consumption is a risk factor for POD (particularly for those with > 24 g a day on average) in the elderly, and contributes to POD through the mediation of Aβ42.

Postoperative Delirium in Patients Receiving Hip Bipolar Hemiarthroplasty for Displaced Femoral Neck Fractures: The Risk Factors and Further Clinical Outcomes

BACKGROUND

Postoperative delirium in patients who have hip fractures may lead to poor outcomes. This study aimed to determine perioperative risk factors and clinical outcomes of postoperative delirium in patients undergoing hip bipolar hemiarthroplasty for displaced femoral neck fractures.

METHODS

Among 1,353 patients who underwent hemiarthroplasty at our institution during 2013-2021, we identified 78 patients with postoperative delirium diagnosed with the confusion assessment method. The mean delirium duration was 28 hours (range: 15-520). We also included 1:2 sex- and age-matched patients who did not have postoperative delirium after the same surgery as a matching cohort for comparison. Patient comorbidities, perioperative data, delirium occurrence, and outcomes were collected for analyses.

RESULTS

A Charlson Comorbidity Index (CCI) score ≥6 (odds ratio (OR): 2.08, P = .017), nighttime surgery (OR: 3.47, p =<.001), surgical delays (OR: 1.01, P = .012), preoperative anemia (OR: 2.1, P = .012), and blood transfusions (OR: 2.47, P = .01) may increase the risk of postoperative delirium. The presentation of delirium was associated with sepsis (OR: 3.77, P = .04), longer hospital stays (P < .001), higher 1-year mortality (OR: 3.97, P = .002), and overall mortality (OR: 2.1, P = .02).

CONCLUSION

Postoperative delirium predicted poor outcomes. Our results emphasized the importance of early identification of patients at risk and optimization of the medical conditions before and after surgery.

Association of Anemia with Dementia and Cognitive Decline among Community-Dwelling Elderly

INTRODUCTION

The association of anemia with dementia in elders is controversial. We examined the potential association of anemia with dementia in a large population of elders.

METHODS

Historical-prospective registry-based study. Included 36,951 community-dwelling elders (65-113 years) that were followed during 2002-2012. Anemia of all kinds was defined according to Clalit Health Services (CHS) definitions: hemoglobin (HGB) <14 g/dL men, <12 g/dL women; and World Health Organization (WHO): HGB <13 g/dL men, <12 g/dL women. Anemia was categorized as mild (HGB 11-13 g/dL men, 11-12 g/dL women) or moderate-severe (HGB <8-10.9 g/dL men and women). Background data, laboratory values, and diagnosis of dementia and cognitive decline (DCD) were reviewed.

RESULTS

During the 10-year follow-up period, DCD was newly diagnosed in 7,180 subjects (19.4%). Subjects with DCD had a higher rate of anemia than those without DCD. Time to development of DCD was 1.5 years shorter in those with than without anemia. On multivariate Cox regression analysis adjusted for age and sex, the hazard ratio (HR) for DCD was 1.45 (95% CI: 1.37-1.54) by CHS and 1.51 (95% CI: 1.41-1.61) WHO anemia criteria. The more severe the anemia, the greater the risk of DCD development (HGB 13-14 g/dL [men only], HR = 1.20 [95% CI: 1.09-1.32]; mild anemia, HR = 1.38 [95% CI: 1.28-1.49]; moderate-severe anemia, HR = 1.64 [CI: 1.41-1.90]). Every decrease in 1 standard deviation of HGB (1.4 g/dL) increased the DCD risk by 15%. A competing risk model has weakened the association of anemia with DCD risk.

CONCLUSIONS AND IMPLICATIONS

Anemia in community-dwelling elders appears to be associated with an increased DCD risk in a dose-response manner. Application of the WHO anemia criteria in men may miss patients with mild anemia that places them at DCD risk. Further research should look at anemia as a cause of reversible dementia.

Risk factors for postoperative delirium following total hip or knee arthroplasty: A meta-analysis

Objectives

The purpose of this study was to identify risk factors for delirium after total joint arthroplasty (TJA) and provide theoretical guidance for reducing the incidence of delirium after TJA.

Methods

The protocol for this meta-analysis is registered with PROSPERO (CRD42020170031). We searched PubMed, the Cochrane Library and Embase for observational studies on risk factors for delirium after TJA. Review Manager 5.3 was used to calculate the relative risk (RR) or standard mean difference (SMD) of potential risk factors related to TJA. STATA 14.0 was used for quantitative publication bias evaluation.

Results

In total, 25 studies including 3,767,761 patients from 9 countries were included. Old age has been widely recognized as a risk factor for delirium. Our results showed that the main risk factors for delirium after TJA were patient factors (alcohol abuse: RR = 1.63; length of education: SMD = −0.93; and MMSE score: SMD = −0.39), comorbidities (hypertension: RR = 1.26; diabetes mellitus: RR = 1.67; myocardial infarction: RR = 17.75; congestive heart failure: RR = 2.54; dementia: RR = 17.75; renal disease: RR = 2.98; history of stroke: RR = 4.83; and history of mental illness: RR = 2.36), surgical factors (transfusion: RR = 1.53; general anesthesia: RR = 1.10; pre-operative albumin: SMD = −0.38; pre-operative hemoglobin: SMD = −0.29; post-operative hemoglobin: SMD = −0.24; total blood loss: SMD = 0.15; duration of surgery: SMD = 0.29; and duration of hospitalization: SMD = 2.00) and drug factors (benzodiazepine use: RR = 2.14; ACEI use: RR = 1.52; and beta-blocker use: RR = 1.62).

Conclusions

Multiple risk factors were associated with delirium after TJA. These results may help doctors predict the occurrence of delirium after surgery and determine the correct treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42020170031.

Hemoglobin Concentration and Post-Operative Delirium in Elderly Patients Undergoing Femoral Neck Fracture Surgery

This study aimed to determine the relationship between hemoglobin (Hb) concentration and post-operative delirium (POD) in elderly patients undergoing femoral neck fracture (FNF) surgery and to investigate whether the change in Hb concentration is associated with POD and the risk factors for POD. A total of 889 patients admitted with FNF between January 2016 and December 2020 were enrolled in this single-center, retrospective, case–control study. Hb concentrations were determined at admission and post-operative day 1 and the change in Hb concentration was defined as the absolute value of difference in pre-operative and post-operative Hb concentration. POD was assessed using the Confusion Assessment Method for the Intensive Care Unit (ICU) or the Confusion Assessment Method once a daily after surgery. The logistic regression analysis was performed for statistical analysis. In total, 172 (19.3%) patients developed POD and 151 (87.8%) patients developed POD within post-operative 3 days. Low pre-operative Hb concentration [p = 0.026, odds ratio (OR) = 0.978] and significant change in Hb concentration (p = 0.006, OR = 1.033) were significantly associated with POD. After excluding change in Hb concentration or pre-operative Hb concentration, neither of them was significantly associated with POD (p > 0.05). The interaction analysis of change in Hb concentration and pre-operative Hb concentration in the logistic regression model was negative. There was no significant relationship between post-operative Hb concentration and POD. Age (p < 0.001, OR = 1.072), stroke history (p = 0.003, OR = 2.489), post-operative ICU transfer (p = 0.007, OR = 1.981), and visual analog scale score within post-operative 2 days (p₁ = 0.016 and p₂ = 0.006) were independently associated with POD in the logistic regression analysis. Patients with low pre-operative Hb concentrations and high changes in Hb concentration seem to have an increased risk of POD and should receive more attention. Old age, stroke history, post-operative ICU transfer, and pain within post-operative 2 days were significantly associated with POD.

Predictors of postoperative delirium in elderly patients following total hip and knee arthroplasty: a systematic review and meta-analysis

BACKGROUND

Postoperative delirium (POD) is widely reported as a common postoperative complication following total joint arthroplasty (TJA) of the hip and knee in elderly patients, leading to many adverse effects. We sought to investigate predictors of delirium after TJA.

METHODS

PubMed, EMBASE, Cochrane Library and Web of Science were searched up to 2020 for studies examining POD following TJA in elderly patients. Pooled odds ratio (OR) and mean difference (MD) of those who experienced delirium compared to those who did not were calculated for each variable. The Newcastle-Ottawa Scale (NOS) was used for the study quality evaluation.

RESULTS

Fifteen studies with 31 potential factors were included. In the primary analysis, 9 factors were associated with POD, comprising advanced age (MD 3.81; 95% confidence interval (CI) 1.80-5.83), dementia (OR 24.85; 95% CI 7.26-85.02), hypertension (OR 2.26; 95% CI 1.31-3.89), diabetes (OR 2.02; 95% CI 1.15-3.55), stroke (OR 14.61; 95% CI 5.26-40.55), psychiatric illness (OR 2.72; 95% CI 1.45-5.08), use of sedative-hypnotics (OR 6.42; 95% CI 2.53-16.27), lower preoperative levels of hemoglobin (MD - 0.56; 95% CI - 0.89-- 0.22), and lower preoperative mini-mental state examination score (MD - 0.40; 95% CI - 0.69-- 0.12). Twelve studies were included in the systematic review, of which 24 factors were additionally correlated with POD using single studies.

CONCLUSIONS

Strategies and interventions should be implemented for the elderly patients receiving TJA surgeries with potential predictors identified in this meta-analysis.

Preoperative Anemia and Risk for Perioperative Neurocognitive Dysfunction in Cardiac Surgery Patients: A Retrospective Analysis

OBJECTIVES

To evaluate whether there is a relationship between preoperative anemia and domain-specific cognitive performance in patients undergoing cardiac surgery.

DESIGN

Retrospective analysis of data collected from a randomized study.

SETTING

Tertiary care university hospital.

PARTICIPANTS

A total of 436 patients age ≥55 years undergoing cardiac surgery.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Neuropsychological testing was performed before and one month after surgery, using a standard battery. Individual Z-scores calculated from the mean and standard deviation of tests at baseline were combined into domain-specific scores. Anemia (hemoglobin <130 g/L for men, <120 g/L for women) was present in 41% of patients. Preoperative anemia had little impact on preoperative cognition. There were no differences in the change in cognitive performance one month after surgery from baseline between patients with and without preoperative anemia. However, in a sensitivity analysis using multiple imputation for missing cognitive test scores, significant associations were observed between preoperative anemia and change in postoperative processing speed (p = 0.016), change in executive function (p = 0.049), and change in fine motor speed (p = 0.016). Nadir hemoglobin during cardiopulmonary bypass, which was lower in anemic than nonanemic patients, was associated with decrements in performance on tests of verbal fluency (p = 0.007), processing speed (p = 0.042), and executive function (p = 0.10) one month after surgery but not delayed neurocognitive recovery (p = 0.06).

CONCLUSIONS

Preoperative anemia may be associated with impairment of selective cognitive domains after surgery. Any effect of preoperative anemia may have on cognition after surgery might be related to lower nadir hemoglobin during cardiopulmonary bypass.

Research status and prospect of peri-extubation delirium

Peri-extubation delirium is a clinical syndrome caused by multiple factors, and it is not a simple disease. It occurs within a period of time after extubation when the effect of general anesthesia is reduced. And the incidence is different in disparate populations, and it is more common in elderly patients. Current studies have shown that iatrogenic factors and patients' own factors are the main risk factors for the syndrome. Early identification of risk factors can help clinicians make early diagnosis. The earlier the diagnosis and treatment begin, the more significantly the prognosis of patients can be improved. At present, the treatment of perioperative delirium is based on non-drug therapy, supplemented by drug therapy. This review will introduce in detail the risk factors, population status and prevention measures of delirium during peri-extubation, and look forward to the new research direction in the future.