New Cutoff Scores for Delirium Screening Tools to Predict Patient Mortality

Exploratory randomised trial of tranexamic acid to decrease postoperative delirium in adults undergoing lumbar fusion-a trial stopped early

Background

Postoperative delirium may be mediated by systemic inflammation and neuroinflammation. By inhibiting the proinflammatory actions of plasmin, tranexamic acid (TXA) may decrease postoperative delirium. To explore this hypothesis, we modified an ongoing randomised trial of TXA on blood loss, adding measures of delirium, cognition, systemic inflammation, and astrocyte activation.

Methods

Adults undergoing elective posterior lumbar fusion randomly received intraoperative i.v. TXA (n=43: 10 mg kg-1 loading dose, 2 mg kg-1 h-1 infusion) or placebo (n=40). Blood was collected before surgery and 24 h after surgery (n=32) for biomarkers (cytokines and S100B). Participants had twice daily delirium assessments (n=65). Participants underwent four measures of cognitive function before surgery and during post-discharge follow-up.

Results

Postoperative blood loss was ∼38% less in the TXA group compared with the placebo group with medians of 128 and 207 ml level-1, respectively, P=0.013. Total blood loss in the TXA and placebo groups did not differ with medians of 305 and 333 ml level-1, respectively, P=0.472. Delirium incidence in the TXA group (7/32=22%) was not significantly less than in the placebo group (11/33=33%); P=0.408, effect size =-0.258 (95% confidence interval -0.744 to 0.229).

Conclusions

A potential 33% relative decrease in postoperative delirium incidence justifies an adequately powered clinical trial to determine if intraoperative TXA decreases delirium in adults undergoing lumbar fusion.

Clinical trial registration

NCT04272606.

Ultrasound-guided femoral nerve block reduced the incidence of postoperative delirium after total knee arthroplasty: A double-blind, randomized study

BACKGROUND

Postoperative delirium (POD) is an acute brain dysfunction that mainly occurs in elderly patients after surgery. Postoperative pain is an important factor in the occurrence of POD, and effective pain management can reduce the risk of POD. Our study aims is to investigate the effect of ultrasound-guided femoral nerve block (FNB) on postoperative pain and the occurrence of POD after knee arthroplasty, and whether its mechanism is related to oxidative stress, inflammatory factors.

METHODS

Patients aged 65 to 80 years who were scheduled to undergo knee arthroplasty under general anesthesia from 2020 to 2023 were randomly divided into 2 groups: the control group (NC group) and the FNB analgesia group (FNB group). After anesthesia induction, the FNB group received ultrasound-guided FNB, whereas the NC group received an equal volume of normal saline. Visual analog scale (VAS), incidence of POD. the postoperative Quality of Recovery-15-Chinese version (QoR-15C) was been evaluated. Venous blood samples were collected from patients to detect the level of malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and C-reactive protein (CRP).

RESULTS

The VAS scores in the FNB group were significantly lower than those in the NC group at 24h. The summation of perioperative remifentanil usage and the number of remedial analgesia in the FNB group were significantly lower than those in the NC group. The incidence rate of POD in the FNB group is lower than the NC group. The occurrence of POD was markedly lower in the FNB group compared to the NC group. Compared with the NC group, the levels of MDA, GSH-Px, and CRP in the FNB group were lower on the first and third days after surgery. The QoR-15C score in the FNB group was higher on the 5th day after surgery.

CONCLUSION

Ultrasound-guided FNB can reduce the incidence of POD after knee replacement surgery, and its mechanism may be related to analgesia improvement and reduction of postoperative inflammatory reaction.

Exploratory Randomised Trial of Tranexamic Acid to Decrease Postoperative Delirium in Adults Undergoing Lumbar Fusion: A trial stopped early

Background

Postoperative delirium may be mediated by perioperative systemic- and neuro-inflammation. By inhibiting the pro-inflammatory actions of plasmin, tranexamic acid (TXA) may decrease postoperative delirium. To explore this hypothesis, we modified an ongoing randomised trial of TXA, adding measures of postoperative delirium, cognitive function, systemic cytokines, and astrocyte activation.

Methods

Adults undergoing elective posterior lumbar fusion randomly received intraoperative intravenous TXA (n=43: 10 mg kg-1 loading dose, 2 mg kg-1 h-1 infusion) or Placebo (n=40). Blood was collected pre- and at 24 h post-operatively (n=32) for biomarkers of systemic inflammation (cytokines) and astrocyte activation (S100B). Participants had twice daily delirium assessments using the 3-minute diagnostic interview for Confusion Assessment Method (n=65). Participants underwent 4 measures of cognitive function preoperatively and during post-discharge follow-up.

Results

Delirium incidence in the TXA group (7/32=22%) was not significantly less than in the Placebo group (11/33=33%); P=0.408, absolute difference=11%, relative difference=33%, effect size = -0.258 (95% CI -0.744 to 0.229). In the Placebo group (n=16), delirium severity was associated with the number of instrumented vertebral levels (P=0.001) and with postoperative interleukin -8 and -10 concentrations (P=0.00008 and P=0.005, respectively) and these associations were not significantly modified by TXA. In the Placebo group, delirium severity was associated with S100B concentration (P=0.0009) and the strength of the association was decreased by TXA (P=0.002).

Conclusions

A potential 33% relative decrease in postoperative delirium incidence justifies an adequately powered clinical trial to determine if intraoperative TXA decreases delirium in adults undergoing lumbar fusion.

Frailty index and risk of delirium in hospitalized patients: a two-sample Mendelian randomization study

Objective

Observational studies suggest that the frailty index (FI) is closely related to delirium, but the relationship between them is still uncertain due to the influence of various confounding factors. Therefore, two-sample Mendelian randomization (MR) was used to explore the causal relationship between the FI and delirium risk.

Methods

This study obtained pooled statistics for the FI and delirium from two of the most extensive genome-wide association studies. To make the results more robust and reliable, supplementary analyses were performed using several robust analytical methods (inverse-variance weighting, MR-Egger regression, and weighted median). In addition, this study used the MR-Egger intercept test, Cochran's Q test, funnel plots and the leave-one-out method to evaluate the pleiotropy and heterogeneity among the abovementioned genetic variation instrumental variables.

Results

Frailty might increase the relative risk of delirium, as shown by IVW (OR = 1.849, 95% CI 0.027∼2.067, P = 0.044), weighted median (OR = 1.726, 95% CI -0.178∼2.664, P = 0.083), MR-Egger regression (OR = 1.768, 95% CI -3.08∼6.171, P = 0.525) and leave-one-out sensitivity analysis (P = 0.058). Although the WME method and MR-Egger regression analysis showed no statistically significant causal relationship between the FI and the risk of delirium, the direction of the causal effect was consistent with the IVW method.

Conclusion

There is a notable correlation between a higher FI and an elevated risk of delirium. This indicates that healthcare providers should take proactive measures to prevent delirium in hospitalized patients with a higher FI.

Anti-inflammatory medication use associated with reduced delirium risk and all-cause mortality: A retrospective cohort study

OBJECTIVE

To investigate the relationship between history of anti-inflammatory medication use and delirium risk, as well as long-term mortality.

METHODS

In this retrospective cohort study, subjects recruited between January 2016 and March 2020 were analyzed. Information about anti-inflammatory medication use history including aspirin, NSAIDs, glucosamine, and other anti-inflammatory drugs, was collected. Logistic regression analysis investigated the relationship between anti-inflammatory medications and delirium. Log-rank analysis and cox proportional hazards model investigated the relationship between anti-inflammatory medications and one-year mortality.

RESULTS

The data from 1274 subjects were analyzed. The prevalence of delirium was significantly lower in subjects with NSAIDs usage (23.0%) than in those without NSAIDs usage (35.0%) (p < 0.001). Logistic regression analysis controlling for age, sex, dementia status, and hospitalization department showed that the risk of delirium tended to be reduced by a history of NSAIDs use (OR, 0.76 [95% CI, 0.55 to 1.03]). The one-year mortality in the subjects with NSAIDs (survival rate, 0.879 [95% CI, 0.845 to 0.906]) was significantly higher than in the subjects without NSAIDs (survival rate, 0.776 [95% CI, 0.746 to 0.803]) (p < 0.001). A history of NSAIDs use associated with the decreased risk of one-year mortality even after adjustment for age, sex, Charlson Comorbidity Index, delirium status, and hospitalization department (HR, 0.70 [95% CI, 0.51 to 0.96]).

CONCLUSION

This study suggested that NSAIDs usage was associated with decreased delirium prevalence and lower one-year mortality. The potential benefit of NSAIDs on delirium risk and mortality were shown.

Healthcare and economic burden of anticholinergic use in adults with overactive bladder: a systematic literature review

Aim: To determine the economic burden associated with anticholinergic medication use in adults with overactive bladder (OAB) in the USA. Methods: A systematic literature review was conducted to identify articles assessing healthcare resource utilization (HCRU) and costs associated with anticholinergic use in adults with OAB. Results: From the 34 articles identified, increased anticholinergic burden, switching anticholinergic treatments and potentially inappropriate anticholinergic use were associated with increased HCRU and/or costs. However, studies comparing patients with OAB receiving anticholinergics to individuals with untreated OAB or without OAB reported a mix of increases and decreases in HCRU and costs. Conclusion: Additional controlled studies assessing the economic impact of anticholinergics in OAB are needed and may enable optimization of economic and potentially patient outcomes.

The potential benefit of metformin to reduce delirium risk and mortality: a retrospective cohort study

PURPOSE

Metformin has been reported to improve age-related disorders, including dementia, and to lower mortality. This study was conducted to investigate whether metformin use lower delirium risk, as well as long-term mortality.

METHODS

In this retrospective cohort study, previously recruited 1,404 subjects were analyzed. The relationship between metformin use and delirium, and the relationship between metformin use and 3-year mortality were investigated.

MAIN FINDINGS

242 subjects were categorized into a type 2 diabetes mellitus (DM)-without-metformin group, and 264 subjects were categorized into a DM-with-metformin group. Prevalence of delirium was 36.0% in the DM-without-metformin group, and 29.2% in the DM-with-metformin group. A history of metformin use reduced the risk of delirium in patients with DM (OR, 0.50 [95% CI, 0.32 to 0.79]) after controlling for confounding factors. The 3-year mortality in the DM-without-metformin group (survival rate, 0.595 [95% CI, 0.512 to 0.669]) was higher than in the DM-with-metformin group (survival rate, 0.695 [95% CI, 0.604 to 0.770]) (p=0.035). A history of metformin use decreased the risk of 3-year mortality after adjustment for confounding factors (HR, 0.69 [95% CI, 0.48 to 0.98]).

CONCLUSIONS

Metformin use may lower the risk of delirium and mortality in DM patients.

Predisposing and Precipitating Risk Factors for Delirium in Elderly Patients Admitted to a Cardiology Ward: An Observational Cohort Study in 1,042 Patients

Aim: Although the risk factors for delirium in general medicine are well-established, their significance in cardiac diseases remains to be determined. Therefore, we evaluated the predisposing and precipitating risk factors in patients hospitalized with acute and chronic heart disease.

Methods and Results: In this observational cohort study, 1,042 elderly patients (≥65 years) admitted to cardiology wards, 167 with and 875 without delirium, were included. The relevant sociodemographic and cardiac- and medical-related clusters were assessed by simple and multiple regression analyses and prediction models evaluating their association with delirium. The prevalence of delirium was 16.0%. The delirious patients were older (mean 80 vs. 76 years; p < 0.001) and more often institutionalized prior to admission (3.6 vs. 1.4%, p = 0.05), hospitalized twice as long (12 ± 10 days vs. 7 ± 7 days; p < 0.001), and discharged more often to nursing homes (4.8 vs. 0.6%, p < 0.001) or deceased (OR, 2.99; 95% CI, 1.53–5.85; p = 0.003). The most relevant risk factor was dementia (OR, 18.11; 95% CI, 5.77–56.83; p < 0.001), followed by history of stroke (OR, 6.61; 95% CI 1.35–32.44; p = 0.020), and pressure ulcers (OR, 3.62; 95% CI, 1.06–12.35; p = 0.040). The predicted probability for developing delirium was highest in patients with reduced mobility and institutionalization prior to admission (PP = 31.2%, p = 0.001). Of the cardiac diseases, only valvular heart disease (OR, 1.57; 95% CI, 1.01–2.44; p = 0.044) significantly predicted delirium. The patients undergoing cardiac interventions did not have higher rates of delirium (OR, 1.39; 95% CI 0.91–2.12; p = 0.124).

Conclusion: In patients admitted to a cardiology ward, age-related functional and cognitive impairment, history of stroke, and pressure ulcers were the most relevant risk factors for delirium. With regards to specific cardiological factors, only valvular heart disease was associated with risk for delirium. Knowing these factors can help cardiologists to facilitate the early detection and management of delirium.

Evaluation of point-of-care thumb-size bispectral electroencephalography device to quantify delirium severity and predict mortality

BACKGROUND

We have developed the bispectral electroencephalography (BSEEG) method for detection of delirium and prediction of poor outcomes.

AIMS

To improve the BSEEG method by introducing a new EEG device.

METHOD

In a prospective cohort study, EEG data were obtained and BSEEG scores were calculated. BSEEG scores were filtered on the basis of standard deviation (s.d.) values to exclude signals with high noise. Both non-filtered and s.d.-filtered BSEEG scores were analysed. BSEEG scores were compared with the results of three delirium screening scales: the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), the Delirium Rating Scale-Revised-98 (DRS) and the Delirium Observation Screening Scale (DOSS). Additionally, the 365-day mortalities and the length of stay (LOS) in the hospital were analysed.

RESULTS

We enrolled 279 elderly participants and obtained 620 BSEEG recordings; 142 participants were categorised as BSEEG-positive, reflecting slower EEG activity. BSEEG scores were higher in the CAM-ICU-positive group than in the CAM-ICU-negative group. There were significant correlations between BSEEG scores and scores on the DRS and the DOSS. The mortality rate of the BSEEG-positive group was significantly higher than that of the BSEEG-negative group. The LOS of the BSEEG-positive group was longer compared with that of the BSEEG-negative group. BSEEG scores after s.d. filtering showed stronger correlations with delirium screening scores and more significant prediction of mortality.

CONCLUSIONS

We confirmed the usefulness of the BSEEG method for detection of delirium and of delirium severity, and prediction of patient outcomes with a new EEG device.

Mortality among patients with sepsis associated with a bispectral electroencephalography (BSEEG) score

We have previously developed a bispectral electroencephalography (BSEEG) device, which was shown to be effective in detecting delirium and predicting patient outcomes. In this study we aimed to apply the BSEEG approach for a sepsis. This was a retrospective cohort study conducted at a single center. Sepsis-positive cases were identified based on retrospective chart review. EEG raw data and calculated BSEEG scores were obtained in the previous studies. The relationship between BSEEG scores and sepsis was analyzed, as well as the relationship among sepsis, BSEEG score, and mortality. Data were analyzed from 628 patients. The BSEEG score from the first encounter (1st BSEEG) showed a significant difference between patients with and without sepsis (p = 0.0062), although AUC was very small indicating that it is not suitable for detection purpose. Sepsis patients with high BSEEG scores showed the highest mortality, and non-sepsis patients with low BSEEG scores showed the lowest mortality. Mortality of non-sepsis patients with high BSEEG scores was as bad as that of sepsis patients with low BSEEG scores. Even adjusting for age, gender, comorbidity, and sepsis status, BSEEG remained a significant predictor of mortality (p = 0.008). These data are demonstrating its usefulness as a potential tool for identification of patients at high risk and management of sepsis.

DNA methylation in the TNF-alpha gene decreases along with aging among delirium inpatients

It has been suggested that aging and inflammation play key roles in the development of delirium. In the present study, we investigated the differences of the DNAm patterns in the TNF gene between patients with delirium and without. The data and samples derived from previous and ongoing cohort studies were analyzed. DNAm levels of the TNF gene were analyzed using the Illumina EPIC array genome-wide method and pyrosequencing method. Correlations between age and DNAm levels of each CpG were calculated. Several CpG in the TNF gene in blood showed negative correlation between their DNAm and age in delirium cases both with the EPIC array and by the pyrosequencing method. However, there was no CpG that had significant correlation between their DNAm and age regardless of delirium status among buccal samples. On the other hand, among peripheral blood mononuclear cells samples, it was found that several CpG showed negative correlation between their DNAm and age in delirium cases. The evidence of DNAm change in the TNF gene among delirious subjects was demonstrated.

The Association Between Frailty and Delirium Among Hospitalized Patients: An Updated Meta-Analysis

OBJECTIVE

The aim of our meta-analysis was to update evidence for the association between frailty and delirium in different types of hospitalized patients, given the large volume of new studies with inconsistent results.

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

In this updated meta-analysis, we searched 3 databases (Embase, PubMed, and the Cochrane Library) for observational studies, exploring the association between frailty and delirium from database inception to September 21, 2020, among hospitalized patients. Relevant data were extracted from the studies that were included. A random effects model was conducted to synthesize and pool the effect size of frailty on delirium due to different frailty score instruments, different countries, and various delirium assessments that were used. The participants enrolled in this meta-analysis were hospitalized patients.

MEASURES

Delirium risk due to frailty.

RESULTS

A total of 30 independent studies from 9 countries, consisting of 217,623 patients, was identified, and the prevalence of frailty ranged from 16.20% to 78.00%. Frail patients exhibited an increased risk for delirium compared to those without frailty [odds ratio (OR) 2.96, 95% confidence interval (CI) 2.36-3.71]. In addition, different types of hospitalized patients had various OR values, which were 2.43 for selective surgical patients (95% CI 1.88-3.14), 3.61 for medical patients (95% CI 3.61-7.89), 3.76 for urgent surgical patients (95% CI 2.88-4.92), and 6.66 for emergency or critical illness patients (95% CI 1.41-31.47). Subgroup analysis based on the frailty score instrument showed the association still existed when using the Clinical Frailty Scale (OR 4.07, 95% CI 2.71-6.11), FRAIL Scale (OR 2.83, 95% CI 1.56-5.13), Frailty Index (OR 6.15, 95% CI 3.75-10.07), frailty phenotype (OR 2.30, 95%CI 1.35-5.66), or Erasmus Frailty Score (OR 2.79, 95% CI 1.63-4.77). However, an association between frailty and delirium was not observed when the Edmonton Frail Scale was used (OR 1.45, 95% CI 0.91-2.30).

CONCLUSIONS AND IMPLICATIONS

A 2.96-fold incremental risk of delirium in frail patients underscores the need for early screening of frailty and comprehensive delirium prevention. Appropriate interventions by clinicians should be performed to manage delirium, potentially reducing adverse clinical outcomes for hospitalized patients.

Topological data analysis (TDA) enhances bispectral EEG (BSEEG) algorithm for detection of delirium

Current methods for screening and detecting delirium are not practical in clinical settings. We previously showed that a simplified EEG with bispectral electroencephalography (BSEEG) algorithm can detect delirium in elderly inpatients. In this study, we performed a post-hoc BSEEG data analysis using larger sample size and performed topological data analysis to improve the BSEEG method. Data from 274 subjects included in the previous study were analyzed as a 1st cohort. Subjects were enrolled at the University of Iowa Hospitals and Clinics (UIHC) between January 30, 2016, and October 30, 2017. A second cohort with 265 subjects was recruited between January 16, 2019, and August 19, 2019. The BSEEG score was calculated as a power ratio between low frequency to high frequency using our newly developed algorithm. Additionally, Topological data analysis (TDA) score was calculated by applying TDA to our EEG data. The BSEEG score and TDA score were compared between those patients with delirium and without delirium. Among the 274 subjects from the first cohort, 102 were categorized as delirious. Among the 206 subjects from the second cohort, 42 were categorized as delirious. The areas under the curve (AUCs) based on BSEEG score were 0.72 (1st cohort, Fp1-A1), 0.76 (1st cohort, Fp2-A2), and 0.67 (2nd cohort). AUCs from TDA were much higher at 0.82 (1st cohort, Fp1-A1), 0.84 (1st cohort, Fp2-A2), and 0.78 (2nd cohort). When sensitivity was set to be 0.80, the TDA drastically improved specificity to 0.66 (1st cohort, Fp1-A1), 0.72 (1st cohort, Fp2-A2), and 0.62 (2nd cohort), compared to 0.48 (1st cohort, Fp1-A1), 0.54 (1st cohort, Fp2-A2), and 0.46 (2nd cohort) with BSEEG. BSEEG has the potential to detect delirium, and TDA is helpful to improve the performance.

Bispectral EEG (BSEEG) quantifying neuro-inflammation in mice induced by systemic inflammation: A potential mouse model of delirium

Most of the animal studies using inflammation-induced cognitive change have relied on behavioral testing without objective and biologically solid methods to quantify the severity of cognitive disturbances. We have developed a bispectral EEG (BSEEG) method using a novel algorithm in clinical study. This method effectively differentiates between patients with and without delirium, and predict long-term mortality. In the present study, we aimed to apply our bispectral EEG (BSEEG) method, which can detect patients with delirium, to a mouse model of delirium with systemic inflammation induced by lipopolysaccharides (LPS) injection. We recorded EEG after LPS injection using wildtype early adulthood mice (2~3-month-old) and aged mice (18-19-month-old). Animal EEG recordings were converted for power spectral density to calculate BSEEG score using the similar BSEEG algorithm previously developed for our human study. The BSEEG score was relatively stable and slightly high during the day. Alternatively, the BSEEG score was erratic and low in average during the night. LPS injection increased the BSEEG score dose-dependently and diminished the diurnal changes. The mean BSEEG score increased much more in the aged mice group as dosage increased. Our results suggest that BSEEG method can objectively "quantify" level of neuro-Inflammation induced by systemic inflammation (LPS), and that this BSEEG method can be useful as a model of delirium in mice.