Non-pharmacological approaches in the prevention of delirium

Random forest algorithm for predicting postoperative delirium in older patients

Objective

In this study, we were aimed to identify important variables via machine learning algorithms and predict postoperative delirium (POD) occurrence in older patients.

Methods

This study was to make the secondary analysis of data from a randomized controlled trial. The Boruta function was used to screen relevant basic characteristic variables. Four models including Logistic Regression (LR), K-Nearest Neighbor (KNN), the Classification and Regression Tree (CART), and Random Forest (RF) were established from the data set using repeated cross validation, hyper-parameter optimization, and Smote technique (Synthetic minority over-sampling technique, Smote), with the calculation of confusion matrix parameters and the plotting of Receiver operating characteristic curve (ROC), Precision recall curve (PRC), and partial dependence graph for further analysis and evaluation.

Results

The basic characteristic variables resulting from Boruta screening included grouping, preoperative Mini-Mental State Examination(MMSE), CHARLSON score, preoperative HCT, preoperative serum creatinine, intraoperative bleeding volume, intraoperative urine volume, anesthesia duration, operation duration, postoperative morphine dosage, intensive care unit (ICU) duration, tracheal intubation duration, and 7-day postoperative rest and move pain score (median and max; VAS-Rest-M, VAS-Move-M, VAS-Rest-Max, and VAS-Move-Max). And Random Forest (RF) showed the best performance in the testing set among the 4 models with Accuracy: 0.9878; Matthews correlation coefficient (MCC): 0.8763; Area under ROC curve (AUC-ROC): 1.0; Area under the PRC Curve (AUC-PRC): 1.0.

Conclusion

A high-performance algorithm was established and verified in this study demonstrating the degree of POD risk changes in perioperative elderly patients. And the major risk factors for the development of POD were CREA and VAS-Move-Max.

The efficacy of earplugs and eye masks for delirium severity and sleep quality in patients undergoing coronary artery bypass grafting in cardiac intensive care units: A single-blind, randomised controlled trial

BACKGROUND AND PURPOSE

Delirium is a neuropsychiatric syndrome with a wide range of possible causes and multiple complications in patients admitted to intensive care units. It is, therefore, necessary to seek appropriate and safe strategies to prevent and manage delirium. This study is intended to examine the efficacy of eye masks and earplugs for delirium severity and sleep quality in patients with coronary artery bypass grafting in a cardiac intensive care unit.

MATERIALS AND METHODS

This single-blind, randomised controlled trial was conducted on 114 patients who were consecutively enrolled and randomly assigned to either the experimental group or the control group. The experimental group received routine care plus eye masks and earplugs, and the control group received only routine care. The delirium severity and sleep quality were measured with the Neelon and Champagne confusion scale and the Verran and Snyder-Halpern sleep scale.

RESULTS

The mean delirium severity score differed significantly between the two groups on the second, third, and fourth postoperative days (p < 0.001). Although the trend of changes in the mean delirium severity score from the first postoperative day (before the intervention) to the second, third, and fourth postoperative days was downward in the two groups (trending towards higher delirium severity), the control group experienced greater changes than the experimental group. An intragroup analysis of delirium severity detected a statistically significant difference in both the experimental and control groups (p < 0.001). The sleep quality domains (sleep disturbance, sleep effectiveness, sleep supplementation) showed a statistically significant difference between the two groups across the three intervention days (p < 0.001).

CONCLUSION

The overnight use of eye masks and earplugs were found to have positive effects on sleep quality domains (sleep disturbance, sleep effectiveness, sleep supplementation) and delirium severity in coronary artery bypass grafting patients admitted to the cardiac intensive care unit for several days. It was also found that a significant interaction effect between the sleep disturbance subscale and delirium severity exists.

CLINICAL TRIAL REGISTRATION NUMBER

(https://en.irct.ir): IRCT20210523051370N2.

Development and evaluation of a concise nurse-driven non-pharmacological delirium reduction workflow for hospitalized patients: An interrupted time series study

We created a concise nurse-driven delirium reduction workflow with the aim of reducing delirium rates and length of stay for hospitalized adults. Our nurse-driven workflow included five evidence-based daytime "sunrise" interventions (patient room lights on, blinds up, mobilization/out-of-bed, water within patient's reach and patient awake) and five nighttime "turndown" interventions (patient room lights off, blinds down, television off, noise reduction and pre-set bedtime). Interventions were also chosen because fidelity could be quickly monitored twice daily without patient interruption from outside the room. To evaluate the workflow, we used an interrupted time series study design between 06/01/17 and 05/30/22 to determine if the workflow significantly reduced the unit's delirium rate and average length of stay. Our workflow is feasible to implement and monitor and initially significantly reduced delirium rates but not length of stay. However, the reduction in delirium rates were not sustained following the emergence of the COVID-19 pandemic.

Family-centered delirium prevention and treatment using video calls: the FACE Delirium trial

PURPOSE

In the FACE Delirium trial, we investigated the feasibility of a structured FAmily-CEntered delirium prevention and treatment during the corona pandemic.

METHODS

Patients hospitalized in a German geriatric medicine department were included in this single-center, prospective, single-arm feasibility study. Their relatives received a short training on delirium and volunteers or paid staff members facilitated video calls. The primary endpoint was reached when contact between patients and their relatives occurred on ≥ 80% of treatment days, either via video call or visit.

RESULTS

38 patients were included (age 83.0 ± 5.9 years; 73.7% women). 76.3% reached the primary endpoint. Due to the pandemic, 99.3% of the contacts were video calls with a duration of 24.8 ± 16.3 min.

CONCLUSION

Family-centered delirium prevention and treatment using video calls is feasible among hospitalized geriatric patients. Daily implementation in clinical practice poses challenges and requires motivated and qualified staff.

Non-pharmacological interventions to prevent and treat delirium in older people: An overview of systematic reviews

BACKGROUND

As advanced age is a major risk factor for confusion status, delirium has become prevalent in the older population, contributing to longer hospital stays, cognitive impairment, and higher risks of complications and mortality. Compared with pharmacological methods, non-pharmacological interventions are preferred and are recommended by the National Institute for Health and Care Excellence for the prevention of delirium. Numerous systematic reviews and meta-analyses have been carried out to investigate the effects of non-pharmacological interventions. However, the outcomes were diverse and the quality varied widely, making it challenging to draw firm conclusions from the evidence.

OBJECTIVE

To summarize the contents and evaluate the effects of non-pharmacological interventions to prevent and treat delirium among older people.

DESIGN

Overview of systematic reviews.

METHODS

A comprehensive literature search was conducted in Medline, Cochrane Library, EMBASE, CINAHL, PsycINFO, JBI EBP Database, China's SinoMed, CNKI, and Wangfang databases from inception to 2nd December 2022. Two reviewers performed the study selection, quality appraisal, and data extraction independently. The AMSTAR 2 tool was used to appraise the methodological quality of eligible reviews. The results were presented in narrative synthesis based on types of intervention, including multicomponent and single-component interventions.

RESULTS

Twenty-four systematic reviews were included in this overview, of which four reviews were of high quality. Multicomponent interventions were the most widely disseminated non-pharmacological strategy, which were effective in preventing delirium with 27 %-54 % reduction in delirium incidence. Additionally, the multicomponent strategy also reduced the incidence of falls and pressure ulcers, and showed trends toward shortening the length of stay and improving cognitive function. Among single-component interventions, physical training, geriatric risk assessment, and reorientation protocol revealed positive effects in delirium prevention. However, the effectiveness of non-pharmacological interventions for treating delirium was limited, and while multicomponent methods had inconsistent impacts on the duration and severity of delirium, single-component methods showed no significant impact.

CONCLUSION

Non-pharmacological interventions are effective in reducing the incidence of delirium and improving other health outcomes among older patients. However, the effects on the duration and severity of delirium need more evidence to confirm.

REGISTRATION NUMBER

CRD42022376651 in PROSPERO.

Predicting postoperative delirium after cardiovascular surgeries from preoperative portable electroencephalography oscillations

Introduction

Postoperative delirium (POD) is common and life-threatening, however, with intensive interventions, a potentially preventable clinical syndrome. Although electroencephalography (EEG) is a promising biomarker of delirium, standard 20-leads EEG holds difficulties for screening usage in clinical practice.

Objective

We aimed to develop an accurate algorithm to predict POD using EEG data obtained from portable device.

Methods

We recruited 128 patients who underwent scheduled cardiovascular surgery. Cognitive function assessments were conducted, and portable EEG recordings were obtained prior to surgery.

Results

Among the patients, 47 (36.7%) patients with POD were identified and they did not significantly differ from patients without POD in sex ratio, age, cognitive function, or treatment duration of intensive care unit. However, significant differences were observed in the preoperative EEG power spectrum densities at various frequencies, especially gamma activity, between patients with and without POD. POD was successfully predicted using preoperative EEG data with a machine learning algorithm, yielding accuracy of 86% and area under the receiver operating characteristic curve of 0.93.

Discussion

This study provides new insights into the objective and biological vulnerability to delirium. The developed algorithm can be applied in general hospitals without advanced equipment and expertise, thereby enabling the reduction of POD occurrences with intensive interventions for high-risk patients.

Delirium in Home Care: A Case Report

Delirium is a challenging medical problem, particularly in the home care setting, and greatly affects both patients and family caregivers. When delirium is not immediately detected and effectively managed, various outcomes are adversely affected. This report describes delirium in an older home-bound man and offers strategies for detecting and managing delirium in a home care setting. The patient is a frail 86-year-old man with multiple medical comorbidities and functional decline after bronchitis that was diagnosed by a general practitioner. Following the diagnosis and subsequent treatment of bronchitis, the patient suffered a major decline in cognitive and physical functioning during normal daily activities. Medical screening revealed confusion, apathy, and extreme fatigue. Using the assessment tool of the Functional Independence Measures and Delirium Observation Screening Scale (DOSS), the presence of functional decline and delirious symptoms were found. Through multidisciplinary collaboration, a treatment plan was initiated. It consisted of hydration following a fixed schedule, adapted nutrition, a temporary adapted medication schedule for pre-diabetes, and an exercise plan. No specific pharmaceuticals were given. The patient made a full recovery over time. All professional and informal caregivers should be aware of the potential presence of delirium when an older patient with a deteriorating physical or mental condition presents itself. Good diagnostics for delirium and possible underlying diseases are necessary. Adequate treatment, with the help of paramedics such as dieticians, physiotherapists, etc. must be provided when necessary.

Effect of using eye masks and earplugs in preventing delirium in intensive care patients: A single-blinded, randomized, controlled trial

BACKGROUND

Delirium, which is frequently encountered in intensive care patients, can be prevented with multicomponent nursing interventions, and thus the negative consequences can be reduced.

AIM

To examine the effect of using eye masks and earplugs in preventing delirium in intensive care units (ICUs).

STUDY DESIGN

A randomized, controlled, single-blind intervention study. This study was conducted in the medical and surgical ICUs of a tertiary hospital, and nurses were given pre-study training on delirium risks, diagnosis, prevention, and management. Data were collected using the patient information form, the Nursing Delirium Screening Scale, the Richard-Campbell Sleep Scale, and the daily follow-up form. Various environmental modifications were made in the ICUs for all patients, and evidence-based nonpharmacological nursing interventions were applied to the patients in both groups during the day and night shifts for 3 days. In addition, the patients in the intervention group were provided with eye masks and earplugs for three nights.

RESULTS

The study included a total of 60 patients (30 in the intervention group and 30 in the control group). There was a statistically significant difference in the development of delirium between the intervention and control groups (night of the 2nd day, p = .019; day of the 3rd day p < .001; night of the 3rd day p ≤ .001). The average total sleep quality score of the intervention group was found to be significantly higher than the control group (p ≤ .001 for three nights). Staying in the internal medicine ICU affected (odds ratio [OR], 11.84; 95% confidence interval [CI], 3.00-46.66; p = .017) more on the development of delirium than in coronary ICU, being in the age group of 65 and over, having a hearing impairment, coming to ICU from the operating room, and education level had an effect.

CONCLUSIONS

The earplugs and eye masks used by the intensive care patients overnight were found to be effective in increasing sleep quality and preventing delirium.

RELEVANCE TO CLINICAL PRACTICE

The use of eye masks and earplugs is recommended for ICUs in preventing delirium.

Independent External Validation of a Preoperative Prediction Model for Delirium After Cardiac Surgery: A Prospective Observational Cohort Study

OBJECTIVE

This investigation provided independent external validation of an existing preoperative risk prediction model.

DESIGN

A prospective observational cohort study of patients undergoing cardiac surgery covering the period between April 16, 2018 and January 18, 2022.

SETTING

Two academic hospitals in Switzerland.

PARTICIPANTS

Adult patients (≥60 years of age) who underwent elective cardiac surgery, including coronary artery bypass graft, mitral or aortic valve replacement or repair, and combined procedures.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was the incidence of postoperative delirium (POD) in the intensive or intermediate care unit, diagnosed using the Intensive Care Delirium Screening Checklist. The prediction model contained 4 preoperative risk factors to which the following points were assigned: Mini-Mental State Examination (MMSE) score ≤23 received 2 points; MMSE 24-27, Geriatric Depression Scale (GDS) >4, prior stroke and/or transient ischemic attack (TIA), and abnormal serum albumin (≤3.5 or ≥4.5 g/dL) received 1 point each. The missing data were handled using multiple imputation. In total, 348 patients were included in the study. Sixty patients (17.4%) developed POD. For point levels in the prediction model of 0, 1, 2, and ≥3, the cumulative incidence of POD was 12.6%, 22.8%, 25.8%, and 35%, respectively. The validation resulted in a pooled area under the receiver operating characteristics curve of 0.60 (median CI, 0.525-0.679).

CONCLUSIONS

The evaluated predictive model for delirium after cardiac surgery in this patient cohort showed only poor discriminative capacity but fair calibration.

Using Machine Learning Algorithms to Predict High-Risk Factors for Postoperative Delirium in Elderly Patients

Purpose

Postoperative delirium (POD) is a common postoperative complication in elderly patients, and it greatly affects the short-term and long-term prognosis of patients. The purpose of this study was to develop a machine learning model to identify preoperative, intraoperative and postoperative high-risk factors and predict the occurrence of delirium after nonbrain surgery in elderly patients.

Patients and Methods

A total of 950 elderly patients were included in the study, including 132 patients with POD. We collected 30 characteristic variables, including patient demographic characteristics, basic medical history, preoperative examination characteristics, type of surgery, and intraoperative information. Three machine learning algorithms, multilayer perceptron (MLP), extreme gradient boosting (XGBoost), and k-nearest neighbor algorithm (KNN), were applied to construct the model, and the k-fold cross-validation method, ROC curve, calibration curve, decision curve analysis (DCA) and external validation were used for model evaluation.

Results

XGBoost showed the best performance among the three prediction models. The ROC curve results showed that XGBoost had a high area under the curve (AUC) value of 0.982 in the training set; the AUC value in the validation set was 0.924, and the prediction model was highly accurate. The k-fold cross-validation method was used for internal validation, and the XGBoost model was stable The calibration curve showed high predictive power of the XGBoost model. The DCA curve showed a higher benefit rate for patients who received interventional treatment under the XGBoost model. The AUC value for the external validation set was 0.88, indicating that the predictive model was extrapolative.

Conclusion

The prediction model of POD derived from the machine learning algorithm in this study has high prediction accuracy and clinical utility, which is beneficial for clinicians to diagnose and treat patients in a timely manner.

Head-to-head comparison of 14 prediction models for postoperative delirium in elderly non-ICU patients: an external validation study

OBJECTIVES

Delirium is associated with increased morbidity, mortality, prolonged hospitalisation and increased healthcare costs. The number of clinical prediction models (CPM) to predict postoperative delirium has increased exponentially. Our goal is to perform a head-to-head comparison of CPMs predicting postoperative delirium in non-intensive care unit (non-ICU) elderly patients to identify the best performing models.

SETTING

Single-site university hospital.

DESIGN

Secondary analysis of prospective cohort study.

PARTICIPANTS AND INCLUSION

CPMs published within the timeframe of 1 January 1990 to 1 May 2020 were checked for eligibility (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). For the time period of 1 January 1990 to 1 January 2017, included CPMs were identified in systematic reviews based on prespecified inclusion and exclusion criteria. An extended literature search for original studies was performed independently by two authors, including CPMs published between 1 January 2017 and 1 May 2020. External validation was performed using a surgical cohort consisting of 292 elderly non-ICU patients.

PRIMARY OUTCOME MEASURES

Discrimination, calibration and clinical usefulness.

RESULTS

14 CPMs were eligible for analysis out of 366 full texts reviewed. External validation was previously published for 8/14 (57%) CPMs. C-indices ranged from 0.52 to 0.74, intercepts from -0.02 to 0.34, slopes from -0.74 to 1.96 and scaled Brier from -1.29 to 0.088. Based on predefined criteria, the two best performing models were those of Dai et al (c-index: 0.739; (95% CI: 0.664 to 0.813); intercept: -0.018; slope: 1.96; scaled Brier: 0.049) and Litaker et al (c-index: 0.706 (95% CI: 0.590 to 0.823); intercept: -0.015; slope: 0.995; scaled Brier: 0.088). For the remaining CPMs, model discrimination was considered poor with corresponding c-indices <0.70.

CONCLUSION

Our head-to-head analysis identified 2 out of 14 CPMs as best-performing models with a fair discrimination and acceptable calibration. Based on our findings, these models might assist physicians in postoperative delirium risk estimation and patient selection for preventive measures.

Postoperative delirium in older patients with cancer: the role of psychological distress and social support

PURPOSE OF REVIEW

Delirium is a common and important adverse event in the perioperative period. Older people with cancer are at significant risk, and outcomes are poor. There is increasing awareness of the effect of psychological distress and social support on pathogenesis and outcomes of delirium in this setting. This review aimed to describe recent research in this evolving area.

RECENT FINDINGS

Across six recent studies of postoperative delirium in older people with cancer, delirium incidence ranged from 8 to 19.8%. Poor social support and high levels of distress are implicated in the development of postoperative delirium. Distress can be related to negative emotional reaction to diagnosis, preconception of cancer diagnosis and interactions with the healthcare system. Prevention of delirium is key, and multicomponent interventions show evidence of effectiveness. 'Emotional distress' has been included in a new core outcome set for studies of interventions to prevent and/or treat delirium.

SUMMARY

Postoperative delirium in older adults with cancer is common and is associated with increased morbidity and mortality. Psychological distress and social support play an important role, but there are many unmet research needs in this area.

Postoperative delirium - treatment and prevention

PURPOSE OF REVIEW

Postoperative delirium (POD) is one of the most severe complications after surgery.The consequences are dramatic: longer hospitalization, a doubling of mortality and almost all cases develop permanent, yet subtle, cognitive deficits specific to everyday life. Actually, no global guideline with standardized concepts of management exists. Advances in prevention, diagnosis and treatment can improve recognition and risk stratification of delirium and its consequences.

RECENT FINDINGS

Management of POD is a multiprofessional approach and consists of different parts: First, the detection of high-risk patients with a validated tool, preventive nonpharmacological concepts and an intraoperative anesthetic management plan that is individualized to the older patient (e.g. avoiding large swings in blood pressure, vigilance in maintaining normothermia, ensuring adequate analgesia and monitoring of anesthetic depth). In addition to preventive standards, treatment and diagnostic concepts must also be available, both pharmaceutical and nonpharmacological.

SUMMARY

Not every POD can be prevented. It is important to detect patients with high risk for POD and have standardized concepts of management. The most important predisposing risk factors are a higher age, preexisting cognitive deficits, multimorbidity and an associated prodelirious polypharmacy. In view of demographic change, the implementation of multidisciplinary approaches to pharmacological and nonpharmacological POD management is highly recommended.

A Multi-Phase Quality Improvement Initiative for the Treatment of Active Delirium in Older Persons

BACKGROUND/OBJECTIVES

The Hospital Elder Life Program emerged 20 years ago as the reference model for delirium prevention in hospitalized older patients. However, implementation has been achieved at only 200 hospitals worldwide over the last 20 years. Among the barriers to implementation for some institutions is an unwillingness of hospital administration to assume the costs associated with implementing programs that service all hospitalized older patients at risk for delirium. Facing such a situation, we implemented a unique and self-evolving model of care of older hospitalized patients who had already developed delirium.

DESIGN

Hypothesis testing was carried out using a pretest-posttest design on program administrative data.

SETTING

Mount Sinai Hospital, New York, NY, a tertiary-care teaching facility. PARTICIPANTS A total of 9,214 consecutively admitted older patients to non-intensive care (ICU) inpatient units over a 5.5-year period, regardless of the suspected presence of delirium or risk status for developing delirium.

INTERVENTION

A delirium intervention program targeting patients in whom delirium has already developed, with a modified delirium team supported by extensive workflow automation with custom tools in our electronic medical records system.

MEASUREMENTS

Length of stay (LOS) for delirious and non-delirious patients on units where this program was piloted. Benzodiazepine, opiate, and antipsychotic use on the same units.

RESULTS

There was a significant drop in LOS by 1.98 days (95% confidence interval = .24-3.71), a decrease in the average morphine dose equivalents administered from .38 mg to .21 mg per patient hospital day, diazepam dose equivalents from .22 mg to .15 mg per patient hospital day, and quetiapine administered from .17 mg to .14 mg per patient hospital day for delirious patients on the program pilot units.

CONCLUSION

Elements of our unique active delirium treatment program may provide some direction to other program developers working on improving the care of older hospitalized delirious patients. However, the supporting evidence presented is limited, and a more rigorous prospective study is needed.

Effects of modified version of the Hospital Elder Life Program on post-discharge cognitive function and activities of daily living among older adults undergoing total knee arthroplasty

OBJECTIVES

This study aimed to investigate the effects of a modified Hospital Elder Life Program (mHELP) on post-discharge cognition and physical function among older adults undergoing total knee arthroplasty (TKA), and to evaluate the incidence of postoperative delirium.

DESIGN

Non-randomized intervention trial.

SETTING AND PARTICIPANTS

A total of 140 patients aged 60 years and older scheduled for elective orthopedic surgery at our institution between August 2017 and December 2018 were included.

METHODS

Ward-level stratification was used with one surgical ward receiving mHELP (intervention group), including orientation communication, early mobilization, vision/hearing impairment equipment, and dehydration prevention, and another ward providing usual care (control group). All participants were assigned to two surgical wards. Outcome measures were collected using MMSE telephone version (tMMSE), activities of daily living (ADL) and instrumental activities of daily living (IADL) instruments at 1, 6, and 12 months after discharge. Multiple linear regression analysis was used to measure effects of mHELP intervention on mean differences in tMMSE, ADL and IADL scores from baseline to 1-, 6- and 12-months.

RESULTS

Effects of mHELP intervention significantly preserved cognitive function at 1 and 12 months, but not at 6 months, compared with controls, regardless of adjustments for confounders. However, no intervention effects were noted in ADL and IADL scores. Postoperative delirium in the whole cohort was 3.6 % (2.5 % in intervention group, 5.1 % in control group, P = 0.41).

CONCLUSIONS

mHELP intervention preserves post-discharge cognitive function, but has no notable effect on ADL and IADL function in older adults undergoing elective TKA surgery.