Validation of the Prediction of Delirium for Intensive Care model to predict subsyndromal delirium

Prevalence and risk factors of subsyndromal delirium in ICU: A systematic review and meta-analysis

OBJECTIVE

To systematically assess the prevalence and risk factors for subsyndromal delirium (SSD) in the intensive care unit.

DESIGN

A systematic reviewand meta-analysis.

METHODOLOGY

This systematic review and meta-analysis was conducted in eight databases, including PubMed, Web of Science, Ovid,Scopus, China Knowledge Resource Integrated Database, Wanfang Database,Weipu Database and Chinese Biomedical Database. All original observational studies of subsyndromal delirium in the ICU were included, with languages limited to English and Chinese. The methodological quality was assessed by the Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality recommendation checklist. Meta-analysis was performed using Stata software (version 18.0).

RESULT

A total of 27 studies involving 7,286 participants were included in this review. The pooled prevalence of SSD was 32.4 % (95 %CI: 27.1 %-37.7 %).Fourteen studies reported 34 independent risk factors, and the following ten factors were significantly associated with SSD: older age, higher Acute Physiology and Chronic Health Evaluation II (APACHE II) score, lower Mini-mental Status Examination (MMSE) score, pain, mechanical ventilation, hypoproteinemia, blood transfusion, longer ICU stay, infection, and physical restraint.

CONCLUSION

We conducted a systematic review and meta-analysis to evaluate the prevalence of SSD in the ICU and identified 10 risk factors associated with SSD. However, the studies have significant heterogeneity, future research should be conducted in multicenter with large samples to strengthen the current evidence.

IMPLICATIONS FOR CLINICAL PRACTICE

Subsyndromal delirium is a frequently occurring adverse event in the ICU, so it is recommended that clinicians and nurses incorporate the assessment of SSD into their daily routine. In this study, we also identified ten risk factors associated with SSD, and some of which could be modified or intervened. These findings provide a basis for ICU medical staff to identify patients at high risk of SSD and then implement individualized interventions to reduce the prevalence of SSD.

Dynamic Nomogram for Subsyndromal Delirium in Adult Intensive Care Unit: A Prospective Cohort Study

Purpose

To develop a dynamic nomogram of subsyndromal delirium (SSD) in intensive care unit (ICU) patients and internally validate its efficacy in predicting SSD.

Patients and Methods

Patients who met the inclusion and exclusion criteria in the ICU of a tertiary hospital in Zhejiang from September 2021 to June 2022 were selected as the research objects. The patient data were randomly divided into the training set and validation set according to the ratio of 7:3. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to screen the predictors of SSD, and R software was used to construct a dynamic nomogram. Receiver operating characteristic (ROC) curve, calibration band and decision curve were used to evaluate the discrimination, calibration and clinical effectiveness of the model.

Results

A total of 1000 eligible patients were included, including 700 in the training set and 300 in the validation set. Age, drinking history, C reactive protein level, APACHE II, indwelling urinary catheter, mechanical ventilation, cerebrovascular disease, respiratory failure, constraint, dexmedetomidine, and propofol were predictors of SSD in ICU patients. The ROC curve values of the training set was 0.902 (95% confidence interval: 0.879-0.925), the best cutoff value was 0.264, the specificity was 78.4%, and the sensitivity was 88.0%. The ROC curve values of the validation set was 0.888 (95% confidence interval: 0.850-0.930), the best cutoff value was 0.543, the specificity was 94.9%, and the sensitivity was 70.9%. The calibration band showed good calibration in the training and validation set. Decision curve analysis showed that the net benefit in the model was significantly high.

Conclusion

The dynamic nomogram has good predictive performance, so it is a precise and effective tool for medical staff to predict and manage SSD in the early stage.

Development and Validation of Subsyndromal Delirium Prediction Model in Patients With Advanced Malignant Tumor: A Case-Control Study

BACKGROUND

Subsyndromal delirium (SSD) is a clinical manifestation between delirium and nondelirium. There is no established guideline for diagnosing SSD, with a few different tools used for diagnosis.

OBJECTIVES

To construct and verify the risk prediction model for subdelirium syndrome in patients with advanced malignant tumors and explore its application value in risk prediction.

METHODS

A total of 455 patients admitted to the Oncology Department in a tertiary grade A hospital in Hengyang City were recruited from December 2020 to May 2021. They were selected as the modeling group. The model was constructed by logistic regression. A total of 195 patients with advanced malignant tumors from June 2021 to July 2021 were selected to validate the developed model.

RESULTS

The predictors incorporated into the model were opioids (odds ratio [OR], 1.818), sleep disorders (OR, 1.783), daily living ability score (OR, 0.969), and pain (OR, 1.810). In the modeling group, the Hosmer-Lemeshow goodness-of-fit test was P = .113, the area under the receiver operating characteristic curve was 0.884, the sensitivity was 0.820, and the specificity was 0.893. In the validation group, the Hosmer-Lemeshow goodness-of-fit test P = .108, the area under the receiver operating characteristic curve was 0.843, the Yuden index was 0.670, the sensitivity was 0.804, and the specificity was 0.866.

CONCLUSIONS

This model has excellent precision in the risk prediction of subdelirium in patients with advanced malignant tumors.

IMPLICATIONS FOR PRACTICE

The model we developed has a guiding significance for specialized tumor nurses to care for patients with advanced malignant tumors and improve their quality of life.

Impact of Subsyndromal Delirium Occurrence and Its Trajectory during ICU Stay

Despite recent advances in the field, the association between subsyndromal delirium (SSD) in the ICU and poor outcomes is not entirely clear. We performed a retrospective multicentric observational study analyzing mental status during the first 72 h of ICU stay. Of the 681 patients included, SSD occurred in 22.7%. Considering the worst cognitive assessment during the first 72 h, 233 (34%) patients had normal mental status, 124 (18%) patients had SSD and 324 (48%) patients had delirium or coma. SSD was not independently associated with an increased risk of death when compared with normal mental status (OR 95%IC 1.0 vs. 1.35 [0.73−1.49], p = 0.340), but was associated with a longer ICU LOS (7.0 (4−12) vs. 4 (3−8) days, p < 0.001). SSD patients who deteriorated to delirium or coma (21%) had a longer ICU LOS in comparison with those who improved or maintained mental status (8 (5−11) vs. 6 (4−8) days, p = 0.025), but did not have an increase in mortality. The main factors associated with the progression from SSD to delirium or coma were the use of mechanical ventilation, the use of intravenous benzodiazepines and a baseline APACHE II score > 23 points. Our findings support the association of SSD with increased ICU LOS, but not with ICU mortality. Monitoring the trajectory of SSD early at ICU admission can help to identify patients with increased risk of conversion from SSD to delirium or coma.

Nurses' assessment of subsyndromal delirium and barriers to assessment: A cross-sectional survey in the intensive care unit

AIMS

The aims of the study are to investigate the current status of nurses' assessment of subsyndromal delirium (SSD) in the intensive care unit (ICU) and explore possible barriers to assessment.

BACKGROUND

SSD is a dynamic, recognizable disorder commonly seen in the ICU that can lead to poor patient outcomes. Timely recognition and management can prevent its progression.

METHODS

A cross-sectional survey design was used to collect data from ICU registered nurses in southwest China. The online survey containing an analysis of the current status of SSD assessment and barriers was completed by 237 nurses.

RESULTS

A total of 51.5% of nurses chose to assess SSD using an assessment tool, the most commonly used being the Confusion Assessment Method for the Intensive Care Unit; the frequency of assessment was mostly once a day (66, 41.0%) and often at shift change (178, 87.3%). There were statistically significant differences in the barrier factor scores by assessment frequency, assessment method, status of training in SSD, ability of SSD-related knowledge to meet clinical needs and willingness to receive SSD training.

CONCLUSION

Our study confirms that the current state of assessment of SSD in the ICU is unsatisfactory, with nurses' lack of assessment knowledge and skills, poor organization and management, and the complexity of patients' conditions being barriers.

IMPLICATIONS FOR NURSING MANAGEMENT

Nursing managers should systematically conduct training programmes on effective SSD assessment knowledge and skills, incorporate SSD assessment into the daily workflow, have standardized assessment tools, develop standardized processes and assign dedicated staff to monitor, audit and provide feedback on SSD assessments.

Cognitive, Functional, and Mortality Outcomes of Attenuated Delirium Syndrome in Stroke Survivors

OBJECTIVES

There is a knowledge gap on the prognostic significance of subsyndromes of delirium. We describe the association of poststroke attenuated delirium syndrome (ADS) with cognitive, functional, and mortality outcomes at 3 months.

METHODS

A longitudinal observational study in which repeated assessments for delirium symptoms were conducted in the first week of stroke using the confusion assessment method. Attenuated delirium syndrome was characterized in survivors who were free of the full delirium syndrome but had ≥2 core features of delirium. Baseline and follow-up assessments were conducted using the Mini-Mental State Examination (MMSE), 10-word list learning and delayed recall test, Animal naming test, and Barthel index.

RESULTS

Among 150 participants recruited consecutively over 2 years, ADS was present in 32 (21.3%). Of 121 who were free of the full delirium syndrome, 21 (17.4%) had died by 3 months. Those who survived were more likely to be receiving treatment for systemic hypertension (88.5%, P = .007). In analyses adjusting for the effect of age, economic status, and systemic hypertension, ADS in the first week of stroke predicted cognitive decline at 3 months ([mean difference (MD) in MMSE scores = -3.8, 95% CI = -7.0 to -0.7, P = .019]). However, ADS was not associated with greater decline in activities of daily life (MD = -0.4, 95% CI = -2.8 to 2.0) or significant odds ratio (OR) of mortality (OR = 2.3, 95% CI = 0.8-6.3).

CONCLUSION

Attenuated delirium syndrome may be an important marker of cognitive impairment at 3 months poststroke. Its detection may lead to identification of stroke survivors who are likely to benefit from evidence-based preventive interventions for poststroke cognitive decline.

Subsyndromal Delirium in Cardiac Surgery Patients: Risk Factors and Outcomes of the Different Trajectories

BACKGROUND

Subsyndromal delirium (SSD), a subthreshold form of delirium, is related to longer length of stay and increased mortality rates among older adults. Risk factors and outcomes of SSD in cardiac surgery patients are not fully understood.

OBJECTIVE

The aim of this study was to assess and describe the characteristics and outcomes related to trajectories of SSD and delirium in cardiac surgery patients.

METHODS

In this secondary analysis of a retrospective case-control (1:1) cohort study, SSD was defined as a score between 1 and 3 on the Intensive Care Delirium Screening Checklist paired with an absence of diagnosis of delirium on the day of assessment. Potential risk factors (eg, age) and outcomes (eg, mortality) were identified from existing literature. Patients were grouped into 4 trajectories: (1) without SSD or delirium, (2) SSD only, (3) both, and (4) delirium only. These trajectories were contrasted using analysis of variance or χ2 test.

RESULTS

Among the cohort of 346 patients, 110 patients did not present with SSD or delirium, 62 presented with only SSD, 69 presented with both, and 105 presented with only delirium. In comparison with patients without SSD or delirium, patients with SSD presented preoperative risk factors known for delirium (ie, older age, higher European System for Cardiac Operative Risk Evaluation II) but underwent less complicated surgical procedures, received fewer transfusions postoperatively, and had a lower positive fluid balance postoperatively than patients who presented with delirium. Patients with both SSD and delirium had worse outcomes in comparison with those with delirium only.

CONCLUSION

This study stresses the importance for healthcare professionals to identify SSD and prevent its progression to delirium.

The Independent Association of Prestroke Psychiatric Symptoms and Acute Phase Delirium with Poststroke Mortality at One Year in Nigeria

BACKGROUND

Undetected acute phase delirium contributes to high poststroke mortality in sub-Saharan Africa (SSA). The present study adds to existing literature by examining the association of prestroke psychiatric symptoms with poststroke mortality at 3 and 12 months in Nigeria.

METHODS

A prospective observational study with repeated delirium assessments conducted using the Confusion Assessment Method (CAM). Delirium was characterised in participants meeting criteria in the Fifth edition of the Diagnostic and Statistical Manual of mental disorders (DSM-V) as well as in those with ≥two core delirium features. Prestroke psychiatric symptoms were ascertained using the Neuropsychiatric Inventory Questionnaire (NPI-Q). Information on mortality was obtained by research supervisors during medical follow-up. Associations were investigated using multivariate logistic regression analyses and presented as odds ratios (O.R) within 95% confidence intervals (C.I).

RESULTS

Forty-five (30%) of 150 participants who provided data in the first week of stroke died by one-year follow-up. Those who died were more likely to have had a prestroke psychiatric symptom (64.4%, p=0.005) and delirium in the acute phase (60.0%, p=0.002). In analyses adjusting for the effect of age, education, tobacco smoking and stroke severity, prestroke psychiatric symptoms (O.R=3.3, 95% C.I=1.3,8.2; O.R=2.2, 95% C.I=1.0,4.6) and acute phase delirium (O.R=3.1, 95% C.I= 1.2,7.6; O.R=3.4, 95% C.I=1.5, 7.6) predicted mortality at 3 and 12 months poststroke, respectively.

CONCLUSION

This study found that prestroke psychiatric symptoms and acute phase delirium independently predicted post-stroke mortality at 3- and 12 months. Detection and treatment of mental health conditions in the population at increased risk of stroke may help reduce poststroke mortality in SSA.

ICU Delirium-Prediction Models: A Systematic Review

Supplemental Digital Content is available in the text.

Objective:

Summarize performance and development of ICU delirium-prediction models published within the past 5 years.

Data Sources:

Systematic electronic searches were conducted in April 2019 using PubMed, Embase, Cochrane Central, Web of Science, and Cumulative Index to Nursing and Allied Health Literature to identify peer-reviewed studies.

Study Selection:

Eligible studies were published in English during the past 5 years that specifically addressed the development, validation, or recalibration of delirium-prediction models in adult ICU populations.

Data Extraction:

Screened citations were extracted independently by three investigators with a 42% overlap to verify consistency using the CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies.

Data Synthesis:

Eighteen studies featuring 23 distinct prediction models were included. Model performance varied greatly, as assessed by area under the receiver operating characteristic curve (0.62–0.94), specificity (0.50–0.97), and sensitivity (0.45–0.96). Most models used data collected from a single time point or window to predict the occurrence of delirium at any point during hospital or ICU admission, and lacked mechanisms for providing pragmatic, actionable predictions to clinicians.

Conclusions:

Although most ICU delirium-prediction models have relatively good performance, they have limited applicability to clinical practice. Most models were static, making predictions based on data collected at a single time-point, failing to account for fluctuating conditions during ICU admission. Further research is needed to create clinically relevant dynamic delirium-prediction models that can adapt to changes in individual patient physiology over time and deliver actionable predictions to clinicians.

Different Cognitive and Functional Outcomes in Attenuated and Full Delirium Syndromes Among Recent Stroke Survivors

BACKGROUND

Very little is known about the outcomes of poststroke delirium in relation to its symptom spectrum. We investigated the 3-months cognitive and functional outcomes of attenuated (ADS) and full delirium syndromes in Nigerian survivors of first ever stroke.

METHODS

A prospective observational study with repeated assessments conducted in the first week of stroke using the confusion assessment method. Full delirium was diagnosed according to criteria in the fifth edition of the diagnostic and statistical manual of mental disorders (DSM-V). ADS was characterised in survivors who were free of full, but had ≥two core features of, delirium. Baseline and follow-up assessments were conducted using the Mini-Mental state examination (MMSE), 10-words list learning and delayed recall test, Animal naming test and Barthel index.

RESULTS

Among 150 participants, ADS was present in 32 (21.3%), full delirium in 29 (19.3%). In linear regression analyses adjusting for age, economic status and systemic hypertension, ADS [(Mean difference (MD) = -3.8, 95% C.I = -7.0, -0.7)] and full delirium (MD = -5.6, 95% C.I = -9.0, -2.1) independently predicted poorer global cognitive functioning at follow-up. Significant declines in memory (MD = -1.9, 95% C.I = -2.8, 0.9), executive (MD = -2.2, 95% C.I = -4.1, -0.3) and physical functioning (MD = -2.8, 95% C.I = -5.5, -0.2), as well as a 4-fold increase in the independent odds (O.R) for dementia (O.R = 4.1, 95% C.I = 1.0,16.1) were also recorded in full, but not attenuated, delirium.

CONCLUSION

Attenuated and full delirium are associated with graded risk of poststroke cognitive decline. Reconsideration of poststroke delirium as a spectrum, rather than threshold-based categorical diagnosis will improve detection and prioritization of stroke survivors at increased risk of cognitive decline.