Risk factors for long-term cognitive impairment in ICU survivors: A multicenter, prospective cohort study

Olfactory epithelium electrical stimulation mitigates memory and synaptic deficits caused by mechanical ventilation

Mechanical ventilation (MV) causes a wide range of cognitive impairments. Unfortunately, to date, we are lacking knowledge about its underlying neural mechanisms and significant treatment options for the condition. Here, we show that MV-induced memory impairment in rats stems from dysfunctions in the olfactory bulb-medial prefrontal cortex-ventral hippocampus network and hippocampal synaptic currents imbalance. More importantly, we introduce a novel treatment approach, namely olfactory epithelium electrical stimulation (OEES) that shows promising preclinical results in mitigating the mentioned behavioral and neural disorders caused by MV. These results pave the way for research on non-invasive brain stimulation approaches and introduce the olfactory system as a potential target for treating cognitive or psychiatric disorders induced by MV.

Patient and family experiences of early cognitive rehabilitation in critical illness: A qualitative study protocol

BACKGROUND

Physical, mental and cognitive impairments are known severe adverse outcomes in critically ill patients who have beenadmitted to an intensive care unit (ICU). Early rehabilitation interventions such as lighter sedation and increased mobilization have improved patient outcomes, but evidence for early cognitive rehabilitation is sparse.

AIM

The study aims to describe the experiences of ICU survivors and their families regarding early cognitive stimulation as part of rehabilitation during and after ICU admission.

DESIGN

Our study has a qualitative, descriptive design using individual and dyad interviews as well as focus groups with ICU survivors and their families.

METHODS

Eligible participants are adult ICU survivors and families who are able to recall events during and after the ICU stay. We will use purposeful sampling in the outpatient clinic in the Department of Intensive Care at the Copenhagen University Hospital. We plan to conduct five individual patient interviews, four dyad interviews with patients and families, and two focus groups with patients. All interviews will follow a semi-structured interview guide based on the study objectives and input from a patient and public involvement (PPI) panel. We will use the framework method for analysis and invite the PPI panel to participate in the analysis process to strengthen the findings. Written informed consent will be obtained from all participants, and data will be anonymized before analyses.

RELEVANCE FOR CLINICAL PRACTICE

This study protocol provides a methodological framework to understand early cognitive rehabilitation from the perspectives of ICU survivors and their families. This study protocol presents one of the first studies to investigate the concept of early cognitive rehabilitation during critical illness from this perspective. The findings will facilitate a tailored approach to early rehabilitation to be investigated in further studies.

Predictive Value of Preoperative Hypersensitive C-Reactive Protein in the Incidence of Postoperative Cognitive Impairment in Valvular Disease Patients: A Retrospective Study

Objective

Postoperative cognitive dysfunction (POCD) is associated with adverse outcomes of cardiac surgery. This study investigated the potential of pre-operative hypersensitive C-reactive protein (Hs-CRP) as a prognostic indicator of POCD in valvular disease (VHD).

Methods

This study retrospectively analyzed 372 VHD patients admitted to the Department of Cardiac Surgery, Fujian Medical University Union Hospital from January 2024 to July 2024. POCD was evaluated by neuropsychological examination before and one month after surgery. Demographics, disease history, blood biochemical parameters, and perioperative data were collected. Patients were divided into a POCD group (N = 103) and a non-POCD group (N = 269) according to the occurrence of POCD. A logistic regression model was used to analyze the relationship between Hs-CPR and POCD in VHD patients.

Results

The 1-month incidence of POCD in VHD patients was 27.6%. There was statistical significance in age and years of education between the two groups (P = 0.047, P = 0.001). The red blood cell count in the POCD group was lower than that in the non-POCD group (P = 0.025), and the Hs-CRP and mechanical ventilation duration in the POCD group was higher than that in the non-POCD group, with statistical significance (P < 0.001). No significant differences were observed in the results of demographic characteristics and other laboratory measures. The incidence of hospitalization days, ICU stay time, acute renal insufficiency, and new cerebral infarction in the POCD group were higher than those in the non-POCD group (P < 0.001, P < 0.001, P = 0.001, P = 0.029). Univariate and multivariate analysis showed that Hs-CRP was an independent risk factor for POCD in patients undergoing surgery for VHD disease.

Conclusion

Our study shows that preoperative Hs-CRP is significantly elevated in POCD patients undergoing VHD surgery, and preoperative Hs-CRP is an independent predictor of POCD.

Neuropsychological functioning and its correlates at 1 year follow-up of severe COVID-19

BACKGROUND

Short-term cognitive impairment is associated with SARS-CoV-2 infection but the long-term impact is yet to be examined in detail. We aim to study the evolution of these symptoms in severe COVID-19 patients admitted to the intensive care unit (ICU) between April and December 2020 1 year after hospital discharge and to analyze its clinical correlates.

METHOD

A total of 58 patients agreed to participate in the 6 months follow-up and 30 at 1 year after hospital discharge. Demographic, clinical and laboratory data were collected and a comprehensive neuropsychological battery including validated tests for the main cognitive domains was administered. To test the magnitude of neurocognitive sequelae, two standard deviations below normative group were considered. To compare the neuropsychological performance at 6 and 12 months follow-up we used repeated measures tests. Finally, regression analyses were performed to test the main effects of medical and psychological factors on multiple cognition.

RESULTS

Almost half of the sample continued to have impaired performance on neuropsychological tests at 12 months follow-up. In comparison with the results obtained at 6 months, significant improvements were found in immediate recall (d = 0.49), delayed recall (d = 0.45), and inhibitory control (d = 0.53). Medical variables predicted cognitive performance at 6 months but not at 12 months follow-up, while anxiety and depression predicted cognitive deficits in the long-term.

CONCLUSIONS

A generalised improvement was observed in severe COVID-19 patients at follow-up. This improvement was particularly notable in verbal memory and executive functioning. However, a considerable proportion of the sample continued to present deficits at 1 year follow-up.

Objective and subjective cognitive status after intensive care unit treatment for COVID-19

Purpose

Intensive care unit (ICU) survivors can experience wide-ranging and long-lasting symptoms after hospital discharge. Cognitive impairment has received increased attention in relation to the COVID-19 pandemic and can affect patients' long-term quality of life. This study aimed to investigate the prevalence of cognitive impairment using an objective neurocognitive test 6 and 12 months following ICU admission and possible predictive factors for scoring below the defined cut-off. We also explored the prevalence of subjective cognitive complaints at 12 months, including the associated factors.

Methods

This was a prospective observational study of a national cohort of COVID-19 ICU survivors during the three first pandemic waves in Norway. Data was collected by the Norwegian Intensive Care and Pandemic Registry and the study group.

Results

At the six-month follow-up, 23.1% (95% CI [18.2─28.5]) of the 273 respondents scored below the cut-off on the Mini-MoCA, indicating mild cognitive impairment. At the 12-month follow-up, the prevalence declined to 11.1% (95% CI [7.5─15.6]) in 253 respondents. Older age (OR 1.06, 95% CI [1.02─1.12]) and depression (OR 1.25, 95% CI [1.07─1.55]) were associated with cognitive impairment at six months. At 12 months, almost half of the patients reported subjective cognitive complaints. Symptoms of mental health problems and fatigue were associated with subjective cognitive complaints in our exploratory analyses.

Conclusion

Cognitive impairment declined significantly from 6 to 12 months in this cohort of COVID-19 ICU patients, while subjective cognitive complaints remained high at 12 months, perhaps attributed to a high total symptom burden.

Post intensive care syndrome: A review of clinical symptoms, evaluation, intervention

Post intensive care syndrome (PICS) is a typical complication of critically ill patients during or after their stay in intensive care unit (ICU), characterized by a high incidence and impairment rate. It significantly impacts the quality of life of patients and their families, as well as consumes a substantial amount of medical resources. Therefore, early intervention and assessment of PICS is crucial. This paper aims to provide clinical professionals with a reference base by focusing on the clinical symptoms, diagnostic assessment, and preventative measures of PICS.

Cognitive impairment in critically ill patients and former critically ill patients: A concept analysis

OBJECTIVES

This concept analysis aimed to clarify the meaning of the concept of cognitive impairment in critically ill patients throughout the trajectory of their rehabilitation during and after an intensive care unit admission.

REVIEW METHODS USED

This study used concept analysis based on Rodgers' evolutionary method.

DATA SOURCES

A systematic search was conducted in Cumulative Index to Nursing and Allied Health Literature, Public MEDLINE, and American Psychological Associations PsycINFO. The web was searched for grey literature.

REVIEW METHODS

Overall search terms used were "patients with cognitive impairments" AND "intensive care unit". Literature published between 2008 and 2022 was included and screened by title and abstract using systematic review software. The descriptive analysis focussed on surrogate terms/related concepts, attributes, and contextual basis.

RESULTS

Thirty studies were included, representing variability in study design and country of origin. The analysis uncovered descriptions of the general terminology and the temporal trajectory of the concept, spanning from the acute phase to a long-term perspective. Attributes of the concept were described as delirium and domains of cognition. Antecedents were juxtaposed to risk factors, which were multifactorial. Consequences of cognitive impairment related to patients' quality of life, such as a decline in their ability to function independently, return to work, and manage everyday life. Also, cognitive impairment was identified as a significant public health problem.

CONCLUSION

Cognitive impairment is a complex concept with many surrogate and related terms. Furthermore, the concept is inextricably intertwined with the concepts of delirium and post-intensive care syndrome. Cognitive impairment may manifest as symptoms that can be challenging to identify and assess due to limitations in current screening tools and the absence of a consensus on timing. In relation to assessment and preventive strategies, the findings underline the need to distinguish between acute and long-term cognitive impairment.

REGISTRATION

There is no study registration number.

Intensive care unit nurses' perception of three different methods for delirium screening: A survey (DELIS-3)

BACKGROUND

Delirium is common in critically ill patients with detrimental effects in terms of increased morbidity, mortality, costs, and human suffering. Delirium detection and management depends on systematic screening for delirium, which can be challenging to implement in clinical practice.

OBJECTIVES

The aim of this study was to explore how nurses in the intensive care unit perceived the use of Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), the Confusion Assessment Method for the Intensive Care Unit-7 (CAM-ICU-7), and Intensive Care Delirium Screening Checklist (ICDSC) for delirium screening of patients in the intensive care unit.

METHODS

This was a cross-sectional, electronic-based survey of nurses' perceptions of delirium screening with the three different instruments for delirium screening. Nurses were asked to grade their perception of the usability of the three instruments and how well they were perceived to detect delirium and delirium symptom changes on a 1- to 6-point Likert scale. Open questions about perceived advantages and disadvantages of each instrument were analysed using the framework method.

RESULTS

One hundred twenty-seven of 167 invited nurses completed the survey and rated the CAM-ICU-7 as faster and easier than the ICDSC, which was more nuanced and reflected changes in the patient's delirium better. Despite being rated as the fastest, easiest, and most used, the CAM-ICU provided less information and was considered inferior to the CAM-ICU-7 and ICDSC. Using familiar instruments made delirium screening easier, but being able to grade and nuance the delirium assessment was experienced as important for clinical practice.

CONCLUSIONS

Both the ICDSC and the CAM-ICU-7 were perceived well suited for detection of delirium and reflected changes in delirium intensity. The CAM-ICU was rated as fast and easy but inferior in its ability to grade and nuance the assessment of delirium. Emphasis on clinical meaningfulness and continued education in delirium screening are necessary for adherence to delirium management guidelines.

Cognitive Impairment, Physical Impairment, and Psychological Symptoms in Intensive Care Unit Survivors

BACKGROUND

Post-intensive care syndrome (PICS) affects 25% to 50% of adults who survive an intensive care unit (ICU) stay. Although the compounding of PICS impairments (cognitive, physical, and psychological) could intensify the syndrome, research on relationships among impairments is limited, particularly in patients with delirium.

OBJECTIVES

To examine associations among PICS impairments and examine delirium status and its relationship to PICS impairments at ICU discharge and 1 month later.

METHODS

A descriptive, correlational study of adults who survived an ICU stay. Participants completed measures for depression, anxiety, posttraumatic stress, physical function, functional status, and cognition at ICU discharge and 1 month later. Relationships among PICS impairments were examined with Spearman correlations; differences in impairments by delirium status were assessed with t tests.

RESULTS

Of 50 enrolled participants, 46 were screened for PICS impairment at ICU discharge and 35 were screened 1 month later. Cognitive impairment was the most common impairment at both time points. A positive correlation was found between cognition and functional status at ICU discharge (ρ = 0.50, P = .001) and 1 month later (ρ = 0.54, P = .001). Cognition and physical functioning were positively correlated 1 month after discharge (ρ = 0.46, P = .006). The group with delirium had significantly lower functional status scores than the group without delirium at ICU discharge (P = .04).

CONCLUSIONS

The findings suggest a moderate correlation between cognitive and physical impairments. This relationship should be explored further; ICU survivors with undiagnosed cognitive impairment may have delayed physical recovery and greater risk for injury.

Objective and subjective cognition in survivors of COVID-19 one year after ICU discharge: the role of demographic, clinical, and emotional factors

BACKGROUND

Intensive Care Unit (ICU) COVID-19 survivors may present long-term cognitive and emotional difficulties after hospital discharge. This study aims to characterize the neuropsychological dysfunction of COVID-19 survivors 12 months after ICU discharge, and to study whether the use of a measure of perceived cognitive deficit allows the detection of objective cognitive impairment. We also explore the relationship between demographic, clinical and emotional factors, and both objective and subjective cognitive deficits.

METHODS

Critically ill COVID-19 survivors from two medical ICUs underwent cognitive and emotional assessment one year after discharge. The perception of cognitive deficit and emotional state was screened through self-rated questionnaires (Perceived Deficits Questionnaire, Hospital Anxiety and Depression Scale and Davidson Trauma Scale), and a comprehensive neuropsychological evaluation was carried out. Demographic and clinical data from ICU admission were collected retrospectively.

RESULTS

Out of eighty participants included in the final analysis, 31.3% were women, 61.3% received mechanical ventilation and the median age of patients was 60.73 years. Objective cognitive impairment was observed in 30% of COVID-19 survivors. The worst performance was detected in executive functions, processing speed and recognition memory. Almost one in three patients manifested cognitive complaints, and 22.5%, 26.3% and 27.5% reported anxiety, depression and post-traumatic stress disorder (PTSD) symptoms, respectively. No significant differences were found in the perception of cognitive deficit between patients with and without objective cognitive impairment. Gender and PTSD symptomatology were significantly associated with perceived cognitive deficit, and cognitive reserve with objective cognitive impairment.

CONCLUSIONS

One-third of COVID-19 survivors suffered objective cognitive impairment with a frontal-subcortical dysfunction 12 months after ICU discharge. Emotional disturbances and perceived cognitive deficits were common. Female gender and PTSD symptoms emerged as predictive factors for perceiving worse cognitive performance. Cognitive reserve emerged as a protective factor for objective cognitive functioning.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04422444; June 9, 2021.

Functional and cognitive rehabilitation interventions during intensive care admission: A protocol for a systematic integrative review

BACKGROUND

Long-term cognitive impairment occurs in up to 60% of intensive care unit (ICU) survivors. Early use of functional and cognitive rehabilitation interventions, while patients are still in ICU, may reduce cognitive decline. We aim to describe the functional and cognitive interventions used during the ICU stay, the healthcare professionals providing interventions, and the potential impact on functional and cognitive rehabilitation.

METHOD

In this integrative systematic review, we will include empirical qualitative, quantitative, mixed- and multiple-methods studies assessing the use of functional and cognitive rehabilitation provided in ICU. We will identify studies in relevant electronic databases from 2012 to 2022, which will be screened for eligibility by at least two reviewers. Literature reported as narrative reviews and editorials will be excluded. We will assess the impact of interventions evaluating a cognitive and functional function, quality of life, and all-cause mortality at 6-12 months after ICU discharge. The Revised Cochrane risk-of-bias Tool will be used for assessing risk of bias in clinical trials. For observational studies, we will use the National Institutes of Health Quality Assessment tool for Observational Cohort and Cross-Sectional Studies. Furthermore, we will use the critical appraisal skills programme for qualitative studies and the mixed methods appraisal tool for mixed methods studies. We will construct four matrices, including results describing which ICU patients and healthcare professionals were engaged in rehabilitation, which interventions were included in early rehabilitation in ICU, the potential impact on patient outcomes of rehabilitation interventions provided in ICU and a narrative synthesis of themes. A summary of the main results will be reported using modified GRADE methodology.

IMPACT

This integrative review will inform the feasibility randomised clinical trial testing the development of a complex intervention targeting functional and cognitive rehabilitation for patients in ICU.

Evaluation of the delirium preventive effect of dual orexin receptor antagonist (DORA) in critically ill adult patients requiring ventilation with tracheal intubation at an advanced emergency center: A single-center, retrospective, observational study

OBJECTIVE

ICU delirium reportedly contributes to increased mortality attributed to underlying diseases, long-term cognitive decline, and increased healthcare costs. Dual orexin receptor antagonists (DORAs), suvorexant and lemborexant, have been suggested for preventing ICU delirium. Although ventilator management is a risk factor for delirium, no study has examined the efficacy of suvorexant and lemborexant in preventing delirium in critically ill patients requiring ventilation. Thus, we retrospectively evaluated the efficacy of DORA in preventing delirium in critically ill adult patients requiring ventilatory management in the emergency room.

METHOD

This retrospective study included patients aged ≥18 years who were admitted to the emergency room and received ventilator support between January 2015 and April 2022. The HR (95% CI) for delirium development in patients taking DORA was estimated using a Cox proportional hazards model, which was adjusted for the patient background and concomitant medications. HRs were calculated for patients taking suvorexant and those taking lemborexant using a stratified analysis.

RESULTS

Of the 297 patients included in the study, 67 were in the DORA group; 50 were on suvorexant and 17 were on lemborexant. The DORA group had a lower incidence of delirium than the control group (p < 0.0001). The risk of delirium was lower in the DORA group compared the control group (HR, 0.22; 95% CI 0.12-0.40).The risk of developing delirium was lower with suvorexant (HR 0.22; 95% CI 0.11-0.41) and lemborexant (HR 0.25; 95% CI 0.08-0.81).

CONCLUSION

DORA is a promising drug that could have the potential to prevent delirium, and its efficacy in preventing delirium should be tested in randomized controlled trials in the future.

Neuropsychological functioning in post-ICU patients after severe COVID-19 infection: The role of cognitive reserve

Background

Cognitive manifestations associated with Severe Acute Respiratory Syndrome by Coronavirus 2 (SARS-CoV-2) are yet to be described in the existing literature. The aim of this exploratory study is to analyze the impact of severe SARS-CoV-2 infection on neuropsychological performance 6 months following hospital discharge, and to identify which medical variables predict worse outcome. In this context, we study if cognitive reserve (CR) may play a protective role on cognitive impairment.

Methods

We enrolled a cohort of 102 severe SARS-CoV-2 survivors who had been admitted to the Intensive Care Unit (ICU) and were contacted 6-months post discharge. A total of 58 agreed to participate in this 6-month follow-up study. Patients with previously known cognitive impairment were excluded. Demographic, clinical and laboratory data were collected. Firstly, to test the magnitude of neurocognitive sequalae two standard deviations below normative group were considered. Secondly, to analyze the main effects of medical variables on cognition and the interaction with cognitive reserve, ANCOVA analyses were performed.

Results

53.4% obtained a score below the cutoff point (<26) in the screening test MOCA. ICU variables including mechanical ventilation, days of sedation or high CRP days were related with cognition. Cognitive Reserve (CR) interacted with delirium (F ​= ​6.8, p ​= ​0.01) and sedation days (F ​= ​9.40, p ​= ​0.003) to predict verbal memory and interacted with high CRP to predict phonemic fluency (F ​= ​6.47, p ​= ​0.01). Finally, no differences in neuropsychological performance were found depending on subjective cognitive impairment (SCI). However, patients with SCI had a higher score in the HAD anxiety subscale (t ​= ​−2.2; p ​< ​0.05).

Conclusions

In our cohort, cognitive dysfunction was related with ICU variables such as delirium, mechanical ventilation, and inflammation. CR modulated the impact of these variables on cognition. Cognitive complaints were related with anxiety but not with cognitive performance. Despite some limitations, including the need of replication of the findings with larger samples and control groups, our study suggests that high CR may be protective for severe COVID-19-related cognitive impairment.

SPLIT ENZ: Survivorship of Patients post Long Intensive care stay, Exploration/Experience in a New Zealand cohort (A mixed methods study protocol) (Preprint)

Background

Post Intensive Care Syndrome (PICS) was defined by the Society of Critical Care Medicine in 2012 with subsequent international research highlighting poor long-term outcomes; reduced quality of life; and impairments, for survivors of critical illness. To date, there has been no published research on the long-term outcomes of survivors of critical illness in New Zealand.

Objective

The aim of this study is to explore long-term outcomes after critical illness in New Zealand. The primary objectives are to describe and quantify symptoms and disability, explore possible risk factors, and to identify unmet needs in survivors of critical illness.

Methods

This will be a mixed methods study with 2 components. First, a prospective cohort study of approximately 100 participants with critical illness will be followed up at 1, 6, and 12 months after hospital discharge. The primary outcome will be disability assessed using the World Health Organization Disability Assessment Scale 2.0. Secondary outcomes will focus on mental health using the Hospital Anxiety and Depression Scale and the Impact of Events Scale-revised, cognitive function using the Montreal Cognitive Assessment (Montreal Cognitive Assessment–BLIND), and health-related quality of life using the European Quality of Life-Five Dimension-Five Level. The second element of the study will use qualitative grounded theory methods to explore participants experiences of recovery and highlight unmet needs.

Results

This study was approved by the New Zealand Northern A Health and Disability Ethics Committee on August 16, 2021 (21/NTA/107), and has been registered with the Australian New Zealand Clinical Trials Registry on October 5, 2021. SPLIT ENZ is due to start recruitment in early 2022, aiming to enroll 125 patients over 2 years. Data collection is estimated to be completed by 2024-2025 and will be published once all data are available for reporting.

Conclusions

Although international research has identified the prevalence of PICS and the extent of disability in survivors of critical illness, there is no published research in New Zealand. Research in this field is particularly pressing in the context of COVID-19, an illness that may include PICS in its sequelae.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN1262100133588; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382566&showOriginal=true&isReview=true

International Registered Report Identifier (IRRID)

PRR1-10.2196/35936