Long-term cognitive impairment after ICU treatment: a prospective longitudinal cohort study (Cog-I-CU)

Patients' and relatives' experiences of cognitive impairment following an intensive care unit admission. A qualitative study

BACKGROUND

Cognitive impairment poses a significant challenge following critical illness in the intensive care unit. A knowledge gap exists concerning how patients experience cognitive impairments.

OBJECTIVES

The aim was to explore patients' and relatives' experiences of patients' cognitive impairment due to critical illness following an intensive care unit admission.

METHODS

A qualitative multicentre study was conducted in Denmark with 3- and 6-month follow-ups using single and dyadic interviews. A phenomenological hermeneutic approach was adopted using a Ricoeur-inspired textual in-depth analysis method. The Consolidated Criteria for Reporting Qualitative Research checklist was used.

RESULTS

Three themes emerged from interviews with 18 patients and 14 relatives: 'It feels like living in a parallel world', 'Getting back to a normal everyday life with a vulnerable self', and 'Managing everyday life using self-invented strategies'. Patients used self-invented strategies to manage their vulnerability and newly acquired cognitive impairments when no help or support was provided specifically targeting their cognitive impairments. Not being as cognitively capable as they previously had been turned their lives upside down. Losing control and not being themselves made them vulnerable. Patients did not want to burden others. However, support from relatives was invaluable in their recovery and rehabilitation.

CONCLUSIONS

Patients experienced multiple cognitive impairments affecting their adaption to everyday life. They strove to overcome their vulnerability using a variety of self-invented strategies and activities.

Inter-rater agreement between patient- and proxy-reported cognitive functioning in intensive care unit patients: A cohort study

BACKGROUND

Health status, including cognitive functioning before critical illness, is associated with long-term outcomes in intensive care unit survivors. Premorbid data are therefore of importance in longitudinal studies. Few patients can self-report at intensive care admission. Consequently, proxy assessments of patients' health status are used. However, it remains unclear how accurately proxies can report on an intensive care patient's cognitive status.

OBJECTIVES

The aim of this study was to examine the agreement between patient- and proxy-reporting of the Cognitive Failures Questionnaire and to compare the agreement between proxy reports using the latter questionnaire and the Informant Questionnaire of Cognitive Decline in the Elderly as a reference.

METHODS

The present cohort study is part of a longitudinal multicentre study collecting both patient and proxy data using questionnaires and clinical data from medical records during intensive care unit stays. Agreement on patient and proxy pairs was examined using intraclass correlation coefficient (ICC), Spearman's correlation, percentage agreement, and Gwet's AC1 statistics. Agreement between the proxy-reported questionnaires was examined using percentage agreement and Gwet's AC1 statistics.

RESULTS

In total, we collected 99 pairs of patient-proxy assessments and 158 proxy-proxy assessments. The ICC for the sum scores revealed moderate agreement (n = 99; ICC = 0.59; 99% confidence interval [CI]: [0.30-0.76]) between patient and proxy. Agreement on items was poor (AC1 = 0.13; 99% CI: [0.01-0.24]) to moderate (AC1 = 0.55; 99% CI: [0.43-0.68]). Agreement using cut-off scores (>43) to indicate cognitive impairment was very good (89.9%, AC1 = 0.87; 99% CI: [0.79-0.95]). Agreement between the proxy-reported Cognitive Failures Questionnaire (>43) and the reference questionnaire (≥3.5) was also very good (n = 158; 85%, AC1 = 0.82; 99% CI: [0.74-0.90]).

CONCLUSIONS

Proxy assessments of the Cognitive Failures Questionnaire (>43) may be used to indicate cognitive impairment if patients are unable to self-report. Agreement was high between the two questionnaires determined by proxies, showing that these can be used interchangeably to assess cognitive functioning if proxy reporting is needed.

Exposure to Sedation and Analgesia Medications: Short-term Cognitive Outcomes in Pediatric Critical Care Survivors With Acquired Brain Injury

Background/Objective: Pediatric intensive care unit (PICU) survivors risk significant cognitive morbidity, particularly those with acquired brain injury (ABI) diagnoses. Studies show sedative and analgesic medication may potentiate neurologic injury, but few studies evaluate impact on survivor outcomes. This study aimed to evaluate whether exposures to analgesic and sedative medications are associated with worse neurocognitive outcome. Methods: A retrospective cohort study was conducted of 91 patients aged 8 to 18 years, undergoing clinical neurocognitive evaluation approximately 1 to 3 months after PICU discharge. Electronic health data was queried for sedative and analgesic medication exposures, including opioids, benzodiazepines, propofol, ketamine, and dexmedetomidine. Doses were converted to class equivalents, evaluated by any exposure and cumulative dose exposure per patient weight. Cognitive outcome was derived from 8 objective cognitive assessments with an emphasis on executive function skills using Principal Components Analysis. Then, linear regression was used to control for baseline cognitive function estimates to calculate a standardized residualized neurocognitive index (rNCI) z-score. Multivariable linear regression evaluated the association between rNCI and medication exposure controlling for covariates. Significance was defined as P < .05. Results: Most (n = 80; 88%) patients received 1 or more study medications. Any exposure and higher cumulative doses of benzodiazepine and ketamine were significantly associated with worse rNCI in bivariate analyses. When controlling for Medicaid, preadmission comorbid conditions, length of stay, delirium, and receipt of other medication classes, receipt of benzodiazepine was associated with significantly worse rNCI (β-coefficient = -0.48, 95% confidence interval = -0.88, -0.08). Conclusions: Exposure to benzodiazepines was independently associated with worse acute phase cognitive outcome using objective assessments focused on executive function skills when controlling for demographic and illness characteristics. Clinician decisions regarding medication regimens in the PICU may serve as a modifiable factor to improve outcomes. Additional inquiry into associations with long-term cognitive outcome and optimal medication regimens is needed.

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.

Neurocognitive deficits in COVID-19 patients five months after discharge from hospital

This observational cohort study explored objective neurocognitive deficits in COVID-19 patients five months after discharge, and any associations with demographic factors and disease severity indicators. Medical notes of all COVID-19 patients admitted to hospital in Region Östergötland, Sweden, March-May 2020, were reviewed. After applying exclusion criteria, 433 patients were screened by telephone. Of these, 185 patients reported persistent and concerning post-COVID-19 problems, including but not restricted to cognitive functions, and were invited to a clinical evaluation. The Repeatable Battery for Assessment of Neuropsychological Status (RBANS) and Colour-Word Interference Test (CWIT) were used to assess immediate memory, visuo-spatial function, language, attention, delayed memory, and executive function. A total of 133 patients had valid test performances. Mean RBANS Global Cognition Score was 83.4, with 37% scoring below cut-off (1.5 SD). Deficits in Attention and Memory indices were most common, each affecting approximately 30% of the patients. After adjustment for sex, language, level of education and premorbid function, neurocognitive performance was positively associated with length of hospital stay, but not with the disease severity indicators WHO CPS and CRP. Findings support that comprehensive neuropsychological assessment should be performed when patients report post-COVID-19 symptoms that affect daily life.

Grip Strength is a Predictor for Subsyndromal Delirium Among Older Adults Following Joint Replacement

Background

Delirium is common in older patients during the postoperative period, increasing the number of adverse events, and grip strength is associated with delirium. Subsyndromal delirium (SSD) is a prostate of clinical delirium; nevertheless, the relationship between grip strength and SSD has not been elucidated. This study aimed to examine the association between grip strength and SSD in the elderly after arthroplasty.

Methods

A total of 181 patients were recruited from two Chinese hospitals. SSD and delirium were evaluated before the surgery and the first week after surgery using the confusion assessment method. The Mini-mental State Examination was used to assess patients' cognitive function, and their grip strength was evaluated with an electronic hand dynamometer before surgery. Logistic regression and ROC curve analysis were conducted to determine the odds ratio and predictive value of grip strength for SSD.

Results

The incidence of SSD and postoperative delirium (POD) was 41.44% and 14.36% for the elderly following arthroplasty respectively, and approximately 1/3 of SSD progressed into POD. Older age, declined cognitive function, fall history, and lower grip strength were risk factors for SSD (P<0.05). The area under the ROC curve of grip strength was 0.863 and 0.900 for males and females respectively, and the cut-off point of it was determined to be 22.050 kg for men and 18.050 kg for women.

Conclusion

SSD and POD are common among older people. Decreased grip strength, advanced age, lower cognitive function, and fall history were independent risk factors for SSD, and grip strength was a significant predictor for SSD in aged patients after the arthroplasty.

Effect of inhaled anaesthetics on cognitive and psychiatric outcomes in critically ill adults: a systematic review and meta-analysis

BACKGROUND

Sedation of critically ill patients with inhaled anaesthetics may reduce lung inflammation, time to extubation, and ICU length of stay compared with intravenous (i.v.) sedatives. However, the impact of inhaled anaesthetics on cognitive and psychiatric outcomes in this population is unclear. In this systematic review, we aimed to summarise the effect of inhaled anaesthetics on cognitive and psychiatric outcomes in critically ill adults.

METHODS

We searched MEDLINE, EMBASE, and PsycINFO for case series, retrospective, and prospective studies in critically ill adults sedated with inhaled anaesthetics. Outcomes included delirium, psychomotor and neurological recovery, long-term cognitive dysfunction, ICU memories, anxiety, depression, post-traumatic stress disorder (PTSD), and instruments used for assessment.

RESULTS

Thirteen studies were included in distinct populations of post-cardiac arrest survivors (n=4), postoperative noncardiac patients (n=3), postoperative cardiac patients (n=2), and mixed medical-surgical patients (n=4). Eight studies reported delirium incidence, two neurological recovery, and two ICU memories. One study reported on psychomotor recovery, long-term cognitive dysfunction, anxiety, depression, and PTSD. A meta-analysis of five trials found no difference in delirium incidence between inhaled and i.v. sedatives (relative risk 0.95 [95% confidence interval: 0.59-1.54]). Compared with i.v. sedatives, inhaled anaesthetics were associated with fewer hallucinations and faster psychomotor recovery but no differences in other outcomes. There was heterogeneity in the instruments used and timing of these assessments.

CONCLUSIONS

Based on the limited evidence available, there is no difference in cognitive and psychiatric outcomes between adults exposed to volatile sedation or intravenous sedation in the ICU. Future studies should incorporate outcome assessment with validated tools during and after hospital stay.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42021236455.

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.

Rest-Activity Rhythm Fragmentation and Weaker Circadian Strength Are Associated With Cognitive Impairment in Survivors of Acute Respiratory Failure

Background: Survivors of acute respiratory failure (ARF) experience long-term cognitive impairment and circadian rhythm disturbance after hospital discharge. Although prior studies in aging and neurodegenerative diseases indicate actigraphy-estimated rest-activity circadian rhythm disturbances are risk factors for cognitive impairment, it is unclear if this applies to ARF survivors. This study explored the relationships of actigraphy-estimated rest-activity circadian rhythms with cognitive functioning in ARF survivors at 3 months after discharge. Methods: 13 ARF survivors (mean age 51 years and 69% males) completed actigraphy and sleep diaries for 9 days, followed by at-home neuropsychological assessment. Principal component factor analysis created global cognition and circadian rhythm variables, and these first components were used to examine the global relationships between circadian rhythm and cognitive measure scores. Results: Global circadian function was associated with global cognition function in ARF survivors (r = .70, p = .024) after adjusting for age, education, and premorbid cognition. Also, greater fragmented rest-activity circadian rhythm (estimated by intradaily variability, r = .85, p = .002), and weaker circadian strength (estimated by amplitude, r = .66, p = .039; relative strength, r = .70, p = .024; 24-h lag serial autocorrelation, r = .67, p = .035), were associated with global cognition and individual cognitive tests. Conclusions: These results suggest circadian rhythm disturbance is associated with poorer global cognition in ARF survivors. Future prospective research with larger samples is needed to confirm these results and increase understanding of the relationship between disrupted circadian rhythms and cognitive impairment among ARF survivors.

Prospective Analysis Between Neutrophil-to-Lymphocyte Ratio on Admission and Development of Delirium Among Older Hospitalized Patients With COVID-19

Objective: To examine any prospective association between neutrophil-to-lymphocyte ratio (NLR) at hospital admission and subsequent delirium in older COVID-19 hospitalized patients comparing by sex and age groups. Methods: The sample consisted of 1,785 COVID-19 adult inpatients (minimum sample size required of 635 participants) admitted to a public general hospital in Madrid (Spain) between March 16th and April 15th, 2020. Variables were obtained from electronic health records. Binary logistic regression models were performed between baseline NLR and delirium adjusting for age, sex, medical comorbidity, current illness severity, serious mental illness history and use of chloroquine and dexamethasone. An NLR cut-off was identified, and stratified analyses were performed by age and sex. Also, another biomarker was tested as an exposure (the systemic immune-inflammation index -SII). Results: 55.3% of the patients were men, with a mean age of 66.8 years. Roughly 13% of the patients had delirium during hospitalization. NLR on admission predicted subsequent delirium development (adjusted OR = 1.02, 95 percent CI: 1.00-1.04, p = 0.024). Patients between 69 and 80 years with NLR values > 6.3 presented a twofold increased risk for delirium (p = 0.004). There were no sex differences in the association between baseline NLR and delirium (p > 0.05) nor SII predicted delirium development (p = 0.341). Conclusion: NLR is a good predictor of delirium during hospitalization, especially among older adults, independently of medical comorbidity, illness severity, and other covariates. Routine blood tests on admission might provide valuable information to guide the decision-making process to be followed with these especially vulnerable patients.

Neurological update: COVID-19

Coronavirus Disease 2019 is predominantly a disorder of the respiratory system, but neurological complications have been recognised since early in the pandemic. The major pathophysiological processes leading to neurological damage in COVID-19 are cerebrovascular disease, immunologically mediated neurological disorders and the detrimental effects of critical illness on the nervous system. It is still unclear whether direct invasion of the nervous system by the Severe Acute Respiratory Syndrome Coronavirus 2 occurs; given the vast numbers of people infected at this point, this uncertainty suggests that nervous system infection is unlikely to represent a significant issue if it occurs at all. In this review, we explore what has been learnt about the neurological complications of COVID-19 over the course of the pandemic, and by which mechanisms these complications most commonly occur.

Post Intensive Care Syndrome (PICS): an overview of the definition, etiology, risk factors, and possible counseling and treatment strategies

INTRODUCTION

Post-intensive care syndrome (PICS) has only recently been recognized as a new clinical entity in patients surviving their intensive care unit (ICU) stay due to critical illness. With increasing survival rates of ICU patients worldwide, there is a rising interest regarding post-ICU recovery.

AREAS COVERED

First, based on the current literature a definition is provided of PICS, including the domains of impairments that comprise PICS along with the etiology and risk factors. Second, preventive measures and possible treatment strategies integrated in the follow-up care are described. Third, the authors will discuss the current SARS-Cov-2 pandemic and the increased risk of PICS in these post-ICU patients and their families.

EXPERT OPINION

PICS is a relatively new entity, which not only encompasses various physical, cognitive, and psychological impairments but also impacts global health due to long-lasting detrimental socioeconomic burdens. Importantly, PICS also relates to caregivers of post-ICU patients. Strategies to reduce this burden will not only be needed within the ICU setting but will also have to take place in an interdisciplinary, multifaceted approach in primary care settings. Additionally, the SARS-Cov-2 pandemic has a high burden on post-ICU patients and their relatives.