Assessing neurocognitive outcomes after critical illness: are delirium and long-term cognitive impairments related?

Prevalence and incidence of cognitive impairment following acute respiratory distress syndrome of any cause: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to synthesize and appraise the evidence on prevalence of cognitive impairment following acute respiratory distress syndrome (ARDS) of any cause.

METHODS

We systematically searched PubMed, Scopus, and Web of Science for observational studies focused on cognitive impairment in adult survivors of ARDS. Risk of bias and certainty of evidence (GRADE) were assessed. A meta-analysis using a random effects model was performed to estimate the overall prevalence of cognitive impairment after ARDS, with subgroup analyses for COVID-19-related ARDS (C-ARDS). Additionally, a meta-regression was conducted to assess the influence of demographic and clinical predictors on cognitive outcomes. Heterogeneity was assessed using τ2 and the I2 statistic.

RESULTS

We identified 14 studies with 1451 participants, with 650 participants (range: 13-98) included in the analyses. In the subgroup of C-ARDS, 12 studies with 563 participants (range: 13-98) were considered. The pooled prevalence of cognitive impairment following ARDS was 36% (95% CI 26-46%), with high heterogeneity between studies (I2 = 92%, τ2 = 0.03). In C-ARDS cohorts, the prevalence was 34% (95% CI 22-45%), with similar levels of heterogeneity (I2 = 92.7%, τ2 = 0.03). Meta-regression analysis showed  that older age predicted a higher prevalence of cognitive impairment following ARDS (b = 0.02, p = 0.033), reducing between-study heterogeneity (I² = 60.04%, τ² = 0.01). ICU stay, sex, and time from ICU discharge to cognitive assessment showed no significant associations (p > 0.05).

CONCLUSIONS

This meta-analysis corroborates previous findings that cognitive impairment remains a persistent issue for ARDS survivors. The prevalence of cognitive impairments following ARDS highlights the importance of future research to unravel the complex underlying mechanisms contributing to these deficits and to develop targeted strategies for prevention and rehabilitation in survivors.

Gamma secretase activating protein promotes end-organ dysfunction after bacterial pneumonia

Pneumonia elicits the production of cytotoxic beta amyloid (Aβ) that contributes to end-organ dysfunction, yet the mechanism(s) linking infection to activation of the amyloidogenic pathway that produces cytotoxic Aβ is unknown. Here, we tested the hypothesis that gamma-secretase activating protein (GSAP), which contributes to the amyloidogenic pathway in the brain, promotes end-organ dysfunction following bacterial pneumonia. First-in-kind Gsap knockout rats were generated. Wild-type and knockout rats possessed similar body weights, organ weights, circulating blood cell counts, arterial blood gases, and cardiac indices at baseline. Intratracheal Pseudomonas aeruginosa infection caused acute lung injury and a hyperdynamic circulatory state. Whereas infection led to arterial hypoxemia in wild-type rats, the alveolar-capillary barrier integrity was preserved in Gsap knockout rats. Infection potentiated myocardial infarction following ischemia-reperfusion injury, and this potentiation was abolished in knockout rats. In the hippocampus, GSAP contributed to both pre- and postsynaptic neurotransmission, increasing the presynaptic action potential recruitment, decreasing neurotransmitter release probability, decreasing the postsynaptic response, and preventing postsynaptic hyperexcitability, resulting in greater early long-term potentiation but reduced late long-term potentiation. Infection abolished early and late long-term potentiation in wild-type rats, whereas the late long-term potentiation was partially preserved in Gsap knockout rats. Furthermore, hippocampi from knockout rats, and both the wild-type and knockout rats following infection, exhibited a GSAP-dependent increase in neurotransmitter release probability and postsynaptic hyperexcitability. These results elucidate an unappreciated role for GSAP in innate immunity and highlight the contribution of GSAP to end-organ dysfunction during infection.NEW & NOTEWORTHY Pneumonia is a common cause of end-organ dysfunction, both during and in the aftermath of infection. In particular, pneumonia is a common cause of lung injury, increased risk of myocardial infarction, and neurocognitive dysfunction, although the mechanisms responsible for such increased risk are unknown. Here, we reveal that gamma-secretase activating protein, which contributes to the amyloidogenic pathway, is important for end-organ dysfunction following infection.

Infection promotes Ser-214 phosphorylation important for generation of cytotoxic tau variants

Patients who recover from hospital-acquired pneumonia exhibit a high incidence of end-organ dysfunction following hospital discharge, including cognitive deficits. We have previously demonstrated that pneumonia induces the production and release of cytotoxic oligomeric tau from pulmonary endothelial cells, and these tau oligomers can enter the circulation and may be a cause of long-term morbidities. Endothelial-derived oligomeric tau is hyperphosphorylated during infection. The purpose of these studies was to determine whether Ser-214 phosphorylation of tau is a necessary stimulus for generation of cytotoxic tau variants. The results of these studies demonstrate that Ser-214 phosphorylation is critical for the cytotoxic properties of infection-induced oligomeric tau. In the lung, Ser-214 phosphorylated tau contributes to disruption of the alveolar-capillary barrier, resulting in increased permeability. However, in the brain, both the Ser-214 phosphorylated tau and the mutant Ser-214-Ala tau, which cannot be phosphorylated, disrupted hippocampal long-term potentiation suggesting that inhibition of long-term potentiation was relatively insensitive to the phosphorylation status of Ser-214. Nonetheless, phosphorylation of tau is essential to its cytotoxicity since global dephosphorylation of the infection-induced cytotoxic tau variants rescued long-term potentiation. Collectively, these data demonstrate that multiple forms of oligomeric tau are generated during infectious pneumonia, with different forms of oligomeric tau being responsible for dysfunction of distinct end-organs during pneumonia.

Intensive Care-Related Cognitive Impairment: A Biopsychosocial Overview

Advancements in critical care medicine have improved survival rates for patients experiencing critical illness in intensive care units (ICUs). While mortality has declined, more than half of ICU survivors experience functional impairments that persist beyond discharge. Of particular concern is ICU-related cognitive impairment, which can extend across the care continuum, ranging from acute and transient presentations in the ICU (eg, delirium) to long-term impairments years after discharge. ICU-related cognitive impairment has received increased attention in the literature, particularly as it relates to ICU survivors who have received and survived critical care in the context of SARS-CoV-2 pandemic and are now experiencing post-acute sequelae of SARS-CoV-2 infection. The medical complexity and heterogeneity of ICU survivors, coupled with the multifactorial etiology of ICU-related cognitive impairments, lead to challenges in how to optimize care for ICU survivors at various stages of recovery. This review aims to provide an overview of cognitive outcomes associated with critical illness by integrating recent literature focused on etiology, assessment, and interventions in the context of ICU-related cognitive impairments. The narrative review employs a biopsychosocial framework to comprehensively evaluate the multifactorial nature of ICU-related cognitive outcomes. Authors also highlight multidisciplinary teams composed of key rehabilitation providers are likely best suited for optimizing recovery trajectories of ICU survivors. This article is protected by copyright. All rights reserved.

Delirium in Intensive Care

Purpose of Review

Delirium in the intensive care unit (ICU) has become increasingly acknowledged as a significant problem for critically ill patients affecting both the actual course of illness as well as outcomes. In this review, we focus on the current evidence and the gaps in knowledge.

Recent Findings

This review highlights several areas in which the evidence is weak and further research is needed in both pharmacological and non-pharmacological treatment. A better understanding of subtypes and their different response to therapy is needed and further studies in aetiology are warranted. Larger studies are needed to explore risk factors for developing delirium and for examining long-term consequences. Finally, a stronger focus on experienced delirium and considering the perspectives of both patients and their families is encouraged.

Summary

With the growing number of studies and a better framework for research leading to stronger evidence, the outcomes for patients suffering from delirium will most definitely improve in the years to come.

Potential for Cognitive Communication Impairment in COVID-19 Survivors: A Call to Action for Speech-Language Pathologists

Purpose Severe acute respiratory syndrome coronavirus 2 is the virus resulting in COVID-19 infections in nearly 4.3 million Americans with COVID-19 in the United States as of July 29, 2020, with nearly 150,000 deaths and hundreds of thousands of survivors (https://www.coronavirus.jhu.edu/map.html). This tutorial reviews (a) what has been reported about neurological insults in cases of COVID-19 infection, (b) what is known from similar conditions in other disorders, and (c) how that combined information can inform clinical decision making. Method PubMed and the Cochrane Central Register of Controlled Trials were searched for COVID-19 or other coronavirus infections, cognitive impairment observed following critical care, and disorders for which intermittent or chronic hypoxia is characteristic. These were combined with searches relating to cognition, brain, and communication. All searches were conducted between April 8 and May 23, 2020. Meta-analyses and randomized clinical trials addressing other critical illnesses were also included to extend findings to potential cognitive communication outcomes following COVID-19. Results COVID-19 infection results in a combination of (a) respiratory infection with mechanical ventilation secondary to inadequate oxygenation, (b) inflammatory system reactivity, and (c) increased blood clotting factors. These affect central nervous system function incurring long-term cognitive communication impairment in a proportion of survivors. Diagnostic and intervention approaches for such impairments are discussed. Conclusions The existing literature on cognitive sequela of COVID-19 infection is small to date, but much can be learned from similar viral infections and disorders. Although COVID-19 is novel, the speech-language pathology approaches to evaluation and intervention of other populations of critical care patients are applicable. However, speech-language pathologists have not routinely been involved in these patients' acute care. As such, this is a call to action to speech-language pathologists to address the unprecedented numbers of patients who will need their services early in the disease process and throughout recovery.

COVID-19 and clinical neuropsychology: A review of neuropsychological literature on acute and chronic pulmonary disease

Objective: The illness resulting from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), better known as COVID-19, has quickly escalated to a worldwide pandemic. Although understanding of the short and long-term manifestations of COVID-19 remains incomplete, there is a preponderance of respiratory pathology in COVID-19 and potential for chronic loss of pulmonary function in recovered patients, raising concerns for associated cognitive impacts.Method: We conducted a narrative review of the existing literature on neuropsychological variables in acute/severe respiratory disease and various forms of chronic pulmonary disease to inform expectations about potential cognitive manifestations of COVID-19.Results: Cognitive dysfunction is common but not inevitable in acute and chronic pulmonary disease, although unique predictors and symptom trajectories appear to be associated with each.Conclusions: Although the full scope of neuropathophysiology associated with COVID-19 remains to be established, pulmonary insults associated with the disease are likely to produce cognitive dysfunction in a substantial percentage of patients.

Intensive Care Admission and Early Neuro-Rehabilitation. Lessons for COVID-19?

Coronavirus disease 2019 (COVID-19) requires admission to intensive care (ICU) for the management of acute respiratory distress syndrome in about 5% of cases. Although our understanding of COVID-19 is still incomplete, a growing body of evidence is indicating potential direct deleterious effects on the central and peripheral nervous systems. Indeed, complex and long-lasting physical, cognitive, and functional impairments have often been observed after COVID-19. Early (defined as during and immediately after ICU discharge) rehabilitative interventions are fundamental for reducing the neurological burden of a disease that already heavily affects lung function with pulmonary fibrosis as a possible long-term consequence. In addition, ameliorating neuromuscular weakness with early rehabilitation would improve the efficiency of respiratory function as respiratory muscle atrophy worsens lung capacity. This review briefly summarizes the polymorphic burden of COVID-19 and addresses possible early interventions that could minimize the neurological and systemic impact. In fact, the benefits of early multidisciplinary rehabilitation after an ICU stay have been shown to be advantageous in several clinical conditions making an early rehabilitative approach generalizable and desirable to physicians from a wide range of different specialties.

Cognitive and psychosocial outcomes of mechanically ventilated intensive care patients with and without delirium

Objective

Delirium is common in intensive care patients and is associated with short- and long-term adverse outcomes. We investigated the long-term risk of cognitive impairment and post-traumatic stress disorder (PTSD) in intensive care patients with and without delirium.

Methods

This is a prospective cohort study in ICUs in two Australian university-affiliated hospitals. Patients were eligible if they were older than 18 years, mechanically ventilated for more than 24 h and did not meet exclusion criteria. Delirium was assessed using the Confusion Assessment Method for Intensive Care Unit. Variables assessing cognitive function and PTSD symptoms were collected at ICU discharge, after 6 and 12 months: Mini-Mental State Examination, Telephone Interview for Cognitive Status, Impact of Events Scale-Revised and Informant Questionnaire for Cognitive Decline (caregiver).

Results

103 participants were included of which 36% developed delirium in ICU. Patients with delirium were sicker and had longer duration of mechanical ventilation and ICU length of stay. After 12 months, 41/60 (68.3%) evaluable patients were cognitively impaired, with 11.6% representing the presence of symptoms consistent with dementia. When evaluated by the patient’s caregiver, the patient’s cognitive function was found to be severely impaired in a larger proportion of patients (14/60, 23.3%). Delirium was associated with worse cognitive function at ICU discharge, but not with long-term cognitive function. IES-R scores, measuring PTSD symptoms, were significantly higher in patients who had delirium compared to patients without delirium. In regression analysis, delirium was independently associated with cognitive function at ICU discharge and PTSD symptoms at 12 months.

Conclusions

Intensive care survivors have significant rates of long-term cognitive decline and PTSD symptoms. Delirium in ICU was independently associated with short-term but not long-term cognitive function, and with long-term PTSD symptoms.

Trial registration Australian New Zealand Clinical Trials Registry, ACTRN12616001116415, 15/8/2016 retrospectively registered, https://www.anzctr.org.au

Accelerated brain ageing in sepsis survivors with cognitive long-term impairment

In the last years, cognitive impairment was emphasized to be a prominent long-term sequelae of sepsis. The level of cognitive impairment is comparable with that in mild cognitive impairment (MCI) patients. Whether sepsis survivors also show a comparable brain atrophy is still unclear. For the analysis of brain atrophy, a novel method named brain age gap estimation (BrainAGE) was used. In this analysis approach, an algorithm identifies age-specific atrophy across the whole brain and calculates a BrainAGE score in years. In case of accelerated brain atrophy, the BrainAGE score is increased in comparison to the healthy age reference group, indicating a difference in estimated chronological age. 20 survivors of severe sepsis (longer than 2 years post sepsis) with persistent cognitive deficits were investigated with a battery of neuropsychological tests. Their MRI images were compared to an age- and sex-matched control group. Sepsis survivors showed a significant higher BrainAGE score of 4.5 years compared to healthy controls. We also found a close relationship between the BrainAGE score and severity of cognitive impairment (a higher BrainAGE score was associated with more severe cognitive impairment). Consequently, sepsis survivors with persistent cognitive impairment showed an accelerated brain ageing, which was closely associated with the severity of cognitive impairment (similar to MCI patients).

Association Between Critical Care Admissions and Cognitive Trajectories in Older Adults

OBJECTIVES

Patients requiring admission to an ICU may subsequently experience cognitive decline. Our objective was to investigate longitudinal cognitive trajectories in older adults hospitalized in ICUs. We hypothesized that individuals hospitalized for critical illness develop greater cognitive decline compared with those who do not require ICU admission.

DESIGN

A retrospective cohort study using prospectively collected cognitive scores of participants enrolled in the Mayo Clinic Study of Aging and ICU admissions retrospectively ascertained from electronic medical records. A covariate-adjusted linear mixed effects model with random intercepts and slopes assessed the relationship between ICU admissions and the slope of global cognitive z scores and domains scores (memory, attention/executive, visuospatial, and language).

SETTING

ICU admissions and cognitive scores in the Mayo Clinic Study of Aging from October 1, 2004, to September 11, 2017.

PATIENTS

Nondemented participants age 50 through 91 at enrollment in the Mayo Clinic Study of Aging with an initial cognitive assessment and at least one follow-up visit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 3,673 participants, 372 had at least one ICU admission with median (25-75th percentile) follow-up after first ICU admission of 2.5 years (1.2-4.4 yr). For global cognitive z score, admission to an ICU was associated with greater decline in scores over time compared with participants not requiring ICU admission (difference in annual slope = -0.028; 95% CI, -0.044 to -0.012; p < 0.001). ICU admission was associated with greater declines in memory (-0.029; 95% CI, -0.047 to -0.011; p = 0.002), attention/executive (-0.020; 95% CI, -0.037 to -0.004; p = 0.016), and visuospatial (-0.013; 95% CI, -0.026 to -0.001; p = 0.041) domains. ICU admissions with delirium were associated with greater declines in memory (interaction p = 0.006) and language (interaction p = 0.002) domains than ICU admissions without delirium.

CONCLUSIONS

In older adults, ICU admission was associated with greater long-term cognitive decline compared with patients without ICU admission. These findings were more pronounced in those who develop delirium while in the ICU.

The Lifetime Effects of Injury: Postintensive Care Syndrome and Posttraumatic Stress Disorder

Postintensive care syndrome (PICS) is a heterogeneous syndrome marked by physical, cognitive, and mental health impairments experienced by critical care survivors. It is a syndrome that bears significant human and health care costs. Additional research is needed to identify risk factors and diagnostic, preventative, and treatment strategies for PICS. Trauma intensive care unit patients are particularly vulnerable to posttraumatic stress disorder, which shares some of the adverse long-term consequences of PICS and also requires additional research into effective preventative and management strategies.

A Systematic Review of Risk Factors Associated With Cognitive Impairment After Pediatric Critical Illness

OBJECTIVES

To identify risk factors associated with cognitive impairment as assessed by neuropsychologic tests in neurotypical children after critical illness.

DATA SOURCES

For this systematic review, we searched the Cochrane Library, Scopus, PubMed, Ovid, Embase, and CINAHL databases from January 1960 to March 2017.

STUDY SELECTION

Included were studies with subjects 3-18 years old at the time of post PICU follow-up evaluation and use of an objective standardized neuropsychologic test with at least one cognitive functioning dimension. Excluded were studies featuring patients with a history of cardiac arrest, traumatic brain injury, or genetic anomalies associated with neurocognitive impairment.

DATA EXTRACTION

Twelve studies met the sampling criteria and were rated using the Newcastle-Ottawa Quality Assessment Scale.

DATA SYNTHESIS

Ten studies reported significantly lower scores in at least one cognitive domain as compared to healthy controls or normed population data; seven of these-four case-control and three prospective cohort studies-reported significant lower scores in more than one cognitive domain. Risk factors associated with post critical illness cognitive impairment included younger age at critical illness and/or older age at follow-up, low socioeconomic status, high oxygen requirements, and use of mechanical ventilation, sedation, and pain medications.

CONCLUSIONS

Identifying risk factors for poor cognitive outcomes post critical illness may help healthcare teams modify patient risk and/or provide follow-up services to improve long-term cognitive outcomes in high-risk children.

Cognitive functioning, mental health, and quality of life in ICU survivors: an overview

Critical illness can and often does lead to significant cognitive impairment and to the development of psychological disorders. These conditions are persistent and, although they improve with time, often fail to completely abate. Although the functional correlates of cognitive and psychological morbidity (depression, anxiety, and posttraumatic stress disorder) have been studied, they may include poor quality of life, inability to return to work or to work at previously established levels, and inability to function effectively in emotional and interpersonal domains. The potential etiologies of cognitive impairment and psychological morbidity in ICU survivors are particularly poorly understood and may vary widely across patients. Potential contributors may include the potentially toxic effects of sedatives and narcotics, delirium, hypoxia, glucose dysregulation, metabolic derangements, and inflammation. Patients with preexisting vulnerabilities, including predisposing genetic factors, and frail elderly populations may be at particular risk for emergence of acceleration of conditions such as mild cognitive impairment.

Delirium prevention program in the surgical intensive care unit improved the outcomes of older adults

BACKGROUND

Hospital-acquired delirium is a known risk factor for negative outcomes in patients admitted to the surgical intensive care unit (SICU). Outcomes worsen as the duration of delirium increases. The purpose of this study was to evaluate the efficacy of a delirium prevention program and determine whether it decreased the incidence and duration of hospital-acquired delirium in older adults (age>50 y) admitted to the SICU.

METHODS

A prospective pre- or post-intervention cohort study was done at an academic level I trauma center. Older adults admitted to the SICU were enrolled in a delirium prevention program. Those with traumatic brain injury, dementia, or 0 d of obtainable delirium status were excluded from analysis. The intervention consisted of multidisciplinary education, a pharmacologic protocol to limit medications associated with delirium, and a nonpharmacologic sleep enhancement protocol. Primary outcomes were incidence of delirium and delirium-free days/30. Secondary outcomes were ventilator-free days/30, SICU length of stay (LOS), daily and cumulative doses of opioids (milligram, morphine equivalents) and benzodiazepines (milligram, lorazepam equivalents), and time spent in severe pain (greater than or equal to 6 on a scale of 1-10). Delirium was measured using the Confusion Assessment Method for the ICU. Data were analyzed using Chi-squared and Wilcoxon rank sum analysis.

RESULTS

Of 624 patients admitted to the SICU, 123 met inclusion criteria: 57 preintervention (3/12-6/12) and 66 postintervention (7/12-3/13). Cohorts were similar in age, gender, ratio of trauma patients, and Injury Severity Score. Postintervention, older adults experienced delirium at the same incidence (pre 47% versus 58%, P=0.26), but for a significantly decreased duration as indicated by an increase in delirium-free days/30 (pre 24 versus 27, P=0.002). After intervention, older adults with delirium had more vent-free days (pre 21 versus 25, P=0.03), shorter SICU LOS (pre 13 [median 12] versus 7 [median 6], P=0.01) and were less likely to be treated with benzodiazepines (pre 85% versus 63%, P=0.05) with a lower daily dose when prescribed (pre 5.7 versus 3.6 mg, P=0.04). After intervention, all older adults spent less time in pain (pre 4.7 versus 3.1 h, P=0.02), received less total opioids (pre 401 versus 260 mg, P=0.01), and had shorter SICU LOS (pre 9 [median 5] versus 6 [median 4], P=0.04).

CONCLUSIONS

Although delirium prevention continues to be a challenge, this study successfully decreased the duration of delirium for older adults admitted to the SICU. Our simple, cost-effective program led to improved pain and sedation outcomes. Older adults with delirium spent less time on the ventilator and all patients spent less time in the SICU.

Understanding brain dysfunction in sepsis

Sepsis often is characterized by an acute brain dysfunction, which is associated with increased morbidity and mortality. Its pathophysiology is highly complex, resulting from both inflammatory and noninflammatory processes, which may induce significant alterations in vulnerable areas of the brain. Important mechanisms include excessive microglial activation, impaired cerebral perfusion, blood-brain-barrier dysfunction, and altered neurotransmission. Systemic insults, such as prolonged inflammation, severe hypoxemia, and persistent hyperglycemia also may contribute to aggravate sepsis-induced brain dysfunction or injury. The diagnosis of brain dysfunction in sepsis relies essentially on neurological examination and neurological tests, such as EEG and neuroimaging. A brain MRI should be considered in case of persistent brain dysfunction after control of sepsis and exclusion of major confounding factors. Recent MRI studies suggest that septic shock can be associated with acute cerebrovascular lesions and white matter abnormalities. Currently, the management of brain dysfunction mainly consists of control of sepsis and prevention of all aggravating factors, including metabolic disturbances, drug overdoses, anticholinergic medications, withdrawal syndromes, and Wernicke's encephalopathy. Modulation of microglial activation, prevention of blood-brain-barrier alterations, and use of antioxidants represent relevant therapeutic targets that may impact significantly on neurologic outcomes. In the future, investigations in patients with sepsis should be undertaken to reduce the duration of brain dysfunction and to study the impact of this reduction on important health outcomes, including functional and cognitive status in survivors.

Delirium: an emerging frontier in the management of critically ill children

Delirium is a syndrome of acute brain dysfunction that commonly occurs in critically ill adults and most certainly is prevalent in critically ill children all over the world. The dearth of information about the incidence, prevalence, and severity of pediatric delirium stems from the simple fact that there have not been well-validated instruments for routine delirium diagnosis at the bedside. This article reviewed the emerging solutions to this problem, including description of a new pediatric tool called the pCAM-ICU. In adults, delirium is responsible for significant increases in both morbidity and mortality in critically ill patients. The advent of new tools for use in critically ill children will allow the epidemiology of this form of acute brain dysfunction to be studied adequately, will allow clinical management algorithms to be developed and implemented following testing, and will present the necessary incorporation of delirium as an outcome measure for future clinical trials in pediatric critical care medicine.

Cognitive functioning, mental health, and quality of life in ICU survivors: an overview

The significant and sometimes permanent effects of critical illness on wide-ranging aspects of functioning are increasingly recognized. Among the areas affected are acute and long-term cognitive functioning, depression, anxiety, PTSD, and quality of life. These and other areas are increasingly being studied and indeed are increasingly the focus of clinical attention and investigations. These conditions have been a focus of attention for more than a dozen years, with much improvement occurring in the ability to characterize these phenomena. For instance, in intervening years, it has been learned that cognitive impairment is highly prevalent and functionally disruptive and that it occurs in wide-ranging domains. Key questions remain unanswered with regard to vital questions such as determining causes, risk factors, and mechanisms as well as the degree to which brain injuries associated with critical illness are amenable to rehabilitation. Little remains known about the effects of critical illness on elderly ICU cohorts and on the neurologic functioning of individuals with preexisting impairment versus those who are normal. Few data exist regarding the development of strategies designed to prevent the emergence of neuropsychological deficits after critical illness. Although great progress has been made and is ongoing, a pressing need exists for additional investigation of cognitive impairment and other conditions,such as PTSD and quality of life after critical illness, that will seek to untangle the many pertinent questions related to this condition and that will ultimately offer help and hope to the thousands of survivors affected by this condition.

Delirium in children and adolescents: A systematic review of the literature

OBJECTIVES

The purpose of this study was to collate all works relating to delirium and probable delirium in children and adolescents published since 1980.

METHODS

A systematic review of the literature in all languages published between 1980 and March 2009 was conducted.

RESULTS

The literature is limited to small case series and case reports including a total of 217 children or adolescents with definite delirium and a further 136 children and adolescents with "probable delirium." These articles, in addition to unsystematic reviews, overviews, editorials, journal commentaries, and pertinent book chapters, are discussed in relation to prevalence, predisposing and precipitating factors, phenomenology, residual psychopathology, mortality, management, and prevention of delirium in childhood and adolescence.

CONCLUSIONS

Delirium is an important but neglected disorder of childhood associated with significant morbidity and high mortality. Current clinical practice for management is based on slim empirical evidence.

Acute respiratory distress syndrome, sepsis, and cognitive decline: a review and case study

The objective of this investigation is to review existing research pertaining to cognitive impairment and decline following critical illness and describe a case involving a 49-year-old female with sepsis and acute respiratory distress syndrome (ARDS) with no prior neurologic history who, compared to baseline neuropsychological test data, experienced dramatic cognitive decline and brain atrophy following treatment in the medical intensive care unit (ICU) at Vanderbilt University Medical Center. The patient participated in detailed clinical interviews and underwent comprehensive neuropsychological testing and neurological magnetic resonance imaging (MRI) at approximately 8 months and 3.5 years after ICU discharge. Compared to pre-ICU baseline test data, her intellectual function declined approximately 2 standard deviations from 139 to 106 (from the 99 to the 61 percentile) on a standardized intelligence test 8 months post-discharge, with little subsequent improvement. Initial diffusion tensor brain magnetic resonance imaging (DT-MRI) at the end of ICU hospitalization showed diffuse abnormal hyperintense areas involving predominately white matter in both hemispheres and the left cerebellum. A brain MRI nearly 4 years after ICU discharge demonstrated interval development of profound and generalized atrophy with sulcal widening and ventricular enlargement. The magnitude of cognitive decline experienced by ICU survivors is difficult to quantify due to the unavailability of pre-morbid neuropsychological data. The current case, conducted on a patient with baseline neuropsychological data, illustrates the trajectory of decline occurring after critical illness and ICU-associated brain injury with marked atrophy and concomitant cognitive impairments.

Cognitive functioning, mental health, and quality of life in ICU survivors: an overview

Critical illness can and often does lead to significant cognitive impairment and to the development of psychological disorders. These conditions are persistent and, although they improve with time, often fail to completely abate. Although the functional correlates of cognitive and psychological morbidity (depression, anxiety, and posttraumatic stress disorder) have been studied, they may include poor quality of life, inability to return to work or to work at previously established levels, and inability to function effectively in emotional and interpersonal domains. The potential etiologies of cognitive impairment and psychological morbidity in ICU survivors are particularly poorly understood and may vary widely across patients. Potential contributors may include the potentially toxic effects of sedatives and narcotics, delirium, hypoxia, glucose dysregulation, metabolic derangements, and inflammation. Patients with preexisting vulnerabilities, including predisposing genetic factors, and frail elderly populations may be at particular risk for emergence of acceleration of conditions such as mild cognitive impairment.

Education and support needs during recovery in acute respiratory distress syndrome survivors

Introduction

There is a limited understanding of the long-term needs of survivors of the acute respiratory distress syndrome (ARDS) as they recover from their episode of critical illness. The Timing it Right (TIR) framework, which emphasizes ARDS survivors' journey from the ICU through to community re-integration, may provide a valuable construct to explore the support needs of ARDS survivors during their recovery.

Methods

Twenty-five ARDS survivors participated in qualitative interviews examining their needs for educational, emotional and tangible support for each phase of the TIR framework. Transcripts were analyzed using framework methodology.

Results

ARDS survivors' support needs varied across the illness trajectory. During the ICU stay, survivors were generally too ill to require information. The transfer to the general ward was characterized by anxiety surrounding decreased surveillance and concern for future health and treatment. Information needs focused on the events surrounding the acute illness, while physical and emotional needs revolved around physical therapy and psychological support for depression and anxiety. As patients were preparing for hospital discharge, they expressed a desire for specific information about the recovery and rehabilitation process following an episode of ARDS (e.g., outpatient physiotherapy, long-term sequela of the illness). Once in the community, survivors wanted guidance on home care, secondary prevention, and ARDS support groups.

Conclusions

Our findings support the need for future educational and support interventions to meet the changing needs of ARDS survivors during their recovery.

Delirium: an emerging frontier in the management of critically ill children

The objectives of this article are (1) to introduce pediatric delirium and provide understanding of acute brain dysfunction with its classification and clinical presentations (2) to understand how delirium is diagnosed and discuss current modes of delirium diagnosis in the critically ill adult population and translation to pediatrics (3) to understand the prevalence and prognostic significance of delirium in the adult and pediatric critically ill population (4) to discuss the pathophysiology of delirium as currently understood, and (5) to provide general management guidelines for delirium.

Postoperative delirium in the elderly: diagnosis and management

Delirium is a common but often undiagnosed complication in the elderly following a major operation. Recognizing the presentation of delirium and the criteria to establish the diagnosis of delirium will improve a clinician’s ability to detect this complication. Treating delirium with environmental, supportive, and pharmacologic interventions reduces the incidence and side effects of postoperative delirium. The purpose of this review is to describe the diagnosis and treatment of postoperative delirium.

ICU Follow-up – Can We Predict the Problems?

Evidence is emerging to help identify critically ill patients at high risk of developing adverse psychological sequelae. This article reviews current research on cognitive and psychological problems after critical care, and highlights the need for early recognition and intervention.

[Postoperative delirium in the critically ill]

Acute confusional states (delirium) occur in up to 80% of patients in the intensive care unit. Delirium is an important independent prognostic determinant of hospital outcome, including duration of mechanical ventilation, nursing home placement, functional decline and death. Additionally, it may herald systemic diseases such as sepsis and multi-organ failure. Recently, a number of new screening instruments have been validated for the monitoring of delirium in non-communicative patients receiving mechanical ventilation. Critical care patients should be routinely assessed for delirium and treated immediately using available preventive and therapeutic measures, both pharmacological and non-pharmacological, to improve the clinical course.

Pathophysiology of delirium in the intensive care unit

Delirium, or acute brain dysfunction, is a life-threatening global disturbance in cognitive functioning that frequently manifests in critically ill patients. This review examines the current status of knowledge regarding the pathophysiology of delirium in the ICU, in particular, evaluating the role of iatrogenic factors such as sedatives and analgesic administration in brain dysfunction. This hypothesis is considered along with several other plausible mechanisms of ICU delirium, including sepsis, postoperative cognitive dysfunction, and changes in biomarkers and neurotransmitters. The review concludes by highlighting potential future directions in molecular genetics for the elucidation of delirium and its long-term consequences.

Loss of IQ in the ICU brain injury without the insult

Critically ill patients are at high risk of developing serious neurological dysfunctions including delirium and long-term neurocognitive impairment. Here a novel mechanism is proposed for this highly deleterious condition. A growing body of evidence has shown that critical illness and its treatment can lead to de novo cerebral atrophy including white and grey matter abnormalities, delirium, and neurocognitive decline. In healthy individuals, normal and consistent connectivity between the posterior parietal cortex (PPC), medial temporal lobe (MTL) and prefrontal cortex (PFC) maintains consciousness and normal cognitive functioning. The circuit is innervated, activated and maintained by the ascending reticular activating system (ARAS) arising from the brainstem. As elderly individuals begin to show signs of grey matter atrophy in the PPC, MTL and PFC, functional connectivity between these regions remains intact; however, the strength of the connections is no longer robust as it once was in the healthy CNS. This circuit continues to be activated and maintained via the ARAS. Individuals treated in the ICU are subject to a number of medical and pharmacological challenges which may disrupt normal CNS connectivity. Serious illnesses such as sepsis, acute respiratory distress syndrome (ARDS), and acute lung injury (ALI), as well as sedative and analgesic medications commonly prescribed in the ICU have the potential to disrupt the functional link in the circuit described above. Minor fluctuations in the ARAS (i.e. hyper or hypo activation) may be sufficient in elderly individuals to cause a disruption which surpasses the critical threshold of functional connectivity necessary to maintain normal (i.e. non-delirious) consciousness. In combination with exposure to other ICU related threats to neurocognitive function, prolonged decoupling of this circuit may lead to deleterious neurodegenerative consequences such as excitotoxicity. Over time this has the potential to result in apoptosis and long-term cognitive impairment. Delirium appears to be a good candidate for the causal mechanism of ICU related cognitive decline and may be a critical point of intervention.