Sepsis-associated delirium

Clinical phenotypes of delirium during critical illness and severity of subsequent long-term cognitive impairment: a prospective cohort study

BACKGROUND

Delirium during critical illness results from numerous insults, which might be interconnected and yet individually contribute to long-term cognitive impairment. We sought to describe the prevalence and duration of clinical phenotypes of delirium (ie, phenotypes defined by clinical risk factors) and to understand associations between these clinical phenotypes and severity of subsequent long-term cognitive impairment.

METHODS

In this multicentre, prospective cohort study, we included adult (≥18 years) medical or surgical ICU patients with respiratory failure, shock, or both as part of two parallel studies: the Bringing to Light the Risk Factors and Incidence of Neuropsychological Dysfunction in ICU Survivors (BRAIN-ICU) study, and the Delirium and Dementia in Veterans Surviving ICU Care (MIND-ICU) study. We assessed patients at least once a day for delirium using the Confusion Assessment Method-ICU and identified a priori-defined, non-mutually exclusive phenotypes of delirium per the presence of hypoxia, sepsis, sedative exposure, or metabolic (eg, renal or hepatic) dysfunction. We considered delirium in the absence of hypoxia, sepsis, sedation, and metabolic dysfunction to be unclassified. 3 and 12 months after discharge, we assessed cognition with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). We used multiple linear regression to separately analyse associations between the duration of each phenotype of delirium and RBANS global cognition scores at 3-month and 12-month follow-up, adjusting for potential confounders.

FINDINGS

Between March 14, 2007, and May 27, 2010, 1048 participants were enrolled, eight of whom could not be analysed. Of 1040 participants, 708 survived to 3 months of follow-up and 628 to 12 months. Delirium was common, affecting 740 (71%) of 1040 participants at some point during the study and occurring on 4187 (31%) of all 13 434 participant-days. A single delirium phenotype was present on only 1355 (32%) of all 4187 participant-delirium days, whereas two or more phenotypes were present during 2832 (68%) delirium days. Sedative-associated delirium was most common (present during 2634 [63%] delirium days), and a longer duration of sedative-associated delirium predicted a worse RBANS global cognition score 12 months later, after adjusting for covariates (difference in score comparing 3 days vs 0 days: -4·03, 95% CI -7·80 to -0·26). Similarly, longer durations of hypoxic delirium (-3·76, 95% CI -7·16 to -0·37), septic delirium (-3·67, -7·13 to -0·22), and unclassified delirium (-4·70, -7·16 to -2·25) also predicted worse cognitive function at 12 months, whereas duration of metabolic delirium did not (1·14, -0·12 to 3·01).

INTERPRETATION

Our findings suggest that clinicians should consider sedative-associated, hypoxic, and septic delirium, which often co-occur, as distinct indicators of acute brain injury and seek to identify all potential risk factors that may impact on long-term cognitive impairment, especially those that are iatrogenic and potentially modifiable such as sedation.

FUNDING

National Institutes of Health and the Department of Veterans Affairs.

Septic Encephalopathy

PURPOSE OF THE REVIEW

To discuss the diagnostic approach to patients with septic encephalopathy as well as the need for specific neuro-monitoring and the perspectives on future therapeutic approaches in this setting.

RECENT FINDINGS

Most of data-concern experimental studies evaluating the pathophysiology of septic encephalopathy. A combination of neurodegenerative pathways with neurovascular injury is the cornerstone for the development of such complication and the long-term neurological sequelae among survivors. Septic encephalopathy is a common complication in septic patients. Clinical presentation may range from mild confusion and disorientation to convulsions and deep coma. The diagnosis of septic encephalopathy is made difficult by the lack of any specific clinical and non-clinical feature, in particular among sedated patients in whom neurological examination is unreliable. In spite of the high mortality rate associated with this condition, there is no prophylactic or targeted therapy to reduce or minimize brain damage in septic patients and clinical management is limited to the treatment of the underlying infection.

Risk Factors for the Development of Postoperative Delirium in Pediatric Intensive Care Patients

OBJECTIVES

To determine and quantify risk factors for postoperative pediatric delirium.

DESIGN

Single-center prospective cohort study.

SETTING

Twenty-two bed PICU in a tertiary care academic medical center in Germany.

PATIENTS

All children admitted after major elective surgery (n = 93; 0-17 yr).

INTERVENTIONS

After awakening, children were screened for delirium using the Cornell Assessment of Pediatric Delirium bid over a period of 5 days. Demographic and clinical data were collected from the initiation of general anesthesia.

MEASUREMENTS AND MAIN RESULTS

A total of 61 patients (66%) were delirious. Younger children developed delirium more frequently, and the symptoms were more pronounced. The number of preceding operations did not influence the risk of delirium. Total IV anesthesia had a lower risk than inhalational anesthesia (p < 0.05). Duration of anesthesia was similar in all groups. Patients with delirium had a longer duration of mechanical ventilation in the PICU (p < 0.001). Significant differences in cumulative doses of various medications (e.g., sedatives, analgesics, and anticholinergics) were noted between groups; these differences were independent of disease severity. Invasive catheters and respiratory devices (p < 0.01) as well as infections (p < 0.001) increased risk of delirium.

CONCLUSIONS

A high prevalence of delirium was noted in the PICU, and several perioperative risk factors were identified. Our data may be a base for development of strategies to prevent and treat postoperative delirium in children.

Fructose-1,6-bisphosphate preserves glucose metabolism integrity and reduces reactive oxygen species in the brain during experimental sepsis

Sepsis is one of the main causes of hospitalization and mortality in Intensive Care Units. One of the first manifestations of sepsis is encephalopathy, reported in up to 70% of patients, being associated with higher mortality and morbidity. The factors that cause sepsis-associated encephalopathy (SAE) are still not well known, and may be multifactorial, as perfusion changes, neuroinflammation, oxidative stress and glycolytic metabolism alterations. Fructose-1,6-bisphosphate (FBP), a metabolite of the glycolytic route, has been reported as neuroprotective agent. The present study used an experimental sepsis model in C57BL/6 mice. We used in vivo brain imaging to evaluate glycolytic metabolism through microPET scans and the radiopharmaceutical ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG). Brain images were obtained before and 12 h after the induction of sepsis in animals with and without FBP treatment. We also evaluated the treatment effects in the brain oxidative stress by measuring the production of reactive oxygen species (ROS), the activity of catalase (CAT) and glutathione peroxidase (GPx), and the levels of fluorescent marker 2'7'-dichlorofluorescein diacetate (DCF). There was a significant decrease in brain glucose metabolism due to experimental sepsis. A significant protective effect of FBP treatment was observed in the cerebral metabolic outcomes. FBP also modulated the production of ROS, evidenced by reduced CAT activity and lower levels of DCF. Our results suggest that FBP may be a possible candidate in the treatment of SAE.

Monitoring of the physical exam in sepsis

PURPOSE OF REVIEW

Monitoring of mental status and peripheral circulatory changes can be accomplished noninvasively in patients in the ICU. Emphasis on physical examination in conditions such as sepsis have gained increased attention as these evaluations can often serve as a surrogate marker for short-term treatment efficacy of therapeutic interventions. Sepsis associated encephalopathy and mental status changes correlate with worse prognosis in patients. Evaluation of peripheral circulation has been shown to be a convenient, easily accessible, and accurate marker for prognosis in patients with septic shock. The purpose of this article is to emphasize the main findings according to recent literature into the monitoring of physical examination changes in patients with sepsis.

RECENT FINDINGS

Several recent studies have expanded our knowledge about the pathophysiology of mental status changes and the clinical assessment of peripheral circulation in patients with sepsis. Sepsis-associated encephalopathy is associated with an increased rate of morbidity and mortality in an intensive care setting. Increased capillary refill time (CRT) and persistent skin mottling are strongly predictive of mortality, whereas temperature gradients can reveal vasoconstriction and more severe organ dysfunction.

SUMMARY

Monitoring of physical examination changes is a significant and critical intervention in patients with sepsis. Utilizing repeated neurologic evaluations, and assessing CRT, mottling score, and skin temperature gradients should be emphasized as important noninvasive diagnostic tools. The significance of these methods can be incorporated during the utilization of therapeutic strategies in resuscitation protocols in patients with sepsis.

Temporal biomarker profiles and their association with ICU acquired delirium: a cohort study

BACKGROUND

Neuroinflammation is thought to play an important role in the pathogenesis of ICU-acquired delirium, but the association between inflammatory and brain-specific proteins and ICU delirium is poor. We investigated whether or not serial determinations of markers may improve this association.

METHODS

Critically ill patients with a high risk of ICU delirium and with an ICU length of stay of at least 6 days were included in the study. Blood was drawn on days 1, 2, 4 and 6 after ICU admission and analyzed for different markers of inflammation and several brain proteins. Differences in courses over time prior to and following the onset of delirium and absolute differences over time were analyzed in patients with and without delirium using repeated measurement analysis of variance. In addition, a cross-sectional analysis of levels of these markers before the first onset of delirium was performed.

RESULTS

Fifty patients were included in this study. In the longitudinal analysis, there were no differences in the levels of any of the markers immediately prior to and following the onset of delirium, but overall, median levels of adiponectin (9019 (IQR 5776-15,442) vs. 6148 (IQR 4447-8742) ng/ml, p = 0.05) were significantly higher in patients with delirium compared to patients without delirium. In the cross-sectional analysis, median levels of the brain protein Tau (90 (IQR 46-224) vs. 31 (IQR 31-52) pg/ml, p = 0.009) and the ratio Tau/amyloid β_1-42 (1.42 ((IQR 0.9-2.57) vs. 0.68 (IQR 0.54-0.96), p = 0.003) were significantly higher in patients with hypoactive delirium compared to patients without. Levels of neopterin (111 (IQR 37-111) vs. 29 (IQR 16-64) mmol/l, p = 0.004) and IL-10 (28 (IQR 12-39) vs. 9 (IQR 4-12) pg/ml, p = 0.001) were significantly higher in patients with hypoactive delirium compared to patients with mixed-type delirium.

CONCLUSIONS

While there are differences in markers (adiponectin and several brain proteins) between patients with and without delirium, the development of delirium is not preceded by a change in the biomarker profile of inflammatory markers or brain proteins. Patients with hypoactive delirium account for the observed differences in biomarkers.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT 01274819 . Registered on 12 January 2011.

Intraperitoneal hypertension, a novel risk factor for sepsis-associated encephalopathy in sepsis mice

Sepsis associated encephalopathy (SAE), appears often indicates the deterioration of the sepsis disease and which have high risk of death. Although several mechanism and hypotheses have been proposed and studied, there is no breakthrough in the treatment of SAE. We performed a systematic research to evaluate the effect of intraperitoneal pressure on SAE. A mice model of sepsis was established by intraperitoneal injection of endotoxin. A total of 48 female BALB/c mouse (30 days old) were randomly divided into a control group (n = 12) and an injection of endotoxin referred to bacterial lipopolysaccharide (LPS) group (n = 12). Intraperitoneal hypertension (IAH) referred to IAH group (n = 12), and LPS + IAH group (n = 12). Following sepsis induction, diagnosis, the brains were analyzed for both function and ultrastructural morphology.We determined that IAH exacerbated sepsis induces sepsis-associated encephalopathy when examining low score of neurological function and more delta wave in EEG, increased neuronal edema in LPS + IAH group, as well as an escalation of Bax and Cleaved-caspase-3, Cleaved-parp, and reduction of Bcl-2 and Mfsd2a in LPS + IAH group. Therefore, IAH can exacerbate and increase incident rate of sepsis-related encephalopathy in sepsis mice by promoting neuronal apoptosis and destruction of the blood-brain barrier.

Effects of Ecballium elaterium on brain in a rat model of sepsis-associated encephalopathy

Despite recent advances in antibiotic therapy, sepsis remains a major clinical challenge in intensive care units. Here we examined the anti-inflammatory and antioxidant effects of Ecballium elaterium (EE) on brain, and explored its therapeutic potential in an animal model of sepsis-associated encephalopathy (SAE) [induced by cecal ligation and puncture (CLP)].

Thirty rats were divided into three groups of 10 each: control, sepsis, and treatment. Rats were subjected to CLP except for the control group, which underwent laparatomy only. The treatment group received 2.5 mg/kg EE while the sepsis group was administered by saline. Twenty-four hours after laparotomy, animals were sacrificied and the brains were removed. Brain homogenates were prepared to assess interleukin 1beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), total antioxidant capacity (TAC), and total oxidant status (TOS). Brain tissue sections were stained by hematoxylin and eosin (H&E) to semi-quantitatively examine the histopathologic changes such as neuron degeneration, pericellular/perivascular edema and inflammatory cell infiltration in the cerebral cortex.

We found a statistically significant reduction in brain tissue homogenate levels of TNF-α 59.5 ± 8.4/50.2 ± 6.2 (p = 0.007) and TOS 99.3 ± 16.9/82.3 ± 7.8 (p = 0.01) in rats treated with EE; although interleukin 6 levels were increased in the treatment group compared to the sepsis group, this was not statistically significant. Neuronal damage (p = 0.00), pericellular/perivascular edema and inflammatory cell infiltration (p = 0.001) were also significantly lower in the treatment group compared to those in the sepsis group.

These data suggest that Ecballium elaterium contains some components that exert protective effects against SAE in part by attenuating accumulation of proinflammatory cytokines, which may be important contributors to its anti-inflammatory effects during sepsis.

Lipocalin-2 protects the brain during inflammatory conditions

Sepsis is a prevalent health issue that can lead to central nervous system (CNS) inflammation with long-term behavioral and cognitive alterations. Using unbiased proteomic profiling of over 100 different cytokines, we found that Lipocalin-2 (LCN2) was the most substantially elevated protein in the CNS after peripheral administration of lipopolysaccharide (LPS). To determine whether the high level of LCN2 in the CNS is protective or deleterious, we challenged Lcn2^-/- mice with peripheral LPS and determined effects on behavior and neuroinflammation. At a time corresponding to peak LCN2 induction in wild-type (WT) mice injected with LPS, Lcn2^-/- mice challenged with LPS had exacerbated levels of pro-inflammatory cytokines and exhibited significantly worsened behavioral phenotypes. To determine the extent of global inflammatory changes dependent upon LCN2, we performed an RNAseq transcriptomic analysis. Compared with WT mice injected with LPS, Lcn2^-/- mice injected with LPS had unique transcriptional profiles and significantly elevated levels of multiple pro-inflammatory molecules. Several LCN2-dependent pathways were revealed with this analysis including, cytokine and chemokine signaling, nucleotide-binding oligomerization domain-like receptor signaling and Janus kinase-signal transducer and activator of transcription signaling. These findings demonstrate that LCN2 serves as a potent protective factor in the CNS in response to systemic inflammation and may be a potential candidate for limiting sepsis-related CNS sequelae.

The impact of sepsis, delirium, and psychological distress on self-rated cognitive function in ICU survivors-a prospective cohort study

Background

Many intensive care unit (ICU) survivors develop psychological problems and cognitive impairment. The relation between sepsis, delirium, and later cognitive problems is not fully elucidated, and the impact of psychological symptoms on cognitive function is poorly studied in ICU survivors. The primary aim of this study was to examine the relationship between sepsis, ICU delirium, and later self-rated cognitive function. A second aim was to investigate the association between psychological problems and self-rated cognitive function 3 months after the ICU stay.

Methods

Patients staying more than 24 h at the general ICU at the Karolinska University Hospital Solna, Stockholm, Sweden, were screened for delirium with the Confusion Assessment Method-ICU (CAM-ICU) during their ICU stay. Sepsis incidence and severity were recorded. Three months later, 216 patients received the Cognitive Failures Questionnaire (CFQ), Hospital Anxiety and Depression Scale (HADS), and Post-Traumatic Stress Symptoms-10 (PTSS-10) questionnaires via postal mail.

Results

One hundred twenty-five patients (60%) responded to all questionnaires. Among respondents, the incidence of severe sepsis or septic shock was 42%. The overall incidence of delirium was 34%. Patients with severe sepsis/septic shock had a higher incidence of delirium, with an odds ratio (OR) of 3.7 (95% confidence interval (CI), 1.7–8.1). Self-rated cognitive problems 3 months post-ICU were found in 58% of the patients. We did not find any association between sepsis or delirium and late self-rated cognitive function. However, there was a correlation between psychological symptoms and self-rated cognitive function, with the strongest correlation between PTSS-10 scores and CFQ scores (r = 0.53; p < 0.001).

Conclusions

ICU delirium is more common in severely septic/septic shock patients. In our cohort, neither severe sepsis nor ICU delirium was associated with self-rated cognitive function 3 months after the ICU stay. Ongoing psychological symptoms, particularly post-traumatic stress was associated with worse self-rated cognitive function. Psychological symptoms need to be taken into account when assessing cognitive function in ICU survivors.

Sepsis and Septic Shock Strategies

Three therapeutic principles most substantially improve organ dysfunction and survival in sepsis: early, appropriate antimicrobial therapy; restoration of adequate cellular perfusion; timely source control. The new definitions of sepsis and septic shock reflect the inadequate sensitivity, specify, and lack of prognostication of systemic inflammatory response syndrome criteria. Sequential (sepsis-related) organ failure assessment more effectively prognosticates in sepsis and critical illness. Inadequate cellular perfusion accelerates injury and reestablishing perfusion limits injury. Multiple organ systems are affected by sepsis and septic shock and an evidence-based multipronged approach to systems-based therapy in critical illness results in improve outcomes.

Evaluation of the appropriate use of a CIWA-Ar alcohol withdrawal protocol in the general hospital setting

BACKGROUND

The Clinical Institute Withdrawal Assessment-Alcohol, Revised (CIWA-Ar) is an assessment tool used to quantify alcohol withdrawal syndrome (AWS) severity and inform benzodiazepine treatment for alcohol withdrawal.

OBJECTIVES

To evaluate the prescribing patterns and appropriate use of the CIWA-Ar protocol in a general hospital setting, as determined by the presence or absence of documented AWS risk factors, patients' ability to communicate, and provider awareness of the CIWA-Ar order.

METHODS

This retrospective chart review included 118 encounters of hospitalized patients placed on a CIWA-Ar protocol during one year. The following data were collected for each encounter: patient demographics, admitting diagnosis, ability to communicate, and admission blood alcohol level; and medical specialty of the clinician ordering CIWA-Ar, documentation of the presence or absence of established AWS risk factors, specific parameters of the protocol ordered, service admitted to, provider documentation of awareness of the active protocol within 48 h of initial order, total benzodiazepine dose equivalents administered and associated adverse events.

RESULTS

57% of patients who started on a CIWA-Ar protocol had either zero or one documented risk factor for AWS (19% and 38% respectively). 20% had no documentation of recent alcohol use. 14% were unable to communicate. 19% of medical records lacked documentation of provider awareness of the ordered protocol. Benzodiazepine associated adverse events were documented in 15% of encounters.

CONCLUSIONS

The judicious use of CIWA-Ar protocols in general hospitals requires mechanisms to ensure assessment of validated alcohol withdrawal risk factors, exclusion of patients who cannot communicate, and continuity of care during transitions.

Sepsis-Associated Encephalopathy: The Blood-Brain Barrier and the Sphingolipid Rheostat

Sepsis is not only a significant cause of mortality worldwide but has particularly devastating effects on the central nervous system of survivors. It is therefore crucial to understand the molecular structure, physiology, and events involved in the pathogenesis of sepsis-associated encephalopathy, so that potential therapeutic advances can be achieved. A key determinant to the development of this type of encephalopathy is morphological and functional modification of the blood–brain barrier (BBB), whose function is to protect the CNS from pathogens and toxic threats. Key mediators of pathologic sequelae of sepsis in the brain include cytokines, including TNF-α, and sphingolipids, which are biologically active components of cellular membranes that possess diverse functions. Emerging data demonstrated an essential role for sphingolipids in the pulmonary vascular endothelium. This raises the question of whether endothelial stability in other organs systems such as the CNS may also be mediated by sphingolipids and their receptors. In this review, we will model the structure and vulnerability of the BBB and hypothesize mechanisms for therapeutic stabilization and repair following a confrontation with sepsis-induced inflammation.

Potentially modifiable factors contributing to sepsis-associated encephalopathy

PURPOSE

Identifying modifiable factors for sepsis-associated encephalopathy may help improve patient care and outcomes.

METHODS

We conducted a retrospective analysis of a prospective multicenter database. Sepsis-associated encephalopathy (SAE) was defined by a score on the Glasgow coma scale (GCS) <15 or when features of delirium were noted. Potentially modifiable risk factors for SAE at ICU admission and its impact on mortality were investigated using multivariate logistic regression analysis and Cox proportional hazard modeling, respectively.

RESULTS

We included 2513 patients with sepsis at ICU admission, of whom 1341 (53%) had sepsis-associated encephalopathy. After adjusting for baseline characteristics, site of infection, and type of admission, the following factors remained independently associated with sepsis-associated encephalopathy: acute renal failure [adjusted odds ratio (aOR) = 1.41, 95% confidence interval (CI) 1.19-1.67], hypoglycemia <3 mmol/l (aOR = 2.66, 95% CI 1.27-5.59), hyperglycemia >10 mmol/l (aOR = 1.37, 95% CI 1.09-1.72), hypercapnia >45 mmHg (aOR = 1.91, 95% CI 1.53-2.38), hypernatremia >145 mmol/l (aOR = 2.30, 95% CI 1.48-3.57), and S. aureus (aOR = 1.54, 95% CI 1.05-2.25). Sepsis-associated encephalopathy was associated with higher mortality, higher use of ICU resources, and longer hospital stay. After adjusting for age, comorbidities, year of admission, and non-neurological SOFA score, even mild alteration of mental status (i.e., a score on the GCS of 13-14) remained independently associated with mortality (adjusted hazard ratio = 1.38, 95% CI 1.09-1.76).

CONCLUSIONS

Acute renal failure and common metabolic disturbances represent potentially modifiable factors contributing to sepsis-associated encephalopathy. However, a true causal relationship has yet to be demonstrated. Our study confirms the prognostic significance of mild alteration of mental status in patients with sepsis.

Incidence and risk factors for delirium development in ICU patients - a prospective observational study

BACKGROUND AND AIMS

Delirium is an acute brain dysfunction and a frequent complication in critically ill patients. When present it significantly worsens the prognosis of patients. The aim of this study was to evaluate the incidence of delirium and risk factors for delirium in a mixed group of trauma, medical and surgical ICU patients.

METHODS

A prospective observational study was conducted in one of the six-bed Intensive Care Units of the University Hospital Ostrava in the Czech Republic during a 12-month period. We evaluated the incidence of delirium and its predisposing and precipitating risk factors. All patients were assessed daily using the Confusion Assessment Method for the ICU (CAM-ICU).

RESULTS AND CONCLUSIONS

Of the total of 332 patients with a median APACHE II (the Acute Physiology and Chronic Health Evaluation) score of 12, who were evaluated for delirium, 48 could not be assessed using CAM-ICU (47 due to prolonged coma, 1 due to language barriers). The incidence of delirium was 26.1%, with trauma and medical patients being more likely to develop delirium than surgical patients. Risk of delirium was significantly associated with age ≥ 65 years, and alcohol abuse in their anamnesis, with APACHE II score on admission, and with the use of sedatives and/or vasopressors. Delirious patients who remained in the ICU for a prolonged period showed a greater need for ventilator support and had a greater ICU-mortality.

Polarization of microglia and its role in bacterial sepsis

Microglial polarization in response to brain inflammatory conditions is a crescent field in neuroscience. However, the effect of systemic inflammation, and specifically sepsis, is a relatively unexplored field that has great interest and relevance. Sepsis has been associated with both early and late harmful events of the central nervous system, suggesting that there is a close link between sepsis and neuroinflammation. During sepsis evolution it is supposed that microglial could exert both neurotoxic and repairing effects depending on the specific microglial phenotype assumed. In this context, here it was reviewed the role of microglial polarization during sepsis-associated brain dysfunction.

Cerebral perfusion alterations and cognitive decline in critically ill sepsis survivors

INTRODUCTION

We investigated the association between cerebral perfusion perturbations in sepsis with possible cognitive decline (CD) after patients' discharge from the intensive care unit (ICU).

METHODS

We studied 28 patients with sepsis and Lawton's Instrumental Activities of Daily Living scale (IADL) scores ≥5 who were discharged from a university ICU institution. We evaluated cerebral circulatory parameters (pulsatility index (PI) and cerebral blood flow index (CBFi) was calculated based on the measured velocity of the middle cerebral artery. Use of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) test was performed daily, and either the Mini Mental State Examination test (MMSE) or Clock Drawing test was performed at ICU discharge. CD was categorized as persistent coma, positive CAM-ICU test at discharge, MMSE <24, or an abnormal Clock test.

RESULTS

Patients had a median pre-ICU IADL score of 6.3 (95% CI 5.9-6.7). Fourteen patients (50%) had CD at discharge. Two were in persistent coma despite sepsis resolution. Information recall was the most affected mental function of the other 12 patients. Only on the first day, patients with CD had higher PI and lower CBFi compared to those without CD (2.2 ± 0.7 vs. 1.4 ± 0.5, p = 0.02; 363 ± 170 vs. 499 ± 133, p = 0.03, respectively). Multivariable analysis revealed delirium, but not PI, as an independent prognostic factor for CD (OR: 29.62, 95%CI 1.91-458.01, p = 0.01).

CONCLUSION

Delirium, but not cerebral perfusion alterations, is an independent risk factor for cognitive impairment in septic patients who were discharged from the ICU.

Neurologic complications of sepsis

Over the past decades, the incidence of sepsis and resultant neurologic sequelae has increased, both in industrialized and low- or middle-income countries, by approximately 5% per year. Up to 300 patients per 100 000 population per year are reported to suffer from sepsis, severe sepsis, and septic shock. Mortality is up to 30%, depending on the precision of diagnostic criteria. The increasing incidence of sepsis is partially explained by demographic changes in society, with aging, increasing numbers of immunocompromised patients, dissemination of multiresistant pathogens, and greater availability of supportive medical care in both industrialized and middle-income countries. This results in more septic patients being admitted to intensive care units. Septic encephalopathy is a manifestation especially of severe sepsis and septic shock where the neurologist plays a crucial role in diagnosis and management. It is well known that timely treatment of sepsis improves outcome and that septic encephalopathy may precede other signs and symptoms. Particularly in the elderly and immunocompromised patient, the brain may be the first organ to show signs of failure. The neurologist diagnosing early septic encephalopathy may therefore contribute to the optimal management of septic patients. The brain is not only an organ failing in sepsis (a "sepsis victim" - as with other organs), but it also overwhelmingly influences all inflammatory processes on a variety of pathophysiologic levels, thus contributing to the initiation and propagation of septic processes. Therefore, the best possible pathophysiologic understanding of septic encephalopathy is essential for its management, and the earliest possible therapy is crucial to prevent the evolution of septic encephalopathy, brain failure, and poor prognosis.

Delirium in critically ill patients

Delirium is common in critically ill patients and associated with increased length of stay in the intensive care unit (ICU) and long-term cognitive impairment. The pathophysiology of delirium has been explained by neuroinflammation, an aberrant stress response, neurotransmitter imbalances, and neuronal network alterations. Delirium develops mostly in vulnerable patients (e.g., elderly and cognitively impaired) in the throes of a critical illness. Delirium is by definition due to an underlying condition and can be identified at ICU admission using prediction models. Treatment of delirium can be improved with frequent monitoring, as early detection and subsequent treatment of the underlying condition can improve outcome. Cautious use or avoidance of benzodiazepines may reduce the likelihood of developing delirium. Nonpharmacologic strategies with early mobilization, reducing causes for sleep deprivation, and reorientation measures may be effective in the prevention of delirium. Antipsychotics are effective in treating hallucinations and agitation, but do not reduce the duration of delirium. Combined pain, agitation, and delirium protocols seem to improve the outcome of critically ill patients and may reduce delirium incidence.

Cerebral Blood Flow Autoregulation in Sepsis for the Intensivist: Why Its Monitoring May Be the Future of Individualized Care

Cerebral blood flow (CBF) autoregulation maintains consistent blood flow across a range of blood pressures (BPs). Sepsis is a common cause of systemic hypotension and cerebral dysfunction. Guidelines for BP management in sepsis are based on historical concepts of CBF autoregulation that have now evolved with the availability of more precise technology for its measurement. In this article, we provide a narrative review of methods of monitoring CBF autoregulation, the cerebral effects of sepsis, and the current knowledge of CBF autoregulation in sepsis. Current guidelines for BP management in sepsis are based on a goal of maintaining mean arterial pressure (MAP) above the lower limit of CBF autoregulation. Bedside tools are now available to monitor CBF autoregulation continuously. These data reveal that individual BP goals determined from CBF autoregulation monitoring are more variable than previously expected. In patients undergoing cardiac surgery with cardiopulmonary bypass, for example, the lower limit of autoregulation varied between a MAP of 40 to 90 mm Hg. Studies of CBF autoregulation in sepsis suggest patients frequently manifest impaired CBF autoregulation, possibly a result of BP below the lower limit of autoregulation, particularly in early sepsis or with sepsis-associated encephalopathy. This suggests that the present consensus guidelines for BP management in sepsis may expose some patients to both cerebral hypoperfusion and cerebral hyperperfusion, potentially resulting in damage to brain parenchyma. The future use of novel techniques to study and clinically monitor CBF autoregulation could provide insight into the cerebral pathophysiology of sepsis and offer more precise treatments that may improve functional and cognitive outcomes for survivors of sepsis.

Potential Role of Aminoprocalcitonin in the Pathogenesis of Alzheimer Disease

Increasing evidence suggests that inflammatory responses cause brain atrophy and play a prominent and early role in the progression of Alzheimer disease. Recent findings show that the neuroendocrine peptide aminoprocalcitonin (NPCT) plays a critical role in the development of systemic inflammatory response; however, the presence, possible function, regulation, and mechanisms by which NPCT may be involved in Alzheimer disease neuropathology remain unknown. We explored the expression of NPCT and its interaction with amyloid-β (Aβ), and proinflammatory and neurogenic effects. By using brain samples of Alzheimer disease patients and APP/PS1 transgenic mice, we evaluated the potential role of NPCT on Aβ-related pathology. We found that NPCT is expressed in hippocampal and cortical neurons and Aβ-induced up-regulation of NPCT expression. Peripherally administered antibodies against NPCT decreased microglial activation, decreased circulating levels of proinflammatory cytokines, and prevented Aβ-induced neurotoxicity in experimental models of Alzheimer disease. Remarkably, anti-NPTC therapy resulted in a significant improvement in the behavioral status of APP/PS1 mice. Our results indicate a central role of NPCT in Alzheimer disease pathogenesis and suggest NPCT as a potential biomarker and therapeutic target.

NK cells promote neutrophil recruitment in the brain during sepsis-induced neuroinflammation

Sepsis could affect the central nervous system and thus induces neuroinflammation, which subsequently leads to brain damage or dysfunction. However, the mechanisms of generation of neuroinflammation during sepsis remain poorly understood. By administration of lipopolysaccharides (LPS) in mice to mimic sepsis, we found that shortly after opening the blood-brain barrier, conventional CD11b(+)CD27(+) NK subset migrated into the brain followed by subsequent neutrophil infiltration. Interestingly, depletion of NK cells prior to LPS treatment severely impaired neutrophil recruitment in the inflamed brain. By in vivo recruitment assay, we found that brain-infiltrated NK cells displayed chemotactic activity to neutrophils, which depended on the higher expression of chemokines such as CXCL2. Moreover, microglia were also responsible for neutrophil recruitment, and their chemotactic activity was significantly impaired by ablation of NK cells. Furthermore, depletion of NK cells could significantly ameliorate depression-like behavior in LPS-treated mice. These data indicated a NK cell-regulated neutrophil recruitment in the blamed brain, which also could be seen on another sepsis model, cecal ligation and puncture. So, our findings revealed an important scenario in the generation of sepsis-induced neuroinflammation.

Neurodevelopmental and Behavioral Outcomes in Children With Sepsis-Associated Encephalopathy Admitted to Pediatric Intensive Care Unit: A Prospective Case Control Study

The authors prospectively compared the neurodevelopmental and behavioral outcomes in 50 consecutive children with sepsis-associated encephalopathy admitted to intensive care unit with healthy controls. Children with sepsis-associated encephalopathy had significantly worse mean verbal IQ, full-scale IQ, General Development Score, and its physical, adaptive, social-emotional, cognitive, and communication subscales. Significant proportion of cases (52% vs 32% in controls) had low intelligence. Decline in school performance (44%), disobedience (28%), and stubbornness/irritable behavior (26%) were the most common behavior changes. Children with Glasgow Coma Scale score ≤10 and ≤8 had impairments in full-scale IQ even though overall Glasgow Coma Scale score did not show significant correlation with developmental outcomes. In conclusion, children with sepsis-associated encephalopathy have delayed neurodevelopment, low verbal IQ, decline in school performance and low intelligence at short-term follow-up. Irritability, shock and duration of sedation are associated with poor behavioral outcomes, especially scholastic performance.

Peripheral T-lymphocyte and natural killer cell population imbalance is associated with septic encephalopathy in patients with severe sepsis

Septic encephalopathy (SE) is a diffuse cerebral dysfunction resulting from a systemic inflammatory response, and is associated with an increased risk of mortality. The pathogenesis of SE is complex and multifactorial, but unregulated immune imbalance may be an important factor. The current retrospective study examined the clinical data of 86 patients with severe sepsis who were admitted to the Intensive Care Unit at Zhongshan Hospital, Xiamen University (Xiamen, China) from January, 2014 to January, 2015. The patients were assigned to SE and non-SE patient groups according to the presence or absence of SE. The proportion of T-lymphocyte subsets and natural killer (NK) cells in the immune cell population, representing the function of the immune system, were analyzed for their association with SE and compared with other clinical predictors and biomarkers. The incidence of SE in the patients was 39.5%, and this group demonstrated higher mortality rates (38 vs. 10% in non-SE patients; P=0.001). Univariate analysis revealed that the SE patients reported a lower percentage of cluster of differentiation 4⁺(CD4⁺) T-lymphocytes (51.67±7.12 vs. 60.72±3.70% in non-SE patients; P<0.01), a lower CD4⁺/cluster of differentiation 8⁺(CD8⁺) ratio (1.59±0.32 vs. 1.85±0.26% in non-SE patients; P<0.01) and a higher percentage of NK cells (11.80±1.44 vs. 9.19±2.36% in non-SE patients; P<0.01). Using a binary logistic regression model, the Acute Physiology and Chronic Health Evaluation II score and the percentage of CD4⁺ T-lymphocytes were demonstrated to be independently associated with SE (respectively, P=0.012 and OR, 4.763; P=0.005 and OR, 0.810). An area under the curve analysis of a receiver operating characteristic curve of the two indicators revealed that these were equally powerful measures in prediction of SE (Z=1.247, P>0.05). The present results confirm that SE leads to higher mortality in patients with severe sepsis, and demonstrate that immune imbalance is important in the development of SE. The proportion of CD4⁺ T-lymphocytes present were revealed in the current study to be a powerful predictor of SE in patients with severe sepsis.

Personalizing blood pressure management in septic shock

This review examines the available evidence for targeting a specific mean arterial pressure (MAP) in sepsis resuscitation. The clinical data suggest that targeting an MAP of 65-70 mmHg in patients with septic shock who do not have chronic hypertension is a reasonable first approximation. Whereas in patients with chronic hypertension, targeting a higher MAP of 80-85 mmHg minimizes renal injury, but it comes with increased risk of arrhythmias. Importantly, MAP alone should not be used as a surrogate of organ perfusion pressure, especially under conditions in which intracranial, intra-abdominal or tissue pressures may be elevated. Organ-specific perfusion pressure targets include 50-70 mmHg for the brain based on trauma brain injury as a surrogate for sepsis, 65 mmHg for renal perfusion and >50 mmHg for hepato-splanchnic flow. Even at the same MAP, organs and regions within organs may have different perfusion pressure and pressure-flow relationships. Thus, once this initial MAP target is achieved, MAP should be titrated up or down based on the measures of organ function and tissue perfusion.

Statins and delirium: is there a role?

Delirium is a serious but potentially avoidable complication in critically ill patients. Various pathophysiological processes have been associated with delirium development; however, neuroinflammation hypothesis and pleiotropic effects are the reasons why HMG-CoA reductase inhibitors have been evaluated for delirium prevention. Statin therapy is associated with favorable outcomes in critically ill patients, but significant variability of results exists in patients who received these agents postoperatively. Study design methodological weaknesses, inconsistent delirium assessment, and lack of information on sedation regimens may have confounded these outcomes. Furthermore, no evidence exists on the type of statin, lipophilic or non-lipophilic, that is associated with the most benefit or when therapy with a statin should be initiated. Thus, the efficacy of HMGM-CoA reductase inhibitors on delirium prevention has not been fully established and non-pharmacological methods should remain mainstay of therapy.

Biomarkers in septic encephalopathy: a systematic review of clinical studies

Objective

The aim of this study was to systematically review the importance of neuron-specific enolase and S100 beta for diagnosing and monitoring septic encephalopathy.

Methods

A PubMed database search was performed to identify studies that evaluated S100 beta and neuron-specific enolase serum levels in patients with sepsis and that were published between January 2000 and April 2012. Only human studies that employed an additional method of neurological assessment were selected.

Results

Nine studies were identified, seven of which associated high concentrations of S100 beta and neuron-specific enolase with the development of septic encephalopathy. Four studies also associated these concentrations with increased mortality. However, two studies did not find such an association when they evaluated S100 beta levels, and one of these studies did not observe a correlation between neuron-specific enolase and septic encephalopathy.

Conclusion

S100 beta and neuron-specific enolase are promising biomarkers for diagnosing and monitoring patients with septic encephalopathy, but more research is necessary.

Clinical neurophysiological assessment of sepsis-associated brain dysfunction: a systematic review

Introduction

Several studies have reported the presence of electroencephalography (EEG) abnormalities or altered evoked potentials (EPs) during sepsis. However, the role of these tests in the diagnosis and prognostic assessment of sepsis-associated encephalopathy remains unclear.

Methods

We performed a systematic search for studies evaluating EEG and/or EPs in adult (≥18 years) patients with sepsis-associated encephalopathy. The following outcomes were extracted: a) incidence of EEG/EP abnormalities; b) diagnosis of sepsis-associated delirium or encephalopathy with EEG/EP; c) outcome.

Results

Among 1976 citations, 17 articles met the inclusion criteria. The incidence of EEG abnormalities during sepsis ranged from 12% to 100% for background abnormality and 6% to 12% for presence of triphasic waves. Two studies found that epileptiform discharges and electrographic seizures were more common in critically ill patients with than without sepsis. In one study, EEG background abnormalities were related to the presence and the severity of encephalopathy. Background slowing or suppression and the presence of triphasic waves were also associated with higher mortality. A few studies demonstrated that quantitative EEG analysis and EP could show significant differences in patients with sepsis compared to controls but their association with encephalopathy and outcome was not evaluated.

Conclusions

Abnormalities in EEG and EPs are present in the majority of septic patients. There is some evidence to support EEG use in the detection and prognostication of sepsis-associated encephalopathy, but further clinical investigation is needed to confirm this suggestion.

Neuropeptide downregulation in sepsis

Neuropeptides are an extremely conserved arm of neurobiology. Despite their effects as neurohormones and neurotransmitters, a multitude of other effects have been described, putting in evidence their importance as regulators of immune responses, such as chemotaxis, oxidative burst, pro-inflammatory signaling, and many others. The effects of neuropeptides in the pathophysiology of sepsis, however, remain poorly investigated. A prospective cohort study to investigate the effects of neuropeptides in sepsis was carried out. Here, we describe that neuropeptides are downregulated during septic shock. We propose that it may be a protective mechanism of the host to avoid further inflammatory injury.

Assessment of cerebral tissue oxygen saturation in septic patients during acetazolamide provocation - a near infrared spectroscopy study

Sepsis-associated encephalopathy is a multifactorially determined process of the brain parenchyma. Among other factors, vasogenic causes have been shown to play a role in its development. The aim of the present work was to assess whether cerebral tissue oxygen saturation is influenced by administration of acetazolamide in septic patients compared to controls.

PATIENTS AND METHODS

15 patients with severe sepsis and 10 healthy controls were studied. Cerebral oxygen saturation was assessed by INVOS 51 OOC Cerebral Oxymeter (NIRS) before and after administration of 15 mg/kg BW acetazolamide in both groups.

RESULTS

The maximal rise that has been found in the partial pressure of CO(2) in the arterial blood of septic patients after administration of acetazolamide was from 35 ± 5 mmHg to 41.1 ± 6.3 mmHg. For the partial pressure of O(2) the observed increase was from 123.7 ± 47.1 mmHg to 139.9 ± 49 mmHg. Vasodilatory stimulus resulted in a similar maximal increase in cerebral oxygen saturation in septic patients and in controls (8.9 ± 6.5% for septic patients and 9.2 ± 4.6% for healthy persons, respectively).

CONCLUSIONS

Cerebral vasoreactivity to acetazolamide is preserved in patients with severe sepsis.

Systemic inflammation, blood-brain barrier vulnerability and cognitive/non-cognitive symptoms in Alzheimer disease: relevance to pathogenesis and therapy

The incidence of dementia is increasing at an alarming rate, and has become a major public health concern. Alzheimer disease (AD) is the most common form of dementia and is characterized by progressive cognitive impairment. In addition to classical neuropathological features such as amyloid plaques and neurofibrillary tangles (NFT), accumulation of activated immune cells has been documented in the AD brain, suggesting a contribution of neuroinflammation in the pathogenesis of AD. Besides cognitive deterioration, non-cognitive symptoms, such as agitation, aggression, depression and psychosis, are often observed in demented patients, including those with AD, and these neuropsychological symptoms place a heavy burden on caregivers. These symptoms often exhibit sudden onset and tend to fluctuate over time, and in many cases, they are triggered by an infection in peripheral organs, suggesting that inflammation plays an important role in the pathogenesis of these non-cognitive symptoms. However, there is no mechanistic explanation for the relationship between inflammation and neuropsychiatric symptoms. Observations from experimental mouse models indicate that alteration of brain blood vessels, especially blood-brain barrier (BBB) dysfunction, may contribute to the relationship. The current review summarizes the results from recent studies on the relationship between inflammation and AD, while focusing on cerebrovascular alterations, which might provide an insight into the pathogenesis of cognitive/non-cognitive symptoms in AD patients and suggest a basis for the development of new therapeutic treatments for these conditions.

Effect of n-3 fatty acids on markers of brain injury and incidence of sepsis-associated delirium in septic patients

BACKGROUND

Data regarding immunomodulatory effects of parenteral n-3 fatty acids in sepsis are conflicting. In this study, the effect of administration of parenteral n-3 fatty acids on markers of brain injury, incidence of sepsis-associated delirium, and inflammatory mediators in septic patients was investigated.

METHODS

Fifty patients with sepsis were randomized to receive either 2 ml/kg/day of a lipid emulsion containing highly refined fish oil (equivalent to n-3 fatty acids 0.12 mg/kg/day) during 7 days after admission to the intensive care unit or standard treatment. Markers of brain injury and inflammatory mediators were measured on days 1, 2, 3 and 7. Assessment for sepsis-associated delirium was performed daily. The primary outcome was the difference in S-100β from baseline to peak level between both the intervention and the control group, compared by t-test. Changes of all markers over time were explored in both groups, fitting a generalized estimating equations model.

RESULTS

Mean difference in change of S-100β from baseline to peak level was 0.34 (95% CI: -0.18-0.85) between the intervention and control group, respectively (P = 0.19). We found no difference in plasma levels of S-100β, neuron-specific enolase, interleukin (IL)-6, IL-8, IL-10, and C-reactive protein between groups over time. Incidence of sepsis-associated delirium was 75% in the intervention and 71% in the control groups (risk difference 4%, 95% CI -24-31%, P = 0.796).

CONCLUSION

Administration of n-3 fatty acids did not affect markers of brain injury, incidence of sepsis-associated delirium, and inflammatory mediators in septic patients.

Insulin alleviates the inflammatory response and oxidative stress injury in cerebral tissues in septic rats

Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction that occurs secondary to infection in the body without overt central nervous system (CNS) infection. SAE is frequently encountered in critically ill patients in intensive care units and can be detected in up to 50–70% of septic patients. Previous studies have demonstrated that inflammatory cytokine release and oxidative stress injury are major pathophysiological mechanisms of SAE in critically ill patients. However, there are no effective strategies for the treatment of SAE. Insulin has important immunomodulatory effects and protective effects against oxidative stress injury in the peripheral organs of septic patients. However, very few studies of the possible effects of insulin in cerebral tissues of septic patients have been reported. Therefore, in this study, we aimed to explore whether insulin therapy can inhibit cytokine production (IL-1, IL-6, and TNF-a) and oxidative stress injury of the brain tissue in septic rats. We observed that the protein concentrations of IL-1, IL-6, and TNF-а, in addition to MDA and H₂O₂ were notably increased, inversely SOD, and GSH were sigificantly decreased in cortex, hippocampus, and hypothalamus of septic rats. Furthermore, the levels of S100 and NSE significantly increased. After 6 hours of insulin therapy, we found that the cytokine concentrations notably decreased and oxidative stress injuries in the cortex, hypothalamus, and hippocampus were alleviated in septic rats. In addition, the S100 and NSE levels significantly decreased. We concluded that insulin can inhibit the production of inflammatory cytokines and the oxidative stress response, thereby improving brain tissue damage.

Transcranial Doppler to assess sepsis-associated encephalopathy in critically ill patients

Background

Transcranial Doppler can detect cerebral perfusion alteration in septic patients. We correlate static Transcranial Doppler findings with clinical signs of sepsis-associated encephalopathy.

Methods

Forty septic patients were examined with Transcranial Doppler on the first and third day of sepsis diagnosis. The pulsatility index (PI) and cerebral blood flow index (CBFi) were calculated by blood velocity in the middle cerebral artery (cm/sec). Patients underwent a daily cognitive assessment with the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) test.

Results

Twenty-one patients (55%) were found to present confusion. The majority of the patients presented a PI > 1.1 (76%). PI on the first day (but not the third day) could predict a positive CAM-ICU test in septic patients (PI cut-off: 1.3, AUC: 0.905, p < 0.01, sensitivity: 95%, specificity: 88%, AUC: 0.618, p = 0.24). Multivariable analysis showed that PI on the first day is related to a positive CAM-ICU test independent of age and APACHE II score (OR: 5.6, 95% CI: 1.1-29, p = 0.03). A decrease of the PI on the third day was observed in the group that presented initially high PI (>1.3) (2.2 ± 0.71 vs. 1.81 ± 0.64; p = 0.02). On the other hand, an increase in PI was observed in the other patients (1.01 ± 0.15 vs. 1.58 ± 0.57; p < 0.01). On only the first day, the mean blood velocity in the middle cerebral artery and CBFi were found to be lower in those patients with a high initial PI (36 ± 21 vs. 62 ± 28 cm/sec; p < 0.01, 328 ± 101 vs. 581 ± 108; p < 0.01, respectively).

Conclusions

Cerebral perfusion disturbance observed with Transcranial Doppler could explain clinical symptoms of sepsis-associated encephalopathy.

Prophylactic antioxidant potential of gallic Acid in murine model of sepsis

Present study is to investigate the effect of Gallic acid pretreatment on survival of septic animals and oxidative stress in different organs like lungs, liver, kidney, spleen, and vascular dysfunction of mice. Sepsis was induced by cecal ligation and puncture (CLP) in healthy adult male albino mice (25–30 g) and was divided into 3 groups each consisting of 6 animals, that is, sham-operated (SO group (Group I), SO + sepsis (Group II), and Gallic acid + sepsis (Group III)). Group III animals were pretreated with Gallic acid at the dose rate of 20 mg/kg body weight for 2 days before induction of sepsis. Animals were sacrificed on 8th day and the tissue samples were obtained for further investigation on lipid peroxidation (LPO), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GSH). Gallic acid pretreatment significant (P < 0.05) reduces kidney, spleen, liver, and lungs' malondialdehyde level in septic mice. However, it fails to improve reduced glutathione level in all given organs, while, Gallic acid pretreated mice showed significant improvement in SOD activity of kidney and spleen when compared to septic mice. Finally, the beneficial effects of Gallic acid pretreatment in sepsis are evident from the observations that Gallic acid partially restored SOD and catalase activity and completely reversed lipid peroxidation. Further studies are required to find out the possible mechanisms underlying the beneficial effects of Gallic acid on large population.

Elevated serum vascular cell adhesion molecule-1 is associated with septic encephalopathy in adult community-onset severe sepsis patients

Background and Aim. Septic encephalopathy (SE) is a common complication of severe sepsis. Increased concentrations of circulating soluble adhesion molecules are reported in septic patients. This study aimed to determine whether serum adhesion molecules are associated with SE. Methods. Seventy nontraumatic, nonsurgical adult patients with severe sepsis admitted through ER were evaluated. Serum adhesion molecules were assessed for their relationship with SE, and compared with other clinical predictors and biomarkers. Results. Twenty-three (32.8%) patients had SE. SE group had higher in-hospital mortality (40% versus 11%, P = 0.009) and their sVCAM-1, sICAM-1, and lactate levels on admission were also higher than non-SE group. By stepwise logistic regression model, sVCAM-1, age, and maximum 24-hours SOFA score were independently associated with septic encephalopathy. The AUC analysis of ROC curve of different biomarkers showed that sVCAM-1 is better to predict SE. The sVCAM-1 levels in the SE group were significantly higher than those of the non-SE group at three time periods (Days 1, 4, and 7). Conclusions. Septic encephalopathy implies higher mortality in nontraumatic, nonsurgical patients with severe sepsis. VCAM-1 level on presentation is a more powerful predictor of SE in these patients than lactate concentration and other adhesion molecules on admission.

Delirium in the ICU and subsequent long-term disability among survivors of mechanical ventilation

OBJECTIVE

Survivors of critical illness are frequently left with long-lasting disability. The association between delirium and disability in critically ill patients has not been described. We hypothesized that the duration of delirium in the ICU would be associated with subsequent disability and worse physical health status following a critical illness.

DESIGN

Prospective cohort study nested within a randomized controlled trial of a paired sedation and ventilator weaning strategy.

SETTING

A single-center tertiary-care hospital.

PATIENTS

One hundred twenty-six survivors of a critical illness.

MEASUREMENTS AND MAIN RESULTS

Confusion Assessment Method for the ICU, Katz activities of daily living, Functional Activities Questionnaire (measuring instrumental activities of daily living), Medical Outcomes Study 36-item Short Form General Health Survey Physical Components Score, and Awareness Questionnaire were used. Associations between delirium duration and outcomes were determined via proportional odds logistic regression with generalized estimating equations (for Katz activities of daily living and Functional Activities Questionnaire scores) or via generalized least squares regression (for Medical Outcomes Study 36-item Short Form General Health Survey Physical Components Score and Awareness Questionnaire scores). Excluding patients who died prior to follow-up but including those who withdrew or were lost to follow-up, we assessed 80 of 99 patients (81%) at 3 months and 63 of 87 patients (72%) at 12 months. After adjusting for covariates, delirium duration was associated with worse activities of daily living scores (p = 0.002) over the course of the 12-month study period but was not associated with worse instrumental activities of daily living scores (p = 0.15) or worse Medical Outcomes Study 36-item Short Form General Health Survey Physical Components Score (p = 0.58). Duration of delirium was also associated with lower Awareness Questionnaire Motor/Sensory Factors scores (p 0.02).

CONCLUSION

In the setting of critical illness, longer delirium duration is independently associated with increased odds of disability in activities of daily living and worse motor-sensory function in the following year. These data point to a need for further study into the determinants of functional outcomes in ICU survivors.

Septic encephalopathy

Every year, more cases of sepsis appear in intensive care units. The most frequent complication of sepsis is septic encephalopathy (SE), which is also the essential determinant of mortality. Despite many years of research, it still is not known at which stage of sepsis the first signs of SE appear; however, it is considered the most frequent form of encephalopathy. Patients have dysfunction of cognitive abilities and consciousness, and sometimes even epileptic seizures. Despite intensive treatment, the effects of SE remain for many years and constitute an important social problem. Numerous studies indicate that changes in the brain involve free radicals, nitric oxide, increased synthesis of inflammatory factors, disturbances in cerebral circulation, microthromboses, and ischemia, which cause considerable neuronal destruction in different areas of the brain. To determine at what point during sepsis the first signs of SE appear, different experimental models are needed to detect the aforementioned changes and to select the proper therapy for this syndrome.