Perioperative Research into Memory (PRiMe): Cognitive impairment following a severe burn injury and critical care admission, part 1

Interaction of major facilitator superfamily domain containing 2A with the blood-brain barrier

The functional and structural integrity of the blood-brain barrier is crucial in maintaining homeostasis in the brain microenvironment; however, the molecular mechanisms underlying the formation and function of the blood-brain barrier remain poorly understood. The major facilitator superfamily domain containing 2A has been identified as a key regulator of blood-brain barrier function. It plays a critical role in promoting and maintaining the formation and functional stability of the blood-brain barrier, in addition to the transport of lipids, such as docosahexaenoic acid, across the blood-brain barrier. Furthermore, an increasing number of studies have suggested that major facilitator superfamily domain containing 2A is involved in the molecular mechanisms of blood-brain barrier dysfunction in a variety of neurological diseases; however, little is known regarding the mechanisms by which major facilitator superfamily domain containing 2A affects the blood-brain barrier. This paper provides a comprehensive and systematic review of the close relationship between major facilitator superfamily domain containing 2A proteins and the blood-brain barrier, including their basic structures and functions, cross-linking between major facilitator superfamily domain containing 2A and the blood-brain barrier, and the in-depth studies on lipid transport and the regulation of blood-brain barrier permeability. This comprehensive systematic review contributes to an in-depth understanding of the important role of major facilitator superfamily domain containing 2A proteins in maintaining the structure and function of the blood-brain barrier and the research progress to date. This will not only help to elucidate the pathogenesis of neurological diseases, improve the accuracy of laboratory diagnosis, and optimize clinical treatment strategies, but it may also play an important role in prognostic monitoring. In addition, the effects of major facilitator superfamily domain containing 2A on blood-brain barrier leakage in various diseases and the research progress on cross-blood-brain barrier drug delivery are summarized. This review may contribute to the development of new approaches for the treatment of neurological diseases.

Perioperative research into memory (PRiMe), part 2: Adult burns intensive care patients show altered structure and function of the default mode network

BACKGROUND

Long-term cognitive impairment (LTCI) is experienced by up to two thirds of patients discharged from burns intensive care units (BICUs), however little is known about its neurobiological basis. This study investigated if patients previously admitted to BICU showed structural and functional MRI changes of the Default Mode Network (DMN).

METHODS

Fifteen patients previously admitted to BICU with a significant burns injury, and 15 matched volunteers, underwent structural and functional MRI scans. Functional connectivity, fractional anisotropy and cortical thickness of the main DMN subdivisions (anterior DMN (aDMN), posterior DMN (pDMN) and right (rTPJ) and left (lTPJ) temporo-parietal junctions) were compared between patients and volunteers, with differences correlated against cognitive performance.

RESULTS

Functional connectivity between rTPJ and pDMN (t = 2.91, p = 0.011) and between rTPJ and lTPJ (t = 3.18, p = 0.008) was lower in patients compared to volunteers. Functional connectivity between rTPJ and pDMN correlated with cognitive performance (r2 =0.33, p < 0.001). Mean fractional anisotropy of rTPJ (t = 2.70, p = 0.008) and lTPJ (T = 2.39, p = 0.015) was lower in patients but there was no difference in cortical thickness.

CONCLUSIONS

Patients previously admitted to BICU show structural and functional disruption of the DMN. Since functional changes correlate with cognitive performance, this should direct further research into intensive-care-related cognitive impairment.

Worse Itch and Fatigue in Racial and Ethnic Minorities: A Burn Model System Study

Racial and ethnic minority patients experience worse hypertrophic scars after burn injury than White patients. Subsequently, minority patients encounter differences in scar-related recovery domains such as itch and fatigue. This study examines disparities regarding postburn injury itch and fatigue in minority patients to better inform counseling and treatment considerations. From the multicenter National Institute of Disability, Independent Living and Rehabilitation Research Burn Model System Database (2015-2019), outcomes were analyzed at three time-points (discharge from index hospitalization, 6- and 12-months post-injury) using the 5D Itch and PROMIS-29 Fatigue measures. Multilevel linear mixed effects regression modeling analyzed associations between race/ethnicities and outcomes over time. Of 893 total patients, minority patients reported higher/worse itch scores at all time points compared to White patients. Itch scores were significantly higher for Black patients at 6 months (β = 1.42, P = .03) and 12 months (β = 3.36, P < .001) when compared to White patients. Black patients reported higher fatigue scores than White patients at all time points. Fatigue scores were significantly higher for Hispanic/Latino patients at discharge (β = 6.17, P < .001), 6 months (β = 4.49, P < .001), and 12 months (β = 6.27, P < .001) than White patients. This study supports investigation of potential factors leading to increased itch and fatigue such as sociocultural factors, disparities in healthcare access, and psychosocial impacts of these symptoms. In the short-term, minority patients may benefit from additional counseling and focused treatments addressing itch and fatigue after burn injury.

Pathological changes in the brain after peripheral burns

Brain injuries are common complications in patients with thermal burns and are associated with unpleasant outcomes. In clinical settings, it was once believed that brain injuries were not major pathological processes after burn, at least in part due to the unavailability of specific clinical manifestations. Burn-related brain injuries have been studied for more than a century, but the underlying pathophysiology has not been completely clarified. This article reviews the pathological changes in the brain following peripheral burns at the anatomical, histological, cytological, molecular and cognitive levels. Therapeutic indications based on brain injury as well as future directions for research have been summarized and proposed.

Post Intensive Care Syndrome (PICS) physical, cognitive, and mental health outcomes 6-months to 7 years after a major burn injury: A cross-sectional study

OBJECTIVES

The Post Intensive Care Syndrome (PICS) has been described in intensive care (ICU) survivors, being present in 50% of patients surviving 12 months, with well-defined risk factors. Severely burned patients combine many of these risk factors, but the prevalence of PICS has not yet been documented in burns. The study aimed to answer this question and identify associations of PICS with clinical characteristics.

METHODS

Cross-sectional descriptive study of major burn survivors admitted to the burn ICU between 2013 and 2019. Main inclusion criteria: major burns>20 %BSA and ICU admission. The PICS components were assessed using three questionnaires: 1) Physical with Burn Specific Health Scale-Brief (BSHS-B); 2) Cognitive health with MacNair Cognitive Difficulties Self-Rating Scale (CDS); 3) Mental health with the Hospital Anxiety and Depression Scale (HADS) questionnaire. PICS was considered present if at least one component out of three was abnormal. Data as mean±SD.

RESULTS

Among the 288 patients admitted during the period, 132 met the inclusion criteria: 53 patients were finally enrolled. They were aged 44 ± 18 years at the time of injury and burned 24 ± 20 BSA % and stayed 25 ± 44 days in the ICU. PICS was identified in 35 patients (66 %): more than one component was altered in 21 patients (60 %). Principal risk factors were more than 3 general anesthetics, prolonged mechanical ventilation (>4 days), ICU stay (>8 days), and hospital stay (>25 days) CONCLUSION: PICS occurred in 66 % of major burns with two or three components affected simultaneously in 60 %, i.e. more frequently than in general ICU patients.

Researches on cognitive sequelae of burn injury: Current status and advances

Burn injury is a devastating disease with high incidence of disability and mortality. The cognitive dysfunctions, such as memory defect, are the main neurological sequelae influencing the life quality of burn-injured patients. The post-burn cognitive dysfunctions are related to the primary peripheral factors and the secondary cerebral inflammation, resulting in the destruction of blood-brain barrier (BBB), as is shown on Computed Tomography (CT) and magnetic resonance imaging examinations. As part of the neurovascular unit, BBB is vital to the nutrition and homeostasis of the central nervous system (CNS) and undergoes myriad alterations after burn injury, causing post-burn cognitive defects. The diagnosis and treatment of cognitive dysfunctions as burn injury sequelae are of great importance. In this review, we address the major manifestations and interventions of post-burn cognitive defects, as well as the mechanisms involved in memory defect, including neuroinflammation, destruction of BBB, and hormone imbalance.

Burns Impair Blood-Brain Barrier and Mesenchymal Stem Cells Can Reverse the Process in Mice

Neurological syndromes are observed in numerous patients who suffer burns, which add to the economic burden of societies and families. Recent studies have implied that blood-brain barrier (BBB) dysfunction is the key factor that induces these central nervous system (CNS) syndromes in peripheral traumatic disease, e.g., surgery and burns. However, the effect of burns on BBB and the underlying mechanism remains, largely, to be determined. The present study aimed to investigate the effect of burns on BBB and the potential of umbilical cord-derived mesenchymal stem cells (UC-MSCs), which have strong anti-inflammatory and repairing ability, to protect the integrity of BBB. BBB permeability was evaluated using dextran tracer (immunohistochemistry imaging and spectrophotometric quantification) and western blot, interleukin (IL)-6, and IL-1β levels in blood and brain were measured by enzyme-linked immunosorbent assay. Furthermore, transmission electron microscopy (TEM) was used to detect transcellular vesicular transport (transcytosis) in BBB. We found that burns increased mouse BBB permeability to both 10-kDa and 70-kDa dextran. IL-6 and IL-1β levels increased in peripheral blood and CNS after burns. In addition, burns decreased the level of tight junction proteins (TJs), including claudin-5, occludin, and ZO-1, which indicated increased BBB permeability due to paracellular pathway. Moreover, increased vesicular density after burns suggested increased transcytosis in brain microvascular endothelial cells. Finally, administering UC-MSCs at 1 h after burns effectively reversed these adverse effects and protected the integrity of BBB. These results suggest that burns increase BBB permeability through both paracellular pathway and transcytosis, the potential mechanism of which might be through increasing IL-6 and IL-1β levels and decreasing Mfsd2a level, and appropriate treatment with UC-MSCs can reverse these effects and protect the integrity of BBB after burns.

Individual recovery of health-related quality of life during 18 months post-burn using a retrospective pre-burn measurement: an exploratory study

Purpose

This study explored the individual trajectories of health-related quality of life (HRQL) compared to recalled pre-burn level of HRQL and investigated whether burn severity and post-traumatic stress disorder (PTSD) symptoms increase the risk of not returning to pre-burn level of HRQL.

Methods

Data were obtained from 309 adult patients with burns in a multicenter study. Patients completed the EQ-5D-3L questionnaire with a Cognition bolt-on shortly after hospital admission, which included a recalled pre-injury measure, and, again, at 3, 6, 12 and 18 months post-burn. Burn severity was indicated by the number of surgeries, and PTSD symptoms were assessed with the IES-R at three months post-burn. Pre- and post-injury HRQL were compared to norm populations.

Results

Recalled pre-injury HRQL was higher than population norms and HRQL at 18 months post-burn was comparable to population norms. Compared to the pre-injury level of functioning, four HRQL patterns of change over time were established: Stable, Recovery, Deterioration, and Growth. In each HRQL domain, a subset of patients did not return to their recalled pre-injury levels, especially with regard to Pain, Anxiety/Depression, and Cognition. Patients with more severe burns or PTSD symptoms were less likely to return to pre-injury level of functioning within 18 months post-burn.

Conclusion

This study identified four patterns of individual change. Patients with more severe injuries and PTSD symptoms were more at risk of not returning to their recalled pre-injury HRQL. This study supports the face validity of using a recalled pre-burn HRQL score as a reference point to monitor HRQL after burns.

Electronic supplementary material

The online version of this article (10.1007/s11136-020-02678-0) contains supplementary material, which is available to authorized users.

The Correlation Between Quality of Life and Acceptability of Disability in Patients With Facial Burn Scars

The purpose of our research is to understand the status of the quality of life and level of disability acceptance in patients with facial burn scars and to explore the correlation between quality of life and disability acceptance and how to improve nursing care for these patients. Patients with facial burn scars were investigated in an outpatient clinic of tertiary hospitals from September 2015 to February 2016. A cross-sectional survey was conducted. The questionnaires used included demographic data and investigations using the burn scars table, Burn-Specific Health Scale-Brief (BSHS-B), and acceptance disability scale (ADS). Differences between participants in terms of demographic characteristics, quality of life, and disability acceptance were assessed using two-tailed independent t-tests. The total score of quality of life and disability acceptance in facial burn scar patients was 137.06 ± 17.05 and 185.68 ± 23.74, respectively. The results of Spearman correlation analysis showed that the overall quality of life score of facial burn scar patients was positively correlated with disability acceptance (r = 0.245, p = 0.007). The quality of life of facial burn scar patients will improve with the improvement of disability acceptance level. Therefore, medical staff can improve the quality of life of patients by improving their disability acceptance level.

A Scoping Review on the Long-Term Outcomes in Persons with Adult-Acquired Burn Injuries

Adult-acquired burn injuries are a life-altering event that can lead to debilitating functional or psychological impairments. With advancements in health care resulting in decreased mortality rates, survivors of burn injuries can expect to live longer. This warrants a shift in focus to better understand what happens to adults once they are discharged from the hospital into the community. Therefore, the purpose of this scoping review was to map the literature regarding the long-term outcomes of community-dwelling adult-acquired burn survivors. A computer-assisted literature search was conducted on literature from January 1, 2000 to August 31, 2018 utilizing four large databases (MEDLINE, EMBASE, CINHAL, and PsycINFO). Articles were included if they had a minimum of five individuals with a burn injury as a result of an accidental injury who were at least 18 years of age at the time of injury. Fifty-four articles were found suitable for inclusion in this review. The majority of studies were conducted in the United States and were longitudinal in design. Four themes were apparent from the articles: postburn complications, psychosocial outcomes, quality of life, and community participation. Data are lacking with respect to outcomes more than 5 years postburn as well as qualitative research. Furthermore, more literature is needed to understand the impact of postburn complications, coping strategies, and posttraumatic growth as well as barriers to community participation. Overall, there is an emerging body of literature that describes the long-term outcomes of adult-acquired burn survivors up to 5 years postburn.