Near Infrared Spectroscopy for High-Temporal Resolution Cerebral Physiome Characterization in TBI: A Narrative Review of Techniques, Applications, and Future Directions.

Multimodal monitoring has been gaining traction in the critical care of patients following traumatic brain injury (TBI). Through providing a deeper understanding of the individual patient's comprehensive physiologic state, or "physiome," following injury, these methods hold the promise of improving personalized care and advancing precision medicine. One of the modalities being explored in TBI care is near-infrared spectroscopy (NIRS), given it's non-invasive nature and ability to interrogate microvascular and tissue oxygen metabolism. In this narrative review, we begin by discussing the principles of NIRS technology, including spatially, frequency, and time-resolved variants. Subsequently, the applications of NIRS in various phases of clinical care following TBI are explored. These applications include the pre-hospital, intraoperative, neurocritical care, and outpatient/rehabilitation setting. The utility of NIRS to predict functional outcomes and evaluate dysfunctional cerebrovascular reactivity is also discussed. Finally, future applications and potential advancements in NIRS-based physiologic monitoring of TBI patients are presented, with a description of the potential integration with other omics biomarkers

Dynamic tracking of microvascular hemoglobin content for continuous perfusion monitoring in the intensive care unit: pilot feasibility study

Purpose: There is a need for bedside methods to monitor oxygen delivery in the microcirculation. Near-infrared spectroscopy commonly measures tissue oxygen saturation, but does not reflect the time-dependent variability of microvascular hemoglobin content (MHC) that attempts to match oxygen supply with demand. The objective of this study is to determine the feasibility of MHC monitoring in critically ill patients using high-resolution near-infrared spectroscopy to assess perfusion in the peripheral microcirculation. Methods: Prospective observational cohort of 36 patients admitted within 48 h at a tertiary intensive care unit. Perfusion was measured on the quadriceps, biceps, and/or deltoid, using the temporal change in optical density at the isosbestic wavelength of hemoglobin (798 nm). Continuous wavelet transform was applied to the hemoglobin signal to delineate frequency ranges corresponding to physiological oscillations in the cardiovascular system. Results: 31/36 patients had adequate signal quality for analysis, most commonly affected by motion artifacts. MHC signal demonstrates inter-subject heterogeneity in the cohort, indicated by different patterns of variability and frequency composition. Signal characteristics were concordant between muscle groups in the same patient, and correlated with systemic hemoglobin levels and oxygen saturation. Signal power was lower for patients receiving vasopressors, but not correlated with mean arterial pressure. Mechanical ventilation directly impacts MHC in peripheral tissue. Conclusion: MHC can be measured continuously in the ICU with high-resolution near-infrared spectroscopy, and reflects the dynamic variability of hemoglobin distribution in the microcirculation. Results suggest this novel hemodynamic metric should be further evaluated for diagnosing microvascular dysfunction and monitoring peripheral perfusion

Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD

Relacionamentos de amizade íntima entre jovens adultos

A literatura é consensual quanto ao importante papel dos amigos no ciclo vital, na maior parte do tempo, para melhorias na qualidade de vida. Este estudo teve como objetivo investigar e descrever características dos relacionamentos íntimos de amizade de jovens adultos. Participaram 98 jovens adultos com idade entre 18 e 30 anos. Os procedimentos de amostragem foram baseados na técnica do Respondent Driven Sampling. Foram utilizados três questionários autoaplicados e os dados foram submetidos a tratamento quantitativo. Os resultados demonstraram uma homogeneidade de características entre amigos íntimos, especialmente para o gênero. O companheirismo despontou como aspecto mais marcante na amizade. Todas as funções da amizade apresentaram correlações positivas entre si. Conclui-se que parece haver um filtro de similaridades entre amigos na adultez jovem e que amizades de boa qualidade em uma determinada função costumam ser de boa qualidade em seu total

Continuous Determination of the Optimal Bispectral Index Value Based on Cerebrovascular Reactivity in Moderate/Severe Traumatic Brain Injury: A Retrospective Observational Cohort Study of a Novel Individualized Sedation Target.

BACKGROUND: We have sought to develop methodology for deriving optimal bispectral index (BIS) values (BISopt) for patients with moderate/severe traumatic brain injury, using continuous monitoring of cerebrovascular reactivity and bispectral electroencephalography. METHODS: Arterial blood pressure, intracranial pressure, and BIS (a bilateral measure that is associated with sedation state) were continuously recorded. The pressure reactivity index, optimal cerebral perfusion pressure (CPPopt), and BISopt were calculated. Using BIS values and the pressure reactivity index, a curve fitting method was applied to determine the minimum value for the pressure reactivity index thus giving the BISopt. RESULTS AND CONCLUSIONS: Identification of BISopt was possible in all of the patients, with both visual inspection of data and using our method of BISopt determination, demonstrating a similarity of median values of 44.62 (35.03-59.98) versus 48 (39.75-57.50) (p = 0.1949). Furthermore, our method outperformed common CPPopt curve fitting methods applied to BISopt with improved percent (%) yields on both the left side 52.1% (36.3-72.4%) versus 31.2% (23.0-48.9%) (p < 0.0001) and the right side 54.1% (35.95-75.9%) versus 33.5% (12.5-47.9%) (p < 0.0001). The BIS values and BISopt were compared with cerebral perfusion pressure, mean arterial pressure, and CPPopt. The results indicated that BISopt's impact on pressure reactivity was distinct from CPPopt, cerebral perfusion pressure, or mean arterial pressure. Real-time BISopt can be derived from continuous physiologic monitoring of patients with moderate/severe traumatic brain injury. This BISopt value appears to be unassociated with arterial blood pressure or CPPopt, supporting its role as a novel physiologic metric for evaluating cerebral autoregulation. BISopt management to optimize cerebrovascular pressure reactivity should be the subject of future studies in moderate/severe traumatic brain injury

Hyperbranched polyglycerol is superior to glucose for long-term preservation of peritoneal membrane in a rat model of chronic peritoneal dialysis

Background: Replacing glucose with a better biocompatible osmotic agent in peritoneal dialysis (PD) solutions is needed in PD clinic. We previously demonstrated the potential of hyperbranched polyglycerol (HPG) as a replacement for glucose. This study further investigated the long-term effects of chronic exposure to HPG as compared to a glucose-based conventional PD solution on peritoneal membrane (PM) structure and function in rats. Methods Adult male Wistar rats received once-daily intraperitoneal injection of 10 mL of HPG solution (1 kDa, HPG 6%) compared to Physioneal™ 40 (PYS, glucose 2.27%) or electrolyte solution (Control) for 3 months. The overall health conditions were determined by blood chemistry analysis. The PM function was determined by ultrafiltration, and its injury by histological and transcriptome-based pathway analyses. Results Here, we showed that there was no difference in the blood chemistry between rats receiving the HPG and the Control, while PYS increased serum alkaline phosphatase, globulin and creatinine and decreased serum albumin. Unlike PYS, HPG did not significantly attenuate PM function, which was associated with smaller change in both the structure and the angiogenesis of the PM and less cells expressing vascular endothelial growth factor, α-smooth muscle actin and MAC387 (macrophage marker). The pathway analysis revealed that there were more inflammatory signaling pathways functioning in the PM of PYS group than those of HPG or Control, which included the signaling for cytokine production in both macrophages and T cells, interleukin (IL)-6, IL-10, Toll-like receptors, triggering receptor expressed on myeloid cells 1 and high mobility group box 1. Conclusions The results from this experimental study indicate the superiority of HPG to glucose in the preservation of the peritoneum function and structure during the long-term PD treatment, suggesting the potential of HPG as a novel osmotic agent for PD.Medicine, Faculty ofScience, Faculty ofNon UBCChemistry, Department ofMedicine, Department ofNephrology, Division ofPathology and Laboratory Medicine, Department ofUrologic Sciences, Department ofReviewedFacult

Impact of age on the host response to sepsis in a murine model of fecal-induced peritonitis

Abstract Introduction Despite older adults being more vulnerable to sepsis, most preclinical research on sepsis has been conducted using young animals. This results in decreased scientific validity since age is an independent predictor of poor outcome. In this study, we explored the impact of aging on the host response to sepsis using the fecal-induced peritonitis (FIP) model developed by the National Preclinical Sepsis Platform (NPSP). Methods C57BL/6 mice (3 or 12 months old) were injected intraperitoneally with rat fecal slurry (0.75 mg/g) or a control vehicle. To investigate the early stage of sepsis, mice were culled at 4 h, 8 h, or 12 h to investigate disease severity, immunothrombosis biomarkers, and organ injury. Mice received buprenorphine at 4 h post-FIP. A separate cohort of FIP mice were studied for 72 h (with buprenorphine given at 4 h, 12 h, and then every 12 h post-FIP and antibiotics/fluids starting at 12 h post-FIP). Organs were harvested, plasma levels of Interleukin (IL)-6, IL-10, monocyte chemoattract protein (MCP-1)/CCL2, thrombin-antithrombin (TAT) complexes, cell-free DNA (CFDNA), and ADAMTS13 activity were quantified, and bacterial loads were measured. Results In the 12 h time course study, aged FIP mice demonstrated increased inflammation and injury to the lungs compared to young FIP mice. In the 72 h study, aged FIP mice exhibited a higher mortality rate (89%) compared to young FIP mice (42%) (p < 0.001). Aged FIP non-survivors also exhibited a trend towards elevated IL-6, TAT, CFDNA, CCL2, and decreased IL-10, and impaired bacterial clearance compared to young FIP non-survivors. Conclusion To our knowledge, this is the first study to investigate the impact of age on survival using the FIP model of sepsis. Our model includes clinically-relevant supportive therapies and inclusion of both sexes. The higher mortality rate in aged mice may reflect increased inflammation and worsened organ injury in the early stage of sepsis. We also observed trends in impaired bacterial clearance, increase in IL-6, TAT, CFDNA, CCL2, and decreased IL-10 and ADAMTS13 activity in aged septic non-survivors compared to young septic non-survivors. Our aging model may help to increase the scientific validity of preclinical research and may be useful for identifying mechanisms of age-related susceptibility to sepsis as well as age-specific treatment strategies

Protocol for co-producing a framework and integrated resource platform for engaging patients in laboratory-based research

Abstract Background Patient engagement in research is the meaningful and collaborative interaction between patients and researchers throughout the research process. Patient engagement can help to ensure patient-oriented values and perspectives are incorporated into the development, conduct, and dissemination of research. While patient engagement is increasingly prevalent in clinical research, it remains relatively unrealized in preclinical laboratory research. This may reflect the nature of preclinical research, in which routine interactions or engagement with patients may be less common. Our team of patient partners and researchers has previously identified few published examples of patient engagement in preclinical laboratory research, as well as a paucity of guidance on this topic. Here we propose the development of a process framework to facilitate patient engagement in preclinical laboratory research. Methods Our team, inclusive of researchers and patient partners, will develop a comprehensive, empirically-derived, and stakeholder-informed process framework for ‘patient engagement in preclinical laboratory research.’ First, our team will create a ‘deliberative knowledge space’ to conduct semi-structured discussions that will inform a draft framework for preclinical patient engagement. Over the course of several sessions, we will identify actions, activities, barriers, and enablers (e.g. considerations and motivations for patient engagement in preclinical laboratory research, define roles of key players). The resulting draft process framework will be further populated with examples and refined through an international consensus-building Delphi survey with patients, researchers, and other collaborator organizations. We will then conduct pilot field tests to evaluate the framework with preclinical laboratory research groups paired with patient partners. These results will be used to create a refined framework enriched with real-world examples and considerations. All resources developed will be made available through an online repository. Discussion Our proposed process framework will provide guidance, best practices, and standardized procedures to promote patient engagement in preclinical laboratory research. Supporting and facilitating patient engagement in this setting presents an exciting new opportunity to help realize the important impact that patients can make