Predicting Outcomes in Patients with Diffuse Axonal Injury: External Validation of the Widely Used Prognostic Instruments.

AIM: Accurate prognosis of diffuse axonal injury (DAI) is important in directing clinical care, allocating resources appropriately, and communicating with families and surrogate decision-makers. METHODS: A study was conducted on patients with clinical DAI due to closed-head traumatic brain injury treated at a trauma center in Brazil from July 2013 to September 2015.  The objective efficacy of the Glasgow Coma Scale (GCS), Trauma and Injury Severity Scoring system (TRISS), New Trauma and Injury Severity Scoring system (NTRISS), Abbreviated Injury Scale (AIS)/head, Corticosteroid Randomization After Significant Head Injury (CRASH), and International Mission on Prognosis and Analysis of Clinical Trials (IMPACT) models in the prediction of mortality at 14 days and 6-months and unfavorable outcomes at 6 months was tested. RESULTS: Our cohort comprised 95 prospectively recruited adults (85 males, 10 females, mean age 30.3 ± 10.9 years) admitted with DAI. Model efficacy was assessed through discrimination (area under the curve [AUC]), and Cox calibration. The AIS/head, TRISS, NTRISS, CRASH, and IMPACT models were able to discriminate both mortality and unfavorable outcomes (AUC 0.78-0.87). IMPACT models resulted in a statistically perfect calibration for both 6-month outcome variables; mortality and 6-month unfavorable outcome. Calibration also revealed that TRISS, NTRISS, and CRASH systematically overpredicted both outcomes, except for 6-month unfavorable outcome with TRISS. CONCLUSIONS: The results of this study suggest that TRISS, NTRISS, CRASH, and IMPACT models satisfactorily discriminate between mortality and unfavorable outcomes. However, only the TRISS and IMPACT models showed accurate calibration when predicting 6-month unfavorable outcome.

A Comprehensive Perspective on Intracranial Pressure Monitoring and Individualized Management in Neurocritical Care: Results of a Survey with Global Experts.

BACKGROUND: Numerous trials have addressed intracranial pressure (ICP) management in neurocritical care. However, identifying its harmful thresholds and controlling ICP remain challenging in terms of improving outcomes. Evidence suggests that an individualized approach is necessary for establishing tolerance limits for ICP, incorporating factors such as ICP waveform (ICPW) or pulse morphology along with additional data provided by other invasive (e.g., brain oximetry) and noninvasive monitoring (NIM) methods (e.g., transcranial Doppler, optic nerve sheath diameter ultrasound, and pupillometry). This study aims to assess current ICP monitoring practices among experienced clinicians and explore whether guidelines should incorporate ancillary parameters from NIM and ICPW in future updates. METHODS: We conducted a survey among experienced professionals involved in researching and managing patients with severe injury across low-middle-income countries (LMICs) and high-income countries (HICs). We sought their insights on ICP monitoring, particularly focusing on the impact of NIM and ICPW in various clinical scenarios. RESULTS: From October to December 2023, 109 professionals from the Americas and Europe participated in the survey, evenly distributed between LMIC and HIC. When ICP ranged from 22 to 25 mm Hg, 62.3% of respondents were open to considering additional information, such as ICPW and other monitoring techniques, before adjusting therapy intensity levels. Moreover, 77% of respondents were inclined to reassess patients with ICP in the 18-22 mm Hg range, potentially escalating therapy intensity levels with the support of ICPW and NIM. Differences emerged between LMIC and HIC participants, with more LMIC respondents preferring arterial blood pressure transducer leveling at the heart and endorsing the use of NIM techniques and ICPW as ancillary information. CONCLUSIONS: Experienced clinicians tend to personalize ICP management, emphasizing the importance of considering various monitoring techniques. ICPW and noninvasive techniques, particularly in LMIC settings, warrant further exploration and could potentially enhance individualized patient care. The study suggests updating guidelines to include these additional components for a more personalized approach to ICP management.

Moderate Traumatic Brain Injury in Adult Population: The Latin American Brain Injury Consortium Consensus for Definition and Categorization.

Moderate traumatic brain injury (TBI) is a diagnosis that describes diverse patients with heterogeneity of primary injuries. Defined by a Glasgow Coma Scale between 9 and 12, this category includes patients who may neurologically worsen and require increasing intensive care resources and/or emergency neurosurgery. Despite the unique characteristics of these patients, there have not been specific guidelines published before this effort to support decision-making in these patients. A Delphi consensus group from the Latin American Brain Injury Consortium was established to generate recommendations related to the definition and categorization of moderate TBI. Before an in-person meeting, a systematic review of the literature was performed identifying evidence relevant to planned topics. Blinded voting assessed support for each recommendation. A priori the threshold for consensus was set at 80% agreement. Nine PICOT questions were generated by the panel, including definition, categorization, grouping, and diagnosis of moderate TBI. Here, we report the results of our work including relevant consensus statements and discussion for each question. Moderate TBI is an entity for which there is little published evidence available supporting definition, diagnosis, and management. Recommendations based on experts' opinion were informed by available evidence and aim to refine the definition and categorization of moderate TBI. Further studies evaluating the impact of these recommendations will be required.

Perfusion tomography in early follow-up of acute traumatic subdural hematoma: a case series.

Perfusion Computed Tomography (PCT) is an alternative tool to assess cerebral hemodynamics during trauma. As acute traumatic subdural hematomas (ASH) is a severe primary injury associated with poor outcomes, the aim of this study was to evaluate the cerebral hemodynamics in this context. Five adult patients with moderate and severe traumatic brain injury (TBI) and ASH were included. All individuals were indicated for surgical evacuation. Before and after surgery, PCT was performed and cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were evaluated. These parameters were associated with the outcome at 6 months post-trauma with the extended Glasgow Outcome Scale (GOSE). Mean age of population was 46 years (SD: 8.1). Mean post-resuscitation Glasgow coma scale (GCS) was 10 (SD: 3.4). Mean preoperative midline brain shift was 10.1 mm (SD: 1.8). Preoperative CBF and MTT were 23.9 ml/100 g/min (SD: 6.1) and 7.3 s (1.3) respectively. After surgery, CBF increase to 30.7 ml/100 g/min (SD: 5.1), and MTT decrease to 5.8s (SD:1.0), however, both changes don't achieve statistically significance (p = 0.06). Additionally, CBV increase after surgery, from 2.34 (SD: 0.67) to 2.63 ml/100 g (SD: 1.10), (p = 0.31). Spearman correlation test of postoperative and preoperative CBF ratio with outcome at 6 months was 0.94 (p = 0.054). One patient died with the highest preoperative MTT (9.97 s) and CBV (4.51 ml/100 g). CBF seems to increase after surgery, especially when evaluated together with the MTT values. It is suggested that the improvement in postoperative brain hemodynamics correlates to favorable outcome.

The intracranial compartmental syndrome: a proposed model for acute brain injury monitoring and management.

For decades, one of the main targets in the management of severe acute brain injury (ABI) has been intracranial hypertension (IH) control. However, the determination of IH has suffered variations in its thresholds over time without clear evidence for it. Meanwhile, progress in the understanding of intracranial content (brain, blood and cerebrospinal fluid) dynamics and recent development in monitoring techniques suggest that targeting intracranial compliance (ICC) could be a more reliable approach rather than guiding actions by predetermined intracranial pressure values. It is known that ICC impairment forecasts IH, as intracranial volume may rapidly increase inside the skull, a closed bony box with derisory expansibility. Therefore, an intracranial compartmental syndrome (ICCS) can occur with deleterious brain effects, precipitating a reduction in brain perfusion, thereby inducing brain ischemia. The present perspective review aims to discuss the ICCS concept and suggest an integrative model for the combination of modern invasive and noninvasive techniques for IH and ICC assessment. The theory and logic suggest that the combination of multiple ancillary methods may enhance ICC impairment prediction, pointing proactive actions and improving patient outcomes.

"THE MANTLE" bundle for minimizing cerebral hypoxia in severe traumatic brain injury.

To ensure neuronal survival after severe traumatic brain injury, oxygen supply is essential. Cerebral tissue oxygenation represents the balance between oxygen supply and consumption, largely reflecting the adequacy of cerebral perfusion. Multiple physiological parameters determine the oxygen delivered to the brain, including blood pressure, hemoglobin level, systemic oxygenation, microcirculation and many factors are involved in the delivery of oxygen to its final recipient, through the respiratory chain. Brain tissue hypoxia occurs when the supply of oxygen is not adequate or when for some reasons it cannot be used at the cellular level. The causes of hypoxia are variable and can be analyzed pathophysiologically following "the oxygen route." The current trend is precision medicine, individualized and therapeutically directed to the pathophysiology of specific brain damage; however, this requires the availability of multimodal monitoring. For this purpose, we developed the acronym "THE MANTLE," a bundle of therapeutical interventions, which covers and protects the brain, optimizing the components of the oxygen transport system from ambient air to the mitochondria.

High flow nasal oxygen and awake prone positioning - Two allies against COVID-19: A systematic review.

INTRODUCTION: Severe acute respiratory distress syndrome coronavirus disease-2 (SARS-CoV-2) can lead to acute hypoxemic respiratory failure (AHRF) with possible multisystemic involvement. Ventilation/perfusion mismatch and shunt increase are critical determinants of hypoxemia. Understanding hypoxemia and the mechanisms involved in its genesis is essential to determine the optimal therapeutic strategy. High flow nasal oxygen (HFNO) and awake prone positioning (APP) in patients with COVID-19 AHRF showed promising benefits. The aim of this systematic review was to depict current situation around the combined use of HFNO and APP in patients with COVID-19 AHRF. Particularly, to investigate and report the pathophysiological rationale for adopting this strategy and to evaluate the (1) criteria for initiation, (2) timing, monitoring and discontinuation, and to assess the (3) impact of HFNO/ APP on outcome. METHODS: We performed a systematic search collecting the articles present in PubMed, Scopus, EMBASE, and Cochrane databases with the following keywords: COVID-19 pneumonia, high flow nasal oxygen, awake prone position ventilation. RESULTS: Thirteen studies displayed inclusion criteria and were included, accounting for 1242 patients who received HFNO/ APP. The combination of HFNO/ APP has an encouraging pathophysiological rationale for implementing this technique. The recognition of patients who can benefit from HFNO/ APP is difficult and there are no validated protocols to start, monitoring, and discontinue HFNO/ APP therapy. The most used method to monitor the efficacy and failure of this combined technique are oxygenation indexes, but discontinuation techniques are inconsistently and poorly described limiting possible generatability. Finally, this technique provided no clear benefits on outcome. CONCLUSIONS: Our systematic search provided positive feedbacks for improving the utilization of this combination technique, although we still need further investigation about methods to guide timing, management, and discontinuation, and to assess the intervention effect on outcome.

Intracranial Pressure Monitoring in Moderate Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

BACKGROUND: The principal aim of this study was to determine the prevalence of intracranial pressure (ICP) monitoring and intracranial hypertension (IHT) in patients treated for moderate traumatic brain injury (TBI). A secondary objective was to assess factors associated with ICP monitoring. METHODS: We conducted a systematic review of the literature to identify studies that assessed ICP monitoring in moderate TBI. The meta-analysis was performed by using a random-effects model. RESULTS: A total of 13 studies comprising 116,714 patients were pooled to estimate the overall prevalence of ICP monitoring and IHT (one episode or more of ICP > 20 mm Hg) after moderate TBI. The prevalence rate for ICP monitoring was 18.3% (95% confidence interval 8.1-36.1%), whereas the proportion of IHT was 44% (95% confidence interval 33.8-54.7%). Three studies were pooled to estimate the prevalence of ICP monitoring according to Glasgow Coma Scale (GCS) (≤ 10 vs. > 10). ICP monitoring was performed in 32.2% of patients with GCS ≤ 10 versus 15.2% of patients with GCS > 10 (p = 0.59). Both subgroups were highly heterogeneous. We found no other variables associated with ICP monitoring or IHT. CONCLUSIONS: The prevalence of ICP monitoring in moderate TBI is low, but the prevalence of IHT is high among patients undergoing ICP monitoring. Current literature is limited in size and quality and does not identify factors associated with ICP monitoring or IHT. Further research is needed to guide the optimal use of ICP monitoring in moderate TBI.

Evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography and its correlation with intracranial pressure in an animal model of intracranial hypertension / Avaliação da hemodinâmica encefálica utilizando Doppler transcraniano e sua correlação com a pressão intracraniana em um modelo animal de hipertensão intracraniana

ABSTRACT Background: Transcranial Doppler has been tested in the evaluation of cerebral hemodynamics as a non-invasive assessment of intracranial pressure (ICP), but there is controversy in the literature about its actual benefit and usefulness in this situation. Objective: To investigate cerebral blood flow assessed by Doppler technique and correlate with the variations of the ICP in the acute phase of intracranial hypertension in an animal model. Methods: An experimental animal model of intracranial hypertension was used. The experiment consisted of two groups of animals in which intracranial balloons were implanted and inflated with 4 mL (A) and 7 mL (B) for controlled simulation of different volumes of hematoma. The values of ICP and Doppler parameters (systolic [FVs], diastolic [FVd], and mean [FVm] cerebral blood flow velocities and pulsatility index [PI]) were collected during the entire procedure (before and during hematoma simulations and venous hypertonic saline infusion intervention). Comparisons between Doppler parameters and ICP monitoring were performed. Results: Twenty pigs were studied, 10 in group A and 10 in group B. A significant correlation between PI and ICP was obtained, especially shortly after abrupt elevation of ICP. There was no correlation between ICP and FVs, FVd or FVm separately. There was also no significant change in ICP after intravenous infusion of hypertonic saline solution. Conclusions: These results demonstrate the potential of PI as a parameter for the evaluation of patients with suspected ICP elevation.

RESUMO Antecedentes: O Doppler transcraniano (DTC) é uma técnica não invasiva para a avaliação da hemodinâmica cerebral, porém existem controvérsias na literatura sobre sua aplicabilidade preditiva em situações de elevada pressão intracraniana (PIC). Objetivo: Investigar o fluxo sanguíneo cerebral pelo DTC e correlacioná-lo com as variações da PIC na fase aguda da hipertensão intracraniana em modelo animal. Métodos: Dois grupos de animais (suínos) foram submetidos a hipertensão intracraniana secundária à indução de diferentes volumes de hematoma, por meio da insuflação de balão intracraniano controlado com 4 e 7 mL de solução salina fisiológica (grupos A e B, respectivamente). Em seguida, administrou-se infusão venosa de solução salina hipertônica (SSH 3%). Foram coletados os valores dos parâmetros de PIC e DTC (velocidade sistólica [FVs], diastólica [FVd] e média [FVm] do fluxo sanguíneo cerebral), bem como o índice de pulsatilidade (IP). Comparações entre os parâmetros do DTC e o monitoramento da PIC foram realizadas. Resultados: Vinte porcos foram estudados, dez no grupo A e dez no grupo B. Correlação significativa entre IP e PIC foi obtida, principalmente logo após a elevação abrupta da PIC. Não houve correlação entre PIC e FVs, FVd ou FVm separadamente. Também não houve alteração significativa na PIC após a infusão de SSH. Conclusões: Esses resultados demonstram o potencial do IP como um bom parâmetro para a avaliação de pacientes com suspeita de elevação da PIC.

Evaluation of cerebral hemodynamics by transcranial Doppler ultrasonography and its correlation with intracranial pressure in an animal model of intracranial hypertension.

BACKGROUND: Transcranial Doppler has been tested in the evaluation of cerebral hemodynamics as a non-invasive assessment of intracranial pressure (ICP), but there is controversy in the literature about its actual benefit and usefulness in this situation. OBJECTIVE: To investigate cerebral blood flow assessed by Doppler technique and correlate with the variations of the ICP in the acute phase of intracranial hypertension in an animal model. METHODS: An experimental animal model of intracranial hypertension was used. The experiment consisted of two groups of animals in which intracranial balloons were implanted and inflated with 4 mL (A) and 7 mL (B) for controlled simulation of different volumes of hematoma. The values of ICP and Doppler parameters (systolic [FVs], diastolic [FVd], and mean [FVm] cerebral blood flow velocities and pulsatility index [PI]) were collected during the entire procedure (before and during hematoma simulations and venous hypertonic saline infusion intervention). Comparisons between Doppler parameters and ICP monitoring were performed. RESULTS: Twenty pigs were studied, 10 in group A and 10 in group B. A significant correlation between PI and ICP was obtained, especially shortly after abrupt elevation of ICP. There was no correlation between ICP and FVs, FVd or FVm separately. There was also no significant change in ICP after intravenous infusion of hypertonic saline solution. CONCLUSIONS: These results demonstrate the potential of PI as a parameter for the evaluation of patients with suspected ICP elevation.

Severe Acute Kidney Injury Secondary to Immunoglobulin Infusion in Life-Threatening Guillain Barre Syndrome.

Immunoglobulin infusion (IVIG) is one of the first line therapy in Guillain Barre Syndrome (GBS). Several medical complications are associated with GBS (pneumonia, sepsis, deep vein thrombosis, dysautonomy). Acute kidney injury (AKI) is an uncommon complication during IVIG infusion. Several risk factors were associated with AKI during IVIG. These are an older age, previous renal disease, concomitant use of nephrotoxic agents, diabetes mellitus, hypovolemia, sepsis or using of IVIG that contained in its preparation sucrose or mannitol as stabilizers to avoid precipitation and aggregation. Infusion rate and total dose play a determinant role. The most important pathophysiological mechanism of AKI are the osmotic stress applied to the epithelium of proximal tubules and glomeruli. The osmotic overload is principally generated by IVIG stabilizers (sucrose). In general, AKI is reversible but approximately 30% hemodialysis is necessary. It is essential to respect doses, infusion rates and closely monitoring renal function parameters during IVIG infusion.

Acute Intracranial Hypertension During Pregnancy: Special Considerations and Management Adjustments.

Pregnancy is associated with a number of pathophysiological changes (including modification of vascular resistance, increased vascular permeability, and coagulative disorders) that can lead to specific (eclampsia, preeclampsia) or not specific (intracranial hemorrhage) neurological complications. In addition to these disorders, pregnancy can affect numerous preexisting neurologic conditions, including epilepsy, brain tumors, and intracerebral bleeding from cerebral aneurysm or arteriovenous malformations. Intracranial complications related to pregnancy can expose patients to a high risk of intracranial hypertension (IHT). Unfortunately, at present, the therapeutic measures that are generally adopted for the control of elevated intracranial pressure (ICP) in the general population have not been examined in pregnant patients, and their efficacy and safety for the mother and the fetus is still unknown. In addition, no specific guidelines for the application of the staircase approach, including escalating treatments with increasing intensity of level, for the management of IHT exist for this population. Although some of basic measures can be considered safe even in pregnant patients (management of stable hemodynamic and respiratory function, optimization of systemic physiology), some other interventions, such as hyperventilation, osmotic therapy, hypothermia, barbiturates, and decompressive craniectomy, can lead to specific concerns for the safety of both mother and fetus. The aim of this review is to summarize the neurological pathophysiological changes occurring during pregnancy and explore the effects of the possible therapeutic interventions applied to the general population for the management of IHT during pregnancy, taking into consideration ethical and clinical concerns as well as the decision for the timing of treatment and delivery.

Dos enfoques conocidos para la determinación de muerte neurológica del adulto: propuesta de un concepto unificado / Two criteria to determine brain death in adults: a proposal to achieve a unified definition / Morte neurológica em adulto: proposta de um conceito unificado

Resumen: Cuanto más progreso en el conocimiento de la injuria encefálica aguda (IEA) irreversible y su potencial evolución a la muerte encefálica (ME), existirán más posibilidades de captación de donantes, con la consiguiente disminución de las listas de espera. A nuestro criterio, el médico intensivista deberá tener presente tal posibilidad cuando se enfrenta a víctimas de neuroinjuria independientemente de su etiología. Además, resulta imprescindible que conozca la fisiopatología del síndrome de ME y los pasos a seguir para la realización de un examen neurológico completo, exhaustivo y riguroso que lo confirme. Al día de hoy, existen dos conceptos de muerte según criterios neurológicos: muerte encefálica total' (MET) y muerte de troncoencéfalo (MT). Si bien ambas definiciones son aceptadas por la comunidad médica mundial, algunos países adoptan una u otra, recibiendo el marco legal correspondiente que lo avale. Debatiremos ambos conceptos, con la intención de intentar generar un concepto unificado y consensuado de ME.

Abstract: The greater the advance in terms of knowing about acute encephalic injury (AEI) and its potential evolution to encephalic death (ED), the higher the possibilities of finding donors, with the corresponding reduction of waiting lists. As we see it, intensivists must consider this possibility whenever they face victims of neuroinjury, regardless of its etiology. In addition to this, it is essential for them to know the pathophysiology of encephalic death syndrome, and the steps to be taken for a complete, thorough and strict neurologic exam. Today, there are two criteria to determine death according to neurologic criteria: "total brain death'' (MET) and ''brainstem death'' (MT). Despite the fact that both criteria are accepted by the global medical community, some countries adopt one or the other criteria, which defines the corresponding legal framework that supports it. We will debate both criteria, aiming to achieve a unified and agreed definition of brain death.

Resumo: Quanto mais avançarmos no conhecimento da lesão encefálica aguda irreversível (IEA) e sua evolução potencial para morte encefálica (ME), maiores serão as possibilidades de captação de doadores, com a consequente redução das listas de espera. Em nossa opinião, o médico intensivista deve ter essa possibilidade em mente ao lidar com vítimas de injúria neurológica, independentemente de sua etiologia. Também é essencial que conheça a fisiopatologia da síndrome de ME e as etapas a seguir para realizar um exame neurológico completo, exaustivo e rigoroso para confirmá-la. Até o momento, existem dois conceitos de morte segundo critérios neurológicos: "morte encefálica total" (MET) e "morte encefálica" (MT). Embora ambas as definições sejam aceitas pela comunidade médica mundial, alguns países adotam uma ou outra, recebendo o respectivo arcabouço legal para apoiá-la. Discutiremos ambos os conceitos, com o intuito de tentar gerar um conceito unificado e consensual de ME.

Management of severe traumatic brain injury in regions with limited resources.

IMPORTANCE: Severe traumatic brain injury (sTBI) is a critical health problem in regions of limited resources (RLRs). Younger populations are among the most impacted. The objective of this review is to analyze recent consensus-based algorithms, protocols and guidelines proposed for the care of patients with TBI in RLRs. OBSERVATIONS: The principal mechanisms for sTBI in RLRs are road traffic injuries (RTIs) and violence. Limitations of care include suboptimal or non-existent pre-hospital care, overburdened emergency services, lack of trained human resources, and surgical and intensive care. Low-cost neuromonitoring systems are currently in testing, and formal neurotrauma registries are forming to evaluate both long-term outcomes and best practices at every level of care from hospital transport to the emergency department (ED), to the operating room and intensive care unit (ICU). CONCLUSIONS AND RELEVANCE: The burden of sTBI is highest in RLRs. As working-age adults are the predominantly affected age-group, an increase in disability-adjusted life years (DALYs) generates a loss of economic growth in regions where economic growth is needed most. Four multi-institutional collaborations between high-income countries (HICs) and LMICs have developed evidence and consensus-based documents focused on capacity building for sTBI care as a means of addressing this substantial burden of disease.