A management algorithm for patients with intracranial pressure monitoring: the Seattle International Severe Traumatic Brain Injury Consensus Conference (SIBICC)

Clinical Capacity Building Through Partnerships: Boots on the Ground in Global Neurosurgery

Global neurosurgery seeks to provide quality neurosurgical health care worldwide and faces challenges because of historical, socioeconomic, and political factors. To address the shortfall of essential neurosurgical procedures worldwide, dyads between established neurosurgical and developing centers have been established. Concerns have been raised about their effectiveness and ability to sustain capacity development. Successful partnerships involve multiple stakeholders, extended timelines, and twinning programs. This article outlines current initiatives and challenges within the neurosurgical community. This narrative review aims to provide a practical tool for colleagues embarking on clinical partnerships, the Engagements and assets, Capacity, Operative autonomy, Sustainability, and scalability (ECOSystem) of care. To create the ECOSystem of care in global neurosurgery, the authors had multiple online discussions regarding important points in the practical tool. All developed tiers were expanded based on logistics, clinical, and educational aspects. An online search was performed from August to November 2023 to highlight global neurosurgery partnerships and link them to tiers of the ECOSystem. The ECOSystem of care involves 5 tiers: Tiers 0 (foundation), 1 (essential), 2 (complexity), 3 (autonomy), and 4 (final). A nonexhaustive list of 16 neurosurgical partnerships was created and serves as a reference for using the ECOSystem. Personal experiences from the authors through their partnerships were also captured. We propose a tiered approach for capacity building that provides structured guidance for establishing neurosurgical partnerships with the ECOSystem of care. Clinical partnerships in global neurosurgery aim to build autonomy, enabling independent provision of quality healthcare services.

Anesthesia for traumatic brain injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) presents complex clinical challenges, requiring a nuanced understanding of its pathophysiology and current management principles to improve patient outcomes. Anesthetists play a critical role in care and need to stay updated with recent evidence and trends to ensure high-quality treatment. The Brain Trauma Foundation Guidelines, last updated in 2016, have shown moderate adherence, and much of the current management relies on expert opinions. This literature review synthesizes the current evidence and provides insights into the role of anesthetists in TBI management.

RECENT FINDINGS

Recent literature has emphasized the importance of tailored anesthetic management principles in treating TBI, focusing on minimizing secondary brain injury during neurosurgical interventions or extracranial surgery. Emerging trends include individualized intracranial pressure approaches and multimodal neuromonitoring for comprehensive assessment of cerebral physiology.

SUMMARY

Anesthesia for TBI patients requires a comprehensive approach that balances anesthetic goals with the unique pathophysiological factors of brain injury. Despite recent research expanding our understanding, challenges remain in standardizing protocols and addressing individual patient response variability. Adherence to established management principles, personalized approaches, and ongoing research is crucial for improving the outcomes.

Decompressive craniectomy in trauma: What you need to know

ABSTRACT

Decompressive craniectomy (DC) is a surgical procedure in which a large section of the skull is removed, and the underlying dura mater is opened widely. After evacuating a traumatic acute subdural hematoma, a primary DC is typically performed if the brain is bulging or if brain swelling is expected over the next several days. However, a recent randomized trial found similar 12-month outcomes when primary DC was compared with craniotomy for acute subdural hematoma. Secondary removal of the bone flap was performed in 9% of the craniotomy group, but more wound complications occurred in the craniectomy group. Two further multicenter trials found that, whereas early neuroprotective bifrontal DC for mild to moderate intracranial hypertension is not superior to medical management, DC as a last-tier therapy for refractory intracranial hypertension leads to reduced mortality. Patients undergoing secondary last-tier DC are more likely to improve over time than those in the standard medical management group. The overall conclusion from the most up-to-date evidence is that secondary DC has a role in the management of intracranial hypertension following traumatic brain injury but is not a panacea. Therefore, the decision to offer this operation should be made on a case-by-case basis. Following DC, cranioplasty is warranted but not always feasible, especially in low- and middle-income countries. Consequently, a decompressive craniotomy, where the bone flap is allowed to "hinge" or "float," is sometimes used. Decompressive craniotomy is also an option in a subgroup of traumatic brain injury patients undergoing primary surgical evacuation when the brain is neither bulging nor relaxed. However, a high-quality randomized controlled trial is needed to delineate the specific indications and the type of decompressive craniotomy in appropriate patients.

Effect of volatile anaesthetic agents on intracranial pressure, cerebrovascular flow and autoregulation: a protocol for a systematic review and meta-analysis

INTRODUCTION

The use of volatile anaesthetic agents for the sedation of patients requiring critical care treatment offers several theoretical advantages over intravenous sedation, which may be of benefit in neurocritical care. However, there are concerns that they may increase intracranial pressure. The objective of this systematic review is to assess whether, and if so, to what extent volatile anaesthetic agents affect intracranial pressure, cerebral blood flow (CBF), cerebral oximetry and cerebrovascular autoregulation. If sufficient data exist, subgroup analyses will be conducted in traumatic brain injury and decompressive craniectomy patients.

METHODS AND ANALYSIS

A database search of PubMed, Medline (including Medline plus), CINAHL (including CINAHL Plus), Embase databases and the Cochrane Central Controlled Trials Register without time limits will be conducted. The search results will be screened by title and abstract by two independent researchers on a rule-in basis against predetermined criteria-controlled studies in humans of contemporary fluorinated volatile anaesthetic agents against a control, which measures intracranial pressure, CBF, cerebral oximetry or cerebrovascular autoregulation. Articles responsive to screening will then be reviewed in full text by two independent researchers, requiring consensus or a tie-break by a third independent researcher. Reference lists and a non-generative AI tool will be examined for missed articles, with all identified articles being reviewed in full text by two independent researchers. The included articles will be assessed for risk of bias and will have data extracted by two independent researchers. If sufficient data exist, a meta-analysis will be performed; otherwise, a narrative description of outcomes will be performed.

ETHICS AND DISSEMINATION

No ethics approval will be sought for this systematic review. This study has no explicit funding. The results of this study will be disseminated in a peer-reviewed journal, in a conference presentation and on PROSPERO.

TRIAL REGISTRATION NUMBER

PROSPERO number CRD42023474587.

A Survey on the Management of Patients with Severe Traumatic Brain Injury During Pregnancy: The MAMA Study

BACKGROUND

Trauma, including traumatic brain injury (TBI), is the leading cause of nonobstetric maternal mortality during pregnancy. Few data are available regarding the optimal management of pregnant patients with TBI, leading to a lack of dedicated guidelines. We performed an international survey to examine the management of severe TBI in pregnant patients, focusing on monitoring, therapy, and intensive care practices.

METHODS

This survey, endorsed by the World Society of Emergency Surgery, was composed of a questionnaire with 79 items divided into four sections: (1) general information (items 1-7), (2) management of the maternal-fetal unit (items 8-43), (3) management of intracranial hypertension (items 44-76), and (4) specific considerations (items 77-79).

RESULTS

One hundred and twenty-two physicians from 110 centers in 35 countries responded. The main findings related to TBI care in pregnant patients included the following: (1) a lack of availability of a specific TBI protocol in pregnancy; (2) an increase in the utilization of magnetic resonance imaging as the primary neuroimaging tool; (3) higher hemoglobin thresholds for transfusion; and (4) a lower utilization of therapeutic hypothermia, neuromuscular blocking agents, and barbiturate coma. We also report large variability in the timing of cesarean section in pregnant patients with TBI (≥ 23 weeks of gestation) needing an emergency craniotomy (simultaneously 23% vs. later cesarean section 50.8%).

CONCLUSIONS

Great variability in the management of pregnant patients with severe TBI was identified worldwide from the results of our survey. These findings, highlighting the lack of robust evidence on this topic, will be helpful to stimulate future investigations and to promote educational efforts on this difficult scenario.

Mortality-Associated Factors in a Traumatic Brain Injury Population in Mexico

BACKGROUND

Traumatic brain injury (TBI) is a major cause of death and disability, with a rising incidence in recent years. Factors such as age, sex, hypotension, low score on the Glasgow Coma Scale, use of invasive mechanical ventilation and vasopressors, etc., have been associated with mortality caused by TBI. The aim of this study was to identify the clinical and sociodemographic characteristics that influence the mortality or survival of patients with TBI in a tertiary care hospital in Mexico.

METHODS

A sample of 94 patients aged 18 years or older, from both sexes, with an admitting diagnosis of mild-to-severe head trauma, with initial prehospital treatment, was taken. Data were extracted from the Single Registry of Patients with TBI at the Ixtapaluca Regional High Specialty Hospital (HRAEI). Normality tests were used to decide on the corresponding statistical analysis.

RESULTS

No factors associated with mortality were found; however, survival analysis showed that the presence of seizures, aggregate limb trauma, and subjects with diabetes mellitus, heart disease or patients with four concomitant comorbidities had 100% mortality. In addition, having seizures in the prehospital setting increased the risk of mortality four times. Although they did not have a direct association with mortality, they significantly decreased survival. A larger sample size is probably required to obtain an association with mortality.

CONCLUSIONS

These results reflect the severity of the clinical situation in this population and, although no risk factors were identified, they enlighten us about the conditions presented by patients who died.

Development of a Quality Indicator Set for the Optimal Acute Management of Moderate to Severe Traumatic Brain Injury in the Australian Context

BACKGROUND

The aim of this study was to develop a consensus-based set of indicators of high-quality acute moderate to severe traumatic brain injury (msTBI) clinical management that can be used to measure structure, process, and outcome factors that are likely to influence patient outcomes. This is the first stage of the PRECISION-TBI program, which is a prospective cohort study that aims to identify and promote optimal clinical management of msTBI in Australia.

METHODS

A preliminary set of 45 quality indicators was developed based on available evidence. An advisory committee of established experts in the field refined the initial indicator set in terms of content coverage, proportional representation, contamination, and supporting evidence. The refined indicator set was then distributed to a wider Delphi panel for assessment of each indicator in terms of validity, measurement feasibility, variability, and action feasibility. Inclusion in the final indicator set was contingent on prespecified inclusion scoring.

RESULTS

The indicator set was structured according to the care pathway of msTBI and included prehospital, emergency department, neurosurgical, intensive care, and rehabilitation indicators. Measurement domains included structure indicators, logistic indicators, and clinical management indicators. The Delphi panel consisted of 44 participants (84% physician, 12% nursing, and 4% primary research) with a median of 15 years of practice. Of the 47 indicators included in the second round of the Delphi, 32 indicators were approved by the Delphi group.

CONCLUSIONS

This study identified a set of 32 quality indicators that can be used to structure data collection to drive quality improvement in the clinical management of msTBI. They will also be used to guide feedback to PRECISION-TBI's participating sites.

Cerebral physiologic insult burden in acute traumatic neural injury: a Canadian High Resolution-TBI (CAHR-TBI) descriptive analysis

BACKGROUND

Over the recent decades, continuous multi-modal monitoring of cerebral physiology has gained increasing interest for its potential to help minimize secondary brain injury following moderate-to-severe acute traumatic neural injury (also termed traumatic brain injury; TBI). Despite this heightened interest, there has yet to be a comprehensive evaluation of the effects of derangements in multimodal cerebral physiology on global cerebral physiologic insult burden. In this study, we offer a multi-center descriptive analysis of the associations between deranged cerebral physiology and cerebral physiologic insult burden.

METHODS

Using data from the Canadian High-Resolution TBI (CAHR-TBI) Research Collaborative, a total of 369 complete patient datasets were acquired for the purposes of this study. For various cerebral physiologic metrics, patients were trichotomized into low, intermediate, and high cohorts based on mean values. Jonckheere-Terpstra testing was then used to assess for directional relationships between these cerebral physiologic metrics and various measures of cerebral physiologic insult burden. Contour plots were then created to illustrate the impact of preserved vs impaired cerebrovascular reactivity on these relationships.

RESULTS

It was found that elevated intracranial pressure (ICP) was associated with more time spent with cerebral perfusion pressure (CPP) < 60 mmHg and more time with impaired cerebrovascular reactivity. Low CPP was associated with more time spent with ICP > 20 or 22 mmHg and more time spent with impaired cerebrovascular reactivity. Elevated cerebrovascular reactivity indices were associated with more time spent with CPP < 60 mmHg as well as ICP > 20 or 22 mmHg. Low brain tissue oxygenation (PbtO2) only demonstrated a significant association with more time spent with CPP < 60 mmHg. Low regional oxygen saturation (rSO2) failed to produce a statistically significant association with any particular measure of cerebral physiologic insult burden.

CONCLUSIONS

Mean ICP, CPP and, cerebrovascular reactivity values demonstrate statistically significant associations with global cerebral physiologic insult burden; however, it is uncertain whether measures of oxygen delivery provide any significant insight into such insult burden.

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.

Intracranial Pressure Monitoring in Patients with Spontaneous Intracerebral Hemorrhage: A Systematic Review with Meta-Analysis

OBJECTIVE

To describe the potential effects of Intracranial pressure monitoring on the outcome of patients with spontaneous intracerebral hemorrhage (ICH).

METHODS

This study is a systematic review with meta-analysis. Patients with spontaneous ICH treated with intracranial pressure monitoring were included. The primary outcome was mortality at 6 months and in-hospital mortality. The secondary outcome was poor neurological function outcome at 6 months.

RESULTS

This analysis compares in-hospital and 6-month mortality rates between patients with intracranial pressure monitoring (ICPm) and those without (no ICPm). Although the ICPm group had a lower in-hospital mortality rate, it was not statistically significant (24.9% vs. 34.1%; OR 0.51, 95% CI 0.20 to 1.31, P = 0.16). Excluding patients with intraventricular hemorrhage revealed a significant reduction in in-hospital mortality for the ICPm group (23.5% vs. 43%; OR 0.39, 95% CI 0.29 to 0.53, P < 0.00001). For 6-month mortality, the ICPm group showed a significant reduction (32% vs. 39.6%; OR 0.76, 95% CI 0.61 to 0.94, P = 0.01), with the effect being more pronounced after excluding intraventricular hemorrhage patients (29.1% vs. 47.2%; OR 0.45, 95% CI 0.34 to 0.60, P < 0.0001). However, there were no statistically significant differences in 6-month functional outcomes between the groups. Increased ICP was associated with higher 3-month mortality (OR 1.12, 95% CI 1.07 to 1.18, P < 0.00001) and lower likelihood of good functional outcomes (OR 1.11, 95% CI 1.04 to 1.18, P < 0.00001).

CONCLUSIONS

Elevated ICP is associated with increased mortality and poor prognosis in ICH patients. Although continuous intracranial pressure monitoring may reduce short-term mortality rates in specific subgroups of ICH patients, it does not improve neurological functional outcomes. While potential patient populations may benefit from ICP monitoring, more research is needed to screen suitable populations for ICP monitoring.

Blood Pressure Management for Hypotensive Patients in Intensive Care and Perioperative Cardiovascular Settings

Blood pressure is a critical physiological parameter, particularly in the context of cardiac intensive care and perioperative settings. As a primary indicator of organ perfusion, the maintenance of adequate blood pressure is imperative for the assurance of sufficient tissue oxygen delivery. Among critically ill and major surgery patients, the continuous monitoring of blood pressure is performed as a standard practice for patients. Nonetheless, uncertainties remain regarding blood pressure goals, and there is no consensus regarding blood pressure targets. This review describes the determinants of blood pressure, examine the influence of blood pressure on organ perfusion, and synthesize the current clinical evidence from various intensive care and perioperative settings to provide a concise guidance for daily clinical practice.

Intracranial pressure monitoring in adult patients with traumatic brain injury: challenges and innovations

Intracranial pressure monitoring enables the detection and treatment of intracranial hypertension, a potentially lethal insult after traumatic brain injury. Despite its widespread use, robust evidence supporting intracranial pressure monitoring and treatment remains sparse. International studies have shown large variations between centres regarding the indications for intracranial pressure monitoring and treatment of intracranial hypertension. Experts have reviewed these two aspects and, by consensus, provided practical approaches for monitoring and treatment. Advances have occurred in methods for non-invasive estimation of intracranial pressure although, for now, a reliable way to non-invasively and continuously measure intracranial pressure remains aspirational. Analysis of the intracranial pressure signal can provide information on brain compliance (ie, the ability of the cranium to tolerate volume changes) and on cerebral autoregulation (ie, the ability of cerebral blood vessels to react to changes in blood pressure). The information derived from the intracranial pressure signal might allow for more individualised patient management. Machine learning and artificial intelligence approaches are being increasingly applied to intracranial pressure monitoring, but many obstacles need to be overcome before their use in clinical practice could be attempted. Robust clinical trials are needed to support indications for intracranial pressure monitoring and treatment. Progress in non-invasive assessment of intracranial pressure and in signal analysis (for targeted treatment) will also be crucial.

The Current Update of Conventional and Innovative Treatment Strategies for Central Nervous System Injury

This review explores the complex challenges and advancements in the treatment of traumatic brain injury (TBI) and spinal cord injury (SCI). Traumatic injuries to the central nervous system (CNS) trigger intricate pathophysiological responses, frequently leading to profound and enduring disabilities. This article delves into the dual phases of injury-primary impacts and the subsequent secondary biochemical cascades-that worsen initial damage. Conventional treatments have traditionally prioritized immediate stabilization, surgical interventions, and supportive medical care to manage both the primary and secondary damage associated with central nervous system injuries. We explore current surgical and medical management strategies, emphasizing the crucial role of rehabilitation and the promising potential of stem cell therapies and immune modulation. Advances in stem cell therapy, gene editing, and neuroprosthetics are revolutionizing treatment approaches, providing opportunities not just for recovery but also for the regeneration of impaired neural tissues. This review aims to emphasize emerging therapeutic strategies that hold promise for enhancing outcomes and improving the quality of life for affected individuals worldwide.

Impact of Intracranial Pressure and Invasive Cerebral Oxygenation Monitoring in Patients with Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Intracranial pressure (ICP) monitoring and monitoring of brain tissue oxygen (Pbto2) in addition to ICP have been used in the management of traumatic brain injury (TBI). However, the optimal monitoring method is inconclusive. We searched 4 databases with no language restrictions through January 2024 for peer-reviewed randomized controlled trials (RCTs) comparing ICP monitoring with combined Pbto2 and ICP monitoring in patients with traumatic brain injury. A favorable neurologic outcome was the primary outcome, and the secondary outcome was survival. Two reviewers screened manuscripts, extracted data, and assessed the risk of bias. We then performed a meta-analysis to assess efficacy using the Grading of Recommendations, Assessment, Development, and Evaluation working group approach. We included 5 trials comprising 512 patients. There was no difference in favorable neurologic outcome (risk ratio: 1.21; 95% confidence interval: 0.93, 1.58; I2: 45%; 5 RCTs: 512 patients; moderate certainty) and survival (risk ratio: 1.10; 95% confidence interval: 0.99, 1.21; I2: 13%; 5 RCTs: 512 patients; moderate certainty). We found no evidence that the combination of Pbto2 and ICP is more useful than ICP. The included RCTs are few and small, and further study is needed to draw conclusions.

Sedation Intensity in Patients with Moderate to Severe Traumatic Brain Injury in the Intensive Care Unit: A TRACK-TBI Cohort Study

BACKGROUND

Interventions to reduce intracranial pressure (ICP) in patients with traumatic brain injury (TBI) are multimodal but variable, including sedation-dosing strategies. This article quantifies the different sedation intensities administered in patients with moderate to severe TBI (msTBI) using the therapy intensity level (TIL) across different intensive care units (ICUs), including the use of additional ICP-lowering therapies.

METHODS

Within the prospective Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, we performed a retrospective analysis of adult patients with msTBI admitted to an ICU for a least 5 days from seven US level 1 trauma centers who received invasive ICP monitoring and intravenous sedation. Sedation intensity was classified prospectively as one of three ordinal levels as part of the validated TIL score, which were collected at least once a day.

RESULTS

A total of 127 patients met inclusion criteria (mean age 41.6 ± 17.7 years; 20% female). The median Injury Severity Score was 27 (interquartile range 17-33), with a median admission Glasgow Coma Score of 3 (interquartile range 3-7); 104 patients had severe TBI (82%), and 23 patients had moderate TBI (18%). The sedation intensity score was highest on the first ICU day (2.69 ± 1.78), independent of patient severity. Time to reaching each sedation intensity level varied by site. Sedation level I was reached within 24 h for all sites, but sedation levels II and III were reached variably between days 1 and 3. Sedation level III was never reached by two of seven sites. The total TIL score was highest on the first ICU day, with a modest decrease for each subsequent ICU day, but there was high site-specific practice-pattern variation.

CONCLUSIONS

Intensity of sedation and other therapies for elevated ICP for patients with msTBI demonstrate large practice-pattern variation across level 1 trauma centers within the TRACK-TBI cohort study, independent of patient severity. Optimizing sedation strategies using patient-specific physiologic and pathoanatomic information may optimize patient outcomes.

The Effect of Recruitment Maneuvers on Cerebrovascular Dynamics and Right Ventricular Function in Patients with Acute Brain Injury: A Single-Center Prospective Study

BACKGROUND

Optimization of ventilatory settings is challenging for patients in the neurointensive care unit, requiring a balance between precise gas exchange control, lung protection, and managing hemodynamic effects of positive pressure ventilation. Although recruitment maneuvers (RMs) may enhance oxygenation, they could also exert profound undesirable systemic impacts.

METHODS

The single-center, prospective study investigated the effects of RMs (up-titration of positive end-expiratory pressure) on multimodal neuromonitoring in patients with acute brain injury. Our primary focus was on intracranial pressure and secondarily on cerebral perfusion pressure (CPP) and other neurological parameters: cerebral autoregulation [pressure reactivity index (PRx)] and regional cerebral oxygenation (rSO2). We also assessed blood pressure and right ventricular (RV) function evaluated using tricuspid annular plane systolic excursion. Results are expressed as the difference (Δ) from baseline values obtained after completing the RMs.

RESULTS

Thirty-two patients were enrolled in the study. RMs resulted in increased intracranial pressure (Δ = 4.8 mm Hg) and reduced CPP (ΔCPP = -12.8 mm Hg) and mean arterial pressure (difference in mean arterial pressure = -5.2 mm Hg) (all p < 0.001). Cerebral autoregulation worsened (ΔPRx = 0.31 a.u.; p < 0.001). Despite higher systemic oxygenation (difference in partial pressure of O2 = 4 mm Hg; p = 0.001) and unchanged carbon dioxide levels, rSO2 marginally decreased (ΔrSO2 = -0.5%; p = 0.031), with a significant drop in arterial content and increase in the venous content. RV systolic function decreased (difference in tricuspid annular plane systolic excursion = -0.1 cm; p < 0.001) with a tendency toward increased RV basal diameter (p = 0.06). Grouping patients according to ΔCPP or ΔPRx revealed that those with poorer tolerance to RMs had higher CPP (p = 0.040) and a larger RV basal diameter (p = 0.034) at baseline.

CONCLUSIONS

In patients with acute brain injury, RMs appear to have adverse effects on cerebral hemodynamics. These findings might be partially explained by RM's impact on RV function. Further advanced echocardiography monitoring is required to prove this hypothesis.

Impact of Therapeutic Interventions on Cerebral Autoregulatory Function Following Severe Traumatic Brain Injury: A Secondary Analysis of the BOOST-II Study

BACKGROUND

The Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II randomized controlled trial used a tier-based management protocol based on brain tissue oxygen (PbtO2) and intracranial pressure (ICP) monitoring to reduce brain tissue hypoxia after severe traumatic brain injury. We performed a secondary analysis to explore the relationship between brain tissue hypoxia, blood pressure (BP), and interventions to improve cerebral perfusion pressure (CPP). We hypothesized that BP management below the lower limit of autoregulation would lead to cerebral hypoperfusion and brain tissue hypoxia that could be improved with hemodynamic augmentation.

METHODS

Of the 119 patients enrolled in the Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II trial, 55 patients had simultaneous recordings of arterial BP, ICP, and PbtO2. Autoregulatory function was measured by interrogating changes in ICP and PbtO2 in response to fluctuations in CPP using time-correlation analysis. The resulting autoregulatory indices (pressure reactivity index and oxygen reactivity index) were used to identify the "optimal" CPP and limits of autoregulation for each patient. Autoregulatory function and percent time with CPP outside personalized limits of autoregulation were calculated before, during, and after all interventions directed to optimize CPP.

RESULTS

Individualized limits of autoregulation were computed in 55 patients (mean age 38 years, mean monitoring time 92 h). We identified 35 episodes of brain tissue hypoxia (PbtO2 < 20 mm Hg) treated with CPP augmentation. Following each intervention, mean CPP increased from 73 ± 14 mm Hg to 79 ± 17 mm Hg (p = 0.15), and mean PbtO2 improved from 18.4 ± 5.6 mm Hg to 21.9 ± 5.6 mm Hg (p = 0.01), whereas autoregulatory function trended toward improvement (oxygen reactivity index 0.42 vs. 0.37, p = 0.14; pressure reactivity index 0.25 vs. 0.21, p = 0.2). Although optimal CPP and limits remained relatively unchanged, there was a significant decrease in the percent time with CPP below the lower limit of autoregulation in the 60 min after compared with before an intervention (11% vs. 23%, p = 0.05).

CONCLUSIONS

Our analysis suggests that brain tissue hypoxia is associated with cerebral hypoperfusion characterized by increased time with CPP below the lower limit of autoregulation. Interventions to increase CPP appear to improve autoregulation. Further studies are needed to validate the importance of autoregulation as a modifiable variable with the potential to improve outcomes.

Prediction of neurocritical care intensity through automated infrared pupillometry and transcranial doppler in blunt traumatic brain injury: the NOPE study

PURPOSE

This pilot study aimed to determine the capacity of automated infrared pupillometry (AIP) alone and in combination with transcranial doppler (TCD) on admission to rule out need for intense neuroAQ2 critical care (INCC) in severe traumatic brain injury (TBI).

METHODS

In this observational pilot study clinicians performed AIP and TCD measurements on admission in blunt TBI patients with a Glasgow Coma Score (GCS) < 9 and/or motor score < 6. A Neurological Pupil index (NPi) < 3, Pulsatility Index (PI) > 1,4 or diastolic blood flow velocity (dV) of < 20 cm/s were used to rule out the need for INCC (exceeding the tier 0 Seattle Consensus Conference). The primary outcome was the negative likelihood ratio (nLR) of NPi < 3 alone or in combination with TCD to detect need for INCC.

RESULTS

A total of 69 TBI patients were included from May 2019 to September 2020. Of those, 52/69 (75%) median age was 45 [28-67], median prehospital GCS of 7 [5-8], median Injury Severity Scale of 13.0 [6.5-25.5], median Marshall Score of 4 [3-5], the median Glasgow Outcome Scale at discharge was 3 [1-5]. NPi < 3 was an independent predictor of INCC. NPi demonstrated a nLR of 0,6 (95%CI 0.4-0.9; AUROC, 0.65, 95% CI 0.51-0.79), a combination of NPi and TCD showed a nLR of 0.6 (95% CI 0.4-1.0; AUROC 0.67 95% CI 0.52-0.83) to predict INCC.

CONCLUSION

This pilot study suggests a possible useful contribution of NPi to determine the need for INCC in severe blunt TBI patients on admission.

Safety and Effect on Intracranial Pressure of 3% Hypertonic Saline Bolus Via Peripheral Intravenous Catheter for Neurological Emergencies

BACKGROUND

Elevated intracranial pressure (ICP) is a neurological emergency in patients with acute brain injuries. Such a state requires immediate and effective interventions to prevent potential neurological deterioration. Current clinical guidelines recommend hypertonic saline (HTS) and mannitol as first-line therapeutic agents. Notably, HTS is conventionally administered through central venous catheters (CVCs), which may introduce delays in treatment due to the complexities associated with CVC placement. These delays can critically affect patient outcomes, necessitating the exploration of more rapid therapeutic avenues. This study aimed to investigate the safety and effect on ICP of administering rapid boluses of 3% HTS via peripheral intravenous (PIV) catheters.

METHODS

A retrospective cohort study was performed on patients admitted to Sisters of Saint Mary Health Saint Louis University Hospital from March 2019 to September 2022 who received at least one 3% HTS bolus via PIV at a rate of 999 mL/hour for neurological emergencies. Outcomes assessed included complications related to 3% HTS bolus and its effect on ICP.

RESULTS

Of 216 3% HTS boluses administered in 124 patients, complications occurred in 8 administrations (3.7%). Pain at the injection site (4 administrations; 1.9%) and thrombophlebitis (3 administrations; 1.4%) were most common. The median ICP reduced by 6 mm Hg after 3% HTS bolus administration (p < 0.001).

CONCLUSIONS

Rapid bolus administration of 3% HTS via PIV catheters presents itself as a relatively safe approach to treat neurological emergencies. Its implementation could provide an invaluable alternative to the traditional CVC-based administration, potentially minimizing CVC-associated complications and expediting life-saving interventions for patients with neurological emergencies, especially in the field and emergency department settings.

Acute Management of Moderate to Severe Traumatic Brain Injury

The focus of this article is on the acute management of traumatic brain injury. The article focuses on the classification of traumatic brain injury, general acute management of traumatic brain injury, the role of the physiatrist on this team, and lastly, behavioral and family considerations in the acute care setting. The article includes a focus on physiologic systems, strategies for the management of various aspects of brain injury, and consideration of factors associated with the continuum of care. Overall, the article reviews this critical period of brain injury recovery and provides a primer for the physiatrist.

Short-term mild hyperventilation on intracranial pressure, cerebral autoregulation, and oxygenation in acute brain injury patients: a prospective observational study

Current guidelines suggest a target of partial pressure of carbon dioxide (PaCO2) of 32-35 mmHg (mild hypocapnia) as tier 2 for the management of intracranial hypertension. However, the effects of mild hyperventilation on cerebrovascular dynamics are not completely elucidated. The aim of this study is to evaluate the changes of intracranial pressure (ICP), cerebral autoregulation (measured through pressure reactivity index, PRx), and regional cerebral oxygenation (rSO2) parameters before and after induction of mild hyperventilation. Single center, observational study including patients with acute brain injury (ABI) admitted to the intensive care unit undergoing multimodal neuromonitoring and requiring titration of PaCO2 values to mild hypocapnia as tier 2 for the management of intracranial hypertension. Twenty-five patients were included in this study (40% female), median age 64.7 years (Interquartile Range, IQR = 45.9-73.2). Median Glasgow Coma Scale was 6 (IQR = 3-11). After mild hyperventilation, PaCO2 values decreased (from 42 (39-44) to 34 (32-34) mmHg, p < 0.0001), ICP and PRx significantly decreased (from 25.4 (24.1-26.4) to 17.5 (16-21.2) mmHg, p < 0.0001, and from 0.32 (0.1-0.52) to 0.12 (-0.03-0.23), p < 0.0001). rSO2 was statistically but not clinically significantly reduced (from 60% (56-64) to 59% (54-61), p < 0.0001), but the arterial component of rSO2 (ΔO2Hbi, changes in concentration of oxygenated hemoglobin of the total rSO2) decreased from 3.83 (3-6.2) μM.cm to 1.6 (0.5-3.1) μM.cm, p = 0.0001. Mild hyperventilation can reduce ICP and improve cerebral autoregulation, with minimal clinical effects on cerebral oxygenation. However, the arterial component of rSO2 was importantly reduced. Multimodal neuromonitoring is essential when titrating PaCO2 values for ICP management.

From ICU Syndromes to ICU Subphenotypes: Consensus Report and Recommendations for Developing Precision Medicine in the ICU

Critical care uses syndromic definitions to describe patient groups for clinical practice and research. There is growing recognition that a "precision medicine" approach is required and that integrated biologic and physiologic data identify reproducible subpopulations that may respond differently to treatment. This article reviews the current state of the field and considers how to successfully transition to a precision medicine approach. To impact clinical care, identification of subpopulations must do more than differentiate prognosis. It must differentiate response to treatment, ideally by defining subgroups with distinct functional or pathobiological mechanisms (endotypes). There are now multiple examples of reproducible subpopulations of sepsis, acute respiratory distress syndrome, and acute kidney or brain injury described using clinical, physiological, and/or biological data. Many of these subpopulations have demonstrated the potential to define differential treatment response, largely in retrospective studies, and that the same treatment-responsive subpopulations may cross multiple clinical syndromes (treatable traits). To bring about a change in clinical practice, a precision medicine approach must be evaluated in prospective clinical studies requiring novel adaptive trial designs. Several such studies are underway, but there are multiple challenges to be tackled. Such subpopulations must be readily identifiable and be applicable to all critically ill populations around the world. Subdividing clinical syndromes into subpopulations will require large patient numbers. Global collaboration of investigators, clinicians, industry, and patients over many years will therefore be required to transition to a precision medicine approach and ultimately realize treatment advances seen in other medical fields.

Random forest-based prediction of intracranial hypertension in patients with traumatic brain injury

BACKGROUND

Treatment and prevention of intracranial hypertension (IH) to minimize secondary brain injury are central to the neurocritical care management of traumatic brain injury (TBI). Predicting the onset of IH in advance allows for a more aggressive prophylactic treatment. This study aimed to develop random forest (RF) models for predicting IH events in TBI patients.

METHODS

We analyzed prospectively collected data from patients admitted to the intensive care unit with invasive intracranial pressure (ICP) monitoring. Patients with persistent ICP > 22 mmHg in the early postoperative period (first 6 h) were excluded to focus on IH events that had not yet occurred. ICP-related data from the initial 6 h were used to extract linear (ICP, cerebral perfusion pressure, pressure reactivity index, and cerebrospinal fluid compensatory reserve index) and nonlinear features (complexity of ICP and cerebral perfusion pressure). IH was defined as ICP > 22 mmHg for > 5 min, and severe IH (SIH) as ICP > 22 mmHg for > 1 h during the subsequent ICP monitoring period. RF models were then developed using baseline characteristics (age, sex, and initial Glasgow Coma Scale score) along with linear and nonlinear features. Fivefold cross-validation was performed to avoid overfitting.

RESULTS

The study included 69 patients. Forty-three patients (62.3%) experienced an IH event, of whom 30 (43%) progressed to SIH. The median time to IH events was 9.83 h, and to SIH events, it was 11.22 h. The RF model showed acceptable performance in predicting IH with an area under the curve (AUC) of 0.76 and excellent performance in predicting SIH (AUC = 0.84). Cross-validation analysis confirmed the stability of the results.

CONCLUSIONS

The presented RF model can forecast subsequent IH events, particularly severe ones, in TBI patients using ICP data from the early postoperative period. It provides researchers and clinicians with a potentially predictive pathway and framework that could help triage patients requiring more intensive neurological treatment at an early stage.

[Current Aspects of Intensive Medical Care for Traumatic Brain Injury - Part 1 - Primary Treatment Strategies, Haemodynamic Management and Multimodal Monitoring]

This two-part article deals with the intensive medical care of traumatic brain injury. Part 1 addresses the primary treatment strategy, haemodynamic management and multimodal monitoring, Part 2 secondary treatment strategies, long-term outcome, neuroprognostics and chronification. Traumatic brain injury is a complex clinical entity with a high mortality rate. The primary aim is to maintain homeostasis based on physiological targeted values. In addition, further therapy must be geared towards intracranial pressure. In addition to this, there are other monitoring options that appear sensible from a pathophysiological point of view with appropriate therapy adjustment. However, there is still a lack of data on their effectiveness. A further aspect is the inflammation of the cerebrum with the "cross-talk" of the organs, which has a significant influence on further intensive medical care.

From spreading depolarization to blood-brain barrier dysfunction: navigating traumatic brain injury for novel diagnosis and therapy

Considerable strides in medical interventions during the acute phase of traumatic brain injury (TBI) have brought improved overall survival rates. However, following TBI, people often face ongoing, persistent and debilitating long-term complications. Here, we review the recent literature to propose possible mechanisms that lead from TBI to long-term complications, focusing particularly on the involvement of a compromised blood-brain barrier (BBB). We discuss evidence for the role of spreading depolarization as a key pathological mechanism associated with microvascular dysfunction and the transformation of astrocytes to an inflammatory phenotype. Finally, we summarize new predictive and diagnostic biomarkers and explore potential therapeutic targets for treating long-term complications of TBI.

Early Intravenous Beta-Blockade with Esmolol in Adults with Severe Traumatic Brain Injury: A Phase 2a Intervention Design Study

BACKGROUND

Targeted beta-blockade after severe traumatic brain injury may reduce secondary brain injury by attenuating the sympathoadrenal response. The potential role and optimal dosage for esmolol, a selective, short-acting, titratable beta-1 beta-blocker, as a safe, putative early therapy after major traumatic brain injury has not been assessed.

METHODS

We conducted a single-center, open-label dose-finding study using an adaptive model-based design. Adults (18 years or older) with severe traumatic brain injury and intracranial pressure monitoring received esmolol within 24 h of injury to reduce their heart rate by 15% from baseline of the preceding 4 h while ensuring cerebral perfusion pressure was maintained above 60 mm Hg. In cohorts of three, the starting dosage and dosage increments were escalated according to a prespecified plan in the absence of dose-limiting toxicity. Dose-limiting toxicity was defined as failure to maintain cerebral perfusion pressure, triggering cessation of esmolol infusion. The primary outcome was the maximum tolerated dosage schedule of esmolol, defined as that associated with less than 10% probability of dose-limiting toxicity. Secondary outcomes include 6-month mortality and 6-month extended Glasgow Outcome Scale score.

RESULTS

Sixteen patients (6 [37.5%] female patients; mean age 36 years [standard deviation 13 years]) with a median Glasgow Coma Scale score of 6.5 (interquartile range 5-7) received esmolol. The optimal starting dosage of esmolol was 10 μg/kg/min, with increments every 30 min of 5 μg/kg/min, as it was the highest dosage with less than 10% estimated probability of dose-limiting toxicity (7%). All-cause mortality was 12.5% at 6 months (corresponding to a standardized mortality ratio of 0.63). One dose-limiting toxicity event and no serious adverse hemodynamic effects were seen.

CONCLUSIONS

Esmolol administration, titrated to a heart rate reduction of 15%, is feasible within 24 h of severe traumatic brain injury. The probability of dose-limiting toxicity requiring withdrawal of esmolol when using the optimized schedule is low. Trial registrationI SRCTN, ISRCTN11038397, registered retrospectively January 7, 2021 ( https://www.isrctn.com/ISRCTN11038397 ).

The Effects of Head Elevation on Intracranial Pressure, Cerebral Perfusion Pressure, and Cerebral Oxygenation Among Patients with Acute Brain Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Head elevation is recommended as a tier zero measure to decrease high intracranial pressure (ICP) in neurocritical patients. However, its quantitative effects on cerebral perfusion pressure (CPP), jugular bulb oxygen saturation (SjvO2), brain tissue partial pressure of oxygen (PbtO2), and arteriovenous difference of oxygen (AVDO2) are uncertain. Our objective was to evaluate the effects of head elevation on ICP, CPP, SjvO2, PbtO2, and AVDO2 among patients with acute brain injury.

METHODS

We conducted a systematic review and meta-analysis on PubMed, Scopus, and Cochrane Library of studies comparing the effects of different degrees of head elevation on ICP, CPP, SjvO2, PbtO2, and AVDO2.

RESULTS

A total of 25 articles were included in the systematic review. Of these, 16 provided quantitative data regarding outcomes of interest and underwent meta-analyses. The mean ICP of patients with acute brain injury was lower in group with 30° of head elevation than in the supine position group (mean difference [MD] - 5.58 mm Hg; 95% confidence interval [CI] - 6.74 to - 4.41 mm Hg; p < 0.00001). The only comparison in which a greater degree of head elevation did not significantly reduce the ICP was 45° vs. 30°. The mean CPP remained similar between 30° of head elevation and supine position (MD - 2.48 mm Hg; 95% CI - 5.69 to 0.73 mm Hg; p = 0.13). Similar findings were observed in all other comparisons. The mean SjvO2 was similar between the 30° of head elevation and supine position groups (MD 0.32%; 95% CI - 1.67% to 2.32%; p = 0.75), as was the mean PbtO2 (MD - 1.50 mm Hg; 95% CI - 4.62 to 1.62 mm Hg; p = 0.36), and the mean AVDO2 (MD 0.06 µmol/L; 95% CI - 0.20 to 0.32 µmol/L; p = 0.65).The mean ICP of patients with traumatic brain injury was also lower with 30° of head elevation when compared to the supine position. There was no difference in the mean values of mean arterial pressure, CPP, SjvO2, and PbtO2 between these groups.

CONCLUSIONS

Increasing degrees of head elevation were associated, in general, with a lower ICP, whereas CPP and brain oxygenation parameters remained unchanged. The severe traumatic brain injury subanalysis found similar results.

Reliability and variability of pressure reactivity index (prx) during oscillatory pattern in arterial blood pressure and intracranial pressure in traumatic brain injured patients

Introduction

Pressure reactivity index (PRx) is used for continuous monitoring of cerebrovascular reactivity in traumatic brain injury (TBI). However, PRx has a noisy character. Oscillations in arterial blood pressure (ABP) introduced by cyclic positive end-expiratory pressure adjustment, can make PRx more reliable. However, if oscillations are introduced by the cycling process of an anti-decubitus-mattress the effect on PRx is confounding, as they affect directly also intracranial pressure (ICP). In our routine monitoring in TBI patients we noticed periods of highly regular, slow, spontaneous oscillations in ABP and ICP signals.

Research question

We set out to explore the nature of these oscillations and establish if PRx remains reliable during the oscillations.

Materials and methods

10 TBI patients' recordings with oscillations in ICP and ABP were analysed. We computed PRx, PRx variability (hourly-average of standard-deviation, SD), phase-shift and coherence between ABP and ICP in the slow frequency range. Metrics were compared between oscillation and peri-oscillation periods.

Results

During oscillations (frequency 0.006 ± 0.002Hz), a significantly lower variability of PRx (SD 0.185vs0.242) and higher coherence ABP-ICP (0.618 ± 0.09 vs 0.534 ± 0.09) were observed. No external oscillations sources could be identified. 34 out of 48 events showed signs of 'active' transmission associated with negative PRx, indicating a potential positive impact on PRx reliability.

Discussion and conclusions

Spontaneous oscillations observed in ABP and ICP signals were found to enhance rather than confound PRx reliability. Further research is warranted to elucidate the nature of these oscillations and develop strategies to leverage them for enhancing PRx reliability in TBI monitoring.

Intracranial Hypertension with Patent Basal Cisterns: Controlled Lumbar Drainage as a Therapeutic Option. Selected Case Series

BACKGROUND

There are pathological conditions in which intracranial hypertension and patent basal cisterns in computed tomography coexist. These situations are not well recognized, which could lead to diagnostic errors and improper management.

METHODS

We present a retrospective case series of patients with traumatic brain injury, subarachnoid hemorrhage, and cryptococcal meningitis who were treated at our intensive care unit. Criteria for deciding placement of an external lumbar drain were (1) intracranial hypertension refractory to osmotherapy, hyperventilation, neuromuscular blockade, intravenous anesthesia, and, in some cases, decompressive craniectomy and (2) a computed tomography scan that showed open basal cisterns and no mass lesion.

RESULTS

Eleven patients were studied. Six of the eleven patients treated with controlled lumbar drainage are discussed as illustrative cases. All patients developed intracranial hypertension refractory to maximum medical treatment, including decompressive craniectomy in Four of the eleven cases. Controlled external lumbar drainage led to immediate and sustained control of elevated intracranial pressure in all patients, with good neurological outcomes. No brain herniation, intracranial bleeding, or meningitis was detected during this procedure.

CONCLUSIONS

Our study provides preliminary evidence that in selected patients who develop refractory intracranial hypertension with patent basal cisterns and no focal mass effect on computed tomography, controlled lumbar drainage appears to be a therapeutic option. In our study there were no deaths or complications. Prospective and larger studies are needed to confirm our results.

Management of traumatic brain injury in Africa: challenges and opportunities

Traumatic brain injury (TBI) is a major public health concern globally, with significant implications for morbidity, mortality, and long-term disability. While extensive research has been conducted on TBI management in high-income countries, limited attention has been given to the specific challenges and opportunities faced by healthcare systems in sub-Saharan Africa (SSA). This perspective study aims to provide a comprehensive overview of the current status of TBI management in SSA, focusing on the unique challenges and potential opportunities for improvement. The findings highlight several key challenges faced by SSA healthcare systems in managing TBIs, including limited resources, inadequate infrastructure, and a shortage of trained healthcare professionals. Furthermore, social and cultural factors, such as ignorance of driving laws, financial constraints, and limited access to modern technology services. However, the study also identifies potential opportunities for improving TBI management in SSA. These include strengthening healthcare infrastructure, enhancing pre-hospital care and transportation systems, and increasing public awareness and education about TBI. This perspective study emphasizes the urgent need for tailored interventions and strategies to address the unique challenges faced by SSA in managing TBIs. Addressing the challenges and opportunities in brain injury management in SSA requires a comprehensive approach which can be through investing in health infrastructure, addressing socio-economic inequalities, implementing prevention strategies, and fostering evidence-based research collaboration. Through this, the region can significantly improve TBI care and outcomes, thereby improving the well-being of people affected by TBI in SSA.

Isolated Traumatic Subarachnoid Hemorrhage on Head Computed Tomography Scan May Not Be Isolated: A Transforming Research and Clinical Knowledge in Traumatic Brain Injury Study (TRACK-TBI) Study

Isolated traumatic subarachnoid hemorrhage (tSAH) after traumatic brain injury (TBI) on head computed tomography (CT) scan is often regarded as a "mild" injury, with reduced need for additional workup. However, tSAH is also a predictor of incomplete recovery and unfavorable outcome. This study aimed to evaluate the characteristics of CT-occult intracranial injuries on brain magnetic resonance imaging (MRI) scan in TBI patients with emergency department (ED) arrival Glasgow Coma Scale (GCS) score 13-15 and isolated tSAH on CT. The prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury Study (TRACK-TBI; enrollment years 2014-2019) enrolled participants who presented to the ED and received a clinically-indicated head CT within 24 h of TBI. A subset of TRACK-TBI participants underwent venipuncture within 24 h for plasma glial fibrillary acidic protein (GFAP) analysis, and research MRI at 2-weeks post-injury. In the current study, TRACK-TBI participants age ≥17 years with ED arrival GCS 13-15, isolated tSAH on initial head CT, plasma GFAP level, and 2-week MRI data were analyzed. In 57 participants, median age was 46.0 years [quartile 1 to 3 (Q1-Q3): 34-57] and 52.6% were male. At ED disposition, 12.3% were discharged home, 61.4% were admitted to hospital ward, and 26.3% to intensive care unit. MRI identified CT-occult traumatic intracranial lesions in 45.6% (26 of 57 participants; one additional lesion type: 31.6%; 2 additional lesion types: 14.0%); of these 26 participants with CT-occult intracranial lesions, 65.4% had axonal injury, 42.3% had subdural hematoma, and 23.1% had intracerebral contusion. GFAP levels were higher in participants with CT-occult MRI lesions compared with without (median: 630.6 pg/mL, Q1-Q3: [172.4-941.2] vs. 226.4 [105.8-436.1], p = 0.049), and were associated with axonal injury (no: median 226.7 pg/mL [109.6-435.1], yes: 828.6 pg/mL [204.0-1194.3], p = 0.009). Our results indicate that isolated tSAH on head CT is often not the sole intracranial traumatic injury in GCS 13-15 TBI. Forty-six percent of patients in our cohort (26 of 57 participants) had additional CT-occult traumatic lesions on MRI. Plasma GFAP may be an important biomarker for the identification of additional CT-occult injuries, including axonal injury. These findings should be interpreted cautiously given our small sample size and await validation from larger studies.

Temperature Control in Acute Brain Injury: An Update

Temperature control in severe acute brain injury (SABI) is a key component of acute management. This manuscript delves into the complex role of temperature management in SABI, encompassing conditions like traumatic brain injury (TBI), acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), aneurysmal subarachnoid hemorrhage (aSAH), and hypoxemic/ischemic brain injury following cardiac arrest. Fever is a common complication in SABI and is linked to worse neurological outcomes due to increased inflammatory responses and intracranial pressure (ICP). Temperature management, particularly hypothermic temperature control (HTC), appears to mitigate these adverse effects primarily by reducing cerebral metabolic demand and dampening inflammatory pathways. However, the effectiveness of HTC varies across different SABI conditions. In the context of post-cardiac arrest, the impact of HTC on neurological outcomes has shown inconsistent results. In cases of TBI, HTC seems promising for reducing ICP, but its influence on long-term outcomes remains uncertain. For AIS, clinical trials have yet to conclusively demonstrate the benefits of HTC, despite encouraging preclinical evidence. This variability in efficacy is also observed in ICH, aSAH, bacterial meningitis, and status epilepticus. In pediatric and neonatal populations, while HTC shows significant benefits in hypoxic-ischemic encephalopathy, its effectiveness in other brain injuries is mixed. Although the theoretical basis for employing temperature control, especially HTC, is strong, the clinical outcomes differ among various SABI subtypes. The current consensus indicates that fever prevention is beneficial across the board, but the application and effectiveness of HTC are more nuanced, underscoring the need for further research to establish optimal temperature management strategies. Here we provide an overview of the clinical evidence surrounding the use of temperature control in various types of SABI.

Inaugural State of the Union: Continuous Cerebral Autoregulation Monitoring in the Clinical Practice of Neurocritical Care and Anesthesia

How continuous cerebral autoregulation (CCA) knowledge should be optimally gained and interpreted is still an active area of research and refinement. We now experience a unique situation of having indices clinically available before definitive evidence of benefit or practice guidelines, in a moment when high rates of institutional variability exist both in the application of monitoring as well as in monitoring-guided treatments. Responses from 47 international clinicians, experts in this field, were collected with polling and discussion of the results. The clinical use of CCA in critical illness was not universal among experts, with 34% not using it. Of those who use a CCA index in clinical practice, 64% use intracranial pressure-based Pressure Reactivity index (PRx). There seems to exist a considerable trust in the physiologic plausibility of CCA to guide individual arterial blood pressure and cerebral perfusion pressure therapy and provide benefit, regardless of the difficulty of proving this. A total of 59% feel the need for phase II and III prospective studies but would continue to use CCA information in their practice even if randomized controlled trials (RCTs) did not show clear clinical benefit. There was nearly universal interest to participate in an RCT, with agreement that the research community must together determine end points and interventions to reduce wasted effort and time, and that investigations should include the following: the most appropriate way of inclusion of CCA into the clinical workflow; whether CCA-guided interventions should be prophylactic, proactive; or reactive; and whether a CCA-centric (unimodal) or a multimodal monitoring-integrated tiered therapy approach should be adopted. Pediatric and neonatal populations were highlighted as having urgent need and even more plausibility than adults. On the whole, the initiative was enthusiastically embraced by the experts, with the general feeling that a strong push should be now made by the community to convert the plausible benefits of CCA monitoring, already implemented in some centers, into a more standardized and RCT-validated clinical reality.

Effects of closed loop ventilation on ventilator settings, patient outcomes and ICU staff workloads - a systematic review

BACKGROUND

Lung protective ventilation is considered standard of care in the intensive care unit. However, modifying the ventilator settings can be challenging and is time consuming. Closed loop modes of ventilation are increasingly attractive for use in critically ill patients. With closed loop ventilation, settings that are typically managed by the ICU professionals are under control of the ventilator's algorithms.

OBJECTIVES

To describe the effectiveness, safety, efficacy and workload with currently available closed loop ventilation modes.

DESIGN

Systematic review of randomised clinical trials.

DATA SOURCES

A comprehensive systematic search in PubMed, Embase and the Cochrane Central register of Controlled Trials search was performed in January 2023.

ELIGIBILITY CRITERIA

Randomised clinical trials that compared closed loop ventilation with conventional ventilation modes and reported on effectiveness, safety, efficacy or workload.

RESULTS

The search identified 51 studies that met the inclusion criteria. Closed loop ventilation, when compared with conventional ventilation, demonstrates enhanced management of crucial ventilator variables and parameters essential for lung protection across diverse patient cohorts. Adverse events were seldom reported. Several studies indicate potential improvements in patient outcomes with closed loop ventilation; however, it is worth noting that these studies might have been underpowered to conclusively demonstrate such benefits. Closed loop ventilation resulted in a reduction of various aspects associated with the workload of ICU professionals but there have been no studies that studied workload in sufficient detail.

CONCLUSIONS

Closed loop ventilation modes are at least as effective in choosing correct ventilator settings as ventilation performed by ICU professionals and have the potential to reduce the workload related to ventilation. Nevertheless, there is a lack of sufficient research to comprehensively assess the overall impact of these modes on patient outcomes, and on the workload of ICU staff.

Traumatic Brain Injury and Traumatic Spinal Cord Injury

OBJECTIVE

This article reviews the mechanisms of primary traumatic injury to the brain and spinal cord, with an emphasis on grading severity, identifying surgical indications, anticipating complications, and managing secondary injury.

LATEST DEVELOPMENTS

Serum biomarkers have emerged for clinical decision making and prognosis after traumatic injury. Cortical spreading depolarization has been identified as a potentially modifiable mechanism of secondary injury after traumatic brain injury. Innovative methods to detect covert consciousness may inform prognosis and enrich future studies of coma recovery. The time-sensitive nature of spinal decompression is being elucidated.

ESSENTIAL POINTS

Proven management strategies for patients with severe neurotrauma in the intensive care unit include surgical decompression when appropriate, the optimization of perfusion, and the anticipation and treatment of complications. Despite validated models, predicting outcomes after traumatic brain injury remains challenging, requiring prognostic humility and a model of shared decision making with surrogate decision makers to establish care goals. Penetrating injuries, especially gunshot wounds, are often devastating and require public health and policy approaches that target prevention.

Temperature management in acute brain injury: A narrative review

Temperature management has been used in patients with acute brain injury resulting from different conditions, such as post-cardiac arrest hypoxic-ischaemic insult, acute ischaemic stroke, and severe traumatic brain injury. However, current evidence offers inconsistent and often contradictory results regarding the clinical benefit of this therapeutic strategy on mortality and functional outcomes. Current guidelines have focused mainly on active prevention and treatment of fever, while therapeutic hypothermia (TH) has fallen into disuse, although doubts persist as to its effectiveness according to the method of application and appropriate patient selection. This narrative review presents the most relevant clinical evidence on the effects of TH in patients with acute neurological damage, and the pathophysiological concepts supporting its use.

Assessment of depth of sedation using Bispectral Index™ monitoring in patients with severe traumatic brain injury in UK intensive care units

Introduction

Severe traumatic brain injury affects ∼4500 per year across the UK. Most patients undergo a period of sedation to prevent secondary brain injury, however the optimal sedation target is unclear. This study aimed to assess the relationship between the electroencephalogram (EEG)-based Bispectral Index™ (BIS™) value and the clinical sedation score, along with other clinical outcomes.

Methods

Patients with severe traumatic brain injury in four UK ICUs were recruited to have blinded BIS data collected for a 24-h period while sedated on the ICU. Drug, physiological, and outcome data were recorded from the ICU record. Sedation management was at the discretion of the ICU clinical team.

Results

Twenty-six participants were recruited to the study. The mean BIS was 38 (inter-quartile range 29-44) and there was poor correlation between BIS and sedation score as a group (correlation coefficient 0.17, 95% confidence interval 0.08-0.26), however the spread in BIS values increased with decreasing sedation score. There was no statistically significant relationship between BIS and intracranial pressure, vasopressor use, osmotherapy use, or need for an additional sedative.

Conclusion

This study supports previous work showing that BIS decreases with decreasing sedation score. However, the variation in BIS values increased with deeper levels of clinical sedation. Patients may not be benefiting from the full potential of sedation in traumatic brain injury and further studies of sedation titrated to an EEG-based parameter are needed.

Clinical trial registration

NCT03575169.

Complications of Intracranial Multimodal Monitoring for Neurocritical Care: A Systematic Review and Meta-Analysis

Intracranial multimodal monitoring (iMMM) is increasingly used for neurocritical care. However, concerns arise regarding iMMM invasiveness considering limited evidence in its clinical significance and safety profile. We conducted a synthesis of evidence regarding complications associated with iMMM to delineate its safety profile. We performed a systematic review and meta-analysis (PROSPERO Registration Number: CRD42021225951) according to the Preferred Reporting Items for Systematic Review and Meta-Analysis and Peer Review of Electronic Search Strategies guidelines to retrieve evidence from studies reporting iMMM use in humans that mention related complications. We assessed risk of bias using the Newcastle-Ottawa Scale and funnel plots. The primary outcomes were iMMM complications. The secondary outcomes were putative risk factors. Of the 366 screened articles, 60 met the initial criteria and were further assessed by full-text reading. We included 22 studies involving 1206 patients and 1434 iMMM placements. Most investigators used a bolt system (85.9%) and a three-lumen device (68.8%), mainly inserting iMMM into the most injured hemisphere (77.9%). A total of 54 postoperative intracranial hemorrhages (pooled rate of 4%; 95% confidence interval [CI] 0-10%; I2 86%, p < 0.01 [random-effects model]) was reported, along with 46 misplacements (pooled rate of 6%; 95% CI 1-12%; I2 78%, p < 0.01) and 16 central nervous system infections (pooled rate of 0.43%; 95% CI 0-2%; I2 64%, p < 0.01). We found 6 system breakings, 18 intracranial bone fragments, and 5 cases of pneumocephalus. Currently, iMMM systems present a similar safety profile as intracranial devices commonly used in neurocritical care. Long-term outcomes of prospective studies will complete the benefit-risk assessment of iMMM in neurocritical care. Consensus-based reporting guidelines on iMMM use are needed to bolster future collaborative efforts.

The Origin of the Burst-Suppression Paradigm in Treatment of Status Epilepticus

After electroencephalography (EEG) was introduced in hospitals, early literature recognized burst-suppression pattern (BSP) as a distinctive EEG pattern characterized by intermittent high-power oscillations alternating with isoelectric periods in coma and epileptic encephalopathies of childhood or the pattern could be induced by general anesthesia and hypothermia. The term was introduced by Swank and Watson in 1949 but was initially described by Derbyshire et al. in 1936 in their study about the anesthetic effects of tribromoethanol. Once the EEG/BSP pattern emerged in the literature as therapeutic goal in refractory status epilepticus, researchers began exploring whether the depth of EEG suppression correlated with improved seizure control and clinical outcomes. We can conclude that, from a historical perspective, the evidence to suppress the brain to a BSP when treating status epilepticus is inconclusive.

[Specialized Concepts for the Management of Severe Neurotrauma]

Neurotrauma results from violence on structures of the central or peripheral nervous system and is a clinically common disease entity with high relevance for patients' long-term outcome. The application of evidence-based diagnostic and therapeutic concepts aims to minimize secondary injury and thus to improve treatment outcome. This article describes the current management of the two main injury patterns of neurotrauma - traumatic brain and spinal cord injury.

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.

Targeted temperature control following traumatic brain injury: ESICM/NACCS best practice consensus recommendations

AIMS AND SCOPE

The aim of this panel was to develop consensus recommendations on targeted temperature control (TTC) in patients with severe traumatic brain injury (TBI) and in patients with moderate TBI who deteriorate and require admission to the intensive care unit for intracranial pressure (ICP) management.

METHODS

A group of 18 international neuro-intensive care experts in the acute management of TBI participated in a modified Delphi process. An online anonymised survey based on a systematic literature review was completed ahead of the meeting, before the group convened to explore the level of consensus on TTC following TBI. Outputs from the meeting were combined into a further anonymous online survey round to finalise recommendations. Thresholds of ≥ 16 out of 18 panel members in agreement (≥ 88%) for strong consensus and ≥ 14 out of 18 (≥ 78%) for moderate consensus were prospectively set for all statements.

RESULTS

Strong consensus was reached on TTC being essential for high-quality TBI care. It was recommended that temperature should be monitored continuously, and that fever should be promptly identified and managed in patients perceived to be at risk of secondary brain injury. Controlled normothermia (36.0-37.5 °C) was strongly recommended as a therapeutic option to be considered in tier 1 and 2 of the Seattle International Severe Traumatic Brain Injury Consensus Conference ICP management protocol. Temperature control targets should be individualised based on the perceived risk of secondary brain injury and fever aetiology.

CONCLUSIONS

Based on a modified Delphi expert consensus process, this report aims to inform on best practices for TTC delivery for patients following TBI, and to highlight areas of need for further research to improve clinical guidelines in this setting.

The effects of hyperbaric oxygen therapy on neuroprotection and recovery after brain resuscitation

OBJECTIVE

Analyze the impact of hyperbaric oxygen therapy on neuroprotection and recovery post severe traumatic brain injury (sTBI) resuscitation.

METHODS

Retrospective analysis of clinical data from 83 sTBI patients admitted between January 2022 to January 2024. Patients were divided into control (n = 41) and observation (n = 42) groups based on treatment received. Control received standard therapy, while the observation group received hyperbaric oxygen therapy. Effects on clinical outcomes, neuroinjury markers (S100β, GFAP, UCH-L1, NSE), neurotrophic factors (NGF, BDNF), neurological function indicators (NIHSS, CSS), and adverse reactions were compared.

RESULTS

The observation group showed a higher total effective rate (80.95%) compared to control (60.98%) (p < 0.05). Neuroinjury markers decreased post-treatment in both groups, with the observation group lower (p < 0.05). NGF and BDNF levels increased post-treatment in both groups, with the observation group higher (p < 0.05). NIHSS and CSS scores decreased post-treatment in both groups, with the observation group lower (p < 0.05). No significant difference in adverse reactions between groups (p > 0.05).

CONCLUSION

Hyperbaric oxygen therapy effectively treats sTBI by improving brain resuscitation success, reducing neuroinjury factors, enhancing neurotrophic factors, and promoting neurological function recovery, without increasing adverse reaction risk.

Updates in traumatic brain injury management: brain oxygenation, middle meningeal artery embolization and new protocols

Traumatic brain injury (TBI) confers significant morbidity and mortality, and is a pathology often encountered by trauma surgeons. Several recent trials have evaluated management protocols of patients with severe TBI. The Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase-II trial (BOOST-II) evaluated efficacy and feasibility of brain oxygen measurement in severe TBI. BOOST phase 3 trial (BOOST-3) and two ongoing trials look to measure functional outcomes in this population. Furthermore, middle meningeal artery embolization has now become standard therapy for adult patients with chronic subdural hematoma (SDH) and has increasing popularity in those with recurrent SDH as an alternative to surgical intervention. In this manuscript, we review the literature, ongoing trials, and discuss current updates in the management of TBI.

Review of Temperature Management in Traumatic Brain Injuries

Therapeutic hypothermia (TH) for severe traumatic brain injury has seen restricted application due to the outcomes of randomized controlled trials (RCTs) conducted since 2000. In contrast with earlier RCTs, recent trials have implemented active normothermia management in control groups, ensuring comparable intensities of non-temperature-related therapeutic interventions, such as neurointensive care. This change in approach may be a contributing factor to the inability to establish the efficacy of TH. Currently, an active temperature management method using temperature control devices is termed "targeted temperature management (TTM)". One of the goals of TTM for severe traumatic brain injury is the regulation of increased intracranial pressure, employing TTM as a methodology for intracranial pressure management. Additionally, fever in traumatic brain injury has been acknowledged as contributing to poor prognosis, underscoring the importance of proactively preventing fever. TTM is also employed for the preemptive prevention of fever in severe traumatic brain injury. As an integral component of current neurointensive care, it is crucial to precisely delineate the targets of TTM and to potentially apply them in the treatment of severe traumatic brain injury.

Therapy Intensity Level Scale for Traumatic Brain Injury: Clinimetric Assessment on Neuro-Monitored Patients Across 52 European Intensive Care Units

Intracranial pressure (ICP) data from traumatic brain injury (TBI) patients in the intensive care unit (ICU) cannot be interpreted appropriately without accounting for the effect of administered therapy intensity level (TIL) on ICP. A 15-point scale was originally proposed in 1987 to quantify the hourly intensity of ICP-targeted treatment. This scale was subsequently modified-through expert consensus-during the development of TBI Common Data Elements to address statistical limitations and improve usability. The latest 38-point scale (hereafter referred to as TIL) permits integrated scoring for a 24-h period and has a five-category, condensed version (TIL(Basic)) based on qualitative assessment. Here, we perform a total- and component-score analysis of TIL and TIL(Basic) to: 1) validate the scales across the wide variation in contemporary ICP management; 2) compare their performance against that of predecessors; and 3) derive guidelines for proper scale use. From the observational Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) study, we extract clinical data from a prospective cohort of ICP-monitored TBI patients (n = 873) from 52 ICUs across 19 countries. We calculate daily TIL and TIL(Basic) scores (TIL24 and TIL(Basic)24, respectively) from each patient's first week of ICU stay. We also calculate summary TIL and TIL(Basic) scores by taking the first-week maximum (TILmax and TIL(Basic)max) and first-week median (TILmedian and TIL(Basic)median) of TIL24 and TIL(Basic)24 scores for each patient. We find that, across all measures of construct and criterion validity, the latest TIL scale performs significantly greater than or similarly to all alternative scales (including TIL(Basic)) and integrates the widest range of modern ICP treatments. TILmedian outperforms both TILmax and summarized ICP values in detecting refractory intracranial hypertension (RICH) during ICU stay. The RICH detection thresholds which maximize the sum of sensitivity and specificity are TILmedian ≥ 7.5 and TILmax ≥ 14. The TIL24 threshold which maximizes the sum of sensitivity and specificity in the detection of surgical ICP control is TIL24 ≥ 9. The median scores of each TIL component therapy over increasing TIL24 reflect a credible staircase approach to treatment intensity escalation, from head positioning to surgical ICP control, as well as considerable variability in the use of cerebrospinal fluid drainage and decompressive craniectomy. Since TIL(Basic)max suffers from a strong statistical ceiling effect and only covers 17% (95% confidence interval [CI]: 16-18%) of the information in TILmax, TIL(Basic) should not be used instead of TIL for rating maximum treatment intensity. TIL(Basic)24 and TIL(Basic)median can be suitable replacements for TIL24 and TILmedian, respectively (with up to 33% [95% CI: 31-35%] information coverage) when full TIL assessment is infeasible. Accordingly, we derive numerical ranges for categorising TIL24 scores into TIL(Basic)24 scores. In conclusion, our results validate TIL across a spectrum of ICP management and monitoring approaches. TIL is a more sensitive surrogate for pathophysiology than ICP and thus can be considered an intermediate outcome after TBI.

Neuromonitoring in the ICU - what, how and why?

PURPOSE OF REVIEW

We selectively review emerging noninvasive neuromonitoring techniques and the evidence that supports their use in the ICU setting. The focus is on neuromonitoring research in patients with acute brain injury.

RECENT FINDINGS

Noninvasive intracranial pressure evaluation with optic nerve sheath diameter measurements, transcranial Doppler waveform analysis, or skull mechanical extensometer waveform recordings have potential safety and resource-intensity advantages when compared to standard invasive monitors, however each of these techniques has limitations. Quantitative electroencephalography can be applied for detection of cerebral ischemia and states of covert consciousness. Near-infrared spectroscopy may be leveraged for cerebral oxygenation and autoregulation computation. Automated quantitative pupillometry and heart rate variability analysis have been shown to have diagnostic and/or prognostic significance in selected subtypes of acute brain injury. Finally, artificial intelligence is likely to transform interpretation and deployment of neuromonitoring paradigms individually and when integrated in multimodal paradigms.

SUMMARY

The ability to detect brain dysfunction and injury in critically ill patients is being enriched thanks to remarkable advances in neuromonitoring data acquisition and analysis. Studies are needed to validate the accuracy and reliability of these new approaches, and their feasibility and implementation within existing intensive care workflows.

"NeuroVanguard": a contemporary strategy in neuromonitoring for severe adult brain injury patients

Severe acute brain injuries, stemming from trauma, ischemia or hemorrhage, remain a significant global healthcare concern due to their association with high morbidity and mortality rates. Accurate assessment of secondary brain injuries severity is pivotal for tailor adequate therapies in such patients. Together with neurological examination and brain imaging, monitoring of systemic secondary brain injuries is relatively straightforward and should be implemented in all patients, according to local resources. Cerebral secondary injuries involve factors like brain compliance loss, tissue hypoxia, seizures, metabolic disturbances and neuroinflammation. In this viewpoint, we have considered the combination of specific noninvasive and invasive monitoring tools to better understand the mechanisms behind the occurrence of these events and enhance treatment customization, such as intracranial pressure monitoring, brain oxygenation assessment and metabolic monitoring. These tools enable precise intervention, contributing to improved care quality for severe brain injury patients. The future entails more sophisticated technologies, necessitating knowledge, interdisciplinary collaboration and resource allocation, with a focus on patient-centered care and rigorous validation through clinical trials.