Multimodal Neuromonitoring Research Articles

Study protocol: Cerebral autoregulation, brain perfusion, and neurocognitive outcomes after traumatic brain injury -CAPCOG-TBI.

Moderate-severe traumatic brain injury (msTBI) stands as a prominent etiology of adult disability, with increased risk for cognitive impairment and dementia. Although some recovery often occurs within the first year post-injury, predicting long-term cognitive outcomes remains challenging, partly due to the significant pathophysiological heterogeneity of TBI, including acute cerebrovascular injury. The primary aim of our recently funded study, cerebral autoregulation, brain perfusion, and neurocognitive outcomes after traumatic brain injury (CAPCOG-TBI), is to determine if acute cerebrovascular dysfunction after msTBI measured using multimodal non-invasive neuromonitoring is associated with cognitive outcome at 1-year post-injury. This longitudinal observational study will be conducted at two Level 1 trauma centers in Texas, USA, and will include adult patients with msTBI, and/or mild TBI with neuroimaging abnormalities. Multimodal cerebral vascular assessment using transcranial Doppler and cerebral near-infrared spectroscopy (NIRS) will be conducted within 7-days of onset of TBI. Longitudinal outcomes, including cognitive/functional assessments (Glasgow Outcome Scale and Patient-Reported Outcomes Measurement Information System), cerebral vascular assessment, and imaging will be performed at follow-ups 3-, 6-, and 12-months post-injury. We aim to recruit 100 subjects with msTBI along with 30 orthopedic trauma controls (OTC). This study is funded by National Institute of Neurological Disease and Stroke (NINDS) and is registered on Clinicaltrial.org (NCT06480838). We anticipate that msTBI patients will exhibit impaired cerebrovascular function in the acute phase compared to the OTC group. The severity of cerebrovascular dysfunction during this stage is expected to inversely correlate with cognitive and functional outcomes at 1-year post-injury. Additionally, recovery from cerebrovascular dysfunction is expected to be linked to cognitive recovery. The results of this study could help to understand the contribution of cerebrovascular dysfunction to cognitive outcomes after TBI and pave the way for innovative vascular-focused interventions aimed at enhancing cognitive recovery and mitigating neurodegeneration following msTB. In addition, its focus toward personalized medicine to aid in the management and prognosis of TBI patients.

Brain hypoxia and metabolic crisis are common in patients with acute brain injury despite a normal intracranial pressure

Patients with acute brain injury are vulnerable to secondary deterioration, which may go undetected by traditional monitoring. However, multimodal neuromonitoring of brain tissue oxygen tension (PbtO2) and energy metabolism may be able to detect such episodes. We report a retrospective, observational study of 94 patients with aneurysmal subarachnoid haemorrhage (SAH) or traumatic brain injury (TBI) who underwent multimodal neuromonitoring during admission. We examined the co-occurrence of pathological neuromonitoring values: elevated intracranial pressure (ICP, > 20 mmHg), inadequate cerebral perfusion pressure (CPP, < 60 mmHg), brain hypoxia (PbtO2 < 20 mmHg), and metabolic crisis (lactate/pyruvate ratio > 40 and a glucose level < 0.2 mmol/L in cerebral microdialysate). Mixed effects linear regression demonstrated significant associations between abnormal ICP/CPP, cerebral hypoxia and metabolic crisis. However, brain hypoxia occurred in 40% and 31% of observations in patients with SAH and TBI, respectively, despite normal concurrent values of ICP. Similarly, metabolic crisis was observed in 8% and 16% of measurements for SAH and TBI, respectively, despite a normal ICP. The pattern was identical for CPP. In conclusion, although all neuromonitoring variables are interrelated, brain hypoxia and metabolic crisis are common despite an absence of abnormalities in conventional monitoring. Multimodal neuromonitoring may help identify such episodes and guide individualised treatment.

Successful management of intracranial hemorrhage with brain herniation in a postpartum patient on extracorporeal membranous oxygenation: A case report.

Managing intracranial hemorrhage in patients supported by extracorporeal oxygenation (ECMO) presents significant clinical challenges. We report a case of a postpartum patient with severe acute respiratory distress syndrome (ARDS) necessitating venovenous ECMO support, complicated by multicompartmental intracranial hemorrhage resulting in brain herniation and necessitating emergent medical and surgical management of refractory intracranial hypertension. Care was guided by multimodal neuromonitoring, including intracranial pressure monitoring and electroencephalography. Despite these challenges, the patient achieved excellent neurological recovery. This case underscores the intricacies of managing neurological complications during ECMO and highlights the potential benefits of comprehensive neuromonitoring strategies.

Feasibility and Safety of Integrating Extended TCD Assessments in a Full Multimodal Neuromonitoring Protocol After Traumatic Brain Injury

Targeting single monitoring modalities such as intracranial pressure (ICP) or cerebral perfusion pressure alone has shown to be insufficient in improving outcome after traumatic brain injury (TBI). Multimodality monitoring (MMM) allows for a more complete description of brain function and for individualized management. Transcranial Doppler (TCD) represents the gold standard for continuous cerebral blood flow velocity assessment, but requires high levels skill and time. In TBI, the practical aspects of conducting extended TCD monitoring sessions have yet to be evaluated. Patients with acute moderate-to-severe TBI admitted to the neurocritical care unit between March 2022 and December 2023 receiving invasive ICP measurements were evaluated for inclusion. Exclusion criteria included trauma incompatible with TCD monitoring and if MMM was unwarranted. Daily MMM sessions (in addition to regular monitoring) were performed using TCD (Delica EMS 9D System or the DWL Doppler Box) for ≤5 d. Quantitative and qualitative feasibility, safety, and quality metrics were assessed. Of 74 patients, 36 (75% male; mean age, 44 ± 17 y) were included. Common reasons for exclusion were skull fractures (n = 12) and decompressive craniectomy (n = 9). We acquired 88 recordings (mean, 275 ± 88 min). Overall monitoring times increased, and set-up times decreased. Physiologic variables (including ICP/brain temperature) did not change with TCD application. A single adverse event (dislodging of a microdialysis catheter) occurred. Implementing extended TCD monitoring in MMM protocols is feasible and safe. Considering these results, inclusion of long-term TCD as part of the MMM is strongly encouraged to allow for in-depth description and direct evaluation of hemodynamic changes after TBI.

Model-predicted brain temperature computational imaging by multimodal noninvasive functional neuromonitoring of cerebral oxygen metabolism and hemodynamics: MRI-derived and clinical validation.

Brain temperature, a crucial yet under-researched neurophysiological parameter, is governed by the equilibrium between cerebral oxygen metabolism and hemodynamics. Therapeutic hypothermia has been demonstrated as an effective intervention for acute brain injuries, enhancing survival rates and prognosis. The success of this treatment hinges on the precise regulation of brain temperature. However, the absence of comprehensive brain temperature monitoring methods during therapy, combined with a limited understanding of human brain heat transmission mechanisms, significantly hampers the advancement of hypothermia-based neuroprotective therapies. Leveraging the principles of bioheat transfer and MRI technology, this study conducted quantitative analyses of brain heat transfer during mild hypothermia therapy. Utilizing MRI, we reconstructed brain structures, estimated cerebral blood flow and oxygen consumption parameters, and developed a brain temperature calculation model founded on bioheat transfer theory. Employing computational cerebral hemodynamic simulation analysis, we established an intracranial arterial fluid dynamics model to predict brain temperature variations across different therapeutic hypothermia modalities. We introduce a noninvasive, spatially resolved, and optimized mathematical bio-heat model that synergizes model-predicted and MRI-derived data for brain temperature prediction and imaging. Our findings reveal that the brain temperature images generated by our model reflect distinct spatial variations across individual participants, aligning with experimentally observed temperatures.

Clinical Impact of Standardized Interpretation and Reporting of Multimodality Neuromonitoring Data.

Evaluate the consistency and clinical impact of standardized multimodality neuromonitoring (MNM) interpretation and reporting within a system of care for patients with severe traumatic brain injury (sTBI). Retrospective, observational historical case-control study. Single-center academic level I trauma center. Standardized interpretation of MNM data summarized within daily reports. Consecutive patients with sTBI undergoing MNM were included. Historical controls were patients monitored before implementation of standardized MNM interpretation; cases were defined as patients with available MNM interpretative reports. Patient characteristics, physiologic data, and clinical outcomes were recorded, and clinical MNM reporting elements were abstracted. The primary outcome was the Glasgow Outcome Scale score 3-6 months postinjury. One hundred twenty-nine patients were included (age 42 ± 18 yr, 82% men); 45 (35%) patients were monitored before standardized MNM interpretation and reporting, and 84 (65%) patients were monitored after that. Patients undergoing standardized interpretative reporting received fewer hyperosmotic agents (3 [1-6] vs. 6 [1-8]; p = 0.04) and spent less time above an intracranial threshold of 22 mm Hg (22% ± 26% vs. 28% ± 24%; p = 0.05). The MNM interpretation cohort had a lower proportion of anesthetic days (48% [24-70%] vs. 67% [33-91%]; p = 0.02) and higher average end-tidal carbon dioxide during monitoring (34 ± 6 mm Hg vs. 32 ± 6 mm Hg; p < 0.01; d = 0.36). After controlling for injury severity, patients undergoing standardized MNM interpretation and reporting had an odds of 1.5 (95% CI, 1.37-1.59) for better outcomes. Standardized interpretation and reporting of MNM data are a novel approach to provide clinical insight and to guide individualized critical care. In patients with sTBI, independent MNM interpretation and communication to bedside clinical care teams may result in improved intracranial pressure control, fewer medical interventions, and changes in ventilatory management. In this study, the implementation of a system for management, including standardized MNM interpretation, was associated with a significant improvement in outcome.

MULTIMODAL NEUROMONITORING IN DIFFERENT NEUROCRITICAL CONDITIONS – FIRST EXPERIENCES IN SINGLE NEUROCRITICAL CARE CENTRE

The study explores the use of multimodal neuromonitoring in a neurocritical care center, focusing on patients with acute brain injuries. The monitoring involves various sensors to track intracranial pressure (ICP), partial brain tissue oxygenation (PbO2), cerebral perfusion pressure (CPP), and more. The research, conducted at the Lithuanian University of Health Sciences, covers a small sample size (13 patients), mainly dealing with subarachnoid hemorrhage and traumatic brain injury cases. Results indicate challenges, such as episodes of intracranial hypertension and cerebral hypoxia, despite adherence to treatment protocols. The study faces limitations due to manual data registration, leading to potential inaccuracies. The outcomes reveal a mortality rate of 23.1%, with the majority experiencing unfavorable results. In conclusion, the study underscores the significance of multimodal monitoring but highlights the need for larger sample sizes, improved data recording methods, and emphasizes the complexity and challenges in managing neurocritical conditions.

The choice of blood transfusion strategy in severe traumatic brain injury

Traumatic brain injury (TBI) remains one of the leading causes of long-term disability, especially among young and middle-aged people. One of the main directions of treatment for patients with TBI is to prevent the development of secondary brain damage due to systemic dysfunction. Anemia occupies an important place among them. Anemia is considered a marker of illness severity in critically ill patients and is included in the list of parameters for risk prediction in intensive care units. However, the relationship between anemia and adverse outcomes in patients with TBI is controversial. Aim. The purpose of the work is to analyze the effect of anemia on the course of severe TBI, to determine the position of anemia in the pathophysiological mechanisms of brain damage, the development of blood transfusion-associated complications, to evaluate different blood transfusion strategies (liberal and restrictive) and their impact on treatment results, taking into account individual tolerance to anemia. Studies suggest that the restrictive transfusion strategy could be useful in reducing complications and length of hospital stay. However, the lack of clear evidence for optimal hemoglobin levels as a trigger to initiate blood transfusions reinforces the need for further clinical studies. The use of multimodal neuromonitoring allows to evaluate the latest approaches to assessing individual hemoglobin thresholds. These methods could help in identifying patients at increased risk of complications and determining optimal strategies to manage anemia. Conclusions. The problem of tolerance to anemia in patients with severe TBI remains a controversial topic, and determining hemoglobin thresholds for blood transfusion in this group of patients requires further studies, special attention should therefore be paid to an individual approach to resolving the issue of red blood cell transfusion, in particular, integrating clinical status of a patient and concomitant pathology. The risk of possible brain damage worsening associated with anemia due to deterioration of cerebral oxygenation should always be weighed against the risk of developing transfusion-associated complications.

Anesthesia for traumatic brain injury.

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 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. 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.

Neuromonitoring in neonatal intensive care units-an important need towards individualized neuroprotective care.

Neuromonitoring has been widely accepted as an important part in neonatal care. Amplitude-integrated EEG (aEEG) and near-infrared spectroscopy (NIRS) are often mentioned in this context, though being only a part of the fully array of methods and examinations that could be considered neuromonitoring. Within the broad array of medical conditions that could be encountered in a neonatal patient, it is important to be aware of the indications for neuromonitoring and especially which neuromonitoring technique to use best for the individual condition. aEEG is now a widely accepted neuromonitor in neonatology with its value in hypoxic events and seizures only rarely questioned. Other methods like NIRS still have to prove themselves in the future. The SafeBoosC-III trial showed that it still remains difficult for some of these methods to prove their value for the improvement of outcome. Bute future developments such as multimodal neuromonitoring with data integration and artificial intelligence analysis could improve the value of these methods.

Unsatisfactory Neurological Outcome in an Intramedullary Thoracic Intermediate-Grade Melanocytoma-Systematic Review and Illustrative Case.

Intramedullary melanocytomas are exceedingly rare, with only twenty-four cases reported up to now. They present as local invasive tumors despite their benign biological behavior. Attempting a complete safe resection often results in severe post-operative neurological deficits, as in our case presented here. A systematic review was conducted across the PubMed and Scopus databases including studies published till February 2024. A total of 19 studies were included, encompassing 24 cases. A similar distribution between sexes was noted (M:F 13:11), with ages ranging from 19 to 79 years. The thoracic segment was most affected, and intermediate-grade melanocytoma (19 cases) was the most common histotype. Radiographically, intramedullary melanocytomas usually appear as hyperintense hemorrhagic lesions peripheral to the central canal with focal nodular enhancement. Intraoperatively, they are black-reddish to tan and are tenaciously adherent lesions. In the sampled studies, IONM employment was uncommon, and post-operative new-onset neurological deficits were described in 16 cases. Adjuvant RT was used in four cases and its value is debatable. Recurrence is common (10 cases), and adjuvant therapies (RT or repeated surgery) seem to play a palliative role. A 68-year-old woman presented with a three-year history of worsening spastic paraparesis and loss of independence in daily activities (McCormick grade 4). An MRI revealed an intramedullary tumor from Th5 to Th7, characterized by T1-weighted hyperintensity and signs of recent intralesional hemorrhage. Multimodal neuromonitoring, comprising the D-Wave, guided the resection of a black-tan-colored tumor with hyper-vascularization and strong adherence to the white matter. During final dissection of the lesion to obtain gross total resection (GTR), a steep decline in MEPs and D-Wave signals was recorded. Post-operatively, the patient had severe hypoesthesia with Th9 level and segmental motor deficits, with some improvement during neurorehabilitation. Histopathology revealed an intermediate-grade melanocytoma (CNS WHO 2021 classification). A four-month follow-up documented the absence of relapse. This literature review highlights that intramedullary T1 hyperintense hemorrhagic thoracic lesions in an adult patient should raise the suspicion of intramedullary melanocytoma. They present as locally aggressive tumors, due to local invasiveness, which often lead to post-operative neurological deficits, and frequent relapses, which overwhelm therapeutic strategies leading to palliative care after several years.

"Roberto Rodríguez" General Teaching Hospital of Moron, Ciego De Avila, Cuba, Neurosurgery and Pediatric Intensive Care Services Pediatric Neuromonitoring in Severe Head Trauma.

Among all types of trauma in children, traumatic brain injury has the greatest potential for the development of devastating consequences, with nearly three million affected each year in the world. A controlled, nonrandomized experimental study was carried out in pediatric patients with severe traumatic brain injury, whose objective was to evaluate the use of continuous multimodal neuromonitoring (MMN) of intracranial parameters as a guide in the treatment of children of different age-groups. The patients were divided into two groups according to the treatment received; clinical and imaging monitoring was performed in both. Group I included those whose treatment was guided by MMN of intracranial parameters such as intracranial pressure, cerebral perfusion pressure, and intracranial compliance, and group II included those who had only clinical and imaging monitoring. Eighty patients were studied, 41 in group I and 39 in group II. There were no significant differences between the groups with respect to the sociodemographic variables and the results; as a consequence, both forms of treatment were outlined, for patients with MMN and for those who only have clinical and imaging monitoring. It is concluded that both treatment schemes can be used depending on technological availability, although the scheme with MMN is optimal.

Improved Outcome Prediction in Neurocritical Care Using Multimodal Neuromonitoring (P4-2.004)

Improved Outcome Prediction in Neurocritical Care Using Multimodal Neuromonitoring (P4-2.004)

Intraparenchymal near-infrared spectroscopy for detection of delayed cerebral ischemia in poor-grade aneurysmal subarachnoid hemorrhage

ObjectiveDetection of delayed cerebral ischemia (DCI) is challenging in comatose patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH). Brain tissue oxygen pressure (PbtO2) monitoring may allow early detection of its occurrence. Recently, a probe for combined measurement of intracranial pressure (ICP) and intraparenchymal near-infrared spectroscopy (NIRS) has become available. In this pilot study, the parameters PbtO2, Hboxy, Hbdeoxy, Hbtotal and rSO2 were measured in parallel and evaluated for their potential to detect perfusion deficits or cerebral infarction. MethodsIn patients undergoing multimodal neuromonitoring due to poor neurological condition after aSAH, Clark oxygen probes, microdialysis and NIRS-ICP probes were applied. DCI was suspected when the measured parameters in neuromonitoring deteriorated. Thus, perfusion CT scan was performed as follow up, and DCI was confirmed as perfusion deficit. Median values for PbtO2, Hboxy, Hbdeoxy, Hbtotal and rSO2 in patients with perfusion deficit (Tmax > 6 s in at least 1 vascular territory) and/or already demarked infarcts were compared in 24- and 48-hour time frames before imaging. ResultsData from 19 patients (14 University Hospital Zurich, 5 Charité Universitätsmedizin Berlin) were prospectively collected and analyzed. In patients with perfusion deficits, the median values for Hbtotal and Hboxy in both time frames were significantly lower. With perfusion deficits, the median values for Hboxy and Hbtotal in the 24 h time frame were 46,3 [39.6, 51.8] µmol/l (no perfusion deficits 53 [45.9, 55.4] µmol/l, p = 0.019) and 69,3 [61.9, 73.6] µmol/l (no perfusion deficits 74,6 [70.1, 79.6] µmol/l, p = 0.010), in the 48 h time frame 45,9 [39.4, 51.5] µmol/l (no perfusion deficits 52,9 [48.1, 55.1] µmol/l, p = 0.011) and 69,5 [62.4, 74.3] µmol/l (no perfusion deficits 75 [70,80] µmol/l, p = 0.008), respectively. In patients with perfusion deficits, PbtO2 showed no differences in both time frames. PbtO2 was significantly lower in patients with infarctions in both time frames. The median PbtO2 was 17,3 [8,25] mmHg (with no infarctions 29 [22.5, 36] mmHg, p = 0.006) in the 24 h time frame and 21,6 [11.1, 26.4] mmHg (with no infarctions 31 [22,35] mmHg, p = 0.042) in the 48 h time frame. In patients with infarctions, the median values of parameters measured by NIRS showed no significant differences. ConclusionsThe combined NIRS-ICP probe may be useful for early detection of cerebral perfusion deficits and impending DCI. Validation in larger patient collectives is needed.

Prospective Observational Study of Volatile Sedation with Sevoflurane After Aneurysmal Subarachnoid Hemorrhage Using the Sedaconda Anesthetic Conserving Device.

Volatile sedation is still used with caution in patients with acute brain injury because of safety concerns. We analyzed the effects of sevoflurane sedation on systemic and cerebral parameters measured by multimodal neuromonitoring in patients after aneurysmal subarachnoid hemorrhage (aSAH) with normal baseline intracranial pressure (ICP). In this prospective observational study, we analyzed a 12-h period before and after the switch from intravenous to volatile sedation with sevoflurane using the Sedaconda Anesthetic Conserving Device with a target Richmond Agitation Sedation Scale score of - 5 to - 4. ICP, cerebral perfusion pressure (CPP), brain tissue oxygenation (PBrO2), metabolic values of cerebral microdialysis, systemic cardiopulmonary parameters, and the administered drugs before and after the sedation switch were analyzed. We included 19 patients with a median age of 61years (range 46-78years), 74% of whom presented with World Federation of Neurosurgical Societies grade 4 or 5 aSAH. We observed no significant changes in the mean ICP (9.3 ± 4.2 vs. 9.7 ± 4.2mm Hg), PBrO2 (31.0 ± 13.2 vs. 32.2 ± 12.4mm Hg), cerebral lactate (5.0 ± 2.2 vs. 5.0 ± 1.9mmol/L), pyruvate (136.6 ± 55.9 vs. 134.1 ± 53.6µmol/L), and lactate/pyruvate ratio (37.4 ± 8.7 vs. 39.8 ± 9.2) after the sedation switch to sevoflurane. We found a significant decrease in mean arterial pressure (MAP) (88.6 ± 7.6 vs. 86.3 ± 5.8mm Hg) and CPP (78.8 ± 8.5 vs. 76.6 ± 6.6mm Hg) after the initiation of sevoflurane, but the decrease was still within the physiological range requiring no additional hemodynamic support. Sevoflurane appears to be a feasible alternative to intravenous sedation in patients with aSAH without intracranial hypertension, as our study did not show negative effects on ICP, cerebral oxygenation, or brain metabolism. Nevertheless, the risk of a decrease of MAP leading to a consecutive CPP decrease should be considered.

A Clinical Practice Guideline for Prevention, Diagnosis and Management of Intraoperative Spinal Cord Injury: Recommendations for Use of Intraoperative Neuromonitoring and for the Use of Preoperative and Intraoperative Protocols for Patients Undergoing Spine Surgery.

Development of a clinical practice guideline following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process. The objectives of this study were to develop guidelines that outline the utility of intraoperative neuromonitoring (IONM) to detect intraoperative spinal cord injury (ISCI) among patients undergoing spine surgery, to define a subset of patients undergoing spine surgery at higher risk for ISCI and to develop protocols to prevent, diagnose, and manage ISCI. All systematic reviews were performed according to PRISMA standards and registered on PROSPERO. A multidisciplinary, international Guidelines Development Group (GDG) reviewed and discussed the evidence using GRADE protocols. Consensus was defined by 80% agreement among GDG members. A systematic review and diagnostic test accuracy (DTA) meta-analysis was performed to synthesize pooled evidence on the diagnostic accuracy of IONM to detect ISCI among patients undergoing spinal surgery. The IONM modalities evaluated included somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), electromyography (EMG), and multimodal neuromonitoring. Utilizing this knowledge and their clinical experience, the multidisciplinary GDG created recommendations for the use of IONM to identify ISCI in patients undergoing spine surgery. The evidence related to existing care pathways to manage ISCI was summarized and based on this a novel AO Spine-PRAXIS care pathway was created. Our recommendations are as follows: (1) We recommend that intraoperative neurophysiological monitoring be employed for high risk patients undergoing spine surgery, and (2) We suggest that patients at "high risk" for ISCI during spine surgery be proactively identified, that after identification of such patients, multi-disciplinary team discussions be undertaken to manage patients, and that an intraoperative protocol including the use of IONM be implemented. A care pathway for the prevention, diagnosis, and management of ISCI has been developed by the GDG. We anticipate that these guidelines will promote the use of IONM to detect and manage ISCI, and promote the use of preoperative and intraoperative checklists by surgeons and other team members for high risk patients undergoing spine surgery. We welcome teams to implement and evaluate the care pathway created by our GDG.

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

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. 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. Thirty-two patients were enrolled in the study. RMs resulted in increased intracranial pressure (Δ = 4.8mm Hg) and reduced CPP (ΔCPP = -12.8mm Hg) and mean arterial pressure (difference in mean arterial pressure = -5.2mm 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 = 4mm 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 = -0.1cm; 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. 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.

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.

Multimodal neuromonitoring in the pediatric intensive care unit

Neuromonitoring is used to assess the central nervous system in the intensive care unit. The purpose of neuromonitoring is to detect neurologic deterioration and intervene to prevent irreversible nervous system dysfunction. Neuromonitoring starts with the standard neurologic examination, which may lag behind the pathophysiologic changes. Additional modalities including continuous electroencephalography (CEEG), multiple physiologic parameters, and structural neuroimaging may detect changes earlier. Multimodal neuromonitoring now refers to an integrated combination and display of non-invasive and invasive modalities, permitting tailored treatment for the individual patient. This chapter reviews the non-invasive and invasive modalities used in pediatric neurocritical care.

The effect of passive leg raising test on intracranial pressure and cerebral autoregulation in brain injured patients: a physiological observational study

BackgroundThe use of the passive leg raising (PLR) is limited in acute brain injury (ABI) patients with increased intracranial pressure (ICP) since the postural change of the head may impact on ICP and cerebral autoregulation. However, the PLR use may prevent a positive daily fluid balance, which had been recently associated to worse neurological outcomes. We therefore studied early and delayed effects of PLR on the cerebral autoregulation of patients recovering from ABI.Materials and methodsThis is a Prospective, observational, single-center study conducted in critically ill patients admitted with stable ABI and receiving invasive ICP monitoring, multimodal neuromonitoring and continuous hemodynamic monitoring. The fluid challenge consisted of 500 mL of crystalloid over 10 min; fluid responsiveness was defined as cardiac index increase ≥ 10%. Comparisons between different variables at baseline and after PLR were made by paired Wilcoxon signed-rank test. The correlation coefficients between hemodynamic and neuromonitoring variables were assessed using Spearman’s rank test.ResultsWe studied 23 patients [12 patients (52.2%) were fluid responders]. The PLR significantly increased ICP [from 13.7 (8.3–16.4) to 15.4 (12.0–19.2) mmHg; p < 0.001], cerebral perfusion pressure (CPP) [from 51.1 (47.4–55.6) to 56.4 (49.6–61.5) mmHg; p < 0.001] and the pressure reactivity index (PRx) [from 0.12 (0.01–0.24) to 0.43 (0.34–0.46) mmHg; p < 0.001]. Regarding Near Infrared Spectroscopy (NIRS)-derived parameters, PLR significantly increased the arterial component of regional cerebral oxygen saturation (O2Hbi) [from 1.8 (0.8–3.7) to 4.3 (2.5–5.6) μM cm; p < 0.001], the deoxygenated hemoglobin (HHbi) [from 1.6 (0.2–2.9) to 2.7 (1.4–4.0) μM cm; p = 0.007] and total hemoglobin (cHbi) [from 3.6 (1.9–5.3) to 7.8 (5.2–10.3): p < 0.001]. In all the patients who had altered autoregulation after PLR, these changes persisted ten minutes afterwards. After the PLR, we observed a significant correlation between MAP and CPP and PRx.ConclusionsIn ABI patient with stable ICP, PLR test increased ICP, but mostly within safety values and thresholds. Despite this, cerebral autoregulation was importantly impaired, and this persisted up to 10 min after the end of the maneuvre. Our results discourage the use of PLR test in ABI even when ICP is stable.