Optimization of Hypothermic Protocols for Neurocognitive Preservation in Aortic Arch Surgery: A Literature Review.

Shifts from deep to moderate hypothermic circulatory arrest (HCA) in aortic arch surgery necessitate an examination of their differential impacts on neurocognitive functions, especially structured verbal memory, given its significance for patient recovery and quality of life. This study evaluates and synthesizes evidence on the effects of deep (≤20.0 °C), low-moderate (20.1-24.0 °C), and high-moderate (24.1-28.0 °C) hypothermic temperatures on structured verbal memory preservation and overall cognitive health in patients undergoing aortic arch surgery. We evaluated the latest literature from major medical databases such as PubMed and Scopus, focusing on research from 2020 to 2024, to gather comprehensive insights into the current landscape of temperature management during HCA. This comparative analysis highlights the viability of moderate hypothermia (20.1-28.0 °C), supported by recent trials and observational studies, as a method to achieve comparable neuroprotection with fewer complications than traditional deep hypothermia. Notably, low-moderate and high-moderate temperatures have been shown to support substantial survival rates, with impacts on structured verbal memory preservation that necessitate careful selection based on individual surgical risks and patient profiles. The findings advocate for a nuanced approach to selecting hypothermic protocols in aortic arch surgeries, emphasizing the importance of tailoring temperature management to optimize neurocognitive outcomes and patient recovery. This study fills a critical gap in the literature by providing evidence-based recommendations for temperature ranges during HCA, calling for ongoing updates to clinical guidelines and further research to refine these recommendations. The implications of temperature on survival rates, complications, and success rates underpin the necessity for evolving cardiopulmonary bypass techniques and cerebral perfusion strategies to enhance patient outcomes in complex cardiovascular procedures.

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.

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.

Preliminary Study on Application of Combined Monitoring of Neuroelectrophysiology-Intracranial Pressure-Cerebral Perfusion Pressure in Craniotomy for Intracranial Aneurysm Clipping: An Anatomical and Clinical Study

SUMMARY: Intracranial aneurysm is a common cerebrovascular disease with high mortality. Neurosurgical clipping for the treatment of intracranial aneurysms can easily lead to serious postoperative complications. Studies have shown that intraoperative monitoring of the degree of cerebral ischemia is extremely important to ensure the safety of operation and improve the prognosis of patients. Aim of this study was to probe the application value of combined monitoring of intraoperative neurophysiological monitoring (IONM)-intracranial pressure (ICP)-cerebral perfusion pressure (CPP) in craniotomy clipping of intracranial aneurysms. From January 2020 to December 2022, 126 patients in our hospital with intracranial aneurysms who underwent neurosurgical clipping were randomly divided into two groups. One group received IONM monitoring during neurosurgical clipping (control group, n=63), and the other group received IONM-ICP-CPP monitoring during neurosurgical clipping (monitoring group, n=63). The aneurysm clipping and new neurological deficits at 1 day after operation were compared between the two groups. Glasgow coma scale (GCS) score and national institutes of health stroke scale (NIHSS) score were compared before operation, at 1 day and 3 months after operation. Glasgow outcome scale (GOS) and modified Rankin scale (mRS) were compared at 3 months after operation. All aneurysms were clipped completely. Rate of new neurological deficit at 1 day after operation in monitoring group was 3.17 % (2/63), which was markedly lower than that in control group of 11.11 % (7/30) (P0.05). Combined monitoring of IONM-ICP-CPP can monitor the cerebral blood flow of patients in real time during neurosurgical clipping, according to the monitoring results, timely intervention measures can improve the consciousness state of patients in early postoperative period and reduce the occurrence of early postoperative neurological deficits.

El aneurisma intracraneal es una enfermedad cerebrovascular común con alta mortalidad. El clipaje neuroquirúrgico para el tratamiento de aneurismas intracraneales puede provocar complicaciones posoperatorias graves. Los estudios han demostrado que la monitorización intraoperatoria del grado de isquemia cerebral es extremadamente importante para garantizar la seguridad de la operación y mejorar el pronóstico de los pacientes. El objetivo de este estudio fue probar el valor de la aplicación de la monitorización combinada de la monitorización neurofisiológica intraoperatoria (IONM), la presión intracraneal (PIC) y la presión de perfusión cerebral (CPP) en el clipaje de craneotomía de aneurismas intracraneales. Desde enero de 2020 hasta diciembre de 2022, 126 pacientes de nuestro hospital con aneurismas intracraneales que se sometieron a clipaje neuroquirúrgico se dividieron aleatoriamente en dos grupos. Un grupo recibió monitorización IONM durante el clipaje neuroquirúrgico (grupo de control, n=63) y el otro grupo recibió monitorización IONM-ICP-CPP durante el clipaje neuroquirúrgico (grupo de monitorización, n=63). Se compararon entre los dos grupos el recorte del aneurisma y los nuevos déficits neurológicos un día después de la operación. La puntuación de la escala de coma de Glasgow (GCS) y la puntuación de la escala de accidentes cerebrovasculares de los institutos nacionales de salud (NIHSS) se compararon antes de la operación, 1 día y 3 meses después de la operación. La escala de resultados de Glasgow (GOS) y la escala de Rankin modificada (mRS) se compararon 3 meses después de la operación. Todos los aneurismas fueron cortados por completo. La tasa de nuevo déficit neurológico 1 día después de la operación en el grupo de seguimiento fue del 3,17 % (2/63), que fue notablemente inferior a la del grupo de control del 11,11 % (7/30) (P 0,05). La monitorización combinada de IONM-ICP-CPP puede controlar el flujo sanguíneo cerebral de los pacientes en tiempo real durante el corte neuroquirúrgico; de acuerdo con los resultados de la monitorización, las medidas de intervención oportunas pueden mejorar el estado de conciencia de los pacientes en el período postoperatorio temprano y reducir la aparición de problemas postoperatorios tempranos y déficits neurológicos.

Point-Counterpoint: Cerebral perfusion pressure is a high-risk concept.

Cerebral perfusion pressure (CPP) is calculated as the difference between mean arterial blood pressure and mean intracranial pressure, being commonly applied in neurocritical care. This commentary discusses recent physiological advances in knowledge as well as bedside practice issues that in combination indicate considering CPP under this perspective may lead to inaccurate assumptions and potentially misleading decision making.

Critical Closing Pressure and Cerebrovascular Resistance Responses to Intracranial Pressure Variations in Neurocritical Patients.

BACKGROUND: Critical closing pressure (CrCP) and resistance-area product (RAP) have been conceived as compasses to optimize cerebral perfusion pressure (CPP) and monitor cerebrovascular resistance, respectively. However, for patients with acute brain injury (ABI), the impact of intracranial pressure (ICP) variability on these variables is poorly understood. The present study evaluates the effects of a controlled ICP variation on CrCP and RAP among patients with ABI. METHODS: Consecutive neurocritical patients with ICP monitoring were included along with transcranial Doppler and invasive arterial blood pressure monitoring. Internal jugular veins compression was performed for 60 s for the elevation of intracranial blood volume and ICP. Patients were separated in groups according to previous intracranial hypertension severity, with either no skull opening (Sk1), neurosurgical mass lesions evacuation, or decompressive craniectomy (DC) (patients with DC [Sk3]). RESULTS: Among 98 included patients, the correlation between change (Δ) in ICP and the corresponding ΔCrCP was strong (group Sk1 r = 0.643 [p = 0.0007], group with neurosurgical mass lesions evacuation r = 0.732 [p < 0.0001], and group Sk3 r = 0.580 [p = 0.003], respectively). Patients from group Sk3 presented a significantly higher ΔRAP (p = 0.005); however, for this group, a higher response in mean arterial pressure (change in mean arterial pressure p = 0.034) was observed. Exclusively, group Sk1 disclosed reduction in ICP before internal jugular veins compression withholding. CONCLUSIONS: This study elucidates that CrCP reliably changes in accordance with ICP, being useful to indicate ideal CPP in neurocritical settings. In the early days after DC, cerebrovascular resistance seems to remain elevated, despite exacerbated arterial blood pressure responses in efforts to maintain CPP stable. Patients with ABI with no need of surgical procedures appear to remain with more effective ICP compensatory mechanisms when compared with those who underwent neurosurgical interventions.

Contribution of intracranial pressure to human dynamic cerebral autoregulation after acute brain injury.

Cerebral perfusion pressure (CPP) is normally expressed by the difference between mean arterial blood pressure (MAP) and intracranial pressure (ICP) but comparison of the separate contributions of MAP and ICP to human cerebral blood flow autoregulation has not been reported. In patients with acute brain injury (ABI), internal jugular vein compression (IJVC) was performed for 60 s. Dynamic cerebral autoregulation (dCA) was assessed in recordings of middle cerebral artery blood velocity (MCAv, transcranial Doppler), and invasive measurements of MAP and ICP. Patients were separated according to injury severity as having whole/undamaged skull, large fractures, or craniotomies, or following decompressive craniectomy. Glasgow coma score was not different for the three groups. IJVC induced changes in MCAv, MAP, ICP, and CPP in all three groups. The MCAv response to step changes in MAP and ICP expressed the dCA response to these two inputs and was quantified with the autoregulation index (ARI). In 85 patients, ARI was lower for the ICP input as compared with the MAP input (2.25 ± 2.46 vs. 3.39 ± 2.28; P < 0.0001), and particularly depressed in the decompressive craniectomy (DC) group (n = 24, 0.35 ± 0.62 vs. 2.21 ± 1.96; P < 0.0005). In patients with ABI, the dCA response to changes in ICP is less efficient than corresponding responses to MAP changes. These results should be taken into consideration in studies aimed to optimize dCA by manipulation of CPP in neurocritical patients.

Ultrasound-guided cerebral resuscitation in patients with severe traumatic brain Injury.

Traumatic brain injury (TBI) is a worldwide public health concern given its significant morbidity and mortality, years of potential life lost, reduced quality of life and elevated healthcare costs. The primary injury occurs at the moment of impact, but secondary injuries might develop as a result of brain hemodynamic abnormalities, hypoxia, and hypotension. The cerebral edema and hemorrhage of the injured tissues causes a decrease in cerebral perfusion pressure (CPP), which leads to higher risk of cerebral ischemia, herniation and death. In this setting, our role as physicians is to minimize damage by the optimization of the CPP and therefore to reduce mortality and improve neurological outcomes. Performing a transcranial doppler ultrasound (TCD) allows to estimate cerebral blood flow velocities and identify states of low flow and high resistance. We propose to include TCD as an initial assessment and further monitoring tool for resuscitation guidance in patients with severe TBI. We present an Ultrasound-Guided Cardio-cerebral Resuscitation (UGCeR) protocol in Patients with Severe TBI.

Long-term outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion.

OBJECTIVE: This study sought to report outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion, and secondarily, to report outcomes of this operative approach by type of underlying aortic disease. METHODS: This was an observational study of aortic surgeries from 2010 to 2018. All patients who underwent hemiarch replacement with retrograde cerebral perfusion were included, whereas patients undergoing partial or total arch replacement or concomitant elephant trunk procedures were excluded. Patients were dichotomized into 2 groups by underlying aortic disease; that is, acute aortic dissection (AAD) or aneurysmal degeneration of the aorta. These groups were analyzed for differences in short-term postoperative outcomes, including stroke and operative mortality (Society of Thoracic Surgeons definition). Multivariable Cox analysis was performed to identify variables associated with long-term survival after hemiarch replacement. RESULTS: A total of 500 patients undergoing hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion were identified, of whom 53.0% had aneurysmal disease and 47.0% had AAD. For the entire cohort, operative mortality was 6.4%, whereas stroke occurred in 4.6% of patients. Comparing AAD with aneurysm, operative mortality and stroke rates were similar across each group. Five-year survival was 84.4% ± 0.02% for the entire hemiarch cohort, whereas 5-year survival was 88.0% ± 0.02% for the aneurysm subgroup and was 80.5% ± 0.03% for the AAD subgroup. On multivariable analysis, AAD was not associated with an increased hazard of death, compared with aneurysm (P = .790). CONCLUSIONS: Morbidity and mortality after hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion are acceptably low, and this operative approach may be as advantageous for AAD as it is for aneurysm.

Neurocritical care management supported by multimodal brain monitoring after acute brain injury / Abordagem de cuidados neurocríticos apoiada por monitorização cerebral multimodal após lesão cerebral aguda

ABSTRACT Objective: To evaluate the association between different intensive care units and levels of brain monitoring with outcomes in acute brain injury. Methods: Patients with traumatic brain injury and subarachnoid hemorrhage admitted to intensive care units were included. Neurocritical care unit management was compared to general intensive care unit management. Patients managed with multimodal brain monitoring and optimal cerebral perfusion pressure were compared with general management patients. A good outcome was defined as a Glasgow outcome scale score of 4 or 5. Results: Among 389 patients, 237 were admitted to the neurocritical care unit, and 152 were admitted to the general intensive care unit. Neurocritical care unit management patients had a lower risk of poor outcome (OR = 0.228). A subgroup of 69 patients with multimodal brain monitoring (G1) was compared with the remaining patients (G2). In the G1 and G2 groups, 59% versus 23% of patients, respectively, had a good outcome at intensive care unit discharge; 64% versus 31% had a good outcome at 28 days; 76% versus 50% had a good outcome at 3 months (p < 0.001); and 77% versus 58% had a good outcome at 6 months (p = 0.005). When outcomes were adjusted by SAPS II severity score, using good outcome as the dependent variable, the results were as follows: for G1 compared to G2, the OR was 4.607 at intensive care unit discharge (p < 0.001), 4.22 at 28 days (p = 0.001), 3.250 at 3 months (p = 0.001) and 2.529 at 6 months (p = 0.006). Patients with optimal cerebral perfusion pressure management (n = 127) had a better outcome at all points of evaluation. Mortality for those patients was significantly lower at 28 days (p = 0.001), 3 months (p < 0.001) and 6 months (p = 0.001). Conclusion: Multimodal brain monitoring with autoregulation and neurocritical care unit management were associated with better outcomes and should be considered after severe acute brain injury.

RESUMO Objetivo: Avaliar a associação entre diferentes tipos de unidades de cuidados intensivos e os níveis de monitorização cerebral com desfechos na lesão cerebral aguda. Métodos: Foram incluídos doentes com traumatismo craniencefálico e hemorragia subaracnoide internados em unidades de cuidados intensivos. A abordagem na unidade de cuidados neurocríticos foi comparada à abordagem na unidade de cuidados intensivos polivalente geral. Os doentes com monitorização cerebral multimodal e pressão de perfusão cerebral ótima foram comparados aos que passaram por tratamento geral. Um bom desfecho foi definido como pontuação de 4 ou 5 na Glasgow outcome scale. Resultados: Dos 389 doentes, 237 foram admitidos na unidade de cuidados neurocríticos e 152 na unidade de cuidados intensivos geral. Doentes com abordagem em unidades de cuidados neurocríticos apresentaram menor risco de um mau desfecho (Odds ratio = 0,228). Um subgrupo de 69 doentes com monitorização cerebral multimodal (G1) foi comparado aos demais doentes (G2). Em G1 e G2, respectivamente, 59% e 23% dos doentes apresentaram bom desfecho na alta da unidade de cuidados intensivos; 64% e 31% apresentaram bom desfecho aos 28 dias; 76% e 50% apresentaram bom desfecho aos 3 meses (p < 0,001); e 77% e 58% apresentaram bom desfecho aos 6 meses (p = 0,005). Quando os desfechos foram ajustados para o escore de gravidade do SAPS II, usando o bom desfecho como variável dependente, os resultados foram os seguintes: para o G1, em comparação ao G2, a odds ratio foi de 4,607 na alta da unidade de cuidados intensivos (p < 0,001), 4,22 aos 28 dias (p = 0,001), 3,250 aos 3 meses (p = 0,001) e 2,529 aos 6 meses (p = 0,006). Os doentes com abordagem da pressão de perfusão cerebral ótima (n = 127) apresentaram melhor desfecho em todos os momentos de avaliação. A mortalidade desses doentes foi significativamente menor aos 28 dias (p = 0,001), aos 3 meses (p < 0,001) e aos 6 meses (p = 0,001). Conclusão: A monitorização cerebral multimodal com autorregulação e abordagem na unidade de cuidados neurocríticos foi associado a melhores desfechos e deve ser levado em consideração após lesão cerebral aguda grave.

Conectividad funcional a partir de la perfusión cerebral en pacientes epilépticos y con enfermedad de Parkinson / Functional connectivity from cerebral perfusion in patients with epilepsy and Parkinson's disease

Introducción: La epilepsia y la enfermedad de Parkinson han sido descritos como trastornos de redes neurales. El estudio de la conectividad por modalidades moleculares puede ser más relevante fisiológicamente que los basados en señales hemodinámicas. Objetivo: Proponer una metodología para la descripción de patrones de conectividad funcional a partir de la perfusión cerebral por tomografía por emisión de fotón único. Métodos: La metodología incluye cuatro pasos principales: preprocesamiento espacial, corrección del volumen parcial, cálculo del índice de perfusión y obtención de la matriz de conectividad funcional mediante el coeficiente de correlación de Pearson. Se implementó en 25 pacientes con distintos trastornos neurológicos: 15 con epilepsia farmacorresistente y 10 con enfermedad de Parkinson. Resultados: Se encontraron diferencias significativas entre los índice de perfusión de varias regiones de los hemisferios ipsilateral y contralateral tanto en pacientes con epilepsia del lóbulo frontal como en pacientes con epilepsia del lóbulo temporal. Igual resultado se obtuvo en los pacientes con enfermedad de Parkinson con distintos estadios de la enfermedad. Para cada grupo se identificaron patrones de conectividad funcional que involucran a regiones relacionadas con la patología en estudio. Conclusiones: Con el desarrollo de esta metodología se ha demostrado que la tomografía por emisión de fotón único aporta información valiosa para estudiar la organización de las redes funcionales del cerebro. Futuras investigaciones con mayor número de pacientes contribuirían a hacer inferencias sobre los correlatos neurales de los distintos trastornos cerebrales(AU)

Introduction: Epilepsy and Parkinson's disease have been described as disorders of neural networks. The study of connectivity by molecular modalities may be more physiologically relevant than those based on hemodynamic signals. Aim: The aim of the present work is to propose a methodology for the description of functional connectivity patterns from brain perfusion by single photon emission tomography. Methods: The methodology includes four main steps: spatial preprocessing, partial volume correction, calculation of the perfusion index and obtaining the functional connectivity matrix using Pearson's correlation coefficient. It was implemented in 25 patients with different neurological disorders: 15 with drug-resistant epilepsy and 10 suffering Parkinson's disease. Results: Significant differences were found between the perfusion indexes of various regions of the ipsilateral and contralateral hemispheres in both patients with frontal lobe epilepsy and patients with temporal lobe epilepsy. The same result was obtained in Parkinson's disease patients with different stages of the disease. For each group, functional connectivity patterns involving regions related to the pathology under study were identified. Conclusions: With the development of this methodology, it has been demonstrated that single photon emission tomography provides valuable information to study the organization of functional brain networks. Future research with a larger number of patients would contribute to make inferences about the neural correlates of the different brain disorders(AU)

Abnormal cerebral microvascular perfusion and reactivity in female offspring of reduced uterine perfusion pressure (RUPP) mice model.

Children born from women with preeclampsia have alterations in cerebral neurovascular development and a high risk for developing cognitive alterations. Because cerebral blood vessels are critical components in cerebrovascular development, we evaluated the brain microvascular perfusion and microvascular reactivity (exposed to external stimuli of warm and cold) in pups born to preeclampsia-like syndrome based on the reduction of uterine perfusion (RUPP). Also, we evaluate the angiogenic proteomic profile in those brains. Pregnant mice showed a reduction in uterine flow after RUPP surgery (-40 to 50%) associated with unfavorable perinatal results compared to sham mice. Furthermore, offspring of the RUPP mice exhibited reduced brain microvascular perfusion at postnatal day 5 (P5) compared with offspring from sham mice. This reduction was preferentially observed in females. Also, brain microvascular reactivity to external stimuli (warm and cold) was reduced in pups of RUPP mice. Furthermore, a differential expression of the angiogenic profile associated with inflammation, extrinsic apoptotic, cancer, and cellular senescence processes as the primary signaling impaired process was found in the brains of RUPP-offspring. Then, offspring (P5) from preeclampsia-like syndrome exhibit impaired brain perfusion and microvascular reactivity, particularly in female mice, associated with differential expression of angiogenic proteins in the brain tissue.

Ecografía Doppler transcraneal para estimar la presión intracraneal y presión de perfusión cerebral en pacientes pediátricos neurocríticos

RESUMEN La ecografía Doppler transcraneal es un método no invasivo que permite una adecuada monitorización de los diferentes parámetros que ayudan a definir conductas para los médicos intensivistas, sin embargo, su utilización no está generalizada entre las comunidades médicas que atienden niños con afecciones neurocríticas. Es propósito de los autores, actualizar el tema en estudio y presentar su experiencia en población pediátrica. Las indicaciones de este método provienen de investigaciones en pacientes adultos, se necesitan estudios multicéntricos en diferentes contextos clínicos para poder establecer esta técnica como un método de diagnóstico confiable en pacientes pediátricos. Concluimos que utilizar el Doppler transcraneal como prueba auxiliar en la estimación de la presión intracraneal y presión de perfusión cerebral, proporciona adoptar recursos terapéuticos frente al paciente lo más acertados posibles y brinda la posibilidad de hacer un seguimiento y evaluación de los tratamientos a pie de cama de forma mínimamente invasiva.

ABSTRACT Transcranial Doppler ultrasound is a non-invasive method that allows adequate monitoring of the different parameters that help define behaviors for intensivist physicians ; however, its use is not widespread among the medical communities that care for children with neurocritical conditions. It is the purpose of the authors to update the topic under study and present their experience with pediatric populations. The indications for this method come from research in adult patients . Multicenter studies in different clinical contexts are needed to establish this technique as a reliable diagnostic method in pediatric patients. We conclude that using transcranial Doppler as an auxiliary test in the estimation of intracranial pressure and cerebral perfusion pressure, provides the implementation of therapeutic resources in front of the patient as accurate as possible and offers the possibility of monitoring and evaluating bedside treatments in a minimally invasive way.

Bentall surgery and total arch repair with debranching of supra-aortic vessels: a case report.

BACKGROUND: The surgical approach to pathologies of the Ascending Thoracic Aorta (ATA) that compromise aortic root and the aortic arch is currently one of the most complex interventions in the spectrum of cardiac surgery, where circulatory arrest with cerebral perfusion plays an important role for Success postoperative and patient survival. CASE PRESENTATION: We present the case of a 57-year-old patient with the only history of arterial hypertension and an ATA Aneurysm that compromised segment of the aortic root up to segment 2 of the aortic arch. A successful Bentall surgery was performed, debranching supra-aortic vessels with Total Circulatory Arrest with Deep Hypothermic Cerebral Perfusion-Antegrade Bilateral. CONCLUSIONS: With the advent of new anesthetic and neuroprotection techniques, perioperative imaging protocols, advanced hemodynamic monitoring, and invaluable advances in perfusion and Extracorporeal Circulation with circulatory arrest, they have made this surgical challenge a valuable tool for today's cardiovascular surgeon.

Review of studies on dynamic cerebral autoregulation in the acute phase of stroke and the relationship with clinical outcome.

Acute stroke is associated with high morbidity and mortality. In the last decades, new therapies have been investigated with the aim of improving clinical outcomes in the acute phase post stroke onset. However, despite such advances, a large number of patients do not demonstrate improvement, furthermore, some unfortunately deteriorate. Thus, there is a need for additional treatments targeted to the individual patient. A potential therapeutic target is interventions to optimize cerebral perfusion guided by cerebral hemodynamic parameters such as dynamic cerebral autoregulation (dCA). This narrative led to the development of the INFOMATAS (Identifying New targets FOr Management And Therapy in Acute Stroke) project, designed to foster interventions directed towards understanding and improving hemodynamic aspects of the cerebral circulation in acute cerebrovascular disease states. This comprehensive review aims to summarize relevant studies on assessing dCA in patients suffering acute ischemic stroke, intracerebral haemorrhage, and subarachnoid haemorrhage. The review will provide to the reader the most consistent findings, the inconsistent findings which still need to be explored further and discuss the main limitations of these studies. This will allow for the creation of a research agenda for the use of bedside dCA information for prognostication and targeted perfusion interventions.

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

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

Presión positiva al final de la espiración, presión intracraneal y presión de perfusión cerebral en el paciente pediátrico crítico con traumatismo craneoencefálico grave / Positive end expiration pressure, intracranial pressure and cerebral perfusion pressure in the severe traumatic brain injury in child / Pressão positiva ao final da expiração, pressão intracraniana e pressão de perfusão cerebral em pacientes pediátricos criticamente enfermos com traumatismo cranioencefálico grave

Resumen: Introducción: el uso de presión positiva al final de la espiración mejora la oxigenación y recluta alvéolos, aunque también provoca alteraciones hemodinámicas e incrementa la presión intracraneal. Material y métodos: se realizó un estudio preexperimental de un solo grupo en pacientes pediátricos aquejados de traumatismo craneoencefálico grave, con hipoxemia asociada, tratados con diferentes niveles de presión positiva al final de la espiración, a los que se les monitorizó la presión intracraneal y la presión de perfusión cerebral para evaluar el efecto de esta maniobra ventilatoria en las variables intracraneales. Resultados: predominaron las edades entre cinco y 17 años, 14 (73.68%) y la escala de coma de Glasgow al ingreso de ocho a nueve puntos (47.36%). La presión intracraneal aumenta cuando la presión positiva al final de la espiración supera los 12 cmH2O. La escala de coma de Glasgow al ingreso de ocho puntos se asoció con secuelas ligeras o ausencia de secuelas (47.36%), todos los niños con tres puntos fallecieron. Conclusiones: el empleo de presión positiva al final de la espiración en el traumatismo craneoencefálico grave requiere de monitorización continua de la presión intracraneal. Corregir la hipertensión intracraneal y la inestabilidad hemodinámica son condiciones necesarias previas al tratamiento.

Abstract: Introduction: the use of positive end expiratory pressure improves oxygenation and recruits pulmonary alveoli, however at the same time it leads to hemodynamic changes and increase intracranial pressure. Material and methods: a prospective descriptive study was done with pediatric patients afflicted with severe traumatic brain injury associated with hypoxemia and treated with different levels of positive end expiratory pressure, to whom the intracranial pressure and cerebral perfusion pressure were monitored so as to evaluate the effect of this ventilation maneuver over the intracranial variables. Results: patients with age between 5-17 years old as well as male sex, 14 (73.68%) were predominant. 9 (47.36%) showed Glasgow coma scale of 8 points on admission. Intracranial pressure starts to rise when the positive end expiratory pressure exceeds 12 cmH2O. Glasgow coma scale with 8 points was associated with mild disability or no disability (47.36%). All the patients that scored 3 points died. Conclusions: the use of positive end expiratory pressure to correct hypoxemia was an applicable therapeutic alternative as long as continuous intracranial pressure monitoring was available in a systematic and personalized way. The correction of intracranial hypertension and hemodynamic instability were a necessary condition before using the ventilatory maneuver in these patients.

Resumo: Introdução: o uso de pressão positiva no final da expiração melhora a oxigenação e recruta alvéolos, embora também cause alterações hemodinâmicas e aumente a pressão intracraniana. Material e métodos: realizou-se um estudo pré-experimental de um único grupo em pacientes pediátricos vítimas de traumatismo cranioencefálico grave, com hipoxemia associada, tratados com diferentes níveis de pressão positiva ao final da expiração, nos quais foram monitoradas a pressão intracraniana e a pressão de perfusão cerebral, para avaliar o efeito desta manobra ventilatória em variáveis intracranianas. Resultados: predominou a faixa etária entre 5-17 anos, 14 (73.68%) e a escala de coma de Glasgow na admissão de 8 pontos, 9 (47.36%). A pressão intracraniana aumenta quando a pressão positiva no final da expiração excede 12 cmH2O. A escala de coma de Glasgow na admissão de 8 pontos foi associada a sequelas leves ou sem sequelas (47.36%), todas as crianças com 3 pontos morreram. Conclusões: a utilização de pressão positiva no final da expiração no TCE grave requer monitorização contínua da pressão intracraniana. A correção da hipertensão intracraniana e da instabilidade hemodinâmica são condições necessárias prévias ao tratamento.

Presión de perfusión cerebral en pacientes pediátricos con traumatismo craneoencefálico grave

RESUMEN Introducción: La mortalidad por traumatismo craneoencefálico grave (TCE g) en el paciente pediátrico, crece de forma directamente proporcional con la severidad de la injuria inicial. Se estima entre el 1 y 7 % de menores de 18 años afectados por dicha enfermedad en el mundo. La incidencia de muerte por esta causa oscila entre 2,8 y 3,75 por cada 100 000 niños anualmente. Metodología: Se realizó un estudio descriptivo de tipo correlacional en el servicio de cuidados intensivos pediátricos del Hospital General Docente "Roberto Rodríguez" de Morón, Ciego de Ávila, Cuba, en el período entre enero de 2003 y diciembre de 2017. Se incluyeron pacientes menores de 18 años. Las intervenciones fueron monitorización continua de la presión intracraneal, a través de una ventriculostomía al exterior y de la presión de perfusión cerebral y las variables presión intracraneal y presión de perfusión cerebral. Resultados: Se estudiaron 41 niños. Predominaron aquellos entre 5 y 17 años con 35 casos (85,3 %). La presión de perfusión cerebral en menores de 1 año fue >47mmhg en los dos casos estudiados, de 1-4 años >47mmhg en 2 casos y de 50mmhg en 23 casos (65,7 %) y 50mmhg se asoció con el grado V de la escala de resultados de Glasgow. Discusión: El control de la presión de perfusión cerebral con valores diferentes ajustados a los diferentes grupos de edades, a través de la manipulación de la presión intracraneal y la presión arterial media en el niño, mostró una adecuada relación con los resultados favorables.

ABSTRACT Introduction: Mortality from severe head injury (TBI g) in pediatric patients increases in direct proportion to the severity of the initial injury. It is estimated between 1 and 7% of children under 18 years of age affected by this disease in the world. The incidence of death from this cause ranges from 2.8 to 3.75 per 100,000 children annually. Methodology: A correlational descriptive study was carried out in the pediatric intensive care service of the General Teaching Hospital "Roberto Rodríguez" in Morón, Ciego de Ávila, Cuba, in the period between January 2003 and December 2017. Minor patients were included of 18 years. The interventions were continuous monitoring of intracranial pressure, through an external ventriculostomy and cerebral perfusion pressure and the variable intracranial pressure and cerebral perfusion pressure. Results: 41 children were studied. Those between 5 and 17 years old predominated with 35 cases (85.3%). Cerebral perfusion pressure in children under 1 year of age was> 47mmhg in the two cases studied, from 1-4 years> 47mmhg in 2 cases and 50mmhg in 23 cases (65.7%) and 50mmhg was associated with grade V on the Glasgow Outcome Scale. Discussion: The control of cerebral perfusion pressure with different values adjusted to the different age groups, through the manipulation of intracranial pressure and mean arterial pressure in the child, showed an adequate relationship with the favorable results.

Cerebral Hemodynamics and Intracranial Compliance Impairment in Critically Ill COVID-19 Patients: A Pilot Study.

Introduction: One of the possible mechanisms by which the new coronavirus (SARS-Cov2) could induce brain damage is the impairment of cerebrovascular hemodynamics (CVH) and intracranial compliance (ICC) due to the elevation of intracranial pressure (ICP). The main objective of this study was to assess the presence of CVH and ICC alterations in patients with COVID-19 and evaluate their association with short-term clinical outcomes. Methods: Fifty consecutive critically ill COVID-19 patients were studied with transcranial Doppler (TCD) and non-invasive monitoring of ICC. Subjects were included upon ICU admission; CVH was evaluated using mean flow velocities in the middle cerebral arteries (mCBFV), pulsatility index (PI), and estimated cerebral perfusion pressure (eCPP), while ICC was assessed by using the P2/P1 ratio of the non-invasive ICP curve. A CVH/ICC score was computed using all these variables. The primary composite outcome was unsuccessful in weaning from respiratory support or death on day 7 (defined as UO). Results: At the first assessment (n = 50), only the P2/P1 ratio (median 1.20 [IQRs 1.00-1.28] vs. 1.00 [0.88-1.16]; p = 0.03) and eICP (14 [11-25] vs. 11 [7-15] mmHg; p = 0.01) were significantly higher among patients with an unfavorable outcome (UO) than others. Patients with UO had a significantly higher CVH/ICC score (9 [8-12] vs. 6 [5-7]; p < 0.001) than those with a favorable outcome; the area under the receiver operating curve (AUROC) for CVH/ICC score to predict UO was 0.86 (95% CIs 0.75-0.97); a score > 8.5 had 63 (46-77)% sensitivity and 87 (62-97)% specificity to predict UO. For those patients undergoing a second assessment (n = 29), after a median of 11 (5-31) days, all measured variables were similar between the two time-points. No differences in the measured variables between ICU non-survivors (n = 30) and survivors were observed. Conclusions: ICC impairment and CVH disturbances are often present in COVID-19 severe illness and could accurately predict an early poor outcome.