Oxytocin Exhibits Neuroprotective Effects on Hippocampal Cultures under Severe Oxygen-Glucose Deprivation Conditions.

Perinatal asphyxia (PA) and hypoxic-ischemic encephalopathy can result in severe, long-lasting neurological deficits. In vitro models, such as oxygen-glucose deprivation (OGD), are used experimentally to investigate neuronal response to metabolic stress. However, multiple variables can affect the severity level of OGD/PA and may confound any measured treatment effect. Oxytocin (OXT) has emerged as a potential neuroprotective agent against the deleterious effects of PA. Previous studies have demonstrated OXT's potential to enhance neuronal survival in immature hippocampal cultures exposed to OGD, possibly by modulating gamma-aminobutyric acid-A receptor activity. Moreover, OXT's precise impact on developing hippocampal neurons under different severities of OGD/PA remains uncertain. In this study, we investigated the effects of OXT (0.1 µM and 1 µM) on 7-day-old primary rat hippocampal cultures subjected to 2 h OGD/sham normoxic conditions. Cell culture viability was determined using the resazurin assay. Our results indicate that the efficacy of 1 µM OXT treatment varied according to the severity of the OGD-induced lesion, exhibiting a protective effect (p = 0.022) only when cellular viability dropped below 49.41% in non-treated OGD cultures compared to normoxic ones. Furthermore, administration of 0.1 µM OXT did not yield significant effects, irrespective of lesion severity (p > 0.05). These findings suggest that 1 µM OXT treatment during OGD confers neuroprotection exclusively in severe lesions in hippocampal neurons after 7 days in vitro. Further research is warranted to elucidate the mechanisms involved in OXT-mediated neuroprotection.

Beyond Control: Temperature Burden in Patients with Spontaneous Subarachnoid Hemorrhage-An Observational Study.

BACKGROUND: Temperature abnormalities are common after spontaneous subarachnoid hemorrhage (SAH). Here, we aimed to describe the evolution of temperature burden despite temperature control and to assess its impact on outcome parameters. METHODS: This retrospective observational study of prospectively collected data included 375 consecutive patients with SAH admitted to the neurological intensive care unit between 2010 and 2022. Daily fever (defined as the area over the curve above 37.9 °C multiplied by hours with fever) and spontaneous hypothermia burden (< 36.0 °C) were calculated over the study period of 16 days. Generalized estimating equations were used to calculate risk factors for increased temperature burdens and the impact of temperature burden on outcome parameters after correction for predefined variables. RESULTS: Patients had a median age of 58 years (interquartile range 49-68) and presented with a median Hunt & Hess score of 3 (interquartile range 2-5) on admission. Fever (temperature > 37.9 °C) was diagnosed in 283 of 375 (76%) patients during 14% of the monitored time. The average daily fever burden peaked between days 5 and 10 after admission. Higher Hunt & Hess score (p = 0.014), older age (p = 0.033), and pneumonia (p = 0.022) were independent factors associated with delayed fever burden between days 5 and 10. Increased fever burden was independently associated with poor 3-month functional outcome (modified Rankin Scale 3-6, p = 0.027), poor 12-month functional outcome (p = 0.020), and in-hospital mortality (p = 0.045), but not with the development of delayed cerebral ischemia (p = 0.660) or intensive care unit length of stay (p = 0.573). Spontaneous hypothermia was evident in the first three days in patients with a higher Hunt & Hess score (p < 0.001) and intraventricular hemorrhage (p = 0.047). Spontaneous hypothermia burden was not associated with poor 3-month outcome (p = 0.271). CONCLUSIONS: Early hypothermia was followed by fever after SAH. Increased fever time burden was associated with poor functional outcome after SAH and could be considered for neuroprognostication.

Cognitive, Mental Health, Functional, and Quality of Life Outcomes 1 Year After Spontaneous Subarachnoid Hemorrhage: A Prospective Observational Study.

BACKGROUND: Patients with spontaneous subarachnoid hemorrhage (SAH) frequently encounter cognitive dysfunction and mental health issues with negative effects on health-related quality of life (HR-QoL). Here, we aimed to describe the prevalence of cognitive deficits, mental health problems, and HR-QoL impairments 1 year after SAH. METHODS: In this prospective observational study, 177 patients with SAH admitted to our neurointensive care unit over a time span of ten years followed the invitation for an in-person 1-year follow-up, including a standardized neuropsychological test battery. Mental health issues (anxiety and depression) and HR-QoL were evaluated using questionnaires (Hospital Anxiety and Depression Scale; 36-item Short Form questionnaire). Functional outcome was assessed with the modified Rankin Scale (mRS) score. RESULTS: Patients were 54 years of age (interquartile range 47-62 years) and presented with a median Hunt and Hess score of 2 (interquartile range 1-3) at admission. Most patients (93%) achieved good functional 1-year outcomes (mRS score 0-2). Seventy-one percent of patients had deficits in at least one cognitive domain, with memory deficits being the most prevalent (51%), followed by deficits in executive functions (36%), visuoconstruction (34%), and attention (21%). Even patients with perimesencephalic SAH (18%) or with full functional recovery (mRS score = 0, 46%) had a comparable prevalence of cognitive deficits (61% and 60%, respectively). Symptoms of depression and anxiety were reported by 16% and 33% of patients, respectively. HR-QoL was impaired in 37% (55 of 147). Patients with cognitive deficits (p = 0.001) or mental health issues (p < 0.001) more frequently reported impaired HR-QoL. CONCLUSIONS: Most patients with SAH have cognitive deficits and mental health issues 1 year after SAH. These deficits impair patients' quality of life.

Blood Pressure Changes in Association with Nimodipine Therapy in Patients with Spontaneous Subarachnoid Hemorrhage.

BACKGROUND: Nimodipine is recommended to prevent delayed cerebral ischemia in patients with spontaneous subarachnoid hemorrhage (SAH). Here, we studied hemodynamic side effects of different nimodipine formulations (per os [PO] and intravenous [IV]) in patients with SAH undergoing continuous blood pressure monitoring. METHODS: This observational cohort study includes consecutive patients with SAH (271 included in the IV group, 49 in the PO group) admitted to a tertiary care center between 2010 and 2021. All patients received prophylactic IV or PO nimodipine. Hemodynamic responses were evaluated based on median values within the first hour after continuous IV nimodipine initiation or PO nimodipine application (601 intakes within 15 days). Significant changes were defined as > 10% drop in systolic blood pressure (SBP) or diastolic blood pressure from baseline (median values 30 min before nimodipine application). With the use of multivariable logistic regression, risk factors associated with SBP drops were identified. RESULTS: Patients were admitted with a median Hunt & Hess score of 3 (2-5; IV 3 [2-5], PO 1 [1-2], p < 0.001) and were 58 (49-69) years of age. Initiation of IV nimodipine was associated with a > 10% SBP drop in 30% (81/271) of patients, with a maximum effect after 15 min. A start or increase in noradrenaline was necessary in 136/271 (50%) patients, and colloids were administered in 25/271 (9%) patients within 1 h after IV nimodipine initiation. SBP drops > 10% occurred after 53/601 (9%) PO nimodipine intakes, with a maximum effect after 30-45 min in 28/49 (57%) patients. Noradrenaline application was uncommon (3% before and 4% after nimodipine PO intake). Hypotensive episodes to an SBP < 90 mm Hg were not observed after IV or PO nimodipine application. In multivariable analysis, only a higher SBP at baseline was associated with a > 10% drop in SBP after IV (p < 0.001) or PO (p = 0.001) nimodipine application, after adjusting for the Hunt & Hess score on admission, age, sex, mechanical ventilation, days after intensive care unit admission, and delayed cerebral ischemia. CONCLUSIONS: Significant drops in SBP occur in one third of patients after the start of IV nimodipine and after every tenth PO intake. Early recognition and counteracting with vasopressors or fluids seems necessary to prevent hypotensive episodes.

The Loss of Temporal Muscle Volume is Associated with Poor Outcome in Patients with Subarachnoid Hemorrhage: An Observational Cohort Study.

BACKGROUND: Intensive care unit (ICU) acquired weakness is a major contributor to poor functional outcome of ICU patients. Quantification of temporal muscle volume assessed on routine computed tomography (CT) scans may serve as a biomarker for muscle wasting in patients suffering from acute brain injury. METHODS: This is a retrospective analysis of prospectively collected data. Temporal muscle volume was assessed on head CT scans of consecutive patients with spontaneous subarachnoid hemorrhage within prespecified time frames (on admission, then weekly ± 2 days). Whenever possible, temporal muscle volume was assessed bilaterally and averaged for the analysis. Poor functional outcome was defined as a 3-month modified Rankin Scale Score ≥ 3. Statistical analysis was performed using generalized estimating equations to handle repeated measurements within individuals. RESULTS: The analysis comprised 110 patients with a median Hunt & Hess score of 4 (interquartile range 3-5). Median age was 61 (50-70) years, 73 patients (66%) were women. Baseline temporal muscle volume was 18.5 ± 0.78 cm3 and significantly decreased over time (p < 0.001) by a mean of 7.9% per week. Higher disease severity (p = 0.002), hydrocephalus (p = 0.020), pneumonia (p = 0.032), and bloodstream infection (p = 0.015) were associated with more pronounced muscle volume loss. Patients with poor functional outcome had smaller muscle volumes 2 and 3 weeks after subarachnoid hemorrhage compared with those with good outcome (p = 0.025). The maximum muscle volume loss during ICU stay was greater in patients with poor functional outcome (- 32.2% ± 2.5% vs. - 22.7% ± 2.5%, p = 0.008). The hazard ratio for poor functional outcome was 1.027 (95% confidence interval 1.003-1.051) per percent of maximum muscle volume loss. CONCLUSIONS: Temporal muscle volume, which is easily assessable on routine head CT scans, progressively decreases during the ICU stay after spontaneous subarachnoid hemorrhage. Because of its association with disease severity and functional outcome, it may serve as a biomarker for muscle wasting and outcome prognostication.

Brain microdialysate tau dynamics predict functional and neurocognitive recovery after poor-grade subarachnoid haemorrhage.

Subarachnoid haemorrhage is a devastating disease that results in neurocognitive deficits and a poor functional outcome in a considerable proportion of patients. In this study, we investigated the prognostic value of microtubule-associated tau protein measured in the cerebral microdialysate for long-term functional and neuropsychological outcomes in poor-grade subarachnoid haemorrhage patients. We recruited 55 consecutive non-traumatic subarachnoid haemorrhage patients who underwent multimodal neuromonitoring, including cerebral microdialysis. Mitochondrial dysfunction was defined as lactate-to-pyruvate ratio >30 together with pyruvate >70 mmol/L and metabolic distress as lactate-to-pyruvate ratio >40. The multidimensional 12-month outcome was assessed by means of the modified Rankin scale (poor outcome: modified Rankin scale ≥4) and a standardized neuropsychological test battery. We used multivariable generalized estimating equation models to assess associations between total microdialysate-tau levels of the first 10 days after admission and hospital complications and outcomes. Patients were 56 ± 12 years old and presented with a median Hunt & Hess score of 5 (interquartile range: 3-5). Overall mean total microdialysate-tau concentrations were highest within the first 24 h (5585 ± 6291 pg/mL), decreased to a minimum of 2347 ± 4175 pg/mL on Day 4 (P < 0.001) and remained stable thereafter (P = 0.613). Higher total microdialysate-tau levels were associated with the occurrence of delayed cerebral ischaemia (P = 0.001), episodes of metabolic distress (P = 0.002) and mitochondrial dysfunction (P = 0.034). Patients with higher tau levels had higher odds for a poor 12-month functional outcome (adjusted odds ratio: 2.61; 95% confidence interval: 1.32-5.17; P = 0.006) and impaired results in the trail making test-B (adjusted odds ratio: 3.35; 95% confidence interval: 1.16-9.68; P = 0.026) indicative of cognitive flexibility. Total microdialysate-tau levels significantly decreased over the first 10 days (P < 0.05) in patients without delayed cerebral ischaemia or good functional outcomes and remained high in those with delayed cerebral ischaemia and poor 12-month outcomes, respectively. Dynamic changes of total tau in the cerebral microdialysate may be a useful biomarker for axonal damage associated with functional and neurocognitive recovery in poor-grade subarachnoid haemorrhage patients. In contrast, ongoing axonal damage beyond Day 3 after bleeding indicates a higher risk for delayed cerebral ischaemia as well as a poor functional outcome.

The location of intraparenchymal bleeding determines functional outcome after spontaneous subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Non-traumatic subarachnoid hemorrhage (SAH) is a devastating disease associated with high morbidity and mortality. A higher blood burden and the presence of intraparenchymal extension of the bleeding (intracerebral hemorrhage [ICH]) are well known predictors of poor outcome. Only few studies have addressed the role of hematoma location on patient's functional outcome. The main aims were to compare clinical and radiographic characteristics between SAH patients with and without ICH and to compare different ICH localizations in relation to long-term functional outcome. METHODS: We prospectively collected data on 280 consecutive SAH patients (aneurysmal and non-aneurysmal) admitted to a tertiary care hospital between 2010 and 2017 and assessed the initial computed tomography scans of the brain acquired after intensive care unit admission. Poor functional outcome was defined as a modified Rankin Scale score >2, 3 months after SAH. We used multivariable logistic linear regression to investigate associations between ICH location and clinical variables as well as functional outcome. RESULTS: Intraparenchymal extension of the hemorrhage was observed in 59/280 patients (21%). The median (interquartile range) ICH volume was 11.3 (4.9-16.2) ml and the location was supratentorial in 55/59 patients (93%). Most parenchymal hemorrhages were located in the frontal (n = 24.41%) and temporal lobes (n = 12.21%), followed by insular ICH (n = 7.12%), corpus callosum (n = 6.10%), parietal (n = 2.3%) and occipital locations (n = 2.3%). Among SAH patients with ICH, those with lesions located in the corpus callosum (n = 6/59) had a significantly higher risk of 3-month poor functional outcome in comparison to all other ICH locations, even after adjusting for Hunt and Hess grade and age (adjusted odds ratio [adjOR] 50.5, 95% confidence interval [CI] 1.3-2004.2, p = 0.034). These results remained robust when comparing the whole SAH cohort (adjOR 21.7, 95% CI 1.4-347.8, p = 0.030).  CONCLUSIONS: Intraparenchymal bleeding in patients with non-traumatic SAH, in particular that involving the corpus callosum, strongly predicts functional outcome.

Long-Term Clinical Trajectory of Patients with Subarachnoid Hemorrhage: Linking Acute Care and Neurorehabilitation.

BACKGROUND: Despite improvements in the critical care management of subarachnoid hemorrhage (SAH), a substantial number of patients still suffer from disabilities. In most areas of the world, longitudinal follow-up is not routinely performed, and the patient's trajectory remains unknown. METHODS: We prospectively collected data of 298 consecutive patients with spontaneous SAH and evaluated clinical trajectories at discharge, 3 months, and 1 year after SAH. In a subgroup of patients transferred to a local neurorehabilitation center (Rehab-Hochzirl), we studied the effects of rehabilitation intensity on clinical trajectories. Any decrease in the modified Rankin Scale (mRS) was defined as an improvement, with mRS ≤ 2 indicating good outcome. We used multivariate generalized linear models to investigate associations with clinical trajectories. RESULTS: Out of the 250 surviving patients, 35% were transferred directly to Rehab-Hochzirl (n = 87 of 250; mRS at discharge = 4), 11% were transferred to another rehabilitation center (n = 27 of 250; mRS = 1), 1% were transferred to a nursing home (n = 3 of 250; mRS = 5), 21% were transferred to their country of origin (n = 52 of 250; mRS = 4), and 32% (n = 79 of 250; mRS = 1) were discharged home. Functional outcome improved in 57% (n = 122 of 215) of patients during the first 3 months, with an additional 16% (35 of 215) improving between 3 and 12 months, resulting in an overall improvement in 73% (n = 157 of 215) of survivors. After 1 year, 60% (n = 179 of 250) of patients were functionally independent. A lower Hunt and Hess scale score at intensive care unit admission, younger age, a lower mRS at intensive care unit discharge, fewer days on mechanical ventilation, and male sex were independently associated with better functional recovery. Although the subgroup of patients transferred to Rehab-Hochzirl were more severely affected, 60% (52 of 87) improved during inpatient neurorehabilitation. CONCLUSIONS: Our results indicate ongoing functional improvement in a substantial number of patients with SAH throughout a follow-up period of 12 months. This effect was also observed in patients with severe disability receiving inpatient neurorehabilitation.

Neurological outcomes 1 year after COVID-19 diagnosis: A prospective longitudinal cohort study.

BACKGROUND AND PURPOSE: Neurological sequelae from coronavirus disease 2019 (COVID-19) may persist after recovery from acute infection. Here, the aim was to describe the natural history of neurological manifestations over 1 year after COVID-19. METHODS: A prospective, multicentre, longitudinal cohort study in COVID-19 survivors was performed. At a 3-month and 1-year follow-up, patients were assessed for neurological impairments by a neurological examination and a standardized test battery including the assessment of hyposmia (16-item Sniffin' Sticks test), cognitive deficits (Montreal Cognitive Assessment < 26) and mental health (Hospital Anxiety and Depression Scale and Post-traumatic Stress Disorder Checklist 5). RESULTS: Eighty-one patients were evaluated 1 year after COVID-19, out of which 76 (94%) patients completed a 3-month and 1-year follow-up. Patients were 54 (47-64) years old and 59% were male. New and persistent neurological disorders were found in 15% (3 months) and 12% (10/81; 1 year). Symptoms at 1-year follow-up were reported by 48/81 (59%) patients, including fatigue (38%), concentration difficulties (25%), forgetfulness (25%), sleep disturbances (22%), myalgia (17%), limb weakness (17%), headache (16%), impaired sensation (16%) and hyposmia (15%). Neurological examination revealed findings in 52/81 (64%) patients without improvement over time (3 months, 61%, p = 0.230) including objective hyposmia (Sniffin' Sticks test <13; 51%). Cognitive deficits were apparent in 18%, whereas signs of depression, anxiety and post-traumatic stress disorders were found in 6%, 29% and 10% respectively 1 year after infection. These mental and cognitive disorders had not improved after the 3-month follow-up (all p > 0.05). CONCLUSION: Our data indicate that a significant patient number still suffer from neurological sequelae including neuropsychiatric symptoms 1 year after COVID-19 calling for interdisciplinary management of these patients.

Factors associated with impaired quality of life three months after being diagnosed with COVID-19.

PURPOSE: To assess patient characteristics associated with health-related quality of life (HR-QoL) and its mental and physical subcategories 3 months after diagnosis with COVID-19. METHODS: In this prospective multicentre cohort study, HR-QoL was assessed in 90 patients using the SF-36 questionnaire (36-item Short Form Health Survey), which consists of 8 health domains that can be divided into a mental and physical health component. Mental health symptoms including anxiety, depression, and post-traumatic stress disorders were evaluated using the Hospital Anxiety and Depression Scale (HADS) and Post-traumatic Stress Disorder Checklist-5 (PCL-5) 3 months after COVID-19. Using descriptive statistics and multivariable regression analysis, we identified factors associated with impaired HR-QoL 3 months after COVID-19 diagnosis. RESULTS: Patients were 55 years of age (IQR, 49-63; 39% women) and were classified as severe (23%), moderate (57%), or mild (20%) according to acute disease severity. HR-QoL was impaired in 28/90 patients (31%). Younger age [per year, adjOR (95%CI) 0.94 (0.88-1.00), p = 0.049], longer hospitalization [per day, adjOR (95%CI) 1.07 (1.01-1.13), p = 0.015], impaired sleep [adjOR (95%CI) 5.54 (1.2-25.61), p = 0.028], and anxiety [adjOR (95%CI) 15.67 (3.03-80.99), p = 0.001) were independently associated with impaired HR-QoL. Twenty-nine percent (n = 26) scored below the normal range on the mental health component of the SF-36 and independent associations emerged for anxiety, depression, and self-reported numbness. Impairments in the physical health component of the SF-36 were reported by 12 (13%) patients and linked to hypogeusia and fatigue. CONCLUSION: Every third patient reported a reduction in HR-QoL 3 months after COVID-19 diagnosis and impairments were more prominent in mental than physical well-being.

Factors Associated With Prolonged Mechanical Ventilation in Patients With Subarachnoid Hemorrhage-The RAISE Score.

OBJECTIVES: Patients suffering from spontaneous subarachnoid hemorrhage frequently require mechanical ventilation. Here, we aimed to identify factors associated with prolonged mechanical ventilation in subarachnoid hemorrhage patients and to create a new predictive score for prolonged mechanical ventilation. DESIGN: Prospective cohort study with retrospective data analysis. SETTING: Neurocritical care unit at a tertiary academic medical center. PATIENTS: Two hundred ninety-seven consecutive nontraumatic adult subarachnoid hemorrhage patients. METHODS: In patients with mechanical ventilation, we identified factors associated with mechanical ventilation greater than 48 hours, greater than 7 days, and greater than 14 days compared with mechanical ventilation less than or equal to 48 hours, less than or equal to 7 days, or less than or equal to 14 days in multivariable generalized linear models. Ventilated patients who died before 48 hours, 7 days, or 14 days and those never ventilated were excluded from the respective analysis. We incorporated those factors into a new prognostic score (the RAISE score) to predict prolonged mechanical ventilation greater than 7 days. The calculation was based on a random dataset of 60% of subarachnoid hemorrhage patients and was internally validated. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were 57 years old (interquartile range, 47-68 yr) and presented with a median Hunt and Hess grade of 3 (1-5). Two hundred forty-two patients (82%) required mechanical ventilation for 9 days (2-20 d). In multivariable analysis, a higher Acute Physiology Score was associated with mechanical ventilation greater than 48 hours, greater than 7 days, and greater than 14 days, a higher Hunt and Hess grade with greater than 7 days and greater than 14 days. Early neuroimaging findings were associated with mechanical ventilation greater than 48 hours (hydrocephalus; high-grade Subarachnoid Hemorrhage Early Brain Edema Score), greater than 7 days (high-grade Subarachnoid Hemorrhage Early Brain Edema Score, co-occurrence of intracerebral bleeding) but not with prolonged mechanical ventilation greater than 14 days. The RAISE score, including age, Acute Physiology Score, Hunt and Hess grade, Subarachnoid Hemorrhage Early Brain Edema Score, and the co-occurrence of intracerebral hemorrhage accurately stratified patients by prolonged mechanical ventilation greater than 7 days (C-statistic 0.932). A RAISE score of 12 predicted 60% likelihood of mechanical ventilation greater than 7 days. CONCLUSIONS: Initial disease severity and neuroimaging findings detected within 24 hours after ICU admission were associated with the need for prolonged mechanical ventilation in patients with subarachnoid hemorrhage. These results may be helpful for patient families and caregivers to better anticipate the course of therapy.

The effect of the volemic and cardiac status on brain oxygenation in patients with subarachnoid hemorrhage: a bi-center cohort study.

BACKGROUND: Fluid management in patients after subarachnoid hemorrhage (SAH) aims at the optimization of cerebral blood flow and brain oxygenation. In this study, we investigated the effects of hemodynamic management on brain oxygenation by integrating advanced hemodynamic and invasive neuromonitoring. METHODS: This observational cohort bi-center study included data of consecutive poor-grade SAH patients who underwent pulse contour cardiac output (PiCCO) monitoring and invasive neuromonitoring. Fluid management was guided by the transpulmonary thermodilution system and aimed at euvolemia (cardiac index, CI ≥ 3.0 L/min/m2; global end-diastolic index, GEDI 680-800 mL/m2; stroke volume variation, SVV < 10%). Patients were managed using a brain tissue oxygenation (PbtO2) targeted protocol to prevent brain tissue hypoxia (BTH, PbtO2 < 20 mmHg). To assess the association between CI and PbtO2 and the effect of fluid challenges on CI and PbtO2, we used generalized estimating equations to account for repeated measurements. RESULTS: Among a total of 60 included patients (median age 56 [IQRs 47-65] years), BTH occurred in 23% of  the monitoring time during the first 10 days since admission. Overall, mean CI was within normal ranges (ranging from 3.1 ± 1.3 on day 0 to 4.1 ± 1.1 L/min/m2 on day 4). Higher CI levels were associated with higher PbtO2 levels (Wald = 14.2; p < 0.001). Neither daily fluid input nor fluid balance was associated with absolute PbtO2 levels (p = 0.94 and p = 0.85, respectively) or the occurrence of BTH (p = 0.68 and p = 0.71, respectively). PbtO2 levels were not significantly different in preload dependent patients compared to episodes of euvolemia. PbtO2 increased as a response to fluid boluses only if BTH was present at baseline (from 13 ± 6 to 16 ± 11 mmHg, OR = 13.3 [95% CI 2.6-67.4], p = 0.002), but not when all boluses were considered (p = 0.154). CONCLUSIONS: In this study a moderate association between increased cardiac output and brain oxygenation was observed. Fluid challenges may improve PbtO2 only in the presence of baseline BTH. Individualized hemodynamic management requires advanced cardiac and brain monitoring in critically ill SAH patients.

Brain Temperature Influences Intracranial Pressure and Cerebral Perfusion Pressure After Traumatic Brain Injury: A CENTER-TBI Study.

BACKGROUND: After traumatic brain injury (TBI), fever is frequent. Brain temperature (BT), which is directly linked to body temperature, may influence brain physiology. Increased body and/or BT may cause secondary brain damage, with deleterious effects on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and outcome. METHODS: Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI), a prospective multicenter longitudinal study on TBI in Europe and Israel, includes a high resolution cohort of patients with data sampled at a high frequency (from 100 to 500 Hz). In this study, simultaneous BT, ICP, and CPP recordings were investigated. A mixed-effects linear model was used to examine the association between different BT levels and ICP. We additionally focused on changes in ICP and CPP during the episodes of BT changes (Δ BT ≥ 0.5 °C lasting from 15 min to 3 h) up or downward. The significance of ICP and CPP variations was estimated with the paired samples Wilcoxon test (also known as Wilcoxon signed-rank test). RESULTS: Twenty-one patients with 2,435 h of simultaneous BT and ICP monitoring were studied. All patients reached a BT of 38 °C and experienced at least one episode of ICP above 20 mm Hg. The linear mixed-effects model revealed an association between BT above 37.5 °C and higher ICP levels that was not confirmed for lower BT. We identified 149 episodes of BT changes. During BT elevations (n = 79) ICP increased, whereas CPP was reduced; opposite ICP and CPP variations occurred during episodes of BT reduction (n = 70). All these changes were of moderate clinical relevance (increase of ICP of 4.5 and CPP decrease of 7.5 mm Hg for BT rise, and ICP reduction of 1.7 and CPP elevation of 3.7 mm Hg during BT defervescence), even if statistically significant (p < 0.0001). It has to be noted, however, that a number of therapeutic interventions against intracranial hypertension was documented during those episodes. CONCLUSIONS: Patients after TBI usually develop BT > 38 °C soon after the injury. BT may influence brain physiology, as reflected by ICP and CPP. An association between BT exceeding 37.5 °C and a higher ICP was identified but not confirmed for lower BT ranges. The relationship between BT, ICP, and CPP become clearer during rapid temperature changes. During episodes of temperature elevation, BT seems to have a significant impact on ICP and CPP.

Individualized blood pressure targets in the postoperative care of patients with intracerebral hemorrhage.

OBJECTIVE: Recent guidelines recommend targeting a systolic blood pressure (SBP) < 140 mm Hg in the early management of patients with spontaneous intracerebral hemorrhage (ICH). The optimal SBP targets for ICH patients after hematoma evacuation (HE) remain unclear. Here, the authors aimed to define the optimal SBP range based on multimodal neuromonitoring data. METHODS: Forty poor-grade ICH patients who had undergone HE and then monitoring of intracerebral pressure, brain tissue oxygen tension (PbtO2), and cerebral metabolism (via cerebral microdialysis [CMD]) were prospectively included. Episodes of brain tissue hypoxia (BTH) (1-hour averaged PbtO2 < 20 mm Hg) and metabolic distress (CMD-lactate/pyruvate ratio [LPR] ≥ 40) were identified and linked to corresponding parameters of hemodynamic monitoring (SBP and cerebral perfusion pressure [CPP]). Multivariable regression analysis was performed using generalized estimating equations to identify associations between SBP levels, PbtO2, and brain metabolism. RESULTS: The mean patient age was 60 (range 51-66) years and the median [IQR] initial ICH volume was 47 [29-60] ml. In multivariable models adjusted for Glasgow Coma Scale score, probe location, ICH volume, and age, lower SBP was independently associated with a higher risk of BTH (≤ 120 mm Hg: adjusted OR 2.9, p = 0.007; 120-130 mm Hg: adj OR 2.4, p = 0.002; 130-140 mm Hg: adj OR 1.6, p = 0.017) compared to a reference range of 140-150 mm Hg at the level of the foramen interventriculare Monroi, which corresponded to a CPP of 70-80 mm Hg and SBP levels between 150 and 160 mm Hg at the heart level. After exclusion of episodes with mitochondrial dysfunction, SBP targets < 140 mm Hg were associated with higher odds of cerebral metabolic distress (≤ 130 mm Hg: OR 2.5, p = 0.041; 130-140 mm Hg: OR 2.3, p = 0.033). Patients with a modified Rankin Scale score ≥ 5 at neurological ICU discharge more often exhibited BTH than patients with better outcomes (51% vs 10%, p = 0.003). CONCLUSIONS: These data suggest that lower SPB and CPP levels are associated with a higher risk for BTH. Further studies are needed to evaluate whether a higher SPB target may prevent BTH and improve outcomes.

Association of Dose of Intracranial Hypertension with Outcome in Subarachnoid Hemorrhage.

BACKGROUND: In patients with aneurysmal subarachnoid hemorrhage (aSAH) the burden of intracranial pressure (ICP) and its contribution to outcomes remains unclear. In this multicenter study, the independent association between intensity and duration, or "dose," of episodes of intracranial hypertension and 12-month neurological outcomes was investigated. METHODS: This was a retrospective analysis of multicenter prospectively collected data of 98 adult patients with aSAH amendable to treatment. Patients were admitted to the intensive care unit of two European centers (Medical University of Innsbruck [Austria] and San Gerardo University Hospital of Monza [Italy]) from 2009 to 2013. The dose of intracranial hypertension was visualized. The obtained visualizations allowed us to investigate the association between intensity and duration of episodes of intracranial hypertension and the 12-month neurological outcomes of the patients, assessed with the Glasgow Outcome Score. The independent association between the cumulative dose of intracranial hypertension and outcome for each patient was investigated by using multivariable logistic regression models corrected for age, occurrence of delayed cerebral ischemia, and the Glasgow Coma Scale score at admission. RESULTS: The combination of duration and intensity defined the tolerance to intracranial hypertension for the two cohorts of patients. A semiexponential transition divided ICP doses that were associated with better outcomes (in blue) with ICP doses associated with worse outcomes (in red). In addition, in both cohorts, an independent association was found between the cumulative time that the patient experienced ICP doses in the red area and long-term neurological outcomes. The ICP pressure-time burden was a stronger predictor of outcomes than the cumulative time spent by the patients with an ICP greater than 20 mmHg. CONCLUSIONS: In two cohorts of patients with aSAH, an association between duration and intensity of episodes of elevated ICP and 12-month neurological outcomes could be demonstrated and was visualized in a color-coded plot.

Hyperactive delirium in patients after non-traumatic subarachnoid hemorrhage.

PURPOSE: Hyperactive delirium is common after subarachnoid hemorrhage (SAH). We aimed to identify risk factors for delirium and to evaluate its impact on outcome. METHODS: We collected daily Richmond Agitation Sedation Scale (RASS) and Intensive Care Delirium Screening Checklist (ICDSC) scores in 276 SAH patients. Hyperactive delirium was defined as ICDSC ≥4 when RASS was >0. We investigated risk factors for delirium and its association with 3-month functional outcome using generalized linear models. RESULTS: Patients were 56 (IQR 47-67) years old and had a Hunt&Hess (H&H) grade of 3 (IQR 1-5). Sixty-five patients (24%) developed hyperactive delirium 6 (IQR 3-16) days after SAH. In multivariable analysis, mechanical ventilation>48 h (adjOR = 4.46; 95%-CI = 1.89-10.56; p = 0.001), the detection of an aneurysm (adjOR = 4.38; 95%-CI = 1.48-12.97; p = 0.008), a lower H&H grade (adjOR = 0.63; 95%-CI = 0.48-0.83; p = 0.001) and a pre-treated psychiatric disorder (adjOR = 3.17; 95%-CI = 1.14-8.83; p = 0.027) were associated with the development of delirium. Overall, delirium was not associated with worse outcome (p = 0.119). Interestingly, patients with delirium more often had a modified Rankin Scale Score (mRS) of 1-3 (77%) compared to an mRS of 0 (14%) or 4-6 (9%). CONCLUSION: Our data indicate that hyperactive delirium is common after SAH patients and requires a certain degree of brain connectivity based ono the highest prevalence found in SAH patients with intermediate outcomes.

The Importance of PbtO2 Probe Location for Data Interpretation in Patients with Intracerebral Hemorrhage.

BACKGROUND/OBJECTIVE: Monitoring of brain tissue oxygen tension (PbtO2) provides insight into brain pathophysiology after intracerebral hemorrhage (ICH). Integration of probe location is recommended to optimize data interpretation. So far, little is known about the importance of PbtO2 catheter location in ICH patients. METHODS: We prospectively included 40 ICH patients after hematoma evacuation (HE) who required PbtO2-monitoring. PbtO2-probe location was evaluated in all head computed tomography (CT) scans within the first 6 days after HE and defined as location in the healthy brain tissue or perilesional when the catheter tip was located within 1 cm of a focal lesion (hypodense or hyperdense). Generalized estimating equations were used to investigate levels of PbtO2 in relation to different probe locations. RESULTS: Patients were 60 [51-66] years old and had a median ICH-volume of 47 [29-60] mL. Neuromonitoring probes remained for a median of 6 [2-11] days. PbtO2-probes were located in healthy brain tissue in 18/40 (45%) patients and in perilesional brain tissue in 22/40 (55%) patients. In the acute phase after HE (0-72 h), PbtO2 levels were significantly lower (21 ± 12 mmHg vs. 29 ± 10 mmHg, p = 0.010) and brain tissue hypoxia (BTH) was more common in the perilesional area as compared to healthy brain tissue (46% vs. 19%, adjOR 4.0, 95% CI 1.54-10.58, p = 0.005). Episodes of BTH significantly decreased over time in patients with probes in perilesional location (p = 0.001) but remained stable in normal appearing area (p = 0.485). A significant association between BTH and poor functional outcome was only found when probes were located in the perilesional brain tissue (adjOR 6.6, 95% CI 1.3-33.8, p = 0.023). CONCLUSIONS: In the acute phase, BTH was more common in the perilesional area compared to healthy brain tissue. The improvement of BTH in the perilesional area over time may be the result of targeted treatment interventions and tissue regeneration. Due to the localized measurement of invasive neuromonitoring devices, integration of probe location in the clinical management of ICH patients and in research protocols seems mandatory.

Brain temperature regulation in poor-grade subarachnoid hemorrhage patients - A multimodal neuromonitoring study.

Elevated body temperature (Tcore) is associated with poor outcome after subarachnoid hemorrhage (SAH). Brain temperature (Tbrain) is usually higher than Tcore. However, the implication of this difference (Tdelta) remains unclear. We aimed to study factors associated with higher Tdelta and its association with outcome. We included 46 SAH patients undergoing multimodal neuromonitoring, for a total of 7879 h of averaged data of Tcore, Tbrain, cerebral blood flow, cerebral perfusion pressure, intracranial pressure and cerebral metabolism (CMD). Three-months good functional outcome was defined as modified Rankin Scale ≤2. Tbrain was tightly correlated with Tcore (r = 0.948, p < 0.01), and was higher in 73.7% of neuromonitoring time (Tdelta +0.18°C, IQR -0.01 - 0.37°C). A higher Tdelta was associated with better metabolic state, indicated by lower CMD-glutamate (p = 0.003) and CMD-lactate (p < 0.001), and lower risk of mitochondrial dysfunction (MD) (OR = 0.2, p < 0.001). During MD, Tdelta was significantly lower (0°C, IQR -0.2 - 0.1; p < 0.001). A higher Tdelta was associated with improved outcome (OR = 7.7, p = 0.002). Our study suggests that Tbrain is associated with brain metabolic activity and exceeds Tcore when mitochondrial function is preserved. Further studies are needed to understand how Tdelta may serve as a surrogate marker for brain function and predict clinical course and outcome after SAH.

The Effect of Temperature Increases on Brain Tissue Oxygen Tension in Patients with Traumatic Brain Injury: A Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury Substudy.

Fever may aggravate secondary brain injury after traumatic brain injury (TBI). The aim of this study was to identify episodes of temperature increases through visual plot analysis and algorithm supported detection, and to describe associated patterns of changes in on brain tissue oxygen tension (PbtO2). Data derive from the high-resolution cohort of the multicenter prospective Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) study. Temperature increases (≥0.5°C) were visually identified in 33 patients within the first 11 days of monitoring. Generalized estimating equations were used to detect significant changes of systemic and neuromonitoring parameters from baseline to the highest temperature. Patients were median 50 (interquartile range [IQR], 35-62) years old, and presented with a Glasgow Coma Scale (GCS) of 8 (IQR, 4-10). In 202 episodes of temperature increases, mean temperature rose by 1.0°C ± 0.5°C within 4 hours. Overall, PbtO2 slightly increased (ΔPbtO2 = 0.9 ± 6.1 mmHg, p = 0.022) during temperature increases. PbtO2 increased in 35% (p < 0.001), was stable in 49% (p = 0.852), and decreased in 16% (p < 0.001) of episodes. During episodes of temperature increases and simultaneous drops in PbtO2, cerebral perfusion pressure (CPP) decreased (ΔCPP -6.3 ± 11.5 mmHg; p < 0.001). Brain tissue hypoxia (PbtO2 <20 mmHg) developed during 27/164 (17%) episodes of effervescences, in the remaining 38/202 episodes baseline PbtO2 was already <20 mmHg. Comparable results were found when using algorithm-supported detection of temperature increases. In conclusion, during effervescences, PbtO2 was mostly stable or slightly increased. A decrease of PbtO2 was observed in every sixth episode, where it was associated with a decrease in CPP. Our data highlight the need for special attention to CPP monitoring and maintenance during episodes of fever.

Early alterations in heart rate are associated with poor outcome in patients with intracerebral hemorrhage.

PURPOSE: Cardiac complications are common after spontaneous intracerebral hemorrhage (ICH). In this study we intended to investigate factors associated with higher alterations in heart rate and their impact on outcome. METHODS: Eighty-eight ICH patients were included. A simplified approach to calculate heart rate variability (HRSD) in analogy to systolic blood pressure variability (SBPSD) with daily standard deviations of HR in the acute (first 24 h) and subacute phase (day1-day7) was used. Using multivariable regression, factors associated with higher HRSD and the association between higher HRSD and poor 3-month outcome (modified Rankin Scale > 3) were analyzed. All models were adjusted for age, atrial fibrillation, mechanical ventilation, vasopressor administration, and mean HR. RESULTS: Patients were 71 (IQR = 60-79) years old and presented with an admission ICH-Score of 2 (IQR = 1-3). In multivariable analysis, intraventricular hemorrhage (adjOR = 8.66, 95%-CI = 1.89-39.60, p = 0.005), a QRS complex >120 ms (adjOR = 19.02; 95%-CI = 2.08-175.05, p = 0.009) and female sex (adjOR = 4.24; 95%-CI = 1.08-16.64, p = 0.038) were associated with higher HRSD in the acute phase. A higher HRSD (adjOR = 1.29, 95%-CI = 1.01-1.66, p = 0.045) in the acute but not in the subacute phase (p = 0.764) was associated with poor 3-month outcome. CONCLUSION: The study suggests that a higher variation in heart rate in the early phase after ICH may discriminate patients with poor outcome.