Lucia Angelica Rivera Lara, MD, MPH

All Publications

• Continuous Monitoring of Cerebral Autoregulation in Adults Supported by Extracorporeal Membrane Oxygenation. Neurocritical care Zhang, L. Q., Chang, H., Kalra, A., Humayun, M., Rosenblatt, K. R., Shah, V. A., Geocadin, R. G., Brown, C. H., Kim, B. S., Whitman, G. J., Rivera-Lara, L., Cho, S. M. 2024

  Abstract

  Impaired cerebral autoregulation (CA) is one of several proposed mechanisms of acute brain injury in patients supported by extracorporeal membrane oxygenation (ECMO). The primary aim of this study was to determine the feasibility of continuous CA monitoring in adult ECMO patients. Our secondary aims were to describe changes in cerebral oximetry index (COx) and other metrics of CA over time and in relation to functional neurologic outcomes.This is a single-center prospective observational study. We measured COx, a surrogate measurement of cerebral blood flow measured by near-infrared spectroscopy, which is an index of CA derived from the moving correlation between mean arterial pressure (MAP) and slow waves of regional cerebral oxygen saturation. A COx value that approaches 1 indicates impaired CA. Using COx, we determined the optimal MAP (MAPOPT) and lower and upper limits of autoregulation for individual patients. These measurements were examined in relation to modified Rankin Scale (mRS) scores.Fifteen patients (median age 57 years [interquartile range 47-69]) with 150 autoregulation measurements were included for analysis. Eleven were on veno-arterial ECMO (VA-ECMO), and four were on veno-venous ECMO (VV-ECMO). Mean COx was higher on postcannulation day 1 than on day 2 (0.2 vs. 0.09, p < 0.01), indicating improved CA over time. COx was higher in VA-ECMO patients than in VV-ECMO patients (0.12 vs. 0.06, p = 0.04). Median MAPOPT for the entire cohort was highly variable, ranging from 55 to 110 mm Hg. Patients with mRS scores 0-3 (good outcome) at 3 and 6 months spent less time outside MAPOPT compared with patients with mRS scores 4-6 (poor outcome) (74% vs. 82%, p = 0.01). The percentage of time when observed MAP was outside the limits of autoregulation was higher on postcannulation day 1 than on day 2 (18.2% vs. 3.3%, p < 0.01).In ECMO patients, it is feasible to monitor CA continuously at the bedside. CA improved over time, most significantly between postcannulation days 1 and 2. CA was more impaired in VA-ECMO patients than in VV-ECMO patients. Spending less time outside MAPOPT may be associated with achieving a good neurologic outcome.

  View details for DOI 10.1007/s12028-023-01932-w

  View details for PubMedID 38326536

  View details for PubMedCentralID 8170265

• Mechanistic Evaluation of Diffusion Weighted Hyperintense Lesions After Large Spontaneous Intracerebral Hemorrhage: A Subgroup Analysis of MISTIE III. Neurocritical care Rivera-Lara, L., Cho, S. M., Li, Y., Ali, H., McBee, N., Awad, I. A., Avadhani, R., Hanley, D. F., Gandhi, D., Walborn, N., Murthy, S. B., Ziai, W. C. 2023

  Abstract

  Ischemic lesions on diffusion weighted imaging (DWI) are common after acute spontaneous intracerebral hemorrhage (ICH) but are poorly understood for large ICH volumes (> 30 mL). We hypothesized that large blood pressure drops and effect modification by cerebral small vessel disease markers on magnetic resonance imaging (MRI) are associated with DWI lesions.This was an exploratory analysis of participants in the Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation phase 3 trial with protocolized brain MRI scans within 7 days from ICH. Multivariable logistic regression analysis was performed to assess biologically relevant factors associated with DWI lesions, and relationships between DWI lesions and favorable ICH outcomes (modified Rankin Scale 0-3).Of 499 enrolled patients, 300 had MRI at median 7.5 days (interquartile range 7-8), and 178 (59%) had DWI lesions. The incidence of DWI lesions was higher in patients with systolic blood pressure (SBP) reduction ≥ 80 mm Hg in first 24 h (76%). In adjusted models, factors associated with DWI lesions were as follows: admission intraventricular hematoma volume (p = 0.03), decrease in SBP ≥ 80 mm Hg from admission to day 1 (p = 0.03), and moderate-to-severe white matter disease (p = 0.01). Patients with DWI lesions had higher odds of severe disability at 1 month (p = 0.04), 6 months (p = 0.036), and 12 months (p < 0.01). No evidence of effect modification by cerebral small vessel disease on blood pressure was found.In patients with large hypertensive ICH, white matter disease, intraventricular hemorrhage volume, and large reductions in SBP over the first 24 h were independently associated with DWI lesions. Further investigation of potential hemodynamic mechanisms of ischemic injury after large ICH is warranted.

  View details for DOI 10.1007/s12028-023-01890-3

  View details for PubMedID 38040993

  View details for PubMedCentralID 5344081

• Reducing the incidence and mortality of traumatic brain injury in Latin America. European journal of trauma and emergency surgery : official publication of the European Trauma Society Rivera-Lara, L., Videtta, W., Calvillo, E., Mejia-Mantilla, J., March, K., Ortega-Gutierrez, S., Obrego, G. C., Paranhos, J. E., Suarez, J. I. 2023

  Abstract

  Traumatic brain injury (TBI) represents a considerable portion of the global injury burden. The incidence of TBI will continue to increase in view of an increase in population density, an aging population, and the increased use of motor vehicles, motorcycles, and bicycles. The most common causes of TBI are falls and road traffic injuries. Deaths related to road traffic injury are three times higher in low-and middle-income countries (LMIC) than in high-income countries (HIC). The Latin American Caribbean region has the highest incidence of TBI worldwide, primarily caused by road traffic injuries. Data from HIC indicates that road traffic injuries can be successfully prevented through concerted efforts at the national level, with coordinated and multisector responses to the problem. Such actions require implementation of proven measures to address the safety of road users and the vehicles themselves, road infrastructure, and post-crash care. In this review, we focus on the epidemiology of TBI in Latin America and the implementation of solutions and preventive measures to decrease mortality and long-term disability.

  View details for DOI 10.1007/s00068-022-02214-4

  View details for PubMedID 36637481

• Coronavirus Disease 2019 Policy Restricting Family Presence May Have Delayed End-of-Life Decisions for Critically Ill Patients CRITICAL CARE MEDICINE Azad, T. D., Al-Kawaz, M. N., Turnbull, A. E., Rivera-Lara, L. 2021; 49 (10): E1037-E1039

  Abstract

  To determine if a restrictive visitor policy inadvertently lengthened the decision-making process for dying inpatients without coronavirus disease 2019.Regression discontinuity and time-to-event analysis.Two large academic hospitals in a unified health system.Adult decedents who received greater than or equal to 1 day of ICU care during their terminal admission over a 12-month period.Implementation of a visit restriction policy.We identified 940 adult decedents without coronavirus disease 2019 during the study period. For these patients, ICU length of stay was 0.8 days longer following policy implementation, although this effect was not statistically significant (95% CI, -2.3 to 3.8; p = 0.63). After excluding patients admitted before the policy but who died after implementation, we observed that ICU length of stay was 2.9 days longer post-policy (95% CI, 0.27-5.6; p = 0.03). A time-to-event analysis revealed that admission after policy implementation was associated with a significantly longer time to first do not resuscitate/do not intubate/comfort care order (adjusted hazard ratio, 2.2; 95% CI, 1.6-3.1; p < 0.0001).Policies restricting family presence may lead to longer ICU stays and delay decisions to limit treatment prior to death. Further policy evaluation and programs enabling access to family-centered care and palliative care during the ongoing coronavirus disease 2019 pandemic are imperative.

  View details for DOI 10.1097/CCM.0000000000005044

  View details for Web of Science ID 000697486100014

  View details for PubMedID 33826588

  View details for PubMedCentralID PMC8439643

• Sweeping TTM conclusion may deprive many post-arrest patients of effective therapy. Intensive care medicine Rivera-Lara, L., Cho, S., Geocadin, R. G. 2021

  View details for DOI 10.1007/s00134-021-06529-5

  View details for PubMedID 34519844

• Optimizing Mean Arterial Pressure in Acutely Comatose Patients Using Cerebral Autoregulation Multimodal Monitoring With Near-Infrared Spectroscopy. Critical care medicine Rivera-Lara, L., Geocadin, R., Zorrilla-Vaca, A., Healy, R. J., Radzik, B. R., Palmisano, C., Mirski, M., White, M. A., Suarez, J., Brown, C., Hogue, C. W., Ziai, W. 2019; 47 (10): 1409-1415

  Abstract

  This study investigated whether comatose patients with greater duration and magnitude of clinically observed mean arterial pressure outside optimal mean arterial blood pressure have worse outcomes than those with mean arterial blood pressure closer to optimal mean arterial blood pressure calculated by bedside multimodal cerebral autoregulation monitoring using near-infrared spectroscopy.Prospective observational study.Neurocritical Care Unit of the Johns Hopkins Hospital.Acutely comatose patients secondary to brain injury.None.The cerebral oximetry index was continuously monitored with near-infrared spectroscopy for up to 3 days. Optimal mean arterial blood pressure was defined as that mean arterial blood pressure at the lowest cerebral oximetry index (nadir index) for each 24-hour period of monitoring. Kaplan-Meier analysis and proportional hazard regression models were used to determine if survival at 3 months was associated with a shorter duration of mean arterial blood pressure outside optimal mean arterial blood pressure and the absolute difference between clinically observed mean arterial blood pressure and optimal mean arterial blood pressure. A total 91 comatose patients were enrolled in the study. The most common etiology was intracerebral hemorrhage. Optimal mean arterial blood pressure could be calculated in 89 patients (97%), and the median optimal mean arterial blood pressure was 89.7 mm Hg (84.6-100 mm Hg). In multivariate proportional hazard analysis, duration outside optimal mean arterial blood pressure of greater than 80% of monitoring time (adjusted hazard ratio, 2.13; 95% CI, 1.04-4.41; p = 0.04) and absolute difference between clinically observed mean arterial blood pressure and optimal mean arterial blood pressure of more than 10 mm Hg (adjusted hazard ratio, 2.44; 95% CI, 1.21-4.92; p = 0.013) were independently associated with mortality at 3 months, after adjusting for brain herniation, admission Glasgow Coma Scale, duration on vasopressors and midline shift at septum.Comatose neurocritically ill adults with an absolute difference between clinically observed mean arterial blood pressure and optimal mean arterial blood pressure greater than 10 mm Hg and duration outside optimal mean arterial blood pressure greater than 80% had increased mortality at 3 months. Noninvasive near-infrared spectroscopy-based bedside calculation of optimal mean arterial blood pressure is feasible and might be a promising tool for cerebral autoregulation oriented-therapy in neurocritical care patients.

  View details for DOI 10.1097/CCM.0000000000003908

  View details for PubMedID 31356469

• Multimodality Monitoring in the Neurocritical Care Unit. Continuum (Minneapolis, Minn.) Rivera Lara, L., Püttgen, H. A. 2018; 24 (6): 1776-1788

  Abstract

  This article focuses on the multiple neuromonitoring devices that can be used to collect bedside data in the neurocritical care unit and the methodology to integrate them into a multimodality monitoring system. The article describes how to apply the collected data to appreciate the physiologic changes and develop therapeutic approaches to prevent secondary injury.The neurologic examination has served as the primary monitor for secondary brain injury in patients admitted to the neurocritical care unit. However, the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care concluded that frequent bedside examinations are not sufficient to detect and prevent secondary brain injury and that integration of multimodality monitoring with advanced informatics tools will most likely enhance our assessments compared to the clinical examinations alone. This article reviews the invasive and noninvasive technologies used to monitor focal and global neurophysiologic cerebral alterations.Multimodal monitoring is still in the early stages of development. Research is still needed to establish more advanced monitors with the bioinformatics to identify useful trends from data gathered to predict clinical outcome or prevent secondary brain injury.

  View details for DOI 10.1212/CON.0000000000000671

  View details for PubMedID 30516605

• Effect of Body Temperature on Cerebral Autoregulation in Acutely Comatose Neurocritically Ill Patients. Critical care medicine Adatia, K., Geocadin, R. G., Healy, R., Ziai, W., Ponce-Mejia, L., Anderson-White, M., Shah, D., Radzik, B. R., Palmisano, C., Hogue, C. W., Brown, C., Rivera-Lara, L. 2018; 46 (8): e733-e741

  Abstract

  Impaired cerebral autoregulation following neurologic injury is a predictor of poor clinical outcome. We aimed to assess the relationship between body temperature and cerebral autoregulation in comatose patients.Retrospective analysis of prospectively collected data.Neurocritical care unit of the Johns Hopkins Hospital.Eighty-five acutely comatose patients (Glasgow Coma Scale score of ≤ 8) admitted between 2013 and 2017.None.Cerebral autoregulation was monitored using multimodal monitoring with near-infrared spectroscopy-derived cerebral oximetry index. Cerebral oximetry index was calculated as a Pearson correlation coefficient between low-frequency changes in regional cerebral oxygenation saturation and mean arterial pressure. Patients were initially analyzed together, then stratified by temperature pattern over the monitoring period: no change (< 1°C difference between highest and lowest temperatures; n = 11), increasing (≥ 1°C; n = 9), decreasing (≥ 1°C; n = 9), and fluctuating (≥ 1°C difference but no sustained direction of change; n = 56). Mixed random effects models with random intercept and multivariable logistic regression analysis were used to assess the association between hourly temperature and cerebral oximetry index, as well as between temperature and clinical outcomes. Cerebral oximetry index showed a positive linear relationship with temperature (β = 0.04 ± 0.10; p = 0.29). In patients where a continual increase or decrease in temperature was seen during the monitoring period, every 1°C change in temperature resulted in a cerebral oximetry index change in the same direction by 0.04 ± 0.01 (p < 0.001) and 0.02 ± 0.01 (p = 0.12), respectively, after adjusting for PaCO2, hemoglobin, mean arterial pressure, vasopressor and sedation use, and temperature probe location. There was no significant difference in mortality or poor outcome (modified Rankin Scale score of 4-6) between temperature pattern groups at discharge, 3, or 6 months.In acute coma patients, increasing body temperature is associated with worsening cerebral autoregulation as measured by cerebral oximetry index. More studies are needed to clarify the impact of increasing temperature on cerebral autoregulation in patients with acute brain injury.

  View details for DOI 10.1097/CCM.0000000000003181

  View details for PubMedID 29727362

  View details for PubMedCentralID PMC6045431

• Determining the Upper and Lower Limits of Cerebral Autoregulation With Cerebral Oximetry Autoregulation Curves: A Case Series. Critical care medicine Rivera-Lara, L., Zorrilla-Vaca, A., Healy, R. J., Ziai, W., Hogue, C., Geocadin, R., Radzik, B., Palmisano, C., Mirski, M. A. 2018; 46 (5): e473-e477

  Abstract

  Critical care guidelines recommend a single target value for mean arterial blood pressure in critically ill patients. However, growing evidence regarding cerebral autoregulation challenges this concept and supports individualizing mean arterial blood pressure targets to prevent brain and kidney hypo- or hyperperfusion. Regional cerebral oxygen saturation derived from near-infrared spectroscopy is an acceptable surrogate for cerebral blood flow and has been validated to measure cerebral autoregulation. This study suggests a novel mechanism to construct autoregulation curves based on near-infrared spectroscopy-measured cerebral oximetry.Case-series study.Neurocritical care unit in a tertiary medical center.Patients with acute neurologic injury and Glasgow coma scale score less than or equal to 8.Autoregulation curves were plotted using the fractional-polynomial model in Stata after multimodal continuous monitoring of regional cerebral oxygen saturation and mean arterial blood pressure. Individualized autoregulation curves of seven patients exhibited varying upper and lower limits of autoregulation and provided useful clinical information on the autoregulation trend (curves moving to the right or left during the acute coma period). The median lower and upper limits of autoregulation were 86.5 mm Hg (interquartile range, 74-93.5) and 93.5 mm Hg (interquartile range, 83-99), respectively.This case-series study showed feasibility of delineating real trends of the cerebral autoregulation plateau and direct visualization of the cerebral autoregulation curve after at least 24 hours of recording without manipulation of mean arterial blood pressure by external stimuli. The integration of multimodal monitoring at the bedside with cerebral oximetry provides a noninvasive method to delineate daily individual cerebral autoregulation curves.

  View details for DOI 10.1097/CCM.0000000000003012

  View details for PubMedID 29419556

  View details for PubMedCentralID PMC5899039

• Effect of erythropoietin and transfusion threshold on neurological recovery after traumatic brain injury: a randomized clinical trial. JAMA Robertson, C. S., Hannay, H. J., Yamal, J. M., Gopinath, S., Goodman, J. C., Tilley, B. C., Baldwin, A., Rivera Lara, L., Saucedo-Crespo, H., Ahmed, O., Sadasivan, S., Ponce, L., Cruz-Navarro, J., Shahin, H., Aisiku, I. P., Doshi, P., Valadka, A., Neipert, L., Waguspack, J. M., Rubin, M. L., Benoit, J. S., Swank, P. 2014; 312 (1): 36-47

  Abstract

  There is limited information about the effect of erythropoietin or a high hemoglobin transfusion threshold after a traumatic brain injury.To compare the effects of erythropoietin and 2 hemoglobin transfusion thresholds (7 and 10 g/dL) on neurological recovery after traumatic brain injury.Randomized clinical trial of 200 patients (erythropoietin, n = 102; placebo, n = 98) with closed head injury who were unable to follow commands and were enrolled within 6 hours of injury at neurosurgical intensive care units in 2 US level I trauma centers between May 2006 and August 2012. The study used a factorial design to test whether erythropoietin would fail to improve favorable outcomes by 20% and whether a hemoglobin transfusion threshold of greater than 10 g/dL would increase favorable outcomes without increasing complications. Erythropoietin or placebo was initially dosed daily for 3 days and then weekly for 2 more weeks (n = 74) and then the 24- and 48-hour doses were stopped for the remainder of the patients (n = 126). There were 99 patients assigned to a hemoglobin transfusion threshold of 7 g/dL and 101 patients assigned to 10 g/dL.Intravenous erythropoietin (500 IU/kg per dose) or saline. Transfusion threshold maintained with packed red blood cells.Glasgow Outcome Scale score dichotomized as favorable (good recovery and moderate disability) or unfavorable (severe disability, vegetative, or dead) at 6 months postinjury.There was no interaction between erythropoietin and hemoglobin transfusion threshold. Compared with placebo (favorable outcome rate: 34/89 [38.2%; 95% CI, 28.1% to 49.1%]), both erythropoietin groups were futile (first dosing regimen: 17/35 [48.6%; 95% CI, 31.4% to 66.0%], P = .13; second dosing regimen: 17/57 [29.8%; 95% CI, 18.4% to 43.4%], P < .001). Favorable outcome rates were 37/87 (42.5%) for the hemoglobin transfusion threshold of 7 g/dL and 31/94 (33.0%) for 10 g/dL (95% CI for the difference, -0.06 to 0.25, P = .28). There was a higher incidence of thromboembolic events for the transfusion threshold of 10 g/dL (22/101 [21.8%] vs 8/99 [8.1%] for the threshold of 7 g/dL, odds ratio, 0.32 [95% CI, 0.12 to 0.79], P = .009).In patients with closed head injury, neither the administration of erythropoietin nor maintaining hemoglobin concentration of greater than 10 g/dL resulted in improved neurological outcome at 6 months. The transfusion threshold of 10 g/dL was associated with a higher incidence of adverse events. These findings do not support either approach in this setting.clinicaltrials.gov Identifier: NCT00313716.

  View details for DOI 10.1001/jama.2014.6490

  View details for PubMedID 25058216

  View details for PubMedCentralID PMC4113910

• Cortical Laminar Necrosis After Severe Hydrocephalus: Case Report and Review of the Literature. The Neurohospitalist Peyton, M. A., Cho, S. M., Xia, Y., Piran, P., Luciano, M., Rivera-Lara, L. 2024; 14 (3): 351-355

  Abstract

  We present a case of cortical laminar necrosis after severe hydrocephalus to highlight considerations for multimodal cerebral autoregulation monitoring to determine mean arterial pressure (MAP) thresholds during neurological emergencies, as well as postoperative head imaging for patients with ventriculoperitoneal shunts (VPS).A 40-year-old woman with a history of Chiari II malformation and non-communicating hydrocephalus with VPS presented in septic shock from a sacral wound. One week after colostomy for fecal diversion, the patient became comatose and had progressive slowing to full suppression on electroencephalogram (EEG).CT imaging revealed hydrocephalus, most likely due to VPS distal obstruction from intraperitoneal surgery. Despite neurosurgical and neurocritical care management, MRI confirmed diffuse cortical hypoxic ischemic injury.The Neurocritical Care Society's Emergency Neurological Life Support (ENLS) protocol for neurological emergencies focuses on managing increased intracranial pressure (ICP) but does not set MAP goals. As ICP may be very high during brain herniation, our case demonstrates that higher MAP may be required to maintain adequate circulation. To determine the optimal MAP target, bedside multimodality monitoring, including ICP monitors, transcranial doppler, and near infrared spectroscopy, can help establish individualized cerebral autoregulation guided thresholds. Outside of a neurological intensive care unit, EEG can monitor cerebral blood flow and indicate windows for intervention before exam or imaging changes. Additionally, our case demonstrates how a post-operative surveillance CT head should be considered for patients with VPS.

  View details for DOI 10.1177/19418744241242504

  View details for PubMedID 38895020

  View details for PubMedCentralID PMC11181968

• Cortical Laminar Necrosis After Severe Hydrocephalus: Case Report and Review of the Literature NEUROHOSPITALIST Peyton, M. A., Cho, S., Xia, Y., Piran, P., Luciano, M., Rivera-Lara, L. 2024

  View details for DOI 10.1177/19418744241242504

  View details for Web of Science ID 001193749700001

• Inaugural State of the Union: Continuous Cerebral Autoregulation Monitoring in the Clinical Practice of Neurocritical Care and Anesthesia. Neurocritical care Park, S., Beqiri, E., Smielewski, P., Aries, M. 2023

  Abstract

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

  View details for DOI 10.1007/s12028-023-01860-9

  View details for PubMedID 37853235

  View details for PubMedCentralID 6863785

• Continuous Monitoring of Cerebral Autoregulation in Adults Supported by Extracorporeal Membrane Oxygenation. Research square Zhang, L. Q., Chang, H., Kalra, A., Humayun, M., Rosenblatt, K. R., Shah, V. A., Geocadin, R. G., Brown, C. H., Kim, B. S., Whitman, G. J., Rivera-Lara, L., Cho, S. M. 2023

  Abstract

  Impaired cerebral autoregulation (CA) is one of several proposed mechanisms of acute brain injury in patients supported by extracorporeal membrane oxygenation (ECMO). The primary aim of this study was to determine the feasibility of continuous CA monitoring in adult ECMO patients. Our secondary aims were to describe changes in cerebral oximetry index (COx) and other metrics of CA over time and in relation to functional neurologic outcomes.This is a single-center prospective observational study. We measured Cox, a surrogate measurement of cerebral blood flow, measured by near-infrared spectroscopy, which is an index of CA derived from the moving correlation between mean arterial pressure and slow waves of regional cerebral oxygen saturation. A COx value that approaches 1 indicates impaired CA. Using COx, we determined the optimal MAP (MAPOPT), lower and upper limits of autoregulation for individual patients. These measurements were examined in relation to modified Rankin Scale (mRS) scores.Fifteen patients (median age=57 years [IQR=47-69]) with 150 autoregulation measurements were included for analysis. Eleven were on veno-arterial ECMO and 4 on veno-venous. Mean COx was higher on post-cannulation day 1 than on day 2 (0.2 vs 0.09, p<0.01), indicating improved CA over time. COx was higher in VA-ECMO patients than in VV-ECMO (0.12 vs 0.06, p=0.04). Median MAPOPT for entire cohort was highly variable, ranging 55-110 mmHg. Patients with mRS 0-3 (good outcome) at 3 and 6 months spent less time outside of MAPOPT compared to patients with mRS 4-6 (poor outcome) (74% vs 82%, p=0.01). The percentage of time when observed MAP was outside the limits of autoregulation was higher on post-cannulation day 1 than on day 2 (18.2% vs 3.3%, p<0.01).In ECMO patients, it is feasible to monitor CA continuously at the bedside. CA improved over time, most significantly between post-cannulation days 1 and 2. CA was more impaired in VA-ECMO than VV-ECMO. Spending less time outside of MAPOPT may be associated with achieving a good neurologic outcome.

  View details for DOI 10.21203/rs.3.rs-3300834/v1

  View details for PubMedID 37790309

  View details for PubMedCentralID PMC10543291

• CEREBRAL OXIMETRY-DERIVED OPTIMAL BLOOD PRESSURE TARGETS IN ANEURYSMAL SUBARACHNOID HEMORRHAGE Shah, V., Humayun, M., Radzik, B., Palmisano, C., Anderson-White, M., Calvillo, E., Chang, H., Zhang, L., Hogue, C., Brown, C., Suarez, J., Geocadin, R., Cho, S., Ziai, W., Rivera-Lara, L. LIPPINCOTT WILLIAMS & WILKINS. 2023: 253

  View details for Web of Science ID 000921450900495

• Assessing risk factors associated with breakthrough early post-traumatic seizures in patients receiving phenytoin prophylaxis. Frontiers in neurology Generoso, E., Diep, C., Hua, C., Rader, E., Ran, R., Lee, N. J., Rivera-Lara, L. 2023; 14: 1329042

  Abstract

  Objective: Post-traumatic seizure (PTS) is a well-known complication of traumatic brain injury (TBI). The objective of this study was to identify risk factors associated with breakthrough early PTS in TBI patients receiving phenytoin prophylaxis.Methods: This was a single-centered retrospective study including adult patients admitted to the intensive care unit (ICU), had a TBI, and started on phenytoin for seizure prophylaxis within 24h of admission. The primary outcome was the incidence and factors associated with early PTS, defined as a confirmed seizure on a continuous electroencephalogram within 7days of TBI. Secondary outcomes included the association between early post-traumatic seizures and ICU length of stay, hospital length of stay, and in-hospital mortality.Results: A total of 105 patients were included in the final analysis. Patients with early PTS were older (65 vs. 48years old, p=0.01), had a higher Marshall score (5 vs. 2, p=0.01), were more likely to have a Marshall score>2 (73 vs. 37%, p=0.01), and had more neurosurgeries for hematoma evacuation (57 vs. 19%, p=0.01). In patients with early PTS, 57% had a level at the time of seizure, and of those, 87.5% had a therapeutic level (>10mcg/mL). Patients with early PTS had a longer ICU length of stay (14.7 vs. 5.9days, p=0.04) and a greater proportion of hospital mortality (21 vs. 2%, p=0.02).Conclusion: Patients with higher age, Marshall score, and neurosurgical procedures for hematoma evacuation had higher incidences of breakthrough early PTS despite the use of phenytoin prophylaxis. The majority of patients with early PTS had therapeutic phenytoin levels at the time of seizure when a level was available; however, approximately half (43%) did not have a level.

  View details for DOI 10.3389/fneur.2023.1329042

  View details for PubMedID 38239322

• Moving towards precision medicine in post-cardiac arrest care: Using cerebrovascular autoregulation to individualize blood pressure. Resuscitation Rivera Lara, L., Genevieve Hirsch, K. 2022

  View details for DOI 10.1016/j.resuscitation.2022.03.033

  View details for PubMedID 35398214

• Impact of Cerebral Autoregulation Monitoring in Cerebrovascular Disease: A Systematic Review. Neurocritical care Al-Kawaz, M., Cho, S. M., Gottesman, R. F., Suarez, J. I., Rivera-Lara, L. 2022

  Abstract

  Cerebral autoregulation (CA) prevents brain injury by maintaining a relatively constant cerebral blood flow despite fluctuations in cerebral perfusion pressure. This process is disrupted consequent to various neurologic pathologic processes, which may result in worsening neurologic outcomes. Herein, we aim to highlight evidence describing CA changes and the impact of CA monitoring in patients with cerebrovascular disease, including ischemic stroke, intracerebral hemorrhage (ICH), and aneurysmal subarachnoid hemorrhage (aSAH). The study was preformed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. English language publications were identified through a systematic literature conducted in Ovid Medline, PubMed, and Embase databases. The search spanned the dates of each database's inception through January 2021. We selected case-control studies, cohort observational studies, and randomized clinical trials for adult patients (≥ 18 years) who were monitored with continuous metrics using transcranial Doppler, near-infrared spectroscopy, and intracranial pressure monitors. Of 2799 records screened, 48 studies met the inclusion criteria. There were 23 studies on ischemic stroke, 18 studies on aSAH, 5 studies on ICH, and 2 studies on systemic hypertension. CA impairment was reported after ischemic stroke but generally improved after tissue plasminogen activator administration and successful mechanical thrombectomy. Persistent impairment in CA was associated with hemorrhagic transformation, malignant cerebral edema, and need for hemicraniectomy. Studies that investigated large ICHs described bilateral CA impairment up to 12 days from the ictus, especially in the presence of small vessel disease. In aSAH, impairment of CA was associated with angiographic vasospasm, delayed cerebral ischemia, and poor functional outcomes at 6 months. This systematic review highlights the available evidence for CA disruption during cerebrovascular diseases and its possible association with long-term neurological outcome. CA may be disrupted even before acute stroke in patients with untreated chronic hypertension. Monitoring CA may help in establishing individualized management targets in patients with cerebrovascular disease.

  View details for DOI 10.1007/s12028-022-01484-5

  View details for PubMedID 35378665

• Neuro-Interventional Use of Oral Antiplatelets: A Survey of Neuro-Endovascular Centers in the United States and Review of the Literature. Journal of pharmacy practice Farrokh, S., Owusu, K., Lara, L. R., Nault, K., Hui, F., Spoelhof, B. 2021; 34 (2): 207-215

  Abstract

  Intra- and postprocedural thrombosis are major complication of aneurysmal coil embolization, stent-assisted coiling, and pipeline embolization. The common but unproven practice of dual antiplatelet therapy with aspirin and a P2Y12 inhibitor in neuro-endovascular patients is inferred from the cardiology literature without large clinical trials to support it in neuro-endovascular patients.We conducted an electronic survey to identify practice variations surrounding the use of oral antiplatelets in patients undergoing endovascular neuro-interventional procedures across neuro-endovascular centers in the United States.An electronic survey was distributed via the Web. Any practicing neuro-intensive care unit (ICU), neuro-interventional or stroke physician, pharmacist, physician assistant, or nurse practitioner was eligible to respond to this survey between June and October 2017.A total of 33 responses were collected during the survey period. A response rate of 16% was calculated after taking into account all comprehensive stroke centers in the United States. Aspirin and clopidogrel was the standard-of-care antiplatelet regimen utilized in the majority of institutions (82%). Alternatively, 4 institutions used monotherapy (aspirin [n = 2], clopidogrel [n = 1], either aspirin or clopidogrel [n = 1]) and 2 institutions reported practitioner-dependent practices. Just under half of the centers reported ticagrelor as the primary alternative in clopidogrel nonresponders (48%).Dual antiplatelet therapy with aspirin and clopidogrel appears to be standard of care in this setting based on our survey. About half of responding institutions use ticagrelor in cases where clopidogrel resistance is suspected. Large society-wide patient registries are needed to provide data for future safety and efficacy studies.

  View details for DOI 10.1177/0897190019854868

  View details for PubMedID 31327286

• Are We Ready to Individualize Hypotension Thresholds in Patients Undergoing Cardiac Bypass Using Noninvasive Neuromonitoring? Critical care medicine Rivera-Lara, L. 2021; 49 (4): 710-712

  View details for DOI 10.1097/CCM.0000000000004767

  View details for PubMedID 33731611

• Remarkable Recovery After a Large Thalamic-Midbrain Intracerebral and Intraventricular Hemorrhage. Neurology. Clinical practice Shah, V. A., Radzik, B., Weingart, J., Suarez, J., Rivera-Lara, L. 2021; 11 (1): 85-87

  View details for DOI 10.1212/CPJ.0000000000000827

  View details for PubMedID 33968477

  View details for PubMedCentralID PMC8101293

• Diffusion-Weighted Imaging Lesions After Intracerebral Hemorrhage and Risk of Stroke: A MISTIE III and ATACH-2 Analysis. Stroke Murthy, S. B., Zhang, C., Gupta, A., Cho, S. M., Rivera-Lara, L., Avadhani, R., Gruber, J., Iadecola, C., Falcone, G. J., Sheth, K. N., Qureshi, A. I., Goldstein, J. N., Hanley, D. F., Kamel, H., Ziai, W. C. 2021; 52 (2): 595-602

  Abstract

  Punctate ischemic lesions noted on diffusion-weighted imaging (DWI) are associated with poor functional outcomes after intracerebral hemorrhage (ICH). Whether these lesions increase long-term risk of stroke is poorly understood.We pooled individual patient data from the ATACH-2 trial (Antihypertensive Treatment of Acute Cerebral Hemorrhage) and the MISTIE III trial (Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation Phase 3). We included subjects with a magnetic resonance imaging scan. The exposure was a DWI lesion. The primary outcome was any stroke, defined as a composite of ischemic stroke or recurrent ICH, whereas secondary outcomes were incident ischemic stroke and recurrent ICH. Using multivariate Cox regression analysis, we evaluated the risk of stroke.Of 505 patients with ICH with magnetic resonance imaging, 466 were included. DWI lesions were noted in 214 (45.9%) subjects, and 34 incident strokes (20 ischemic stroke and 14 recurrent ICH) were observed during a median follow-up of 324 days (interquartile range, 91-374). Presence of a DWI lesion was associated with a 6.9% (95% CI, 2.2-11.6) absolute increase in risk of all stroke (hazard ratio, 2.6 [95% CI, 1.2-5.7]). Covariate adjustment with Cox regression models also demonstrated this increased risk. In the secondary analyses, there was an increased risk of ischemic stroke (hazard ratio, 3.5 [95% CI, 1.1-11.0]) but not recurrent ICH (hazard ratio, 1.7 [95% CI, 0.6-5.1]).In a heterogeneous cohort of patients with ICH, presence of a DWI lesion was associated with a 2.5-fold heightened risk of stroke among ICH survivors. This elevated risk persisted for ischemic stroke but not for recurrent ICH.

  View details for DOI 10.1161/STROKEAHA.120.031628

  View details for PubMedID 33467877

  View details for PubMedCentralID PMC8340082

• Near-infrared Spectroscopy-derived Cerebral Autoregulation Indices Independently Predict Clinical Outcome in Acutely Ill Comatose Patients. Journal of neurosurgical anesthesiology Rivera-Lara, L., Geocadin, R., Zorrilla-Vaca, A., Healy, R., Radzik, B. R., Palmisano, C., White, M. A., Sha, D., Ponce-Mejia, L., Brown, C., Hogue, C., Ziai, W. C. 2020; 32 (3): 234-241

  Abstract

  Outcome prediction in comatose patients with acute brain injury remains challenging. Regional cerebral oxygenation (rSO2) derived from near-infrared spectroscopy (NIRS) is a surrogate for cerebral blood flow and can be used to calculate cerebral autoregulation (CA) continuously at the bedside from the derived cerebral oximetry index (COx). We hypothesized that COx derived thresholds for CA are associated with outcomes in patients with acute coma from neurological injury.A prospective cohort study was conducted in 88 acutely comatose adults with heterogenous brain injury diagnoses who were continuously monitored with COx for up to 3 consecutive days. Multivariable logistic regression was performed to investigate association between averaged COx and short (in-hospital and 3 mo) and long-term (6 mo) outcomes.Six month mortality rate was 62%. Median COx in nonsurvivors at hospital discharge was 0.082 [interquartile range, IQR: 0.045 to 0.160] compared with 0.042 [IQR: -0.005 to 0.110] in survivors (P=0.012). At 6 months, median COx was 0.075 [IQR: 0.27 to 0.158] in nonsurvivors compared with 0.029 [IQR: -0.015 to 0.077] in survivors (P=0.02). In the multivariable logistic regression model adjusted for confounders, average COx ≥0.05 was associated with both in-hospital mortality (adjusted odds ratio [OR]=2.9, 95% confidence interval [CI]=1.15-7.33, P=0.02), mortality at 6 months (adjusted OR=4.4, 95% CI=1.41-13.7, P=0.01), and severe disability (modified Rankin Score ≥4) at 6 months (adjusted OR=4.4, 95% CI=1.07-17.8, P=0.04). Area under the receiver operating characteristic curve for predicting mortality and severe disability at 6 months were 0.783 and 0.825, respectively.Averaged COx ≥0.05 is independently associated with short and long-term mortality and long-term severe disability in acutely comatose adults with neurological injury. We propose that COx ≥0.05 represents an accurate threshold to predict long-term functional outcome in acutely comatose adults.

  View details for DOI 10.1097/ANA.0000000000000589

  View details for PubMedID 30864999

  View details for PubMedCentralID PMC6732251

• Lateral Brain Displacement and Cerebral Autoregulation in Acutely Comatose Patients. Critical care medicine Adatia, K., Geocadin, R. G., Healy, R., Ziai, W., Ponce-Mejia, L., Anderson-White, M., Shah, D., Radzik, B. R., Palmisano, C., Hogue, C. W., Brown, C., Suarez, J. I., Rivera-Lara, L. 2020; 48 (7): 1018-1025

  Abstract

  Lateral displacement and impaired cerebral autoregulation are associated with worse outcomes following acute brain injury, but their effect on long-term clinical outcomes remains unclear. We assessed the relationship between lateral displacement, disturbances to cerebral autoregulation, and clinical outcomes in acutely comatose patients.Retrospective analysis of prospectively collected data.Neurocritical care unit of the Johns Hopkins Hospital.Acutely comatose patients (Glasgow Coma Score ≤ 8).None.Cerebral oximetry index, derived from near-infrared spectroscopy multimodal monitoring, was used to evaluate cerebral autoregulation. Associations between lateral brain displacement, global cerebral autoregulation, and interhemispheric cerebral autoregulation asymmetry were assessed using mixed random effects models with random intercept. Patients were grouped by functional outcome, determined by the modified Rankin Scale. Associations between outcome group, lateral displacement, and cerebral oximetry index were assessed using multivariate linear regression. Increasing lateral brain displacement was associated with worsening global cerebral autoregulation (p = 0.01 septum; p = 0.05 pineal) and cerebral autoregulation asymmetry (both p < 0.001). Maximum lateral displacement during the first 3 days of coma was significantly different between functional outcome groups at hospital discharge (p = 0.019 pineal; p = 0.008 septum), 3 months (p = 0.026; p = 0.007), 6 months (p = 0.018; p = 0.010), and 12 months (p = 0.022; p = 0.012). Global cerebral oximetry index was associated with functional outcomes at 3 months (p = 0.019) and 6 months (p = 0.013).During the first 3 days of acute coma, increasing lateral brain displacement is associated with worsening global cerebral autoregulation and cerebral autoregulation asymmetry, and poor long-term clinical outcomes in acutely comatose patients. The impact of acute interventions on outcome needs to be explored.

  View details for DOI 10.1097/CCM.0000000000004365

  View details for PubMedID 32371609

• Correction to: Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials. Canadian journal of anaesthesia = Journal canadien d'anesthesie Zorrilla-Vaca, A., Healy, R., Grant, M. C., Joshi, B., Rivera-Lara, L., Brown, C., Mirski, M. A. 2019; 66 (11): 1427-1429

  Abstract

  In the article entitled "Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials" Can J Anesth 2018; 65: 529-42, we wish to clarify the following items.

  View details for DOI 10.1007/s12630-019-01380-1

  View details for PubMedID 31414381

• Clinical Reasoning: A 68-year-old man with rapid cognitive decline. Neurology Berth, S. H., Seth, A., Cohen, A., Rivera Lara, L., Hui, F., Sun, L. R. 2019; 93 (7): 315-318

  View details for DOI 10.1212/WNL.0000000000007954

  View details for PubMedID 31405937

• Influence of Intracerebral Hemorrhage Location on Outcomes in Patients With Severe Intraventricular Hemorrhage. Stroke Eslami, V., Tahsili-Fahadan, P., Rivera-Lara, L., Gandhi, D., Ali, H., Parry-Jones, A., Nelson, L. S., Thompson, R. E., Nekoobakht-Tak, S., Dlugash, R., McBee, N., Awad, I., Hanley, D. F., Ziai, W. C. 2019; 50 (7): 1688-1695

  Abstract

  Background and Purpose- We investigated the prognostic significance of spontaneous intracerebral hemorrhage location in presence of severe intraventricular hemorrhage. Methods- We analyzed diagnostic computed tomography scans from 467/500 (excluding primary intraventricular hemorrhage) subjects from the CLEAR (Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage) III trial. We measured intracerebral hemorrhage engagement with specific anatomic regions, and estimated association of each region with blinded assessment of dichotomized poor stroke outcomes: mortality, modified Rankin Scale score of 4 to 6, National Institutes of Health Stroke Scale score of >4, stroke impact scale score of <60, Barthel Index <86, and EuroQol visual analogue scale score of <50 and <70 at days 30 and 180, respectively, using logistic regression models. Results- Frequency of anatomic region involvement consisted of thalamus (332 lesions, 71.1% of subjects), caudate (219, 46.9%), posterior limb internal capsule (188, 40.3%), globus pallidus/putamen (127, 27.2%), anterior limb internal capsule (108, 23.1%), and lobar (29, 6.2%). Thalamic location was independently associated with mortality (days 30 and 180) and with poor outcomes on most stroke scales at day 180 on adjusted analysis. Posterior limb internal capsule and globus pallidus/putamen involvement was associated with increased odds of worse disability at days 30 and 180. Anterior limb internal capsule and caudate locations were associated with decreased mortality on days 30 and 180. Anterior limb internal capsule lesions were associated with decreased long-term morbidity. Conclusions- Acute intracerebral hemorrhage lesion topography provides important insights into anatomic correlates of mortality and functional outcomes even in severe intraventricular hemorrhage causing obstructive hydrocephalus. Models accounting for intracerebral hemorrhage location in addition to volumes may improve outcome prediction and permit stratification of benefit from aggressive acute interventions. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT00784134.

  View details for DOI 10.1161/STROKEAHA.118.024187

  View details for PubMedID 31177984

  View details for PubMedCentralID PMC6771028

• Glasgow Coma Scale Score Fluctuations are Inversely Associated With a NIRS-based Index of Cerebral Autoregulation in Acutely Comatose Patients. Journal of neurosurgical anesthesiology Healy, R. J., Zorrilla-Vaca, A., Ziai, W., Mirski, M. A., Hogue, C. W., Geocadin, R., Radzik, B., Palmisano, C., Rivera-Lara, L. 2019; 31 (3): 306-310

  Abstract

  The Glasgow Coma Scale (GCS) is an essential coma scale in critical care for determining the neurological status of patients and for estimating their long-term prognosis. Similarly, cerebral autoregulation (CA) monitoring has shown to be an accurate technique for predicting clinical outcomes. However, little is known about the relationship between CA measurements and GCS scores among neurological critically ill patients. This study aimed to explore the association between noninvasive CA multimodal monitoring measurements and GCS scores.Acutely comatose patients with a variety of neurological injuries admitted to a neurocritical care unit were monitored using near-infrared spectroscopy-based multimodal monitoring for up to 72 hours. Regional cerebral oxygen saturation (rScO2), cerebral oximetry index (COx), GCS, and GCS motor data were measured hourly. COx was calculated as a Pearson correlation coefficient between low-frequency changes in rScO2 and mean arterial pressure. Mixed random effects models with random intercept was used to determine the relationship between hourly near-infrared spectroscopy-based measurements and GCS or GCS motor scores.A total of 871 observations (h) were analyzed from 57 patients with a variety of neurological conditions. Mean age was 58.7±14.2 years and the male to female ratio was 1:1.3. After adjusting for hemoglobin and partial pressure of carbon dioxide in arterial blood, COx was inversely associated with GCS (β=-1.12, 95% confidence interval [CI], -1.94 to -0.31, P=0.007) and GCS motor score (β=-1.06, 95% CI, -2.10 to -0.04, P=0.04). In contrast rScO2 was not associated with GCS (β=-0.002, 95% CI, -0.01 to 0.01, P=0.76) or GCS motor score (β=-0.001, 95% CI, -0.01 to 0.01, P=0.84).This study showed that fluctuations in GCS scores are inversely associated with fluctuations in COx; as COx increases (impaired autoregulation), more severe neurological impairment is observed. However, the difference in COx between high and low GCS is small and warrants further studies investigating this association. CA multimodal monitoring with COx may have the potential to be used as a surrogate of neurological status when the neurological examination is not reliable (ie, sedation and paralytic drug administration).

  View details for DOI 10.1097/ANA.0000000000000513

  View details for PubMedID 29782388

  View details for PubMedCentralID PMC6240506

• Impact of antiepileptic drugs for seizure prophylaxis on short and long-term functional outcomes in patients with acute intracerebral hemorrhage: A meta-analysis and systematic review. Seizure Spoelhof, B., Sanchez-Bautista, J., Zorrilla-Vaca, A., Kaplan, P. W., Farrokh, S., Mirski, M., Freund, B., Rivera-Lara, L. 2019; 69: 140-146

  Abstract

  The purpose of this analysis is to assess the effect of antiepileptics (AEDs) on seizure prevention and short and long term functional outcomes in patients with acute intracerebral hemorrhage.The meta-analysis was conducted using the PRISMA guidelines. A literature search was performed of the PubMed, the Cochrane Library, and EMBASE databases. Search terms included "Anticonvulsants", "Intracerebral Hemorrhage", and related subject headings. Articles were screened and included if they were full-text and in English. Articles that did not perform multivariate regression were not included. Overall effect size was evaluated with forest plots and publication bias was assessed with the Begg's and Egger's tests.A total of 3912 articles were identified during the initial review. After screening, 54 articles remained for full review and 6 articles were included in the final analysis. No significant association between the use of AEDs after ICH and functional outcome (OR 1.53 [95%CI: 0.81-2.88] P = 0.18, I2 = 81.7%). Only one study evaluated the effect AEDs had in preventing post-ICH seizures.The use of prophylactic AEDs was not associated with improved short and long outcomes after acute ICH. This analysis supports the 2015 AHA/ASA recommendation against prophylactic AEDs (class III; level of evidence b).

  View details for DOI 10.1016/j.seizure.2019.04.017

  View details for PubMedID 31048270

• Cerebral microhemorrhages and cerebral fat embolism in hemoglobin S-C disease. Neurology. Clinical practice Cho, S. M., Ling, G., Rivera-Lara, L. 2019; 9 (2): e13-e14

  View details for DOI 10.1212/CPJ.0000000000000559

  View details for PubMedID 31041140

  View details for PubMedCentralID PMC6461432

• The role of impaired brain perfusion in septic encephalopathy. Critical care (London, England) Rivera-Lara, L. 2019; 23 (1): 54

  View details for DOI 10.1186/s13054-018-2299-z

  View details for PubMedID 30782168

  View details for PubMedCentralID PMC6381612

• Acute Kidney Injury Following Acute Ischemic Stroke and Intracerebral Hemorrhage: A Meta-Analysis of Prevalence Rate and Mortality Risk. Cerebrovascular diseases (Basel, Switzerland) Zorrilla-Vaca, A., Ziai, W., Connolly, E. S., Geocadin, R., Thompson, R., Rivera-Lara, L. 2018; 45 (1-2): 1-9

  Abstract

  The epidemiology of acute renal dysfunction after stroke is routinely overlooked following stroke events. Our aim in this meta-analysis is to report the prevalence of acute kidney injury (AKI) following acute stroke and its impact on mortality.A systematic literature search was performed on PubMed, EMBASE and Google Scholar for observational studies examining the prevalence and mortality risk of stroke patients with AKI as a complication. The pooled prevalence rates and odds ratios for mortality risk were calculated using subgroup analyses between the stroke subtypes: acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH).A total of 12 studies (4,532,181 AIS and 615,636 ICH) were included. The pooled prevalence rate of AKI after all stroke types was 11.6% (95% CI 10.6-12.7). Subgroup analyses revealed that the pooled prevalence rate of AKI after AIS was greater but not statistically significantly different than ICH (19.0%; 95% CI 8.2-29.7 vs. 12.9%; 95% CI 10.3-15.5, p = 0.5). AKI was found to be a significant risk factor of mortality in AIS (adjusted OR [aOR] 2.23; 95% CI 1.28-3.89; I2 = 98.8%), whereas this relationship did not reach statistical significance in ICH (aOR 1.20; 95% CI 0.68-2.12; I2 = 74.2%).This meta-analysis provides evidence that AKI is a common complication following both AIS and ICH and it is associated with increased mortality following AIS but not ICH. This highlights the need for early assessment of renal function in the acute phase of AIS, in particular, and avoidance of factors than may induce AKI in vulnerable patients.

  View details for DOI 10.1159/000479338

  View details for PubMedID 29176313

• Cerebrovascular Events After Continuous-Flow Left Ventricular Assist Devices. Neurocritical care Tahsili-Fahadan, P., Curfman, D. R., Davis, A. A., Yahyavi-Firouz-Abadi, N., Rivera-Lara, L., Nassif, M. E., LaRue, S. J., Ewald, G. A., Zazulia, A. R. 2018; 29 (2): 225-232

  Abstract

  Cerebrovascular events (CVE) are among the most common and serious complications after implantation of continuous-flow left ventricular assist devices (CF-LVAD). We studied the incidence, subtypes, anatomical distribution, and pre- and post-implantation risk factors of CVEs as well as the effect of CVEs on outcomes after CF-LVAD implantation at our institution.Retrospective analysis of clinical and neuroimaging data of 372 patients with CF-LVAD between May 2005 and December 2013 using standard statistical methods.CVEs occurred in 71 patients (19%), consisting of 35 ischemic (49%), 26 hemorrhagic (37%), and 10 ischemic+hemorrhagic (14%) events. History of coronary artery disease and female gender was associated with higher odds of ischemic CVE (OR 2.84 and 2.5, respectively), and diabetes mellitus was associated with higher odds of hemorrhagic CVE (OR 3.12). While we found a higher rate of ischemic CVEs in patients not taking any antithrombotic medications, no difference was found between patients with ischemic and hemorrhagic CVEs. Occurrence of CVEs was associated with increased mortality (HR 1.62). Heart transplantation was associated with improved survival (HR 0.02). In patients without heart transplantation, occurrence of CVE was associated with decreased survival.LVADs are associated with high rates of CVE, increased mortality, and lower rates of heart transplantation. Further investigations to identify the optimal primary and secondary stroke prevention measures in post-LVAD patients are warranted.

  View details for DOI 10.1007/s12028-018-0531-y

  View details for PubMedID 29637518

• Influence of Bleeding Pattern on Ischemic Lesions After Spontaneous Hypertensive Intracerebral Hemorrhage with Intraventricular Hemorrhage. Neurocritical care Rivera-Lara, L., Murthy, S. B., Nekoovaght-Tak, S., Ali, H., McBee, N., Dlugash, R., Ram, M., Thompson, R., Awad, I. A., Hanley, D. F., Ziai, W. C. 2018; 29 (2): 180-188

  Abstract

  Concomitant acute ischemic lesions are detected in up to a quarter of patients with spontaneous intracerebral hemorrhage (ICH). Influence of bleeding pattern and intraventricular hemorrhage (IVH) on risk of ischemic lesions has not been investigated.Retrospective study of all 500 patients enrolled in the CLEAR III randomized controlled trial of thrombolytic removal of obstructive IVH using external ventricular drainage. The primary outcome measure was radiologically confirmed ischemic lesions, as reported by the Safety Event Committee and confirmed by two neurologists. We assessed predictors of ischemic lesions including analysis of bleeding patterns (ICH, IVH and subarachnoid hemorrhage) on computed tomography scans (CT). Secondary outcomes were blinded assessment of mortality and modified Rankin scale (mRS) at 30 and 180 days.Ischemic lesions occurred in 23 (4.6%) during first 30 days after ICH. Independent risk factors associated with ischemic lesions in logistic regression models adjusted for confounders were higher IVH volume (p = 0.004) and persistent subarachnoid hemorrhage on CT scan (p = 0.03). Patients with initial IVH volume ≥ 15 ml had five times the odds of concomitant ischemic lesions compared to IVH volume < 15 ml. Patients with ischemic lesions had significantly higher odds of death at 1 and 6 months (but not poor outcome; mRS 4-6) compared to patients without concurrent ischemic lesions.Occurrence of ischemic lesions in the acute phase of IVH is not uncommon and is significantly associated with increased early and late mortality. Extra-parenchymal blood (larger IVH and visible subarachnoid hemorrhage) is a strong predictor for development of concomitant ischemic lesions after ICH.

  View details for DOI 10.1007/s12028-018-0516-x

  View details for PubMedID 29589328

  View details for PubMedCentralID PMC6160362

• Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials. Canadian journal of anaesthesia = Journal canadien d'anesthesie Zorrilla-Vaca, A., Healy, R., Grant, M. C., Joshi, B., Rivera-Lara, L., Brown, C., Mirski, M. A. 2018; 65 (5): 529-542

  Abstract

  Although evidence from observational studies in a variety of clinical settings supports the utility of cerebral oximetry as a predictor of outcomes, prospective clinical trials thus far have reported conflicting results. This systematic review and meta-analysis was designed to evaluate the influence of management associated with intraoperative cerebral oximetry on postoperative outcomes. The primary outcome was postoperative cognitive dysfunction (POCD), with secondary outcomes that included postoperative delirium, length of intensive care unit (ICU) stay, and hospital length of stay (LOS).After searching the PubMed, EMBASE, Cochrane Library, Scopus, and Google Scholar databases, all randomized controlled trials (RCTs) assessing the impact of intraoperative cerebral oximetry-guided management on clinical outcomes following surgery were identified.Fifteen RCTs comprising 2,057 patients (1,018 in the intervention group and 1,039 in control group) were included. Intraoperative management guided by the use of cerebral oximetry was associated with a reduction in the incidence of POCD (risk ratio [RR] 0.54; 95% confidence interval [CI], 0.33 to 0.90; P = 0.02; I2 = 85%) and a significantly shorter length of ICU stay (standardized mean difference [SMD], -0.21 hr; 95% CI, -0.37 to -0.05; P = 0.009; I2 = 48%). In addition, overall hospital LOS (SMD, -0.06 days; 95% CI, -0.18 to 0.06; P = 0.29; I2 = 0%) and incidence of postoperative delirium (RR, 0.69; 95% CI, 0.36 to 1.32; P = 0.27; I2 = 0%) were not impacted by the use of intraoperative cerebral oximetry.Intraoperative cerebral oximetry appears to be associated with a reduction in POCD, although this result should be interpreted with caution given the significant heterogeneity in the studies examined. Further large (ideally multicentre) RCTs are needed to clarify whether POCD can be favourably impacted by the use of cerebral oximetry-guided management.

  View details for DOI 10.1007/s12630-018-1065-7

  View details for PubMedID 29427259

• Comparison of intensive versus conventional insulin therapy in traumatic brain injury: a meta-analysis of randomized controlled trials. Brain injury Núñez-Patiño, R. A., Zorrilla-Vaca, A., Rivera-Lara, L. 2018; 32 (6): 693-703

  Abstract

  To compare intensive insulin therapy (IIT) and conventional insulin therapy (CIT) on clinical outcomes of patients with traumatic brain injury (TBI).MEDLINE, EMBASE, Google Scholar, ISI Web of Science, and Cochrane Library were systematically searched for randomized controlled trials (RCTs) comparing IIT to CIT in patients with TBI. Study-level characteristics, intensive care unit (ICU) events, and long-term functional outcomes were extracted from the articles. Meta-analysis was performed with random-effect models.Seven RCTs comprising 1070 patients were included. Although IIT was associated with better neurologic outcome (GOS > 3) (RR=0.87, 95% CI=0.78-0.97; P=0.01; I2=0%), sensitivity analysis revealed that one study influenced this overall estimate (RR=0.90, 95% CI=0.80-1.01, P=0.07; I2=0%). IIT was strongly associated with higher risk of hypoglycaemia (RR=5.79, 95% CI=3.27-10.26, P<0.01; I2=38%). IIT and CIT did not differ in terms of early or late mortality (RR=0.96, 95% CI=0.79-1.17, P=0.7; I2=0%), infection rate (RR=0.82, 95% CI=0.59-1.14, P=0.23; I2=68%), or ICU length of stay (SMD= -0.14, 95% CI=-0.35 to 0.07, P=0.18; I2=45%0.) Conclusions: IIT did not improve long-term neurologic outcome, mortality, or infection rate and was associated with increased risk of hypoglycaemia. Additional well-designed RCTs with defined TBI subgroups should be performed to generate more powerful conclusions.

  View details for DOI 10.1080/02699052.2018.1457181

  View details for PubMedID 29580096

• Epidemiology of septic meningitis associated with neuraxial anesthesia: a historical review and meta-analysis. Minerva anestesiologica Zorrilla-Vaca, A., Healy, R. J., Rivera-Lara, L., Grant, M. C., Maragakis, L. L., Escandón-Vargas, K., Mirski, M. A. 2018; 84 (3): 363-377

  Abstract

  Neuraxial anesthesia in the form of spinal and epidural are two of the most frequent forms of regional anesthesia. We aimed to describe and compare the relevant epidemiological, clinical and microbiological characteristics of all reported cases of septic meningitis associated with the use of spinal and epidural anesthetics.We performed a systematic review of septic meningitis associated with neuraxial anesthesia. We included all relevant case-reports and observational studies in which authors described septic meningitis in association with spinal, epidural or combined neuraxial anesthesia using local anesthetics.A total of 234 cases of septic meningitis were reported following review of 71 case-report articles and 22 epidemiological studies. In total, there have been 199, 25 and 10 reported cases of septic meningitis associated to spinal, epidural and combined neuraxial anesthesia, respectively. The lack of use of surgical masks was the most common risk factor (41, 16.7%). Streptococcus salivarius was the most common bacteria (17.0%) related to spinal anesthesia and Staphylococcus aureus (26.7%) was the most common one related to epidural. The time to symptom onset was significantly reduced in spinal (median time, 24 hours IQR [8-72] vs. 96 hours IQR [84-240]; P=0.003) compared to epidural anesthesia. The overall mortality rate is 15.3% and 13.3% for reported cases related to spinal and epidural anesthesia, respectively.While the true incidence remains speculative, this review suggests that given increasing indications for spinals and epidurals, septic meningitis remains an important associated with neuraxial anesthesia.

  View details for DOI 10.23736/S0375-9393.17.11920-6

  View details for PubMedID 29108403

• Cerebral Blood Flow Autoregulation in Sepsis for the Intensivist: Why Its Monitoring May Be the Future of Individualized Care. Journal of intensive care medicine Goodson, C. M., Rosenblatt, K., Rivera-Lara, L., Nyquist, P., Hogue, C. W. 2018; 33 (2): 63-73

  Abstract

  Cerebral blood flow (CBF) autoregulation maintains consistent blood flow across a range of blood pressures (BPs). Sepsis is a common cause of systemic hypotension and cerebral dysfunction. Guidelines for BP management in sepsis are based on historical concepts of CBF autoregulation that have now evolved with the availability of more precise technology for its measurement. In this article, we provide a narrative review of methods of monitoring CBF autoregulation, the cerebral effects of sepsis, and the current knowledge of CBF autoregulation in sepsis. Current guidelines for BP management in sepsis are based on a goal of maintaining mean arterial pressure (MAP) above the lower limit of CBF autoregulation. Bedside tools are now available to monitor CBF autoregulation continuously. These data reveal that individual BP goals determined from CBF autoregulation monitoring are more variable than previously expected. In patients undergoing cardiac surgery with cardiopulmonary bypass, for example, the lower limit of autoregulation varied between a MAP of 40 to 90 mm Hg. Studies of CBF autoregulation in sepsis suggest patients frequently manifest impaired CBF autoregulation, possibly a result of BP below the lower limit of autoregulation, particularly in early sepsis or with sepsis-associated encephalopathy. This suggests that the present consensus guidelines for BP management in sepsis may expose some patients to both cerebral hypoperfusion and cerebral hyperperfusion, potentially resulting in damage to brain parenchyma. The future use of novel techniques to study and clinically monitor CBF autoregulation could provide insight into the cerebral pathophysiology of sepsis and offer more precise treatments that may improve functional and cognitive outcomes for survivors of sepsis.

  View details for DOI 10.1177/0885066616673973

  View details for PubMedID 27798314

  View details for PubMedCentralID PMC5515688

• Validation of Near-Infrared Spectroscopy for Monitoring Cerebral Autoregulation in Comatose Patients. Neurocritical care Rivera-Lara, L., Geocadin, R., Zorrilla-Vaca, A., Healy, R., Radzik, B. R., Palmisano, C., Mirski, M., Ziai, W. C., Hogue, C. 2017; 27 (3): 362-369

  Abstract

  Transcranial Doppler (TCD) noninvasively measures cerebral blood flow (CBF) velocity and is a well-studied method to monitor cerebral autoregulation (CA). Near-infrared spectroscopy (NIRS) has emerged as a promising noninvasive method to determine CA continuously by using regional cerebral oxygen saturation (rSO2) as a surrogate for CBF. Little is known about its accuracy to determine CA in patients with intracranial lesions. The purpose of this study was to assess the accuracy of rSO2-based CA monitoring with TCD methods in comatose patients with acute neurological injury.Thirty-three comatose patients were monitored at the bedside to measure CA using both TCD and NIRS. Patients were monitored daily for up to three days from coma onset. The cerebral oximetry index (COx) was calculated as the moving correlation between the slow waves of rSO2 and mean arterial pressure (MAP). The mean velocity index (Mx) was calculated as a similar coefficient between slow waves of TCD-measured CBF velocity and MAP. Optimal blood pressure was defined as the MAP with the lowest Mx and COx. Averaged Mx and COx as well as optimal MAP, based on both Mx and COx, were compared using Pearson's correlation. Bias analysis was performed between these same CA metrics.The median duration of monitoring was 60 min (interquartile range [IQR] 48-78). There was a moderate correlation between the averaged values of COx and Mx (R = 0.40, p = 0.005). Similarly, there was a strong correlation between optimal MAP calculated for COx and Mx (R = 0.87, p < 0.001). Bland-Altman analysis showed moderate agreement with bias (±standard deviation) of -0.107 (±0.191) for COx versus Mx and good agreement with bias of 1.90 (±7.94) for optimal MAP determined by COx versus Mx.Monitoring CA with NIRS-derived COx is correlated and had good agreement with previously validated TCD-based method. These results suggest that COx may be an acceptable substitute for Mx monitoring in patients with acute intracranial injury.

  View details for DOI 10.1007/s12028-017-0421-8

  View details for PubMedID 28664392

  View details for PubMedCentralID PMC5772737

• Adult intestinal colonization botulism mimicking brain death. Muscle & nerve Freund, B., Hayes, L., Rivera-Lara, L., Sumner, C., Chaudhry, V., Chatham-Stephens, K., Benedict, K., Kalb, S., Blythe, D., Brooks, R., Probasco, J. C. 2017; 56 (4): E27-E28

  View details for DOI 10.1002/mus.25689

  View details for PubMedID 28500638

• Drug Interactions in Neurocritical Care. Neurocritical care Spoelhof, B., Farrokh, S., Rivera-Lara, L. 2017; 27 (2): 287-296

  Abstract

  Drug-drug interactions (DDIs) are common and avoidable complications that are associated with poor patient outcomes. Neurocritical care patients may be at particular risk for DDIs due to alterations in pharmacokinetic profiles and exposure to medications with a high DDI risk. This review describes the principles of DDI pharmacology, common and severe DDIs in Neurocritical care, and recommendations to minimize adverse outcomes. A review of published literature was performed using PubMed by searching for 'Drug Interaction' and several high DDI risk and common neurocritical care medications. Key medication classes included anticoagulants, antimicrobials, antiepileptics, antihypertensives, sedatives, and selective serotonin reuptake inhibitors. Additional literature was also reviewed to determine the risk in neurocritical care and potential therapeutic alternatives. Clinicians should be aware of interactions in this setting, the long-term complications, and therapeutic alternatives.

  View details for DOI 10.1007/s12028-016-0369-0

  View details for PubMedID 28054285

• Permanent CSF shunting after intraventricular hemorrhage in the CLEAR III trial. Neurology Murthy, S. B., Awad, I., Harnof, S., Aldrich, F., Harrigan, M., Jallo, J., Caron, J. L., Huang, J., Camarata, P., Lara, L. R., Dlugash, R., McBee, N., Eslami, V., Hanley, D. F., Ziai, W. C. 2017; 89 (4): 355-362

  Abstract

  To study factors associated with permanent CSF diversion and the relationship between shunting and functional outcomes in spontaneous intraventricular hemorrhage (IVH).Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR III), a randomized, multicenter, double-blind, placebo-controlled trial, was conducted to determine if pragmatically employed external ventricular drainage (EVD) plus intraventricular alteplase improved outcome, in comparison to EVD plus saline. Outcome measures were predictors of shunting and blinded assessment of mortality and modified Rankin Scale at 180 days.Among the 500 patients with IVH, CSF shunting was performed in 90 (18%) patients at a median of 18 (interquartile range [IQR] 13-30) days. Patient demographics and IVH characteristics were similar among patients with and without shunts. In the multivariate analysis, black race (odds ratio [OR] 1.98; 95% confidence interval [CI] 1.18-3.34), duration of EVD (OR 1.10; CI 1.05-1.15), placement of more than one EVD (OR 1.93; CI 1.13-3.31), daily drainage CSF per 10 mL (OR 1.07; CI 1.04-1.10), and intracranial pressure >30 mm Hg (OR 1.70; CI 1.09-2.88) were associated with higher odds of permanent CSF shunting. Patients who had CSF shunts had similar odds of 180-day mortality, while survivors with shunts had increased odds of poor functional outcome, compared to survivors without shunts.Among patients with spontaneous IVH requiring emergency CSF diversion, those with early elevated intracranial pressure, high CSF output, and placement of more than one EVD are at increased odds of permanent ventricular shunting. Administration of intraventricular alteplase, early radiographic findings, and CSF measures were not useful predictors of permanent CSF diversion.

  View details for DOI 10.1212/WNL.0000000000004155

  View details for PubMedID 28659429

  View details for PubMedCentralID PMC5574677

• Cerebral Autoregulation-oriented Therapy at the Bedside: A Comprehensive Review. Anesthesiology Rivera-Lara, L., Zorrilla-Vaca, A., Geocadin, R. G., Healy, R. J., Ziai, W., Mirski, M. A. 2017; 126 (6): 1187-1199

  Abstract

  This comprehensive review summarizes the evidence regarding use of cerebral autoregulation-directed therapy at the bedside and provides an evaluation of its impact on optimizing cerebral perfusion and associated functional outcomes. Multiple studies in adults and several in children have shown the feasibility of individualizing mean arterial blood pressure and cerebral perfusion pressure goals by using cerebral autoregulation monitoring to calculate optimal levels. Nine of these studies examined the association between cerebral perfusion pressure or mean arterial blood pressure being above or below their optimal levels and functional outcomes. Six of these nine studies (66%) showed that patients for whom median cerebral perfusion pressure or mean arterial blood pressure differed significantly from the optimum, defined by cerebral autoregulation monitoring, were more likely to have an unfavorable outcome. The evidence indicates that monitoring of continuous cerebral autoregulation at the bedside is feasible and has the potential to be used to direct blood pressure management in acutely ill patients.

  View details for DOI 10.1097/ALN.0000000000001625

  View details for PubMedID 28383324

• Predictors of Outcome With Cerebral Autoregulation Monitoring: A Systematic Review and Meta-Analysis. Critical care medicine Rivera-Lara, L., Zorrilla-Vaca, A., Geocadin, R., Ziai, W., Healy, R., Thompson, R., Smielewski, P., Czosnyka, M., Hogue, C. W. 2017; 45 (4): 695-704

  Abstract

  To compare cerebral autoregulation indices as predictors of patient outcome and their dependence on duration of monitoring.Systematic literature search and meta-analysis using PubMed, EMBASE, and the Cochrane Library from January 1990 to October 2015.We chose articles that assessed the association between cerebral autoregulation indices and dichotomized or continuous outcomes reported as standardized mean differences or correlation coefficients (R), respectively. Animal and validation studies were excluded.Two authors collected and assessed the data independently. The studies were grouped into two sets according to the type of analysis used to assess the relationship between cerebral autoregulation indices and predictors of outcome (standardized mean differences or R).Thirty-three studies compared cerebral autoregulation indices and patient outcomes using standardized mean differences, and 20 used Rs. The only data available for meta-analysis were from patients with traumatic brain injury or subarachnoid hemorrhage. Based on z score analysis, the best three cerebral autoregulation index predictors of mortality or Glasgow Outcome Scale for patients with traumatic brain injury were the pressure reactivity index, transcranial Doppler-derived mean velocity index based on cerebral perfusion pressure, and autoregulation reactivity index (z scores: 8.97, 6.01, 3.94, respectively). Mean velocity index based on arterial blood pressure did not reach statistical significance for predicting outcome measured as a continuous variable (p = 0.07) for patients with traumatic brain injury. For patients with subarachnoid hemorrhage, autoregulation reactivity index was the only cerebral autoregulation index that predicted patient outcome measured with the Glasgow Outcome Scale as a continuous outcome (R = 0.82; p = 0.001; z score, 3.39). We found a significant correlation between the duration of monitoring and predictive value for mortality (R = 0.78; p < 0.001).Three cerebral autoregulation indices, pressure reactivity index, mean velocity index based on cerebral perfusion pressure, and autoregulation reactivity index were the best outcome predictors for patients with traumatic brain injury. For patients with subarachnoid hemorrhage, autoregulation reactivity index was the only cerebral autoregulation index predictor of Glasgow Outcome Scale. Continuous assessment of cerebral autoregulation predicted outcome better than intermittent monitoring.

  View details for DOI 10.1097/CCM.0000000000002251

  View details for PubMedID 28291094

• Management of infections associated with neurocritical care. Handbook of clinical neurology Rivera-Lara, L., Ziai, W., Nyquist, P. 2017; 140: 365-378

  Abstract

  The reported incidence of hospital-acquired infections (HAIs) in the neurointensive care unit (NICU) ranges from 20% to 30%. HAIs in US hospitals cost between $28 and $45 billion per year in direct medical costs. These infections are associated with increased length of hospital stay and increased morbidity and mortality. Infection risk is increased in NICU patients due to medication side-effects, catheter and line placement, neurosurgical procedures, and acquired immune suppression secondary to steroid/barbiturate use and brain injury itself. Some of these infections may be preventable but many are not. Their appearance do not always constitute a failure of prevention or physician error. Neurointensivists require indepth knowledge of common nosocomial infections, their diagnosis and treatment, and an approach to evidence-based practices that improve processes of care and reduce HAIs.

  View details for DOI 10.1016/B978-0-444-63600-3.00020-9

  View details for PubMedID 28187810

• Acute Stroke Emergency Management Evidence-Based Critical Care pp 303-314 George, P., Rivera Lara , L. Springer, Cham. 2017
• Elevated relative risk of aneurysmal subarachnoid hemorrhage with colder weather in the mid-Atlantic region. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Rivera-Lara, L., Kowalski, R. G., Schneider, E. B., Tamargo, R. J., Nyquist, P. 2015; 22 (10): 1582-7

  Abstract

  We have previously reported an increase of 0.6% in the relative risk of aneurysmal subarachnoid hemorrhage (aSAH) in response to every 1°F decrease in the maximum daily temperature (Tmax) in colder seasons from patients presenting to our regional tertiary care center. We hypothesized that this relationship would also be observed in the warmer summer months with ambient temperatures greater than 70°F. From prospectively collected incidence data for aSAH patients, we investigated absolute Tmax, average daily temperatures, intraday temperature ranges, and the variation of daily Tmax relative to 70°F to assess associations with aSAH incidence for patients admitted to our institution between 1991 and 2009 during the hottest months and days on which Tmax>70°F. For all days treated as a group, the mean Tmax (± standard deviation) was lower when aSAH occurred than when it did not (64.4±18.2°F versus 65.8±18.3°F; p=0.016). During summer months, the odds ratio (OR) of aSAH incidence increased with lower mean Tmax (OR 1.019; 95% confidence interval 1.001-1.037; p=0.043). The proportion of days with aSAH admissions was lower on hotter days than the proportion of days with no aSAH (96% versus 98%; p=0.006). aSAH were more likely to occur during the summer and on days with a temperature fluctuation less than 10°F (8% versus 4%; p=0.002). During the hottest months of the year in the mid-Atlantic region, colder maximum daily temperatures, a smaller heat burden above 70°F, and smaller intraday temperature fluctuations are associated with increased aSAH admissions in a similar manner to colder months. These findings support the hypothesis that aSAH incidence is more likely with drops in temperature, even in the warmer months.

  View details for DOI 10.1016/j.jocn.2015.03.033

  View details for PubMedID 26149403

• Diploic arteriovenous fistulas--classification and endovascular management. Acta neurochirurgica Rivera-Lara, L., Gailloud, P., Nyquist, P. 2015; 157 (9): 1485-8

  Abstract

  The authors report on two cases of diploic arteriovenous fistulas (AVFs) in the left parieto-occipital region of a 20-year-old female and the right parietal region of a 68-year-old male. The clinical presentation, angiographic appearance, and endovascular management of these rare lesions are discussed.Retrospective data from two patients with diplopic AVFs are examined with a review of all published cases of diploic arteriovenous fistulas.Where previously reported diploic AVFs showed venous drainage to be intracranial or combined, two case studies examined by the authors found exclusively extracranial drainage in the AVFs. In both case studies the lesions were primarily fed by the middle meningeal artery and treated via a transarterial endovascular approach using n-BCA glue.After reviewing all reported cases of AVF in the literature and combining our two new observations, we concluded that diploic AVFs can have three types of venous outflow: draining toward dural sinuses only, toward extracranial veins only, and combining the dural and extracranial pathways.

  View details for DOI 10.1007/s00701-015-2505-6

  View details for PubMedID 26163259

• Postoperative care of the surgical patient with neurological disease. International anesthesiology clinics Rivera-Lara, L., Mirski, M. 2015; 53 (1): 166-76

  View details for DOI 10.1097/AIA.0000000000000039

  View details for PubMedID 25551748

• Therapeutic hypothermia for acute neurological injuries. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics Rivera-Lara, L., Zhang, J., Muehlschlegel, S. 2012; 9 (1): 73-86

  Abstract

  Therapeutic hypothermia (TH) is the intentional reduction of core body temperature to 32°C to 35°C, and is increasingly applied by intensivists for a variety of acute neurological injuries to achieve neuroprotection and reduction of elevated intracranial pressure. TH improves outcomes in comatose patients after a cardiac arrest with a shockable rhythm, but other off-label applications exist and are likely to increase in the future. This comprehensive review summarizes the physiology and cellular mechanism of action of TH, as well as different means of TH induction and maintenance with potential side effects. Indications of TH are critically reviewed by disease entity, as reported in the most recent literature, and evidence-based recommendations are provided.

  View details for DOI 10.1007/s13311-011-0092-7

  View details for PubMedID 22173727

  View details for PubMedCentralID PMC3271145

• Delayed sudden coma due to artery of percheron infarction. Archives of neurology Rivera-Lara, L., Henninger, N. 2011; 68 (3): 386-7

  View details for DOI 10.1001/archneurol.2010.377

  View details for PubMedID 21403026

• Cerebral hemodynamic effects of acute hyperoxia and hyperventilation after severe traumatic brain injury. Journal of neurotrauma Rangel-Castilla, L., Lara, L. R., Gopinath, S., Swank, P. R., Valadka, A., Robertson, C. 2010; 27 (10): 1853-63

  Abstract

  The purpose of this study was to examine the effects of hyperventilation or hyperoxia on cerebral hemodynamic parameters over time in patients with severe traumatic brain injury (TBI). We prospectively studied 186 patients with severe TBI. CO₂ and O₂ reactivity tests were conducted twice a day on days 1-5 and once daily on days 6-10 after injury. During hyperventilation there was a significant decrease in intracranial pressure (ICP), mean arterial pressure (MAP), jugular venous oxygen saturation (Sjvo₂), brain tissue Po₂ (Pbto₂), and flow velocity (FV). During hyperoxia there was an increase in Sjvo₂ and Pbto₂, and a small but consistent decrease in ICP, end-tidal carbon dioxide (etco₂), partial arterial carbon dioxide pressure (Paco₂), and FV. Brain tissue oxygen reactivity during the first 12 h after injury averaged 19.7 ± 3.0%, and slowly decreased over the next 7 days. The autoregulatory index (ARI; normal = 5.3 ± 1.3) averaged 2.2 ± 1.5 on day 1 post-injury, and gradually improved over the 10 days of monitoring. The ARI significantly improved during hyperoxia, by an average of 0.4 ± 1.8 on the left, and by 0.5 ± 1.8 on the right. However, the change in ARI with hyperoxia was much smaller than that observed with hyperventilation. Hyperventilation increased ARI by an average of 1.3 ± 1.9 on the left, and 1.5 ± 2.0 on the right. Pressure autoregulation, as assessed by dynamic testing, was impaired in these head-injured patients. Acute hyperoxia significantly improved pressure autoregulation, although the effect was smaller than that induced by hyperventilation. The very small change in Paco₂ induced by hyperoxia does not appear to explain this finding. Rather, the vasoconstriction induced by acute hyperoxia may allow the cerebral vessels to respond better to transient hypotension. Further studies are needed to define the clinical significance of these observations.

  View details for DOI 10.1089/neu.2010.1339

  View details for PubMedID 20684672

  View details for PubMedCentralID PMC2953927