Brain Monitoring in Critically Neurologically Impaired Patients

Assessment of neurologic injury and the evolution of severe neurologic injury is limited in comatose or critically ill patients that lack a reliable neurologic examination. For common yet severe pathologies such as the comatose state after cardiac arrest, aneurysmal subarachnoid hemorrhage (aSAH), and severe traumatic brain injury (TBI), critical medical decisions are made on the basis of the neurologic injury. Decisions regarding active intensive care management, need for neurosurgical intervention, and withdrawal of care, depend on a reliable, high-quality assessment of the true state of neurologic injury, and have traditionally relied on limited assessments such as intracranial pressure monitoring and electroencephalogram. However, even within TBI there exists a spectrum of disease that is likely not captured by such limited monitoring and thus a more directed effort towards obtaining a more robust biophysical signature of the individual patient must be undertaken. In this review, multimodal monitoring including the most promising serum markers of neuronal injury, cerebral microdialysis, brain tissue oxygenation, and pressure reactivity index to access brain microenvironment will be discussed with their utility among specific pathologies that may help determine a more complete picture of the neurologic injury state for active intensive care management and long-term outcomes. Goal-directed therapy guided by a multi-modality approach appears to be superior to standard intracranial pressure (ICP) guided therapy and should be explored further across multiple pathologies. Future directions including the application of optogenetics to evaluate brain injury and recovery and even as an adjunct monitoring modality will also be discussed

The Protective Effect of Glibenclamide in a Model of Hemorrhagic Encephalopathy of Prematurity

brain science

Blood Pressure Variability and Outcome in Traumatic Brain Injury: A Propensity Score Matching Study

Introduction: Patients with tIPH (used here to refer to traumatic intraparenchymal hemorrhagic contusion) or intraparenchymal hemorrhage face high rates of mortality and persistent functional deficits. Prior studies have found an association between blood pressure variability (BPV) and neurologic outcomes in patients with spontaneous IPH. Our study investigated the association between BPV and discharge destination (a proxy for functional outcome) in patients with tIPH. Methods: We retrospectively reviewed the charts of patients admitted to a Level I trauma center for ≥ 24 hours with tIPH. We examined variability in hourly BP measurements over the first 24 hours of hospitalization. Our outcome of interest was discharge destination (home vs facility). We performed 1:1 propensity score matching and multivariate regressions to identify demographic and clinical factors predictive of discharge home. Results: We included 354 patients; 91 were discharged home and 263 to a location other than home. The mean age was 56 (SD 21), 260 (73%) were male, 22 (6%) were on anticoagulation, and 54 (15%) on antiplatelet therapy. Our propensity-matched cohorts included 76 patients who were discharged home and 76 who were discharged to a location other than home. One measure of BPV (successive variation in systolic BP) was identified as an independent predictor of discharge location in our propensity-matched cohorts (odds ratio 0.89, 95% confidence interval 0.8-0.98; P = 0.02). Our model demonstrated good goodness of fit (P-value for Hosmer-Lemeshow test = 0.88) and very good discriminatory capability (AUROC = 0.81). High Glasgow Coma Scale score at 24 hours and treatment with fresh frozen plasma were also associated with discharge home.Conclusion: Our study suggests that increased BPV is associated with lower rates of discharge home after initial hospitalization among patients with tIPH. Additional research is needed to evaluate the impact of BP control on patient outcomes

Transfer of Patients with Spontaneous Intracranial Hemorrhage who Need External Ventricular Drain: Does Admission Location Matter?

Introduction: Patients with spontaneous intracranial hemorrhage (sICH) are associated with high mortality and require early neurosurgical interventions. At our academic referral center, the neurocritical care unit (NCCU) receives patients directly from referring facilities. However, when no NCCU bed is immediately available, patients are initially admitted to the critical care resuscitation unit (CCRU). We hypothesized that the CCRU expedites transfer of sICH patients and facilitates timely external ventricular drain (EVD) placement comparable to the NCCU.Methods: This is a pre-post study of adult patients transferred with sICH and EVD placement. Patients admitted between January 2011–July 2013 (2011 Control) were compared with patients admitted either to the CCRU or the NCCU (2013 Control) between August 2013–September 2015. The primary outcome was time interval from arrival at any intensive care units (ICU) to time of EVD placement (ARR-EVD). Secondary outcomes included time interval from emergency department transfer request to arrival, and in-hospital mortality. We assessed clinical association by multivariable logistic regressions.Results: We analyzed 259 sICH patients who received EVDs: 123 (48%) CCRU; 81 (31%) 2011 Control; and 55 (21%) in the 2013 Control. The groups had similar characteristics, age, disease severity, and mortality. Median ARR-EVD time was 170 minutes [106-311] for CCRU patients; 241 minutes [152-490] (p < 0.01) for 2011 Control; and 210 minutes [139-574], p = 0.28) for 2013 Control.  Median transfer request-arrival time for CCRU patients was significantly less than both control groups. Multivariable logistic regression showed each minute delay in ARR-EVD was associated with 0.03% increased likelihood of death (odds ratio 1.0003, 95% confidence interval, 1.0001-1.006, p = 0.043).Conclusion: Patients admitted to the CCRU had shorter transfer times when compared to patients admitted directly to other ICUs. Compared to the specialty NCCU, the CCRU had similar time interval from arrival to EVD placement. A resuscitation unit like the CCRU can complement the specialty unit NCCU in caring for patients with sICH who require EVDs

Strain-related regional alterations of calcium-handling proteins in myocardial remodeling

BackgroundCardiac remodeling has been shown to have deleterious effects at both the global and local levels. The objective of this study is to investigate the role of strain in the initiation of structural and functional changes of myocardial tissue and its relation to alteration of calcium-handling proteins during cardiac remodeling after myocardial infarction.MethodsSixteen sonomicrometry transducers were placed in the left ventricular free wall of 9 sheep to measure the regional strain in the infarct, adjacent, and remote myocardial regions. Hemodynamic, echocardiographic, and sonomicrometry data were collected before myocardial infarction, after infarction, and 2, 6, and 8 weeks after infarction. Regional myocardial tissues were collected for calcium-handling proteins at the end study.ResultsAt time of termination, end-systolic strains in 3 regionally distinct zones (remote, adjacent, and infarct) of myocardium were measured to be −14.65 ± 1.13, −5.11 ± 0.60 (P ≤ .05), and 0.92 ± 0.56 (P ≤ .05), respectively. The regional end-systolic strain correlated strongly with the abundance of 2 major calcium-handling proteins: sarcoplasmic reticulum Ca2+ adenosine triphosphatase subtype 2a (r2 = 0.68, P ≤ .05) and phospholamban (r2 = 0.50, P ≤ .05). A lesser degree of correlation was observed between the systolic strain and the abundance of sodium/calcium exchanger type 1 protein (r2 = 0.17, P ≤ .05).ConclusionsRegional strain differences can be defined in the different myocardial regions during postinfarction cardiac remodeling. These differences in regional strain drive regionally distinct alterations in calcium-handling protein expression