Perioperative Care of Patients at High Risk for Stroke During or After Non-cardiac, Non-neurological Surgery: 2020 Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care.

Perioperative stroke is associated with considerable morbidity and mortality. Stroke recognition and diagnosis are challenging perioperatively, and surgical patients receive therapeutic interventions less frequently compared with stroke patients in the outpatient setting. These updated guidelines from the Society for Neuroscience in Anesthesiology and Critical Care provide evidence-based recommendations regarding perioperative care of patients at high risk for stroke. Recommended areas for future investigation are also proposed

Venous Air Embolism in Deep Brain Stimulation

Background/Aims: During the placement of electrodes for deep brain stimulation (DBS), patients are commonly in a seated position, awake, and spontaneously breathing. Air may be entrained through bone or dural veins causing venous air emboli (VAE) and this phenomenon can result in significant hemodynamic changes. Although VAEs have been described in many types of neurosurgical procedures, their incidence during DBS surgery is unknown. Methods: Following approval from the Institutional Review Board, the University of Florida Movement Disorders Center database comprising 286 DBS leads placed since 2002 was reviewed. Intraoperative cough, which has been associated with VAE, as well as hemodynamic instability were the focus of the review. Additionally, a prospective evaluation of the incidence of VAE using precordial Doppler ultrasound was undertaken over a 3-month period (June 2007-August 2007). Results: The retrospective review revealed a 3.2% incidence of cough per lead. Prospective monitoring in 21 consecutive patients with 22 leads yielded the detection of 1 VAE, and an incidence of 4.5% per lead. Conclusion: VAEs are rare but potentially serious complications of DBS surgery unless recognized. Patient positioning and the occurrence of cough are two important predictors to consider in VAE. Precordial Doppler is a safe, non-invasive monitor that can be used in the early detection of VAE in these procedures. Copyright (c) 2008 S. Karger AG, Base

Temporal Profile of Microtubule-Associated Protein 2: A Novel Indicator of Diffuse Brain Injury Severity and Early Mortality after Brain Trauma

This study compared cerebrospinal fluid (CSF) levels of microtubule-associated protein 2 (MAP-2) from adult patients with severe traumatic brain injury (TBI) with uninjured controls over 10 days, and examined the relationship between MAP-2 concentrations and acute clinical and radiologic measures of injury severity along with mortality at 2 weeks and over 6 months. This prospective study, conducted at two Level 1 trauma centers, enrolled adults with severe TBI (Glasgow Coma Scale [GCS] score ≤8) requiring a ventriculostomy, as well as controls. Ventricular CSF was sampled from each patient at 6, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, and 240 h following TBI and analyzed via enzyme-linked immunosorbent assay for MAP-2 (ng/mL). Injury severity was assessed by the GCS score, Marshall Classification on computed tomography (CT), Rotterdam CT score, and mortality. There were 151 patients enrolled—130 TBI and 21 control patients. MAP-2 was detectable within 6 h of injury and was significantly elevated compared with controls ( p  < 0.001) at each time-point. MAP-2 was highest within 72 h of injury and decreased gradually over 10 days. The area under the receiver operating characteristic curve for deciphering TBI versus controls at the earliest time-point CSF was obtained was 0.96 (95% CI 0.93–0.99) and for the maximal 24-h level was 0.98 (95% CI 0.97–1.00). The area under the curve for initial MAP-2 levels predicting 2-week mortality was 0.80 at 6 h, 0.81 at 12 h, 0.75 at 18 h, 0.75 at 24 h, and 0.80 at 48 h. Those with Diffuse Injury III-IV had much higher initial ( p  = 0.033) and maximal ( p  = 0.003) MAP-2 levels than those with Diffuse Injury I-II. There was a graded increase in the overall levels and peaks of MAP-2 as the degree of diffuse injury increased within the first 120 h post-injury. These data suggest that early levels of MAP-2 reflect severity of diffuse brain injury and predict 2-week mortality in TBI patients. These findings have implications for counseling families and improving clinical decision making early after injury and guiding multidisciplinary care. Further studies are needed to validate these findings in a larger sample

Perioperative Practices in Moyamoya Syndrome Revascularization: An International Transdisciplinary Survey

Background There are no evidence‐based resources guiding the perioperative management of patients with moyamoya syndrome who are undergoing revascularization surgery. We investigated practice patterns among a transdisciplinary group aiming at identifying possible heterogeneity of practices on key components of care that warrant prospective studies. Methods We disseminated a web‐based Qualtrics survey internationally to physician members of the following: Neurocritical Care Society, Society of Critical Care Medicine, American Academy of Neurology, Society for Neuroscience in Anesthesiology and Critical Care, American Association of Neurological Surgeons, Asian Society of Neuroanesthesia and Critical Care, Indian Society of Neuroanesthesia and Critical Care, Japanese Society for Neuroscience in Anesthesiology and Critical Care, and World Federation of Neurosurgical Societies. The survey contained questions on demographics and aspects of preoperative, intraoperative, and postoperative care. Results Among the 175 physicians who managed at least 1 adult (aged ≥18 years) undergoing moyamoya revascularization in the preceding 24 months, 18 countries (United States, 84.6%) and 4 disciplines (anesthesiology [44.7%, 76/170], critical care medicine [30.6%, 52/170], neurology [32.4%, 55/170], and neurosurgery [15.3%, 26/170]) were represented. Anesthesiologists preferred total intravenous over volatile anesthesia (56.3%, 40/71 versus 42.3%, 30/71) and arterial line zeroing at the circle of Willis/tragus over the phlebostatic axis/right atrium intraoperatively (84.3%, 59/70 versus 11.4%, 8/70) and postoperatively (68.9%, 42/61 versus 24.6%, 15/61). Intraoperative blood pressure goals were primarily targeted to baseline blood pressure (34.8%, 48/138), whereas postoperative blood pressure goals were mainly determined by neurosurgeon preference (48.9%, 65/133). The predominant hemodynamic target was mean arterial pressure intraoperatively (50.4%, 68/135) and systolic blood pressure postoperatively (48.5%, 63/130). Crystalloid infusion was the preferred method to achieve perioperative hemodynamic goals (median rank, 1.0), followed by colloid infusion (median rank, 2.0) and phenylephrine (median rank, 2.0); however, colloid infusion and phenylephrine were considered contraindicated by 18.2% (10/55) and 20.0% (11/55), respectively. Conclusions We demonstrate perioperative practice heterogeneity for moyamoya syndrome revascularization among physicians for both methods and targets of hemodynamic management, constituting equipoise for prospective studies targeting optimal management strategies

Predicting Clinical Outcomes 7-10 Years after Severe Traumatic Brain Injury: Exploring the Prognostic Utility of the IMPACT Lab Model and Cerebrospinal Fluid UCH-L1 and MAP-2

Background Severe traumatic brain injury (TBI) is a major contributor to disability and mortality in the industrialized world. Outcomes of severe TBI are profoundly heterogeneous, complicating outcome prognostication. Several prognostic models have been validated for acute prediction of 6-month global outcomes following TBI (e.g., morbidity/mortality). In this preliminary observational prognostic study, we assess the utility of the International Mission on Prognosis and Analysis of Clinical Trials in TBI (IMPACT) Lab model in predicting longer term global and cognitive outcomes (7-10 years post injury) and the extent to which cerebrospinal fluid (CSF) biomarkers enhance outcome prediction. Methods Very long-term global outcome was assessed in a total of 59 participants (41 of whom did not survive their injuries) using the Glasgow Outcome Scale-Extended and Disability Rating Scale. More detailed outcome information regarding cognitive functioning in daily life was collected from 18 participants surviving to 7-10 years post injury using the Cognitive Subscale of the Functional Independence Measure. A subset (n = 10) of these participants also completed performance-based cognitive testing (Digit Span Test) by telephone. The IMPACT lab model was applied to determine its prognostic value in relation to very long-term outcomes as well as the additive effects of acute CSF ubiquitin C-terminal hydrolase-L1 (UCH-L1) and microtubule associated protein 2 (MAP-2) concentrations. Results The IMPACT lab model discriminated favorable versus unfavorable 7- to 10-year outcome with an area under the receiver operating characteristic curve of 0.80. Higher IMPACT lab model risk scores predicted greater extent of very long-term morbidity (beta = 0.488 p = 0.000) as well as reduced cognitive independence (beta = - 0.515, p = 0.034). Acute elevations in UCH-L1 levels were also predictive of lesser independence in cognitive activities in daily life at very long-term follow-up (beta = 0.286, p = 0.048). Addition of two CSF biomarkers significantly improved prediction of very long-term neuropsychological performance among survivors, with the overall model (including IMPACT lab score, UCH-L1, and MAP-2) explaining 89.6% of variance in cognitive performance 7-10 years post injury (p = 0.008). Higher acute UCH-L1 concentrations were predictive of poorer cognitive performance (beta = - 0.496, p = 0.029), whereas higher acute MAP-2 concentrations demonstrated a strong cognitive protective effect (beta = 0.679, p = 0.010). Conclusions Although preliminary, results suggest that existing prognostic models, including models with incorporation of CSF markers, may be applied to predict outcome of severe TBI years after injury. Continued research is needed examining early predictors of longer-term outcomes following TBI to identify potential targets for clinical trials that could impact long-ranging functional and cognitive outcomes

αII-Spectrin Breakdown Product Cerebrospinal Fluid Exposure Metrics Suggest Differences in Cellular Injury Mechanisms after Severe Traumatic Brain Injury

Traumatic brain injury (TBI) produces αII-spectrin breakdown products (SBDPs) that are potential biomarkers for TBI. To further understand these biomarkers, the present study examined (1) the exposure and kinetic characteristics of SBDPs in cerebrospinal fluid (CSF) of adults with severe TBI, and (2) the relationship between these exposure and kinetic metrics and severity of injury. This clinical database study analyzed CSF concentrations of 150-, 145-, and 120-kDa SBDPs in 38 severe TBI patients. Area under the curve (AUC), mean residence time (MRT), maximum concentration (Cmax), time to maximum concentration (Tmax), and half-life (t1/2) were determined for each SBDP. Markers of calpain proteolysis (SBDP150 and SBDP145) had a greater median AUC and Cmax and a shorter MRT than SBDP120, produced by caspase-3 proteolysis in the CSF in TBI patients (p < 0.001). AUC and MRT for SBDP150 and SBDP15 were significantly greater in patients with worse Glasgow Coma Scale (GCS) scores at 24 h after injury compared to those whose GCS scores improved (AUC p = 0.013, MRT p = 0.001; AUC p = 0.009, MRT p = 0.021, respectively). A positive correlation was found between patients with longer elevations in intracranial pressure (ICP) measurements of 25 mm Hg or higher and those with a greater AUC and MRT for all three biomarkers. This is the first study to show that the biomarkers of proteolysis differentially associated with calpain and caspase-3 activity have distinct CSF exposure profiles following TBI that suggest a prominent role for calpain activity. Further studies are being conducted to determine if exposure and kinetic metrics for biofluid-based biomarkers can predict clinical outcome