Curriculum Innovation: Design, Implementation, and Evaluation of an Interdisciplinary Teamwork-Focused Neurocritical Care In Situ Simulation Training Program.

Introduction and Problem Statement: Neurocritical care (NCC) is a niche clinical subspecialty dependent on interdisciplinary cohesion to operate in critical situations. Team cohesion in an intensive care unit (ICU) depends not only on technical skills or medical knowledge but also on nontechnical skills such as teamwork, communication, and leadership. Developing and practicing these skills as an interdisciplinary team is not standard in most professional training programs. Objectives: This project aimed to (1) design and implement a NCC in situ simulation program aimed at practicing teamwork, (2) demonstrate feasibility and acceptability of recurring in situ simulations, and (3) assess baseline teamwork scores and clinician preparedness to respond to a clinical emergency. Methods and Curriculum Description: The NLN Jeffries Simulation Theory was used to guide the simulation program design. A 1-year pilot project consisted of monthly NCC in situ simulations. Debriefing with Good Judgment was used to guide postsimulation reflection. Feasibility was evaluated by participation metrics and simulation schedule adherence. Acceptability was assessed through postsimulation evaluations. Teamwork and preparedness were measured using the Mayo High Performance Teamwork Scale (MHPTS) and 10-point Likert scale, respectively. Statistical comparison of MHPTS scores between disciplines and preparedness before vs after simulation was conducted. Results and Assessment Data: In 1 year, we conducted 12 in situ simulations, with 167 simulation learner encounters, representing 95 unique learners and 72% of our core NCC team (i.e., nurses, advanced practice providers [APPs], fellows, faculty). Analysis of program evaluations (84% survey completion rate) showed that 91% of all learners strongly agreed that the simulation provided an experiential, collaborative, trusting, and learner-centered environment. Overall, MHPTS scores were similar between disciplines, although in pairwise comparison, pharmacists rated teamwork significantly lower than both nurses (p = 0.01) and APPs (p = 0.004). Learners rated their preparedness to respond to a clinical emergency significantly higher after the simulation (p < 0.001). Discussion and Lessons Learned: In situ simulation training is a feasible and acceptable method to introduce teamwork training into ICU culture. Team-based simulation improves self-reported preparation to respond to clinical emergencies. Simulation training that takes place in the clinical setting provides a powerful tool for enhancing teaching and addressing patient care gaps.

Clinical Grading Scales and Neuroprognostication in Acute Brain Injury.

Prediction of neurological clinical outcome after acute brain injury is critical because it helps guide discussions with patients and families and informs treatment plans and allocation of resources. Numerous clinical grading scales have been published that aim to support prognostication after acute brain injury. However, the development and validation of clinical scales lack a standardized approach. This in turn makes it difficult for clinicians to rely on prognostic grading scales and to integrate them into clinical practice. In this review, we discuss quality measures of score development and validation and summarize available scales to prognosticate outcomes after acute brain injury. These include scales developed for patients with coma, cardiac arrest, ischemic stroke, nontraumatic intracerebral hemorrhage, subarachnoid hemorrhage, and traumatic brain injury; for each scale, we discuss available validation studies.

Anticoagulation Holiday: Resumption of Direct Oral Anticoagulants for Atrial Fibrillation in Patients with Index Traumatic Intracranial Hemorrhage.

Background: The optimal time to restart direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF) after traumatic intracranial hemorrhage (tICH) is unknown. Physicians must weigh the risk of recurrent hemorrhage against ischemic stroke. We investigated rates of stroke while holding anticoagulation, hemorrhage after anticoagulation resumption, and factors associated with the decision to restart anticoagulation. Methods: Patients presenting to our level I trauma center for tICH while on a DOAC for NVAF were retrospectively reviewed over 2 years. Age, sex, DOAC use, antiplatelet use, congestive heart failure, hypertension, age, diabetes, previous stroke, vascular disease, sex score for stroke risk in NVAF, injury mechanism, bleeding pattern, Injury Severity Score, use of a reversal agent, Glasgow Coma Scale at 24 hours, hemorrhage expansion, neurosurgical intervention, Morse Fall Risk, DOAC restart date, rebleed events, and ischemic stroke were recorded to study rates of recurrent hemorrhage and stroke, and factors that influenced the decision to restart anticoagulation. Results: Twenty-eight patients sustained tICH while on a DOAC. Fall was the most common mechanism (89.3%), and subdural hematoma was the predominant bleeding pattern (60.7%). Of the 25 surviving patients, 16 patients (64%) restarted a DOAC a median 29.5 days after tICH. One patient had recurrent hemorrhage after resuming anticoagulation. One patient had an embolic stroke after 118 days off anticoagulation. Age >80, Injury Severity Score ≥16, and expansion of tICH influenced the decision to indefinitely hold anticoagulation. Conclusion: The low stroke rate observed in this study suggests that holding DOACs for NVAF for 1 month is sufficient to reduce the risk of stroke after tICH. Additional data are required to determine optimal restart timing.

Persistent Blunting of Penumbral Leukocyte Mobilization by Beta Blockade Administered for Two Weeks After Traumatic Brain Injury.

INTRODUCTION: Beta-blockers (BB) after traumatic brain injury (TBI) accelerate cognitive recovery weeks after injury. BBs also inhibit leukocyte (LEU) mobilization to the penumbral blood brain barrier (BBB) 48-h after TBI. It is unclear whether the latter effects persist longer and accompany the persistent cognitive improvement. We hypothesized that 2 wk of BB after TBI reduce penumbral BBB leukocyte-endothelial interactions. METHODS: Thirty CD1 mice underwent TBI (controlled cortical impact, CCI: 6 m/s velocity, 1 mm depth, 3 mm diameter) or sham craniotomy followed by i.p. saline (NS) or propranolol (1, 2, 4 mg/kg) every 12 h for 14 d. On day 14, in vivo pial intravital microscopy visualized endothelial-LEU interactions and BBB microvascular leakage. Day 14 Garcia neurological test scores and animal weights were compared to preinjury levels reflecting concurrent clinical recovery. RESULTS: LEU rolling was greatest in CCI + NS when compared to sham (P = 0.03). 4 mg/kg propranolol significantly reduced postCCI LEU rolling down to uninjured sham levels (P = 0.03). LEU adhesion and microvascular permeability were not impacted at this time interval. Untreated injured animals (CCI + NS) scored lower Garcia neurological test and greater weight loss recovery at day 14 when compared to preinjury (P < 0.05). Treatment with higher doses of propranolol (2, 4 mg/kg), improved weight loss recovery (P < 0.001). CONCLUSIONS: LEU rolling alone, was influenced by BB therapy 14 d after TBI suggesting that certain penumbral neuroinflammatory cellular effects of BB therapy after TBI persist up to 2 wk after injury potentially explaining the pervasive beneficial effects of BBs on learning and memory.

Application of a TEG-Platelet Mapping Algorithm to Guide Reversal of Antiplatelet Agents in Adults with Mild-to-Moderate Traumatic Brain Injury: An Observational Pilot Study.

BACKGROUND: Traumatic intracranial hemorrhages expand in one third of cases, and antiplatelet medications may exacerbate hematoma expansion. However, the reversal of an antiplatelet effect with platelet transfusion has been associated with harm. We sought to determine whether a thromboelastography platelet mapping (TEG-PM)-guided algorithm could limit platelet transfusion in patients with hemorrhagic traumatic brain injury (TBI) prescribed antiplatelet medications without a resultant clinically significant increase in hemorrhage volume, late hemostatic treatments, or delayed operative intervention. METHODS: A total of 175 consecutive patients with TBI were admitted to our university-affiliated, level I trauma center between March 2016 and December 2019: 54 preintervention patients (control) and 121 patients with TEG-PM (study). After exclusion for anticoagulant administration, availability of neuroimaging and emergent neurosurgery, 62 study patients and 37 control patients remained. Intervention consisted of administration of desmopressin (DDAVP) for nonsurgical patients with significant inhibition at the arachidonic acid or adenosine diphosphate receptor sites. For surgical patients with significant inhibition, dual therapy with DDAVP and platelet transfusion was employed. Study patients were compared with a group of historical controls, which were identified from a prospectively maintained registry and typically treated with empiric platelet transfusion. RESULTS: Median age was 75 years (interquartile range 85-67) and 77 years (interquartile range 81-65) in the TEG-PM and control patient groups, respectively. Admission hemorrhage volumes were similar (10.7 cm3 [20.1] in patients with TEG-PM vs. 14.1 cm3 [19.7] in controls; p = 0.41). There were no significant differences in admission Glasgow Coma Scale, mechanism of trauma, or baseline comorbidities. A total of 57% of controls versus 10% of patients with TEG-PM (p < 0.001) were transfused platelets; 52% of intervention patients and 0% controls were treated with DDAVP. Expansion hemorrhage volumes were not significantly different (14.0 cm3 [20.2] patients with TEG-PM versus 13.6 cm3 [23.7] controls; p = 0.93). There was no significant difference in rates of clinical deterioration, delayed neurosurgical intervention, or late platelet transfusion between groups. CONCLUSIONS: Among patients with hemorrhagic TBI prescribed preinjury antiplatelet therapy, our study suggests that the use of a TEG-PM algorithm may reduce platelet transfusions without a concurrent increase in clinically significant hematoma expansion. Further study is required to prove a causative relationship.

Beta blockade in TBI: Dose-dependent reductions in BBB leukocyte mobilization and permeability in vivo.

BACKGROUND: Traumatic brain injury (TBI) is accompanied by a hyperadrenergic catecholamine state that can cause penumbral neuroinflammation. Prospective human studies demonstrate improved TBI survival with beta blockade (bb), although mechanisms remain unclear. We hypothesized that deranged post-TBI penumbral blood brain barrier (BBB) leukocyte mobilization and permeability are improved by bb. METHODS: CD1 male mice (n = 64) were randomly assigned to severe TBI-controlled cortical impact: 6 m/s velocity, 1 mm depth, 3 mm diameter-or sham craniotomy, and IP injection of either saline or propranolol (1, 2, or 4 mg/kg) every 12 hours for 2 days. At 48 hours, in vivo pial intravital microscopy visualized live endothelial-leukocyte (LEU) interactions and BBB microvascular leakage. Twice daily clinical recovery was assessed by regaining of lost body weight and the Garcia Neurological Test (motor, sensory, reflex, balance assessments). Brain edema was determined by hemispheric wet-to-dry ratios. RESULTS: Propranolol after TBI reduced both in vivo LEU rolling and BBB permeability in a dose-dependent fashion compared with no treatment (p < 0.001). Propranolol reduced cerebral edema (p < 0.001) and hastened recovery of lost body weight at 48 hours (p < 0.01). Compared with no treatment (14.9 ± 0.2), 24-hour Garcia Neurologic Test scores were improved with 2 (15.8 ± 0.2, p = 0.02) and 4 (16.1 ± 0.1, p = 0.001) but not with 1 mg/kg propranolol. CONCLUSION: Propranolol administration reduces post-TBI LEU mobilization and microvascular permeability in the murine penumbral neurovasculature and leads to reduced cerebral edema. This is associated with hastened recovery of post-TBI weight loss and neurologic function with bb treatment. Dose-dependent effects frame a mechanistic relationship between bb and improved human outcomes after TBI.

Association of External Ventricular Drain Wean Strategy with Shunt Placement and Length of Stay in Subarachnoid Hemorrhage: A Prospective Multicenter Study.

BACKGROUND: Survivors of aneurysmal subarachnoid hemorrhage (SAH) face a protracted intensive care unit (ICU) course and are at risk for developing refractory hydrocephalus with the need for a permanent ventriculoperitoneal shunt (VPS). Management of the external ventricular drain (EVD) used to provide temporary cerebrospinal fluid diversion may influence the need for a VPS, ICU length of stay (LOS), and drain complications, but the optimal EVD management approach is unknown. Therefore, we sought to determine the effect of EVD discontinuation strategy on VPS rate. METHODS: This was a prospective multicenter observational study at six neurocritical care units in the United States. The target population included adults with suspected aneurysmal SAH who required an EVD. Patients were preassigned to rapid or gradual EVD weans based on their treating center. The primary outcome was the rate of VPS placement. Secondary outcomes were EVD duration, ICU LOS, hospital LOS, and drain complications. RESULTS: A rapid EVD wean protocol was associated with a lower rate of VPS placement, including a delayed posthospitalization shunt, in an adjusted Cox proportional analysis (hazard ratio 0.52 [p = 0.041]) and adjusted logistic regression model (odds ratio 0.43 [95% confidence interval 0.18-1.03], p = 0.057). A rapid wean was also associated with 2.1 fewer EVD days (p = 0.007) and saved an estimated 2.5 ICU days (p = 0.049), as compared with a gradual wean protocol. There were fewer nonfunctioning EVDs in the rapid group (odds ratio 0.32 [95% confidence interval 0.11-0.92]). Furthermore, we found that the time to first wean and the number of weaning attempts were important independent covariates that affected the likelihood of receiving a VPS and the duration of ICU admission. CONCLUSIONS: A rapid EVD wean was associated with decreased rates of VPS placement, decreased ICU LOS, and decreased drain complications in survivors of aneurysmal SAH. These findings suggest that a randomized multicentered controlled study comparing rapid vs. gradual EVD weaning protocols is justified.

Standardized Transfer Process for a Neurointensive Care Unit and Assessment of Patient Bounceback.

BACKGROUND: Patients who require readmission to an intensive care unit (ICU) after transfer to a lower level of care ("bounceback") suffer from increased mortality and longer hospital stays. We aimed to create a multifaceted standardized transfer process for patients moving from the neurointensive care unit (neuro-ICU) to a lower level of care. We hypothesized that this process would lead to improvement in provider-rated safety and a decreased rate of bouncebacks to the neuro-ICU after transfer. METHODS: The study took place at the Hospital of the University of Pennsylvania from October 2018 to October 2020. A standardized five-step transfer process was created and implemented for transferring patients from the neuro-ICU to a lower level of care. Patient care providers completed a survey before and after implementation of the protocol to assess a variety of components related to safety concerns when transferring patients. The rate of bouncebacks pre and post intervention was calculated by using a two-sample Wilcoxon rank-sum test, and disposition at discharge was calculated by using Fisher's exact test. RESULTS: Of the 1176 total patient transfers out of the neuro-ICU, 29 patients bounced back within 48 h. The average age of patients who bounced back was 63.3 years old, with a similar distribution among men and women. The most common reason for bounceback was respiratory distress, followed by cardiac arrhythmia, stroke, and sepsis. Implementation of the standardized process led to a decrease in provider-rated concern of overall safety (5 to 3, p = 0.008). There was improvement in transfer delays due to bed availability (3 to 4.5, p = 0.020), identification of high-risk patients (5 to 6, p = 0.021), patient assignment to the appropriate level of care (5 to 6, p = 0.019), and use of the electronic medical record handoff indicator (5 to 6, p = 0.003). There was no statistically significant difference in terms of patient bounceback rate after implementation of the process (2.4% vs. 2.5%, p = 1.00) or patient disposition at discharge (p = 0.553). CONCLUSIONS: Patients who bounceback to the neuro-ICU within 48 h had an increased length of hospital stay, had an increased length of ICU stay, and were more likely to be intubated for more than 96 h. Implementation of a standardized five-step transfer process from the neuro-ICU to a lower level of care resulted in improvement in multiple provider-rated safety outcomes and identification of high-risk patients but led to no difference in the patient bounceback rate or patient disposition at discharge.

Use of Thromboelastography in the Evaluation and Management of Patients With Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

Traumatic brain injury is associated with coagulopathy that increases mortality risk. Viscoelastic hemostatic assays such as thromboelastography (Haemonetics SA, Signy, Switzerland) provide rapid coagulopathy assessment and may be particularly useful for goal-directed treatment of traumatic brain injury patients. We conducted a systematic review to assess thromboelastography in the evaluation and management of coagulopathy in traumatic brain injury patients. DATA SOURCES: MEDLINE, PubMed Central, Embase, and CENTRAL. STUDY SELECTION: Clinical studies of adult patients with traumatic brain injury (isolated or polytrauma) who were assessed by either standard thromboelastography or thromboelastography with platelet mapping plus either conventional coagulation assays or platelet function assays from January 1999 to June 2021. DATA EXTRACTION: Demographics, injury mechanism and severity, diagnostic, laboratory data, therapies, and outcome data were extracted for analysis and comparison. DATA SYNTHESIS: Database search revealed 1,169 sources; eight additional articles were identified by the authors. After review, 31 publications were used for qualitative analysis, and of these, 16 were used for quantitative analysis. Qualitative and quantitative analysis found unique patterns of thromboelastography and thromboelastography with platelet mapping parameters in traumatic brain injury patients. Patterns were distinct compared with healthy controls, nontraumatic brain injury trauma patients, and traumatic brain injury subpopulations including those with severe traumatic brain injury or penetrating traumatic brain injury. Abnormal thromboelastography K-time and adenosine diphosphate % inhibition on thromboelastography with platelet mapping are associated with decreased survival after traumatic brain injury. Subgroup meta-analysis of severe traumatic brain injury patients from two randomized controlled trials demonstrated improved survival when using a viscoelastic hemostatic assay-guided resuscitation strategy (odds ratio, 0.39; 95% CI, 0.17-0.91; p = 0.030). CONCLUSIONS: Thromboelastography and thromboelastography with platelet mapping characterize coagulopathy patterns in traumatic brain injury patients. Abnormal thromboelastography profiles are associated with poor outcomes. Conversely, treatment protocols designed to normalize abnormal parameters may be associated with improved traumatic brain injury patient outcomes. Current quality of evidence in this population is low; so future efforts should evaluate viscoelastic hemostatic assay-guided hemostatic resuscitation in larger numbers of traumatic brain injury patients with specific focus on those with traumatic brain injury-associated coagulopathy.

Critical Low Catastrophe: A Case Report of Treatment-Refractory Hypoglycemia following Overdose of Long-Acting Insulin.

Overdose of long-acting insulin can cause unpredictable hypoglycemia for prolonged periods of time. The initial treatment of hypoglycemia includes oral carbohydrate intake as able and/or parenteral dextrose infusion. Refractory hypoglycemia following these interventions presents a clinical challenge in the absence of clear guidelines for management. Octreotide has sometimes been used, but its use is generally limited to sulfonylurea overdose. In this case report, we present a case of refractory hypoglycemia following an overdose of 900 units of long-acting insulin glargine that failed to respond to usual modes of therapy mentioned above. Stress-dose corticosteroids were then initiated, followed by subsequent improvement in IV dextrose and glucagon requirements and blood glucose levels. Hence, corticosteroids may serve as an adjunctive therapy in managing hypoglycemia and can be considered earlier in the course of treatment in patients with refractory hypoglycemia to prevent volume overload, especially when large volumes of dextrose infusions are required.

Early mobilization in neurocritical care patients.

PURPOSE OF REVIEW: To examine the potential benefits of early mobilization in neurocritically ill patients and to summarize the recent evidence for and against early mobilization. RECENT FINDINGS: Early ICU mobilization in medically critically ill patients may decrease ICU and hospital length of stay, increase discharge-to-home, and reduce medical costs. Whether these benefits apply to neurologically critically ill patients remains unclear, as neuro ICU patients are often excluded from trials of early mobility. Neurocritically ill patients may present with hemodynamic instability, acute hemiplegia, altered consciousness and visual field deficits which complicate mobilization, or have cerebral ischemia, which may be exacerbated when upright or active. Results of early mobilization in neurocritical care are mixed. For example, a randomized trial in acute ischemic stroke demonstrated that very early mobilization was associated with worse outcomes. However, many smaller intervention trials in neurocritical care demonstrate safety and feasibility with early mobilization, including those in patients with invasive devices, for example, external ventricular drains. SUMMARY: Given successes in other critically ill populations, early mobility of neurocritically ill patients may be warranted. However, caution should be exercised given the results in acute stroke trials. In addition, before routine use, the character, quality, dose, duration, and timing of early mobilization therapies requires further definition.

Evidence-Based Management of External Ventricular Drains.

PURPOSE OF REVIEW: The optimal management of external ventricular drains (EVD) in the setting of acute brain injury remains controversial. Therefore, we sought to determine whether there are optimal management approaches based on the current evidence. RECENT FINDINGS: We identified 2 recent retrospective studies on the management of EVDs after subarachnoid hemorrhage (SAH) which showed conflicting results. A multicenter survey revealed discordance between existing evidence from randomized trials and actual practice. A prospective study in a post-traumatic brain injury (TBI) population demonstrated the benefit of EVDs but did not determine the optimal management of the EVD itself. The recent CLEAR trials have suggested that specific positioning of the EVD in the setting of intracerebral hemorrhage with intraventricular hemorrhage may be a promising approach to improve blood clearance. Evidence on the optimal management of EVDs remains limited. Additional multicenter prospective studies are critically needed to guide approaches to the management of the EVD.

Safety and Feasibility of Early Mobilization in Patients with Subarachnoid Hemorrhage and External Ventricular Drain.

BACKGROUND/OBJECTIVE: In November 2014, our Neurointensive Care Unit began a multi-phased progressive early mobilization initiative for patients with subarachnoid hemorrhage and an external ventricular drain (EVD). Our goal was to transition from a culture of complete bed rest (Phase 0) to a physical and occupational therapy (PT/OT)-guided mobilization protocol (Phase I), and ultimately to a nurse-driven mobilization protocol (Phase II). We hypothesized that nurses could mobilize patients as safely as an exclusively PT/OT-guided approach. METHODS: In Phase I, patients were mobilized only with PT/OT at bedside; no independent time out of bed occurred. In Phase II, nurses independently mobilized patients with EVDs, and patients could remain out of bed for up to 3 h at a time. Physical and occupational therapists continued routine consultation during Phase II. RESULTS: Phase II patients were mobilized more frequently than Phase I patients [7.1 times per ICU stay (± 4.37) versus 3.0 times (± 1.33); p = 0.02], although not earlier [day 4.9 (± 3.46) versus day 6.0 (± 3.16); p = 0.32]. All Phase II patients were discharged to home PT services or acute rehabilitation centers. No patients were discharged to skilled nursing or long-term acute care hospitals, versus 12.5% in Phase I. In a multivariate analysis, odds of discharge to home/rehab were 3.83 for mobilized patients, independent of age and severity of illness. Other quality outcomes (length of stay, ventilator days, tracheostomy placement) between Phase I and Phase II patients were similar. No adverse events were attributable to early mobilization. CONCLUSIONS: Nurse-driven mobilization for patients with EVDs is safe, feasible, and leads to more frequent ambulation compared to a therapy-driven protocol. Nurse-driven mobilization may be associated with improved discharge disposition, although exact causation cannot be determined by these data.

A Diagnostic Conundrum of Distributive Shock: Autoimmune Polyglandular Syndrome Type II.

Autoimmune polyglandular syndrome (AIPS) is a heterogeneous condition characterized by the loss of immune tolerance and resultant dysfunction of multiple endocrine organs. Although this condition is insidious in nature, it frequently presents initially as adrenal insufficiency (AI). For patients in shock, physicians routinely assess for infections, volume depletion as well as cardiogenic and iatrogenic causes of shock. However, the case described in this report emphasizes the need for high suspicion of AI syndrome when the etiology of shock remains unclear after primary assessment. A subsequent evaluation for autoimmune etiology, especially in young adults in appropriate clinical setting, may also be warranted. HOW TO CITE THIS ARTICLE: Kumar MP, Thyagarajan B, Haller N, Ciltea D. A Diagnostic Conundrum of Distributive Shock: Autoimmune Polyglandular Syndrome Type II. Indian J Crit Care Med 2019;23(12):582-583.

Relative Deficiency of Plasma A Disintegrin and Metalloprotease with Thrombospondin Type 1 Repeats 13 Activity and Elevation of Human Neutrophil Peptides in Patients with Traumatic Brain Injury.

Traumatic microvascular injury (tMVI) is a universal endophenotype of traumatic brain injury (TBI) that is responsible for significant neurological morbidity and mortality. The mechanism underlying tMVI is not fully understood. The present study aims to determine plasma levels of von Willebrand factor (VWF), a disintegrin and metalloprotease with thrombospondin type 1 repeats (ADAMTS) 13 activity, and human neutrophil peptides (HNP) 1-3 and to correlate these biomarkers with functional outcomes after moderate-severe TBI. Thirty-one consecutive TBI patients (Glasgow Coma Scale [GCS] range, 3-12) were enrolled into the study between February 2010 and November 2014. Blood samples were collected on 0, 1, 2, 3, and 5 days after admission and analyzed for plasma levels of VWF antigen (VWFAg), collagen-binding activity (VWFAc), ADAMTS13 activity, and HNP1-3 proteins. Mean values of plasma VWFAg, VWFAc, and HNP1-3 were significantly increased in TBI patients compared to those in healthy controls (n = 30). Conversely, mean plasma values of ADAMTS13 activity in TBI patients were significantly decreased during the first 2 days after admission. This resulted in a dramatic reduction in the ratio of ADAMTS13 activity to VWFAg or ADAMTS13 to VWFAc in all 5 post-TBI days. Cluster analysis demonstrated that high median plasma levels of VWFAg and HNP1-3 were observed in the cluster with a high mortality rate. These results demonstrate that a relative deficiency of plasma ADAMTS13 activity, resulting from activation of neutrophils and endothelium, may contribute to the formation of microvascular thrombosis and mortality after moderate-severe TBI.

Influence of spatial delay on the modulational instability in a composite system with a controllable nonlinearity.

A theoretical investigation of the modulational instability (MI) in a composite system with a nonlocal response function is presented. A composite system of silver nanoparticles in acetone is chosen, whose nonlinearity can be delicately varied by controlling the volume fraction of the constituents, thus enabling the possibility of nonlinearity management. A pump-probe counterpropagation configuration has been assumed, and the interplay between the competing nonlinearities and the nonlocalities in the MI dynamics is systematically explored. A different class of nonlocalities have been considered, and the study reveals that the nonlocality critically depends on the kind of nonlocal function. However, the general behavior is that the strength of nonlocality suppresses the MI gain, while for a rectangular function it assists the emergence of new spectral windows. We also show that the cross coupling effects are significant in enhancing MI, especially in the defocusing nonlinearity. We also emphasize the impact of the relative strength of the nonlinearities in the MI dynamics at different settings of competing nonlinearities. Thus, we emphasize the importance of the different class of nonlocal response in the MI dynamics and explore the interplay between the higher order nonlinear effects and nonlocalities in the counterpropagating configurations.

Education Research: Variation in priorities for neurocritical care education expressed across role groups.

OBJECTIVE: To define expectations for neurocritical care (NCC) core competencies vs competencies considered within the domain of other subspecialists. METHODS: An electronic survey was disseminated nationally to NCC nurses, physicians, fellows, and neurology residents through Accreditation Council for Graduate Medical Education neurology residency program directors, United Council for Neurologic Subspecialties neurocritical care fellowship program directors, and members of the Neurocritical Care Society. RESULTS: A total of 268 neurocritical care providers and neurology residents from 30 institutions responded. Overall, >90% supported NCC graduates independently interpreting and managing systemic and cerebral hemodynamic data, or performing brain death determination, neurovascular ultrasound, vascular access, and airway management. Over 75% endorsed that NCC graduates should independently interpret EEG and perform bronchoscopies. Fewer but substantial respondents supported graduates being independent performing intracranial bolt (45.8%), ventriculostomy (39.0%), tracheostomy (39.8%), or gastrostomy (19.1%) procedures. Trainees differed from physicians and program directors, respectively, by advocating independence in EEG interpretation (92.8%, 61.8%, and 65.3%) and PEG placement (29.3%, 9.1%, and 8.5%). CONCLUSIONS: Broad support exists across NCC role groups for wide-ranging NCC competencies including skills often performed by other neurology and non-neurology subspecialties. Variations highlight natural divergences in expectations among trainee, physician, and nurse role groups. These results establish expectations for core competencies within NCC and initiate dialogue across subspecialties about best practice standards for the spectrum of critically ill patients requiring neurologic care.