Dynamic trajectories of life-threatening mass effect in patients with large middle cerebral artery stroke

Background

Life-threatening, space-occupying mass effect due to cerebral edema and/or hemorrhagic transformation is an early complication of patients with middle cerebral artery (MCA) stroke. Little is known about longitudinal trajectories of laboratory and vital signs leading up to radiographic and clinical deterioration related to this mass effect.

Methods

We curated a granular retrospective dataset of 635 patients with large middle cerebral artery (MCA) stroke totaling 108,547 data points for repeated measurements of 10 covariates, and 40 time-independent covariates. We assessed longitudinal trajectories of the 10 longitudinal variables during the 72 hours preceding three outcomes representative of life-threatening mass effect: midline shift (MLS) ≥5mm, pineal gland shift (PGS) >4mm, and decompressive hemicraniectomy (DHC). We used a "backward looking" trajectory approach. Patients were aligned according to the time of outcome occurrence and the trajectory of each variable was assessed prior to that outcome by accounting for both cases and non-cases.

Results

Of 635 patients, 49% were female, and mean age was 69 years. Thirty five percent of patients had MLS ≥ 5mm, 24.1% had PGS >4mm, and DHC occurred in 10.7%. For the three outcomes of interest, backward-looking trajectories showed mild increases in white blood cell count (10 up to 11 K/UL within 72 hours), temperature (up to half a degree within 24 hours), and sodium (1-3 mEq/L within 24 hours) leading up to outcomes. We also observed a decrease in heart rate (75 - 65 beats per minute) 24 hours prior to DHC.

Conclusions

Univariable longitudinal profiling showed that temperature, white blood cell count, and sodium increase prior to radiographic and clinical indicators of space-occupying mass effect. These findings will inform development of multivariable dynamic risk models to aid prediction of life-threatening space-occupying mass effect.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Reversible Cerebral Vasoconstriction Syndrome in Patients with Coronavirus Disease: A Multicenter Case Series

BACKGROUND AND OBJECTIVES

RCVS (Reversible Cerebral Vasoconstrictive Syndrome) is a condition associated with vasoactive agents that alter endothelial function. There is growing evidence that endothelial inflammation contributes to cerebrovascular disease in patients with coronavirus disease 2019 (COVID-19). In our study, we describe the clinical features, risk factors, and outcomes of RCVS in a multicenter case series of patients with COVID-19.

MATERIALS AND METHODS

Multicenter retrospective case series. We collected clinical characteristics, imaging, and outcomes of patients with RCVS and COVID-19 identified at each participating site.

RESULTS

Ten patients were identified, 7 women, ages 21 - 62 years. Risk factors included use of vasoconstrictive agents in 7 and history of migraine in 2. Presenting symptoms included thunderclap headache in 5 patients with recurrent headaches in 4. Eight were hypertensive on arrival to the hospital. Symptoms of COVID-19 included fever in 2, respiratory symptoms in 8, and gastrointestinal symptoms in 1. One patient did not have systemic COVID-19 symptoms. MRI showed subarachnoid hemorrhage in 3 cases, intraparenchymal hemorrhage in 2, acute ischemic stroke in 4, FLAIR hyperintensities in 2, and no abnormalities in 1 case. Neurovascular imaging showed focal segment irregularity and narrowing concerning for vasospasm of the left MCA in 4 cases and diffuse, multifocal narrowing of the intracranial vasculature in 6 cases. Outcomes varied, with 2 deaths, 2 remaining in the ICU, and 6 surviving to discharge with modified Rankin scale (mRS) scores of 0 (n=3), 2 (n=2), and 3 (n=1).

CONCLUSIONS

Our series suggests that patients with COVID-19 may be at risk for RCVS, particularly in the setting of additional risk factors such as exposure to vasoactive agents. There was variability in the symptoms and severity of COVID-19, clinical characteristics, abnormalities on imaging, and mRS scores. However, a larger study is needed to validate a causal relationship between RCVS and COVID-19.

Paediatric gastroenterology in Singapore: historical aspects and recent advances

Paediatric gastroenterology in Singapore began in the 1970s. Led by Professor Phua Kong Boo and Professor Quak Seng Hock, paediatric gastroenterology has enjoyed significant strides in the areas of diagnostics, interventions, patient care and research. Several advances such as endoscopy, parenteral nutrition and liver transplantation are well established. The first paediatric small bowel transplant is anticipated in the next decade. Robust research activities have ensured the generation of local data on gastrointestinal disorders. One such research led to the discovery of the changing trends in the incidence of inflammatory bowel disease among the paediatric population in Singapore. The impact of the nation’s paediatric gastroenterology extends internationally, with the notable involvement of Professor Phua in developing the rotavirus vaccine trials and other ongoing collaborative work with international centres. This review explores the history of paediatric gastroenterology from its origins to its remarkable transformation over the decades as centres of excellence in the region.

Blunt and Penetrating Severe Traumatic Brain Injury

Severe traumatic brain injury is a common problem. Current practices focus on the importance of early resuscitation, transfer to high-volume centers, and provider expertise across multiple specialties. In the emergency department, patients should receive urgent intracranial imaging and consideration for tranexamic acid. Close observation in the intensive care unit environment helps identify problems, such as seizure, intracranial pressure crisis, and injury progression. In addition to traditional neurologic examination, patients benefit from use of intracranial monitors. Monitors gather physiologic data on intracranial and cerebral perfusion pressures to help guide therapy. Brain tissue oxygenation monitoring and cerebromicrodialysis show promise in studies.

Cerebral Venous Sinus Thromboses in Patients with SARS-CoV-2 Infection: Three Cases and a Review of the Literature

INTRODUCTION

Early studies suggest that acute cerebrovascular events may be common in patients with coronavirus disease 2019 (COVID-19) and may be associated with a high mortality rate. Most cerebrovascular events described have been ischemic strokes, but both intracerebral hemorrhage and rarely cerebral venous sinus thrombosis (CVST) have also been reported. The diagnosis of CVST can be elusive, with wide-ranging and nonspecific presenting symptoms that can include headache or altered sensorium alone.

OBJECTIVE

To describe the presentation, barriers to diagnosis, treatment, and outcome of CVST in patients with COVID-19.

METHODS

We abstracted data on all patients diagnosed with CVST and COVID-19 from March 1 to August 9, 2020 at Boston Medical Center. Subsequently, we reviewed the literature and extracted all published cases of CVST in patients with COVID-19 from January 1, 2020 through August 9, 2020 and included all studies with case descriptions.

RESULTS

We describe the clinical features and management of CVST in 3 women with COVID-19 who developed CVST days to months after initial COVID-19 symptoms. Two patients presented with encephalopathy and without focal neurologic deficits, while one presented with visual symptoms. All patients were treated with intravenous hydration and anticoagulation. None suffered hemorrhagic complications, and all were discharged home. We identified 12 other patients with CVST in the setting of COVID-19 via literature search. There was a female predominance (54.5%), most patients presented with altered sensorium (54.5%), and there was a high mortality rate (36.4%).

CONCLUSIONS

During this pandemic, clinicians should maintain a high index of suspicion for CVST in patients with a recent history of COVID-19 presenting with non-specific neurological symptoms such as headache to provide expedient management and prevent complications. The limited data suggests that CVST in COVID-19 is more prevalent in females and may be associated with high mortality.

Myoclonus in Patients With Coronavirus Disease 2019: A Multicenter Case Series

OBJECTIVES

To describe the risk factors for and outcomes after myoclonus in a cohort of patients with coronavirus disease 2019.

DESIGN

Multicenter case series.

SETTING

Three tertiary care hospitals in Massachusetts, Georgia, and Virginia.

PATIENTS

Eight patients with clinical myoclonus in the setting of coronavirus disease 2019.

INTERVENTIONS & MEASUREMENTS AND MAIN RESULTS

Outcomes in patients with myoclonus were variable, with one patient who died during the study period and five who were successfully extubated cognitively intact and without focal neurologic deficits. In five cases, the myoclonus completely resolved within 2 days of onset, while in three cases, it persisted for 10 days or longer. Seven patients experienced significant metabolic derangements, hypoxemia, or exposure to sedating medications that may have contributed to the development of myoclonus. One patient presented with encephalopathy and developed prolonged myoclonus in the absence of clear systemic provoking factors.

CONCLUSIONS

Our findings suggest that myoclonus may be observed in severe acute respiratory syndrome coronavirus 2 infected patients, even in the absence of hypoxia. This association warrants further evaluation in larger cohorts to determine whether the presence of myoclonus may aid in the assessment of disease severity, neurologic involvement, or prognostication.

Fibrinogen Concentrate for the Treatment of Thrombolysis-Associated Hemorrhage in Adult Ischemic Stroke Patients

In patients with ischemic stroke who receive systemic recombinant tissue plasminogen activator (rt-PA), the risk of secondary hemorrhage is 1-7%. Fibrinogen supplementation with cryoprecipitate is recommended in patients with rt-PA-associated symptomatic hemorrhage. We examined whether fibrinogen concentrate can be used safely in this setting. A single-center retrospective case series was performed in patients who received fibrinogen concentrate for post-rt-PA hemorrhage between January-2012 and December-2017. The primary outcome was the incidence of in-hospital thromboembolic events and infusion reactions. Secondary outcomes included incidence of clinically significant ICH expansion within 24-hours and patient serum fibrinogen response to fibrinogen concentrate therapy. Thromboembolic events occurred in 3 (12.5%) of 24 patients included in the analysis. No patients experienced infusion-related reactions. Five of 22 patients with ICH experienced clinically significant hemorrhage expansion. Hypofibrinogenemia was corrected in 87.5%(7/8) of patients with baseline hypofibrinogenemia, with a median increase in serum fibrinogen 166 mg/dL. Median fibrinogen increase in patients without baseline hypofibrinogenemia was 18 mg/dL. Fibrinogen concentrate is a safe potential therapeutic option to restore fibrinogen levels in acute ischemic stroke patients with thrombolysis-associated hemorrhage.

Staphylococcus aureus nasal decolonization before cardiac and orthopaedic surgeries: first descriptive survey in France

The objective was to describe French hospital nasal screening and decolonization procedures before clean surgery procedures. Information for participants was sent to the French Society for Infection Control members in June 2018. Seventy hospitals participated in the survey; 40% (N = 28) declared having institutional decolonization procedures: 64% (N = 18) in orthopaedic and 56% (N = 15) in cardiac surgeries. All hospitals used mupirocin for nasal decolonization and body decolonization with chlorhexidine (N = 16) or povidone iodine (N = 10). This study is the first to be performed in France giving information in this field. Screening/decolonization procedures are heterogeneous and the evaluation of their clinical impact remains complex.

COVID-19 in patients with myasthenia gravis

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic, but little is known about its potential impact on patients with myasthenia gravis (MG).

METHODS

We studied the clinical course of COVID-19 in five hospitalized patients with autoimmune MG (four with acetylcholine receptor antibodies, one with muscle-specific tyrosine kinase antibodies) between April 1, 2020-April 30-2020.

RESULTS

Two patients required intubation for hypoxemic respiratory failure, whereas one required significant supplemental oxygen. One patient with previously stable MG had myasthenic exacerbation. One patient treated with tocilizumab for COVID-19 was successfully extubated. Two patients were treated for MG with intravenous immunoglobulin without thromboembolic complications.

DISCUSSION

Our findings suggest that the clinical course and outcomes in patients with MG and COVID-19 are highly variable. Further large studies are needed to define best practices and determinants of outcomes in this unique population.

Tracheal resection: the team brief in multi-stage airway surgery

The multidisciplinary team brief and effective clinical decision-making are critical to airway surgery. To illustrate this, we present the case of a 58-year-old female with papillary thyroid cancer invading the trachea. We describe a basic framework that was used to aid planning the management of this patient. Tracheal resection is a complex airway operation requiring the evaluation of airway obstruction risk, the formulation of strategies for complex airway management and lung ventilation during complete resection of the tracheal segment and a handover plan for safe tracheal extubation. We suggest that team performance is facilitated by a standardised structure for consideration of anticipated events and important decisions to be made before the operation. Furthermore, it can provide a platform to engage the team when unanticipated events occur and alternate plans have to be made in a time-critical manner.

Effects of Osmotic Therapy on Pupil Reactivity: Quantification Using Pupillometry in Critically Ill Neurologic Patients

BACKGROUND

Osmotic therapy is a critical component of medical management for cerebral edema. While up to 90% of neurointensivists report using these treatments, few quantitative clinical measurements guide optimal timing, dose, or administration frequency. Its use is frequently triggered by a qualitative assessment of neurologic deterioration and/or pupil size, and anecdotally appears to improve pupil asymmetry suggestive of uncal herniation. However, subjective pupil assessment has poor reliability, making it difficult to detect or track subtle changes. We hypothesized that osmotic therapy reproducibly improves quantitative pupil metrics.

METHODS

We included patients at two centers who had recorded quantitative pupil measurements within 2 h before and after either 20% mannitol or 23.4% hypertonic saline in the neurosciences intensive care unit. The primary outcome was the Neurologic Pupil Index (NPi), a composite metric ranging from 0 to 5 in which > 3 is considered normal. Secondary outcomes included pupil size, percent change, constriction and dilation velocity, and latency. Results were analyzed with Wilcoxon signed-rank tests, Chi-square and multi-level linear regression to control for other edema-reducing interventions.

RESULTS

Out of 72 admissions (403 paired pupil observations), NPi significantly differed within 2 h of osmotic therapy when controlling for other commonly used interventions in our whole cohort (β = 0.08, p = 0.0168). The effect was most pronounced (β = 0.57) in patients with abnormal NPi prior to intervention (p = 0.0235).

CONCLUSIONS

Pupil reactivity significantly improves after osmotic therapy in a heterogenous critically ill population when controlling for various other interventions. Future work is necessary to determine dose-dependent effects and clinical utility.

The Effect of Ambient Light Conditions on Quantitative Pupillometry

BACKGROUND

Automated devices collecting quantitative measurements of pupil size and reactivity are increasingly used for critically ill patients with neurological disease. However, there are limited data on the effect of ambient light conditions on pupil metrics in these patients. To address this issue, we tested the range of pupil reactivity in healthy volunteers and critically ill patients in both bright and dark conditions.

METHODS

We measured quantitative pupil size and reactivity in seven healthy volunteers and seven critically ill patients with the Neuroptics-200 pupillometer in both bright and dark ambient lighting conditions. Bright conditions were created by overhead LED lighting in a room with ample natural light. Dark conditions consisted of a windowless room with no overhead light source. The primary outcome was the Neurological Pupil Index (NPi), a composite metric ranging from 0 to 5 in which > 3 is considered normal. Secondary outcomes included resting and constricted pupil size, change in pupil size, constriction velocity, dilation velocity, and latency. Results were analyzed with multi-level linear regression to account for both inter- and intra-subject variability.

RESULTS

Fourteen subjects underwent ten pupil readings each in bright and dark conditions, yielding 280 total measurements. In healthy subjects, median NPi in bright and dark conditions was 4.2 and 4.3, respectively. In critically ill subjects, median NPi was 2.85 and 3.3, respectively. Multi-level linear regression demonstrated significant differences in pupil size, pupil size change, constriction velocity, and dilation velocity in various light levels in healthy patients, but not NPi. In the critically ill, NPi and pupil size change were significantly affected.

CONCLUSION

Ambient light levels impact pupil parameters in both healthy and critically ill subjects. Changes in NPi under different light conditions are small and more consistent in healthy subjects, but significantly differ in the critically ill. Practitioners should standardize lighting conditions to maximize measurement reliability.

Abstract P5-04-26: Identification of preclinical mechanisms driving acquired resistance to endocrine therapy in estrogen-receptor positive (ER+) breast cancer cells

Estrogen Receptor positive (ER+) breast cancer accounts for the majority of breast cancer cases and standard of care for these tumors is treatment with endocrine therapy, including the blockade of estrogen production (i.e. aromatase inhibitors; AIs) as well as the use of antagonists of ER function, i.e. selective estrogen receptor modulators (SERMs, i.e. tamoxifen) and selective estrogen receptor degraders (SERDs, i.e. fulvestrant). Despite the initial dependency of ER+ breast tumors on estrogen and ER for their survival and proliferation, treatment in the metastatic setting invariably leads to therapeutic resistance. While mechanisms of resistance to AIs include mutations in the estrogen receptor gene ESR1, less is known about mechanisms of resistance to SERMs and SERDs, thus it is essential to further investigate the latter, in order to successfully treat relapsed patients. To pre-clinically model cell-autonomous acquired resistance to these agents, we used T47D, an ER+ and p53- estrogen-responsive cell line treated with increasing concentrations of the SERM/SERD hybrid (SSH) ER-targeting agent GDC-0810 over the period of several months during which individual clones with acquired resistance to GDC-0810 were selected. GDC-0810-resistant clones were cross-resistant to other endocrine agents, including SERMs (tamoxifen) and SERDs (fulvestrant), consistent with general loss of dependency on ER. Surprisingly, the cells also lost sensitivity to palbociclib, the latter likely linked to their loss of one copy of the retinoblastoma (Rb) tumor suppressor gene. Comprehensive genetic and phenotypic characterization of the resistant clones relative to the parental cells revealed multiple mutations and deletions in DNA repair and cell cycle genes, and associated defects in DNA repair and cell cycle checkpoints. Cell cycle, proteomic, and mRNA expression analysis of parental versus resistant clones at baseline and upon DNA damage, identified a distinct cell cycle profile in the GDC-0810-resistant clones, characterized by accumulation of cells in the mitotic phase. A broad chemical screen identified pharmacologic inhibitors of cell cycle regulators and chemotherapeutic drug classes that preferentially target the ER-independent, GDC-0810 resistant clones compared to the parental cells. Our work provides novel insights into mechanisms and biomarkers of acquired resistant to estrogen therapies in ER+ breast cancer and reveals the acquisition of actionable dependencies that may potentially be exploited in resistant tumors. Furthermore, our studies provide rationale for testing specific chemotherapy regimens upon endocrine resistance accompanied by cell cycle and DNA repair checkpoint dysfunction in ER+ breast cancer.

Citation Format: Ong C, Daemen A, Merrick K, O'Brien T, Friedman L, Hatzivassiliou G. Identification of preclinical mechanisms driving acquired resistance to endocrine therapy in estrogen-receptor positive (ER+) breast cancer cells [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-26.

Nitrogen deprivation in Fusarium oxysporum promotes mycotoxin production via intermediates in the Krebs cycle and unreported methylmalonyl-CoA mutase activity

INTRODUCTION

Fusarium oxysporum has a high affinity for lignin and cellulose-based substrates and is known to grow in a wide range of environments. It is these properties and its ability to produce mycotoxins that have contributed to its pathogenicity in cereal crops that can affect human and animal health when ingested.

OBJECTIVES

Identify the mechanisms of mycotoxin production and map the functional output of F. oxysporum under varying growth conditions.

METHODS

Liquid and gas-based chromatography coupled with mass spectrometry was used to identify and map the untargeted metabolic pathway of F. oxysporum grown using nitrogen limited and organic/inorganic nitrogen supplemented media.

RESULTS

Over 1300 metabolites were identified, relating to 42 metabolic pathways. Of these, 520 metabolites merged at pyruvate (glycolysis), succinate (Krebs cycle) and aspartate-glutamate metabolic pathways. CoA depletion at the growth stage triggered the initiation of fatty acid and branched amino acid degradation. This in turn activated propionyl CoA carnitine acetyltransferase enzymes, resulting in nitrogen preservation (urea, putrescine and organic acids end-products). CoA then transferred into the TCA cycle via previously unreported β-alanine and propionyl CoA metabolic pathways, the latter likely being a novel methylmalonyl-CoA mutase activity for F. oxysporum.

CONCLUSIONS

The lower supplementation of inorganic nitrogen compounds (≤ 50 mM) and the elimination of nitrates/organic nitrogen sources resulted in TCA autophagy events that boosted mycotoxin-based metabolism and decreased overall F. oxysporum growth. Such knowledge of functional mycotoxin production can be used to supplement agricultural crops and reduce the risk of mycotoxin contamination in human and animal food supplies.