Sudden vision loss heralding COVID-19-associated aspergillosis. Report of 2 cases.

Purpose: To describe clinical, radiographic, laboratory and cytopathologic findings in 2 patients who developed vision loss due to endogenous aspergillus endophthalmitis during hospitalization for COVID-19 pneumonia. Observations: Two unvaccinated sexagenarian male smokers lost vision within one month of contracting COVID-19 pneumonia. Initially, both received high dose steroids, nasal cannula oxygen and remdesivir. Immunomodulators tocilizumab or baricitinib were added during week 2 in case 1 and 2 respectively. Upon presentation after discharge from a post-COVID rehabilitation unit, visual acuities were light perception and hand motion. In both cases, inpatient blood and ocular fluid cultures were negative, serum 1,3-beta-D-glucan was positive, and vitreous cytopathology revealed filamentous fungi and PCR was positive for Aspergillus fumigatus. Large solitary intravitreal fungus balls were debulked in patient 1 and excised in patient 2. Final visual acuities were no light perception and 20/200 respectively. MRI revealed previously unsuspected brain and lung lesions consistent with disseminated aspergillosis in patient 2. Conclusions: Vision loss due to fungal endophthalmitis may be the first or only sign of systemic aspergillosis associated with COVID-19 pneumonia. Aspergillosis should be suspected in patients who develop vision loss. Diagnosis limited by negative fungal cultures may be confirmed by vitreous cytopathology and PCR. Systemic imaging for disseminated aspergillosis is indicated. Ultimate visual acuity may depend upon surgical approach.

Serial D-dimers after anticoagulant cessation in unprovoked venous thromboembolism: Data from the REVERSE cohort study.

INTRODUCTION: While several risk stratification tools have been developed to predict the risk of recurrence in patients with an unprovoked venous thromboembolism (VTE), only 1 in 4 patients are categorized as low-risk. Rather than a one-time measure, serial D-dimer assessment holds promise to enhance the prediction of VTE recurrence after oral anticoagulant (OAC) cessation. METHODS: Using the REVERSE cohort, we compared VTE recurrence among patients with normal D-dimer levels (<490 ng/mL among males under age 70, <500 ng/mL in others) at OAC cessation and 1-month follow-up, to those with an elevated D-dimer level at either timepoint. We also evaluated VTE recurrence based on absolute increase in D-dimer levels between the two timepoints (e.g., ∆D-dimer) according to quartiles. RESULTS: Among 214 patients with serial D-dimer levels measured at OAC cessation and 1-month follow-up, an elevated D-dimer level at either timepoint was associated with a numerically higher risk of recurrent VTE than patients with normal D-dimer levels at both timepoints (6.9 % vs. 4.2 % per year, hazard ratio 1.6; 95 % CI 0.9-2.7). Among women with <2 HERDOO2 criteria, a normal D-dimer level at both timepoints predicted a very low risk of recurrent VTE during follow-up (0.8 % per year, 95 % CI 0.1-2.8). Irrespective of baseline value, recurrent VTE risk was only 3 % per year (95 % CI 1.4-5.6) among patients in the lowest ∆D-dimer quartile. CONCLUSION: Serial normal D-dimer levels have the potential to identify patients at a low risk of recurrent VTE. In addition, ∆D-dimer, irrespective of its elevation above cutoff threshold, may predict recurrent VTE.

Pneumatic Retinopexy with Focal Laser Photocoagulation for Myopic Foveoschisis with Macular Detachment.

PURPOSE: To describe the clinical course and imaging of a case of myopic foveoschisis (MF) with macular detachment (MD), microbreak and epiretinal membrane (ERM) managed with pneumatic retinopexy (PR) and focal laser photocoagulation (FLP) of the microbreak. METHODS: Retrospective Case Review of a highly myopic, phakic Caucasian man who developed vision loss due to MF with MD. RESULTS: 66 year old phakic man with a refractive error of -13.25-2.25x150 in his left eye (OS) and one month visual loss who was diagnosed with MF with MD, microbreak and ERM developed recurrent, isolated, posterior, partial macular detachment one month after PR. CMT was 901um. Repeat PR with supplemental FLP surrounding the inferior macular periarteriolar microbreak achieved re-attachment and improvement in the retinoschisis with return of visual acuity from 20/150 to baseline 20/40+ at 18 month follow-up. CONCLUSION: PR with FLP may provide an alternative to vitrectomy and MP for the repair of MF with MD and ERM.

The risk of major bleeding in patients with factor V Leiden or prothrombin G20210A gene mutation while on extended anticoagulant treatment for venous thromboembolism.

BACKGROUND: Thrombophilia predisposes to venous thromboembolism (VTE) because of acquired or hereditary factors. Among them, it has been suggested that gene mutations of the factor V Leiden (FVL) or prothrombin G20210A mutation (PGM) might reduce the risk of bleeding, but little data exist for patients treated using anticoagulants. OBJECTIVES: To assess whether thrombophilia is protective against bleeding. METHODS: This multicentre, multinational, prospective cohort study evaluated adults receiving long-term anticoagulants after a VTE event. We analyzed the incidence of major bleeding as the primary outcome, according to the genotype for FVL and PGM (wild-type and heterozygous/homozygous carriers). RESULTS: Of 2260 patients with genotype testing, during a median follow-up of 3 years, 106 patients experienced a major bleeding event (17 intracranial and 7 fatal). Among 439 carriers of FVL, 19 experienced major bleeding and there were no differences between any mutation vs wild-type (hazard ratio [HR], 0.89 [0.53-1.49]; p = .66). The comparison of major bleeding events between the 158 patients with any-PGM mutation (heterozygous or homozygous) vs wild-type also showed a nonstatistically significant difference with HR of 0.53 (0.19-1.43), p = .21. However, multivariate analysis demonstrated that major bleeds or clinically relevant nonmajor bleeding were statistically less likely for patients with either FVL and/or PGM compared with patients with both wild-type factor V and prothrombin genes (HR, 0.73; 95% CI = 0.55-0.97; p = .03). CONCLUSION: This study demonstrates that thrombophilia, defined as the presence of either FVL or the prothrombin G20210A mutation, is related with a lower rate of major/clinically relevant nonmajor bleeding while on anticoagulants in the extended treatment for VTE.

Early Release Science of the exoplanet WASP-39b with JWST NIRCam.

Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy (for example, refs. 1,2) provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution and high precision, which, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST's Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0-4.0 micrometres, exhibit minimal systematics and reveal well defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous water in the atmosphere and place an upper limit on the abundance of methane. The otherwise prominent carbon dioxide feature at 2.8 micrometres is largely masked by water. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100-times solar (that is, an enrichment of elements heavier than helium relative to the Sun) and a substellar C/O ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation (for example, refs. 3,4,) or disequilibrium processes in the upper atmosphere (for example, refs. 5,6).

Rationing scarce healthcare capacity: A study of the ventilator allocation guidelines during the COVID-19 pandemic.

In the United States, even though national guidelines for allocating scarce healthcare resources are lacking, 26 states have specific ventilator allocation guidelines to be invoked in case of a shortage. While several states developed their guidelines in response to the recent COVID-19 pandemic, New York State developed these guidelines in 2015 as "pandemic influenza is a foreseeable threat, one that we cannot ignore." The primary objective of this study is to assess the existing procedures and priority rules in place for allocating/rationing scarce ventilator capacity and propose alternative (and improved) priority schemes. We first build machine learning models using inpatient records of COVID-19 patients admitted to New York-Presbyterian/Columbia University Irving Medical Center and an affiliated community health center to predict survival probabilities as well as ventilator length-of-use. Then, we use the resulting point estimators and their uncertainties as inputs for a multiclass priority queueing model with abandonments to assess three priority schemes: (i) SOFA-P (Sequential Organ Failure Assessment based prioritization), which most closely mimics the existing practice by prioritizing patients with sufficiently low SOFA scores; (ii) ISP (incremental survival probability), which assigns priority based on patient-level survival predictions; and (iii) ISP-LU (incremental survival probability per length-of-use), which takes into account survival predictions and resource use duration. Our findings highlight that our proposed priority scheme, ISP-LU, achieves a demonstrable improvement over the other two alternatives. Specifically, the expected number of survivals increases and death risk while waiting for ventilator use decreases. We also show that ISP-LU is a robust priority scheme whose implementation yields a Pareto-improvement over both SOFA-P and ISP in terms of maximizing saved lives after mechanical ventilation while limiting racial disparity in access to the priority queue.

Predicting major bleeding during extended anticoagulation for unprovoked or weakly provoked venous thromboembolism.

No clinical prediction model has been specifically developed or validated to identify patients with unprovoked venous thromboembolism (VTE) who are at high risk of major bleeding during extended anticoagulation. In a prospective multinational cohort study of patients with unprovoked VTE receiving extended anticoagulation after completing ≥3 months of initial treatment, we derived a new clinical prediction model using a multivariable Cox regression model based on 22 prespecified candidate predictors for the primary outcome of major bleeding. This model was then compared with modified versions of 5 existing clinical scores. A total of 118 major bleeding events occurred in 2516 patients (annual risk, 1.7%; 95% confidence interval [CI], 1.4-2.1). The incidences of major bleeding events per 100 person-years in high-risk and non-high-risk patients, respectively, were 3.9 (95% CI, 3.0-5.1) and 1.1 (0.8-1.4) using the newly derived creatinine, hemoglobin, age, and use of antiplatelet agent (CHAP) model; 3.3 (2.6-4.1) and 1.0 (0.7-1.3) using modified ACCP score, 5.3 (0.6-19.2) and 1.7 (1.4-2.0) using modified RIETE score, 3.1 (2.3-3.9) and 1.1 (0.9-1.5) using modified VTE-BLEED score, 5.2 (3.3-7.8) and 1.5 (1.2-1.8) using modified HAS-BLED score, and 4.8 (1.3-12.4) and 1.7 (1.4-2.0) using modified outpatient bleeding index score. Modified versions of the ACCP, VTE-BLEED, and HAS-BLED scores help identify patients with unprovoked VTE who are at high risk of major bleeding and should be considered for discontinuation of anticoagulation after 3 to 6 months of initial treatment. The CHAP model may further improve estimation of bleeding risk by using continuous predictor variables, but external validation is required before its implementation in clinical practice.

Cohort study of intervened functionally univentricular heart in England and Wales (2000-2018).

OBJECTIVE: Given the paucity of long-term outcome data for complex congenital heart disease (CHD), we aimed to describe the treatment pathways and survival for patients who started interventions for functionally univentricular heart (FUH) conditions, excluding hypoplastic left heart syndrome. METHODS: We performed a retrospective cohort study using all procedure records from the National Congenital Heart Diseases Audit for children born in 2000-2018. The primary outcome was mortality, ascertained from the Office for National Statistics in 2020. RESULTS: Of 53 615 patients, 1557 had FUH: 55.9% were boys and 67.4% were of White ethnic groups. The largest diagnostic categories were tricuspid atresia (28.9%), double inlet left ventricle (21.0%) and unbalanced atrioventricular septal defect (AVSD) (15.2%). The ages at staged surgery were: initial palliation 11.5 (IQR 5.5-43.5) days, cavopulmonary shunt 9.2 (IQR 6.0-17.1) months and Fontan 56.2 (IQR 45.5-70.3) months. The median follow-up time was 10.8 (IQR 7.0-14.9) years and the 1, 5 and 10-year survival rates after initial palliation were 83.6% (95% CI 81.7% to 85.4%), 79.4% (95% CI 77.3% to 81.4%) and 77.2% (95% CI 75.0% to 79.2%), respectively. Higher hazards were present for unbalanced AVSD HR 2.75 (95% CI 1.82 to 4.17), atrial isomerism HR 1.75 (95% CI 1.14 to 2.70) and low weight HR 1.65 (95% CI 1.13 to 2.41), critical illness HR 2.30 (95% CI 1.67 to 3.18) or acquired comorbidities HR 2.71 (95% CI 1.82 to 4.04) at initial palliation. CONCLUSION: Although treatment pathways for FUH are complex and variable, nearly 8 out of 10 children survived to 10 years. Longer-term analyses of outcome based on diagnosis (rather than procedure) can inform parents, patients and clinicians, driving practice improvements for complex CHD.

How to write a guideline: a proposal for a manuscript template that supports the creation of trustworthy guidelines.

Trustworthy health guidelines should provide recommendations, document the development process, and highlight implementation information. Our objective was to develop a guideline manuscript template to help authors write a complete and useful report. The McMaster Grading of Recommendations Assessment, Development and Evaluation Centre collaborated with the American Society of Hematology (ASH) to develop guidelines for the management of venous thromboembolism. A template for reporting the guidelines was developed based on prior approaches and refined using input from other key stakeholders. The proposed guideline manuscript template includes: (1) title for guideline identification, (2) abstract, including a summary of key recommendations, (3) overview of all recommendations (executive summary), and (4) the main text, providing sufficient detail about the entire process, including objectives, background, and methodological decisions from panel selection and conflict-of-interest management to criteria for updating, as well as supporting information, such as links to online (interactive) tables. The template further allows for tailoring to the specific topic, using examples. Initial experience with the ASH guideline manuscript template was positive, and challenges included drafting descriptions of recommendations involving multiple management pathways, tailoring the template for a specific guideline, and choosing key recommendations to highlight. Feedback from a larger group of guideline authors and users will be needed to evaluate its usefulness and refine. The proposed guideline manuscript template is the first detailed template for transparent and complete reporting of guidelines. Consistent application of the template may simplify the preparation of an evidence-based guideline manuscript and facilitate its use.

Improving Appropriate Use of Omega-3 Fatty Acids for Patients With Dyslipidemia: Effect of Online CME.

Hypertriglyceridemia is associated with an increased risk of atherosclerotic cardiovascular (CV) disease. Clinical trials have demonstrated the effectiveness of eicosapentaenoic acid ethyl ester (EPA), an omega-3 polyunsaturated fatty acid, on triglyceride lowering and on CV risk reduction. However, many clinicians have limited understanding of the effects of EPA and limited experience using EPA to reduce the risk of CV disease. An analysis was conducted to determine whether an online continuing medical education (CME) intervention could improve knowledge and competence of primary care physicians (PCPs) and cardiologists related to the role of EPA in management of CV risk in patients with dyslipidemia. The intervention comprised 2 online video-based CME activities. The effects of education were assessed for learners who completed 4 pre- and postassessment questions for each activity, using a matched pre-/postassessment design. For all questions combined, a McNemar's χ2 test assessed differences from pre- to postassessment. Matched-learner data indicated that 34% of PCPs improved their knowledge as a result of participating in the activities, and 42% had their knowledge reinforced. Among cardiologists, 28% improved their knowledge, and 61% had their knowledge reinforced. For these learner subsets, there was a significant 17% relative increase in self-assessed confidence in appropriate use of EPA for PCPs (n = 1644, P < 0.001) and a 12% increase for cardiologists (n = 524; P < 0.001). The improvements observed in this online CME intervention demonstrate the benefits of educating the appropriate target audience base and suggest that this type of intervention can translate into improvements in clinical care.

Physical Activity Surveillance in the United States for Work and Commuting: Understanding the Impact on Population Health and Well-being.

OBJECTIVE: To summarize and describe the current US surveillance systems that assess physical activity (PA) for work and commuting. METHODS: An expert group conducted an environmental scan, generating a list (n = 18) which was ultimately reduced to 12, based on the inclusion of PA and/or sedentary behavior data. RESULTS: The 12 surveys or surveillance systems summarized provide nationally representative data on occupational-level PA or individual-level PA at work, data on active commuting, some are scorecards that summarize workplace health best practices and allow benchmarking, and one is a comprehensive nationally representative survey of employers assessing programs and practices in different worksites. CONCLUSIONS: The various surveillance systems and surveys/scorecards are disparate and need to be better analyzed and summarized to understand the impact of occupational-level PA and commuting on population health and well-being, life expectancy, and workforce productivity.

A modeling approach to derive baseline risk estimates for GRADE recommendations: Concepts, development, and results of its application to the American Society of Hematology 2019 guidelines on prevention of venous thromboembolism in surgical hospitalized patients.

OBJECTIVE: The goal of this study was to develop an approach that can be used where baseline risk estimates that are directly applicable to prioritized patient-important outcomes are not available from published studies. STUDY DESIGN: The McMaster University GRADE Centre and the ASH guideline panel for the prevention of VTE in surgical patients developed a modeling approach based on explicit assumptions about the distribution of symptoms, anatomical location, and severity of VTE events. RESULTS: We applied the approach to derive modeled estimates of baseline risk. These estimates were used to calculated absolute measures of anticipated effects that informed the discussion of the evidence and the formulation of 30 guideline recommendations. CONCLUSION: Our approach can assist guideline developers facing a lack of information about baseline risk estimates that directly apply to outcomes of interest. The use of modeled estimates increases transparency in the process and makes the baseline risk used by guideline experts explicit during their decision-making.

Postoperative low molecular weight heparin bridging treatment for patients at high risk of arterial thromboembolism (PERIOP2): double blind randomised controlled trial.

OBJECTIVE: To determine the efficacy and safety of dalteparin postoperative bridging treatment versus placebo for patients with atrial fibrillation or mechanical heart valves when warfarin is temporarily interrupted for a planned procedure. DESIGN: Prospective, double blind, randomised controlled trial. SETTING: 10 thrombosis research sites in Canada and India between February 2007 and March 2016. PARTICIPANTS: 1471 patients aged 18 years or older with atrial fibrillation or mechanical heart valves who required temporary interruption of warfarin for a procedure. INTERVENTION: Random assignment to dalteparin (n=821; one patient withdrew consent immediately after randomisation) or placebo (n=650) after the procedure. MAIN OUTCOME MEASURES: Major thromboembolism (stroke, transient ischaemic attack, proximal deep vein thrombosis, pulmonary embolism, myocardial infarction, peripheral embolism, or vascular death) and major bleeding according to the International Society on Thrombosis and Haemostasis criteria within 90 days of the procedure. RESULTS: The rate of major thromboembolism within 90 days was 1.2% (eight events in 650 patients) for placebo and 1.0% (eight events in 820 patients) for dalteparin (P=0.64, risk difference -0.3%, 95% confidence interval -1.3 to 0.8). The rate of major bleeding was 2.0% (13 events in 650 patients) for placebo and 1.3% (11 events in 820 patients) for dalteparin (P=0.32, risk difference -0.7, 95% confidence interval -2.0 to 0.7). The results were consistent for the atrial fibrillation and mechanical heart valves groups. CONCLUSIONS: In patients with atrial fibrillation or mechanical heart valves who had warfarin interrupted for a procedure, no significant benefit was found for postoperative dalteparin bridging to prevent major thromboembolism. TRIAL REGISTRATION: Clinicaltrials.gov NCT00432796.

Long-term risk of recurrent venous thromboembolism after a first contraceptive-related event: Data from REVERSE cohort study.

INTRODUCTION: The risk of recurrent venous thromboembolism (VTE) after combined oral contraceptive (COC) use is variably reported. We assessed the long-term risk of recurrent VTE in women on COC at the time of a first VTE, in comparison to women without COC use. Our secondary aim assessed the impact of COC use on the recurrent VTE risk in high-risk and low-risk hyperpigmentation, edema, or redness in either leg; D-dimer level ≥250 µg/L; obesity with body mass index ≥30; or older age, ≥65 years (HERDOO2) subgroups. METHODS: The REVERSE cohort study derived the HERDOO2 clinical decision rule to predict recurrent VTE in patients who discontinued anticoagulation after 5-7 months for a first unprovoked VTE. Incidence rates of recurrent VTE among women with and without COC exposure were calculated as the number of recurrent VTE over the number of person-years of follow-up, and Cox proportional hazards model was used to compare risks between groups. RESULTS: The risk of recurrent VTE among COC users was 1.1% (95% confidence interval [CI] 0.3-2.9) per patient-year as compared with 3.2% per patient-year (95% CI 2.4-4.3) among nonusers (hazard ratio 0.37; 95% CI 0.1-1.0). Women who were COC users and high risk by HERDOO2 score had a recurrence rate of 3.5% (95% CI 0.4-12.5) compared with 6.1% (95% CI 4.3-8.5) among women who were non-COC users and at high risk by HERDOO2 score (HR 0.6, 95% CI 0.1-2.5). CONCLUSIONS: Women who were COC users at the time of an otherwise unprovoked VTE event had a lower VTE recurrence rate during long-term follow-up, compared with nonusers. The use of HERDOO2 rule may help identify higher risk women with COC use.

Influence of Incentive Design and Organizational Characteristics on Wellness Participation and Health Outcomes.

OBJECTIVE: To explore how changing incentive designs influence wellness participation and health outcomes. METHODS: Aggregated retrospective data were evaluated using cluster analysis to group 174 companies into incentive design types. Numerous statistical models assessed between-group differences in wellness participation, earning incentives, and over-time differences in health outcomes. RESULTS: Four incentive design groups based on requirements for earning incentives were identified. The groups varied in support for and participation in wellness initiatives within each company. All four design types were associated with improved low density lipoprotein (LDL) (P < 0.01), three with improved blood pressure (P < 0.001), and two with improved fasting glucose (P < 0.03). No incentive plan types were associated with improved body mass index (BMI), but designs predominantly focused on health outcomes (eg, Outcomes-Focused) exhibited a significant increase over time in BMI risk. CONCLUSION: Incentive design and organizational characteristics impact population-level participation and health outcomes.

Body Mass Index and Risk for Intubation or Death in SARS-CoV-2 Infection : A Retrospective Cohort Study.

BACKGROUND: Obesity is a risk factor for pneumonia and acute respiratory distress syndrome. OBJECTIVE: To determine whether obesity is associated with intubation or death, inflammation, cardiac injury, or fibrinolysis in coronavirus disease 2019 (COVID-19). DESIGN: Retrospective cohort study. SETTING: A quaternary academic medical center and community hospital in New York City. PARTICIPANTS: 2466 adults hospitalized with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection over a 45-day period with at least 47 days of in-hospital observation. MEASUREMENTS: Body mass index (BMI), admission biomarkers of inflammation (C-reactive protein [CRP] level and erythrocyte sedimentation rate [ESR]), cardiac injury (troponin level), and fibrinolysis (D-dimer level). The primary end point was a composite of intubation or death in time-to-event analysis. RESULTS: Over a median hospital length of stay of 7 days (interquartile range, 3 to 14 days), 533 patients (22%) were intubated, 627 (25%) died, and 59 (2%) remained hospitalized. Compared with overweight patients, patients with obesity had higher risk for intubation or death, with the highest risk among those with class 3 obesity (hazard ratio, 1.6 [95% CI, 1.1 to 2.1]). This association was primarily observed among patients younger than 65 years and not in older patients (P for interaction by age = 0.042). Body mass index was not associated with admission levels of biomarkers of inflammation, cardiac injury, or fibrinolysis. LIMITATIONS: Body mass index was missing for 28% of patients. The primary analyses were conducted with multiple imputation for missing BMI. Upper bounding factor analysis suggested that the results are robust to possible selection bias. CONCLUSION: Obesity is associated with increased risk for intubation or death from COVID-19 in adults younger than 65 years, but not in adults aged 65 years or older. PRIMARY FUNDING SOURCE: National Institutes of Health.

A remnant planetary core in the hot-Neptune desert.

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune 'desert'1,2 (a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b3, which is thought to have an unusually massive core, and recent discoveries such as LTT9779b4 and NGTS-4b5, on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune's but an anomalously large mass of [Formula: see text] Earth masses and a density of [Formula: see text] grams per cubic centimetre, similar to Earth's. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than [Formula: see text] per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation6. Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.

Pharmacologic thromboprophylaxis in adult patients undergoing neurosurgical interventions for preventing venous thromboembolism.

The impact of pharmacologic prophylaxis for venous thromboembolism in patients undergoing neurosurgical intervention remains uncertain. We reviewed the efficacy and safety of pharmacologic compared with nonpharmacologic thromboprophylaxis in neurosurgical patients. Three databases were searched through April 2018, including those for randomized controlled trials (RCTs) and for nonrandomized controlled studies (NRSs). Independent reviewers assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Seven RCTs and 3 NRSs proved eligible. No studies reported on symptomatic proximal and distal deep vein thrombosis (DVT). Two RCTs reported on screening-detected proximal and distal DVTs. We used the findings of these 2 RCTs as the closest surrogate outcomes to inform the proximal and distal DVT outcomes. These 2 RCTs suggest that pharmacologic thromboprophylaxis may decrease the risk of developing asymptomatic proximal DVT (relative risk [RR], 0.50; 95% confidence interval [CI], 0.30-0.84; low certainty). Findings were uncertain for mortality (RR, 1.27; 95% CI, 0.57-2.86; low certainty), symptomatic pulmonary embolism (PE) (RR, 0.84; 95% CI, 0.03-27.42; very low certainty), asymptomatic distal DVT (RR, 0.54; 95% CI, 0.27-1.08; very low certainty), and reoperation (RR, 0.43; 95% CI, 0.06-2.84; very low certainty) outcomes. NRSs also reported uncertain findings for whether pharmacologic prophylaxis affects mortality (RR, 0.72; 95% CI, 0.46-1.13; low certainty) and PE (RR, 0.18; 95% CI, 0.01-3.76). For risk of bleeding, findings were uncertain in both RCTs (RR, 1.57; 95% CI, 0.70-3.50; low certainty) and NRSs (RR, 1.45; 95% CI, 0.30-7.12; very low certainty). In patients undergoing neurosurgical procedures, low certainty of evidence suggests that pharmacologic thromboprophylaxis confers benefit for preventing asymptomatic (screening-detected) proximal DVT with very low certainty regarding its impact on patient-important outcomes.