Publications by authors named "Cassandra Hall"
The canonical theory for planet formation in circumstellar disks proposes that planets are grown from initially much smaller seeds. The long-considered alternative theory proposes that giant protoplanets can be formed directly from collapsing fragments of vast spiral arms induced by gravitational instability-if the disk is gravitationally unstable. For this to be possible, the disk must be massive compared with the central star: a disk-to-star mass ratio of 1:10 is widely held as the rough threshold for triggering gravitational instability, inciting substantial non-Keplerian dynamics and generating prominent spiral arms.
View Article and Find Full Text PDFIntroduction: Patients with atrial fibrillation (AF) are frequently admitted from the emergency department (ED), and when discharged, are not reliably prescribed indicated anticoagulation. We report the impact of a novel computerized ED AF pathway orderset on discharge rate and risk-appropriate anticoagulation in patients with primary AF.
Methods: The orderset included options for rate and rhythm control of primary AF, structured risk assessment for thrombotic complications, recommendations for anticoagulation as appropriate, and follow up with an electrophysiologist.
Objective: Lack of empathic communication between providers and patients may contribute to low value diagnostic testing in emergency care. Accordingly, we measured the perception of physician empathy and trust in patients undergoing low-value computed tomography (CT) in the emergency department (ED).
Methods: Multicenter study of ED patients undergoing CT scanning, acknowledged by ordering physicians as unlikely to show an emergent condition.
Objective: To test the hypothesis that adjunctive inhaled NO would improve RV function and viability in acute PE.
Methods: This was a randomized, placebo-controlled, double blind trial conducted at four academic hospitals. Eligible patients had acute PE without systemic arterial hypotension but had RV dysfunction and a treatment plan of standard anticoagulation.
Background: The pulmonary embolism rule out criteria (PERC) reliably predicts a low probability of PE in adults. We examine the diagnostic accuracy of the objective components of the PERC rule in children previously tested for PE.
Methods: Children aged 5-17 who had a D-dimer or pulmonary vascular imaging ordered from 2004 to 2014 in a large multicenter hospital network were identified by query of administrative databases.
Background: Approximately 80% of patients presenting to emergency departments (ED) with chest pain do not have any true cardiopulmonary emergency such as acute coronary syndrome (ACS). However, psychological contributors such as anxiety are thought to be present in up to 58%, but often remain undiagnosed leading to chronic chest pain and ED recidivism.
Methods: To evaluate ED provider beliefs and their usual practices regarding the approach and disposition of patients with low risk chest pain associated with anxiety, we constructed a 22-item survey using a modified Delphi technique.
Objective: We assessed emergency department (ED) patient perceptions of how physicians can improve their language to determine patient preferences for 11 phrases to enhance physician empathy toward the goal of reducing low-value advanced imaging.
Methods: Multi-center survey study of low-risk ED patients undergoing computerized tomography (CT) scanning.
Results: We enroled 305 participants across nine sites.
Background: We sought to measure the diagnostic accuracy of D-dimer in children with suspected pulmonary embolism (PE).
Methods: We queried our electronic medical record for quantitative D-dimer values obtained in all children ages 5-17 over 10 years in our 10-hospital system. Patients who had a D-dimer obtained in the evaluation of PE underwent supervised chart review to extract baseline demographics (age, sex, ethnicity), medical history, laboratory data and imaging results.
Background: We sought to determine clinical variables in children tested for suspected pulmonary embolism (PE) that predict PE+ outcome for the development of paediatric PE prediction rule.
Methods: Data were collected by query of a laboratory database for D-dimer from January 2004 to December 2014 for a large multicentre hospital system and the radiology database for pulmonary vascular imaging in children aged 5-17. Using explicit, predefined methods, trained abstractors, determined if D-dimer was sent in the evaluation of PE and then recorded predictor data which was tested for association with PE+ outcome using univariate techniques.
Background: The study hypothesis is that administration of inhaled nitric oxide (NO) plus oxygen to subjects with submassive pulmonary embolism (PE) will improve right ventricular (RV) systolic function and reduce RV strain and necrosis, while improving patient dyspnea, more than treatment with oxygen alone.
Methods: This article describes the rationale and protocol for a registered (NCT01939301), nearly completed phase II, 3-center, randomized, double-blind, controlled trial. Eligible patients have pulmonary imaging-proven acute PE.
Purpose: The authors hypothesize patient facial affect may influence clinician pretest probability (PTP) estimate of cardiopulmonary emergency (CPE) and desire to order a computerized tomographic pulmonary angiogram (CTPA).
Method: This prospective study was conducted at three Indiana University-affiliated hospitals in two parts: collecting videos of patients undergoing CTPA for suspected acute pulmonary embolism watching a humorous video (August 2014-April 2015) and presenting the medical histories and videos to clinicians to determine the impact of patient facial affect on physicians' PTP estimate of CPE and desire to order a CTPA (June-November 2015). Patient outcomes were adjudicated as CPE+ or CPE- by three independent reviewers.
Background: Many clinicians use a global visual interpretation of patient appearance to decide if a patient looks sick or not. For patients with suspected acute pulmonary embolism (PE), we tested the relationship between visual appearance of a happy patient facial affect and probability of PE+ on CT pulmonary angiography (CTPA).
Methods: Eligible patients were selected by usual care to undergo CTPA, the criterion standard for PE+ or PE-.