Publications by authors named "Varesh Prasad"

Many early warning algorithms are downstream of clinical evaluation and diagnostic testing, which means that they may not be useful when clinicians fail to suspect illness and fail to order appropriate tests. Depending on how such algorithms handle missing data, they could even indicate "low risk" simply because the testing data were never ordered. We considered predictive methodologies to identify sepsis at triage, before diagnostic tests are ordered, in a busy Emergency Department (ED).

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Usual care regarding vasopressor initiation is ill-defined. We aimed to develop a quantitative "dynamic practice" model for usual care in the emergency department (ED) regarding the timing of vasopressor initiation in sepsis. In a retrospective study of 589 septic patients with hypotension in an urban tertiary care center ED, we developed a multi-variable model that distinguishes between patients who did and did not subsequently receive sustained (>24 h) vasopressor therapy.

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Usual care regarding vasopressor (VP) initiation is ill-defined. We aimed to further validate a quantitative model for usual care in the Emergency Department (ED) regarding the timing of VP initiation in sepsis. We retrospectively studied a cohort of adult critically-ill ED patients who also received antibiotics in the ED.

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Background: Recent literature suggests a significant association between blood pressure variability (BPV) and postoperative outcomes after cardiac surgery. However, its outcome prediction ability remains unclear. Current prediction models use static preoperative patient factors.

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Sepsis and septic shock are major global public health concerns. The main therapies for sepsis-related hypotension are fluid resuscitation and vasopressor therapy, though it can be challenging to determine the amount of fluid that should be given or the optimal timing to transition to vasopressor administration. To characterize patients' response to fluid bolus therapy (FBT) and analyze the sepsis progress using multiple vital signs, we mined a database containing 761 patients presenting to the Emergency Department (ED) with vital signs and laboratory values indicating high risk of septic shock.

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Hemodynamic management of sepsis in the emergency department relies on fluid resuscitation and vasoactive therapy to maintain adequate blood pressure and end-organ perfusion. While typical practice targets certain thresholds of blood pressure (such as 65 mmHg mean arterial or 90 mmHg systolic blood pressure [SBP]), little consideration is given to temporal dynamics of blood pressure. In this work, we use unsupervised learning methods to reveal characteristic SBP trajectories in the two hours either surrounding the start of hypotensive episodes (SBP <; 90 mmHg) or immediately preceding the initiation of vasopressor therapy.

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Background: Multiple studies completed in the ambulatory nonsurgical setting show a significant association between short- and long-term blood pressure variability and poor outcomes. However, perioperative blood pressure variability outcomes have not been well studied, especially in the cardiac surgical setting. In this study, we sought to assess whether systolic and mean arterial blood pressure variability were associated with 30-day mortality and in-hospital renal failure in patients undergoing cardiac surgery requiring cardiopulmonary bypass.

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Major surgeries can result in high rates of adverse postoperative events. Reliable prediction of which patient might be at risk for such events may help guide peri- and postoperative care. We show how archiving and mining of intraoperative hemodynamic data in orthotopic liver transplantation (OLT) can aid in the prediction of postoperative 180-day mortality and acute renal failure (ARF), improving upon predictions that rely on preoperative information only.

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Optimal management of sepsis and septic shock in the emergency department (ED) involves timely decisions related to intravenous fluid resuscitation and initiation of vasoactive medication support. A decision-support tool trained on electronic health record data, can help improve this complex decision. We retrospectively extracted vital signs, lab measurements, and fluid administration information from 807 patient visits over a two-year period to a major ED.

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Liver transplantation remains the only curative treatment option for a variety of end-stage liver diseases. Prediction of major adverse events following surgery has traditionally focused on static predictors that are known prior to surgery. The effects of intraoperative management can now be explored due to the archiving of high-resolution monitoring data.

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Drug eluting stents are associated with late stent thrombosis (LST), delayed healing and prolonged exposure of stent struts to blood flow. Using macroscale disturbed and undisturbed fluid flow waveforms, we numerically and experimentally determined the effects of microscale model strut geometries upon the generation of prothrombotic conditions that are mediated by flow perturbations. Rectangular cross-sectional stent strut geometries of varying heights and corresponding streamlined versions were studied in the presence of disturbed and undisturbed bulk fluid flow.

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We introduce a microfluidic approach to generating monodisperse, stable nanoparticle-shelled bubbles using air-in-oil-in-water (A/O/W) compound bubbles as templates. The oil phase of the A/O/W compound bubbles comprises a volatile organic solvent and a hydrophobic silica nanoparticle. Upon evaporation of the organic solvent, the nanoparticles in the oil layer form a stiff shell at the air-water interface, which drastically enhances the stability of the bubbles against dissolution and coarsening.

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