Palliative Care Exposure Relative to Predicted Risk of Six-Month Mortality in Hospitalized Adults.

Context: The optimal strategy for implementing mortality-predicting algorithms to facilitate clinical care, prognostic discussions, and palliative care interventions remains unknown.

Objectives: To develop and validate a real-time predictive model for 180 day mortality using routinely available clinical and laboratory admission data and determine if palliative care exposure varies with predicted mortality risk.

Methods: Adult admissions between October 1, 2013 and October.

Improving Mortality Attribution in Otolaryngology - Head and Neck Surgery.

Objective/hypothesis: Mortality attribution can have significant implications for reimbursement, hospital/department rankings, and perceptions of safety. This work seeks to compare the accuracy of externally assigned diagnosis-related group (DRG)-based service line mortality attribution in otolaryngology to an internal review process that assigns mortality to the teams that cared for a patient during hospitalization.

Study Design: Retrospective case series.

Reducing intraoperative red blood cell unit wastage in a large academic medical center.

Background: The wastage of red blood cell (RBC) units within the operative setting results in significant direct costs to health care organizations. Previous education-based efforts to reduce wastage were unsuccessful at our institution. We hypothesized that a quality and process improvement approach would result in sustained reductions in intraoperative RBC wastage in a large academic medical center.

Transfusion reactions in pediatric compared with adult patients: a look at rate, reaction type, and associated products.

Background: The majority of reports on transfusion reactions address adult patients. Less is known about the types, incidence, and other clinical details of transfusion reactions in pediatric populations. Furthermore, to our knowledge, there have been no previous reports directly comparing these aspects between adults and pediatric patient populations to assess if there are differences.

Diastolic field stimulation: the role of shock duration in epicardial activation and propagation.

Detailed knowledge of tissue response to both systolic and diastolic shock is critical for understanding defibrillation. Diastolic field stimulation has been much less studied than systolic stimulation, particularly regarding transient virtual anodes. Here we investigated high-voltage-induced polarization and activation patterns in response to strong diastolic shocks of various durations and of both polarities, and tested the hypothesis that the activation versus shock duration curve contains a local minimum for moderate shock durations, and it grows for short and long durations.

Implementation of a transfusion algorithm to reduce blood product utilization in pediatric cardiac surgery.

Aim: The goal of this project is to measure the impact of standardization of transfusion practice on blood product utilization and postoperative bleeding in pediatric cardiac surgery patients.

Background: Transfusion is common following cardiopulmonary bypass (CPB) in children and is associated with increased mortality, infection, and duration of mechanical ventilation. Transfusion in pediatric cardiac surgery is often based on clinical judgment rather than objective data.

Blood product positive patient identification: comparative simulation-based usability test of two commercial products.

Background: The blood product administration process has been subject to various quality improvement initiatives aimed at reducing errors, including blood product labels that are missing, inaccessible, unreadable, or mismatched to orders and/or patients. This article reports the results of a formal simulation-based usability test of two comparable technologies designed to reduce blood product administration errors.

Study Design And Methods: Nineteen nurses and three anesthesia providers evaluated one of the two products during simulated use in realistic scenarios during 90-minute test sessions.

The potential of dual camera systems for multimodal imaging of cardiac electrophysiology and metabolism.

Fluorescence imaging has become a common modality in cardiac electrodynamics. A single fluorescent parameter is typically measured. Given the growing emphasis on simultaneous imaging of more than one cardiac variable, we present an analysis of the potential of dual camera imaging, using as an example our straightforward dual camera system that allows simultaneous measurement of two dynamic quantities from the same region of the heart.

Effects of unipolar stimulation on voltage and calcium distributions in the isolated rabbit heart.

Background: The effect of electric stimulation on the polarization of cardiac tissue (virtual electrode effect) is well known; the corresponding response of intracellular calcium concentration ([Ca(2+)](i)) and its dependence on coupling interval between conditioning stimulus (S1) and test stimulus (S2) has yet to be elucidated.

Objective: Because uncovering the transmembrane potential (V(m))-[Ca(2+)](i) relationship during an electric shock is imperative for understanding arrhythmia induction and defibrillation, we aimed to study simultaneous V(m) and [Ca(2+)](i) responses to strong unipolar stimulation.

Methods: We used a dual-camera optical system to image concurrently V (m) and [Ca(2+)](i) responses to unipolar stimulation (20 ms +/- 20 mA) in Langendorff-perfused rabbit hearts.

High-resolution high-speed panoramic cardiac imaging system.

A panoramic cardiac imaging system consisting of three high-speed CCD cameras has been developed to image the surface electrophysiology of a rabbit heart via fluorescence imaging using a voltage-sensitive fluorescent dye. A robust, unique mechanical system was designed to accommodate the three cameras and to adapt to the requirements of future experiments. A unified computer interface was created for this application - a single workstation controls all three CCD cameras, illumination, stimulation, and a stepping motor that rotates the heart.

A high-voltage cardiac stimulator for field shocks of a whole heart in a bath.

Defibrillators are a critical tool for treating heart disease; however, the mechanisms by which they halt fibrillation are still not fully understood and are the subject of ongoing research. Clinical defibrillators do not provide the precise control of shock timing, duration, and voltage or other features needed for detailed scientific inquiry, and there are few, if any, commercially available units designed for research applications. For this reason, we have developed a high-voltage, programmable, capacitive-discharge stimulator optimized to deliver defibrillation shocks with precise timing and voltage control to an isolated animal heart, either in air or in a bath.

Cathodal stimulation in the recovery phase of a propagating planar wave in the rabbit heart reveals four stimulation mechanisms.

The stimulation of cardiac tissue in the recovery phase has significant importance in relation to reentry induction. In the theoretical experiment proposed by Winfree, termed the 'pinwheel' experiment, a point stimulus (S2) is applied in the wake of a freely propagating planar wave (S1). Reentry induced from this S1-S2 pinwheel protocol has been observed experimentally in heart preparations.

Examination of stimulation mechanism and strength-interval curve in cardiac tissue.

Understanding the basic mechanisms of excitability through the cardiac cycle is critical to both the development of new implantable cardiac stimulators and improvement of the pacing protocol. Although numerous works have examined excitability in different phases of the cardiac cycle, no systematic experimental research has been conducted to elucidate the correlation among the virtual electrode polarization pattern, stimulation mechanism, and excitability under unipolar cathodal and anodal stimulation. We used a high-resolution imaging system to study the spatial and temporal stimulation patterns in 20 Langendorff-perfused rabbit hearts.

Spatiotemporal dynamics of damped propagation in excitable cardiac tissue.

Compared to steadily propagating waves (SPW), damped waves (DW), another solution to the nonlinear wave equation, are seldom studied. In cardiac tissue after electrical stimulation in an SPW wake, we observe DW with diminished amplitude and velocity that either gradually decrease as the DW dies, or exhibit a sharp amplitude increase after a delay to become an SPW. The cardiac DW-SPW transition is a key link in understanding defibrillation and stimulation close to the refractory period, and is ideal for a general study of DW dynamics.

Effects of elevated extracellular potassium on the stimulation mechanism of diastolic cardiac tissue.

During cardiac disturbances such as ischemia and hyperkalemia, the extracellular potassium ion concentration is elevated. This in turn changes the resting transmembrane potential and affects the excitability of cardiac tissue. To test the hypothesis that extracellular potassium elevation also alters the stimulation mechanism, we used optical fluorescence imaging to examine the mechanism of diastolic anodal unipolar stimulation of cardiac tissue under 4 mM (normal) and 8 mM (elevated) extracellular potassium.