Non-invasive biomarkers for detecting progression toward hypovolemic cardiovascular instability in a lower body negative pressure model.

Occult hemorrhages after trauma can be present insidiously, and if not detected early enough can result in patient death. This study evaluated a hemorrhage model on 18 human subjects, comparing the performance of traditional vital signs to multiple off-the-shelf non-invasive biomarkers. A validated lower body negative pressure (LBNP) model was used to induce progression towards hypovolemic cardiovascular instability.

Prediction of Occult Hemorrhage in the Lower Body Negative Pressure Model: Initial Validation of Machine Learning Approaches.

Introduction: Detection of occult hemorrhage (OH) before progression to clinically apparent changes in vital signs remains an important clinical problem in managing trauma patients. The resource-intensiveness associated with continuous clinical patient monitoring and rescue from frank shock makes accurate early detection and prediction with noninvasive measurement technology a desirable innovation. Despite significant efforts directed toward the development of innovative noninvasive diagnostics, the implementation and performance of the newest bedside technologies remain inadequate.

Detection of subclinical hemorrhage using electrical impedance: a porcine study.

Analyze the performance of electrical impedance tomography (EIT) in an innovative porcine model of subclinical hemorrhage and investigate associations between EIT and hemodynamic trends.. Twenty-five swine were bled at slow rates to create an extended period of subclinical hemorrhage during which the animal's heart rate (HR) and blood pressure (BP) remained stable from before hemodynamic deterioration, where stable was defined as <15% decrease in BP and <20% increase in HRi.

Another head's up on head's up.

A commentary on D. K. Lee et al and "head's-up" CPR.

Epinephrine plus chest compressions is superior to epinephrine alone in a hypoxia-induced porcine model of pseudo-pulseless electrical activity.

Aim: Pseudo-pulseless electrical activity (pseudo-PEA) is a global hypotensive ischemic state with retained coordinated myocardial contractile activity and an organized ECG with no clinically detectable pulses. The role of standard external chest compressions (CPR) and its associated intrinsic hemodynamics remains unclear in the setting of pseudo-PEA. We undertook an experimental trial to compare epinephrine alone versus epinephrine with CPR in the treatment of pseudo-PEA.

Quantitative characterization of left ventricular function during pulseless electrical activity using echocardiography during out-of-hospital cardiac arrest.

Background: Several prospective studies have demonstrated that the echocardiographic detection of any myocardial activity during PEA is strongly associated with higher rates of return of spontaneous circulation (ROSC). We hypothesized that PEA represents a spectrum of disease in which not only the presence of myocardial activity, but more specifically that the degree of left ventricular (LV) function would be a predictor of outcomes. The purpose of this study was to retrospectively assess the association between LV function and outcomes in patients with OHCA.

Predicting Future Occurrence of Acute Hypotensive Episodes Using Noninvasive and Invasive Features.

Introduction: Early prediction of the acute hypotensive episode (AHE) in critically ill patients has the potential to improve outcomes. In this study, we apply different machine learning algorithms to the MIMIC III Physionet dataset, containing more than 60,000 real-world intensive care unit records, to test commonly used machine learning technologies and compare their performances.

Materials And Methods: Five classification methods including K-nearest neighbor, logistic regression, support vector machine, random forest, and a deep learning method called long short-term memory are applied to predict an AHE 30 minutes in advance.

Early Detection of Hypotension Using a Multivariate Machine Learning Approach.

Introduction: The ability to accurately detect hypotension in trauma patients at the earliest possible time is important in improving trauma outcomes. The earlier an accurate detection can be made, the more time is available to take corrective action. Currently, there is limited research on combining multiple physiological signals for an early detection of hemorrhagic shock.

Intravenous calcium as a pressor in a swine model of hypoxic pseudo-pulseless electrical mechanical activity-a preliminary report.

Background: Pseudo-pulseless electrical activity (pseudo-PEA) is a lifeless form of profound cardiac shock characterized by measurable cardiac mechanical activity without clinically detectable pulses. Pseudo-PEA may constitute up to 40% of reported cases of cardiac arrest. Resuscitation from pseudo-PEA is often associated with hypotension refractory to catecholamine pressors.

Addition of a biomarker panel to a clinical score to identify patients at low risk for appendicitis.

Background: The diagnosis of pediatric acute appendicitis can be difficult. Although scoring systems such as the Pediatric Appendicitis Score (PAS) are helpful, they lack adequate sensitivity and specificity as standalone diagnostics. When used for risk stratification, they often result in large percentages of moderate-risk patients requiring further diagnostic evaluation.

A disposable, flexible skin patch for clinical optical perfusion monitoring at multiple depths.

Stable, relative localization of source and detection fibers is necessary for clinical implementation of quantitative optical perfusion monitoring methods such as diffuse correlation spectroscopy (DCS) and diffuse reflectance spectroscopy (DRS). A flexible and compact device design is presented as a platform for simultaneous monitoring of perfusion at a range of depths, enabled by precise location of optical fibers in a robust and secure adhesive patch. We will discuss preliminary data collected on human subjects in a lower body negative pressure model for hypovolemic shock.

Instrument to detect syncope and the onset of shock.

Currently the diagnosis of hemorrhagic shock is essentially clinical, relying on the expertise of nurses and doctors. One of the first measurable physiological changes that marks the onset of hemorrhagic shock is a decrease in capillary blood flow. Diffuse correlation spectroscopy (DCS) quantifies this decrease.

Coronary perfusion pressure during external chest compression in pseudo-EMD, comparison of systolic versus diastolic synchronization.

Background: The fraction of cardiac arrest patients presenting with pulseless electrical activity is increasing, and it is likely that many of these patients have pseudo-electromechanical dissociation (P-EMD), a state in which there is residual cardiac contraction without a palpable pulse. The efficacy of cardiopulmonary resuscitation (CPR) with external chest compression synchronized with the P-EMD cardiac systole and diastole has not been fully evaluated.

Hypothesis: During external chest compression in P-EMD, the coronary perfusion pressure (CPP) will be greater with systolic synchronization compared with diastolic phase synchronization.

Emergency department initiation of cardiopulmonary bypass: a case report and review of the literature.

Background: Out-of-hospital cardiac arrest carries a dismal prognosis. Percutaneous extracorporeal membrane oxygenation (ECMO) has been used with success for in-hospital arrests, and some literature suggests improvement in long-term survival for out-of-hospital arrests as well.

Objectives: This case highlights the use of ECMO in the emergency department.

Inhomogeneity and temporal effects in AutoPulse Assisted Prehospital International Resuscitation--an exception from consent trial terminated early.

Background: The ASPIRE trial (AutoPulse Assisted Prehospital International Resuscitation) was multicenter exception from consent clinical trial that compared mechanical cardiopulmonary resuscitation (CPR) with a device (AutoPulse-CPR) to traditional manual CPR (manual-CPR) in out-of-hospital cardiac arrest. Enrollment was suspended early due to safety concerns. One site (site C) made a potentially important protocol change midtrial, and enrollment at that site was noted to be independently associated with outcome.

Outcomes from low versus high-flow cardiopulmonary resuscitation in a swine model of cardiac arrest.

Background: Return of spontaneous circulation (ROSC) is improved by greater vital organ blood flow during cardiopulmonary resuscitation (CPR). We tested the hypothesis that myocardial flow above the threshold needed for ROSC may be associated with greater vital organ injury and worse outcome.

Methods: Aortic and right atrial pressures were measured with micromanometers in 27 swine.

A randomized controlled trial comparing the Arctic Sun to standard cooling for induction of hypothermia after cardiac arrest.

Context: Hypothermia improves neurological outcome for comatose survivors of out-of-hospital cardiac arrest. Use of computer controlled high surface area devices for cooling may lead to faster cooling rates and potentially improve patient outcome.

Objective: To compare the effectiveness of surface cooling with the standard blankets and ice packs to the Arctic Sun, a mechanical device used for temperature management.

A swine model of pseudo-pulseless electrical activity induced by partial asphyxiation.

Background: The incidence of pulseless electrical activity (PEA) as a presenting rhythm during cardiac arrest is increasing. The current animal models of PEA arrest, post-countershock or total asphyxiation, unreliably generate PEA for a specific time period. Neither of these models predictably generate pseudo-PEA.

Prehospital interventions to improve neurological outcome following cardiac arrest.

As many cases of cardiac arrest occur outside of the health care setting, prehospital treatment may dramatically affect patient outcomes. The three major interventions that have been studied are chest compressions and ventilation, electrical defibrillation, and medications. Recent studies show that increasing the rate of cardiopulmonary resuscitation (CPR), decreasing the rate of ventilation, and initiation of CPR prior to defibrillation may result in improved survival.