Cellular host response sepsis test for risk stratification of patients in the emergency department: A pooled analysis.

OBJECTIVES: Sepsis is one of the most common, costly, and misdiagnosed conditions in U.S. emergency departments (EDs). ED providers often treat on nonspecific signs, subjective suspicion, or presumption of infection, resulting in over- and undertreatment. An increased understanding of host response has opened a new direction for sepsis diagnostics. The IntelliSep test is a U.S. Food and Drug Administration-cleared cellular host response diagnostic that could help distinguish sepsis in ED settings. Our objective was to evaluate the potential of the cellular host response test to expedite appropriate care for patients who present with signs of infection. METHODS: We performed a pooled analysis of five adult (≥18 years) cohorts enrolled at seven geographically diverse U.S. sites in separate studies. Structured blinded adjudication was used to classify presence or absence of sepsis, and only patients with high confidence in the adjudicated label were included (n = 1002), defined as patients for whom there was consensus in the determination of sepsis per the Sepsis-3 and severe sepsis per the Sepsis-2 definitions between both the independent adjudication panel and the site-level physician. RESULTS: Among patients with signs or suspicion of infection, the test achieved similar or better performance compared to other indicators in identifying patients at high risk for sepsis (specificity > 83%) and significantly superior performance in identifying those at low risk (sensitivity > 92%; 0% sepsis-associated mortality). The test also stratified severity of illness, as shown by 30-day in-hospital mortality (p < 0.001), hospital length of stay (p < 0.01), and use of hospital resources (p < 0.001). CONCLUSIONS: Our data suggest that the cellular host response test provides clinically actionable results for patients at both high and low risk for sepsis and provides a rapid, objective means for risk stratification of patients with signs of infection. If integrated into standard of care, the test may help improve outcomes and reduce unnecessary antibiotic use.

Validation of a Novel, Rapid Sepsis Diagnostic for Emergency Department Use.

OBJECTIVES: To assess the in vitro IntelliSep test, a microfluidic assay that quantifies the state of immune activation by evaluating the biophysical properties of leukocytes, as a rapid diagnostic for sepsis. DESIGN: Prospective cohort study. SETTING: Five emergency departments (EDs) in Louisiana, Missouri, North Carolina, and Washington. PATIENTS: Adult patients presenting to the ED with signs (two of four Systemic Inflammatory Response Syndrome criteria, where one must be temperature or WBC count) or suspicion (provider-ordered culture) of infection. INTERVENTIONS: All patients underwent testing with the IntelliSep using ethylene diamine tetraacetic acid-anticoagulated whole blood followed by retrospective adjudication for sepsis by sepsis-3 criteria by a blinded panel of physicians. MEASUREMENTS AND MAIN RESULTS: Of 599 patients enrolled, 572 patients were included in the final analysis. The result of the IntelliSep test is reported as the IntelliSep Index (ISI), ranging from 0.1 to 10.0, divided into three interpretation bands for the risk of sepsis: band 1 (low) to band 3 (high). The median turnaround time for ISI results was 7.2 minutes. The ISI resulted band 1 in 252 (44.1%), band 2 in 160 (28.0%), and band 3 in 160 (28.0%). Sepsis occurred in 26.6% (152 of 572 patients). Sepsis prevalence was 11.1% (95% CI, 7.5-15.7%) in band 1, 28.1% (95% CI, 21.3-35.8%) in band 2, and 49.4% (95% CI, 41.4-57.4%) in band 3. The Positive Percent Agreement of band 1 was 81.6% and the Negative Percent Agreement of band 3 was 80.7%, with an area under the receiver operating characteristic curve of 0.74. Compared with band 1, band 3 correlated with adverse clinical outcomes, including mortality, and resource utilization. CONCLUSIONS: Increasing ISI interpretation band is associated with increasing probability of sepsis in patients presenting to the ED with suspected infection.

Biophysical Changes of Leukocyte Activation (and NETosis) in the Cellular Host Response to Sepsis.

Sepsis, the leading cause of mortality in hospitals, currently lacks effective early diagnostics. A new cellular host response test, the IntelliSep test, may provide an indicator of the immune dysregulation characterizing sepsis. The objective of this study was to examine the correlation between the measurements performed using this test and biological markers and processes associated with sepsis. Phorbol myristate acetate (PMA), an agonist of neutrophils known to induce neutrophil extracellular trap (NET) formation, was added to whole blood of healthy volunteers at concentrations of 0, 200, and 400 nM and then evaluated using the IntelliSep test. Separately, plasma from a cohort of subjects was segregated into Control and Diseased populations and tested for levels of NET components (citrullinated histone (cit-H3) DNA and neutrophil elastase (NE) DNA) using customized ELISA assays and correlated with ISI scores from the same patient samples. Significant increases in IntelliSep Index (ISI) scores were observed with increasing concentrations of PMA in healthy blood (0 and 200: p < 10-10; 0 and 400: p < 10-10). Linear correlation was observed between the ISI and quantities of NE DNA and Cit-H3 DNA in patient samples. Together these experiments demonstrate that the IntelliSep test is associated with the biological processes of leukocyte activation and NETosis and may indicate changes consistent with sepsis.

Assessment of a cellular host response test to risk-stratify suspected COVID-19 patients in the Emergency Department setting.

OBJECTIVE: Assess the IntelliSep Index (ISI) for risk stratification of patients presenting to the Emergency Department (ED) with respiratory symptoms suspected of COVID-19 during the pandemic. METHODS: An observational single-center study of prospective cohort of patients presenting to the ED during the early COVID-19 pandemic with respiratory symptoms and a CBC drawn within 4.5 hours of initial vital signs. A sample of this blood was aliquoted for performance of the ISI, and patients were followed for clinical outcomes. The study required no patient-centered activity beyond standard of care and treating clinicians were unaware of study enrollment and ISI test results. MAIN FINDINGS: 282 patients were included. The ISI ranges 0.1 to 10.0, with three interpretation bands indicating risk of adverse outcome: low (green), 0.1-4.9; intermediate (yellow), 5.0-6.2; and high (red), 6.3-10.0. Of 193 (68.4%) tested for SARS-CoV-2, 96 (49.7%) were positive. The ISI resulted in 182 (64.5%) green, 54 (18.1%) yellow, and 46 (15.6%) red band patients. Green band patients had a 1.1% (n = 2) 3-day mortality, while yellow and red band had 3.7% (n = 2, p > .05) and 10.9% (n = 5, p < .05) 3-day mortalities, respectively. Fewer green band patients required admission (96 [52.7%]) vs yellow (44 [81.5%]) and red (43 [93.5%]). Green band patients had more hospital free days (median 23 (Q1-Q3 20-25) than yellow (median 22 [Q1-Q3 0-23], p < 0.05) and red (median 21 [Q1-Q3 0-24], p < 0.01). SOFA increased with interpretation band: green (2, [Q1-Q3 0-4]) vs yellow (4, [Q1-Q3 2-5], p < 0.001) and red (5, [Q1-Q3 3-6]) p < 0.001). CONCLUSIONS: The ISI rapidly risk-stratifies patients presenting to the ED during the early COVID-19 pandemic with signs or suspicion of respiratory infection.

The impact of a peer-based education on fruits and vegetables intake among housewives.

BACKGROUND: Evidence indicates the lower intake of fruits and vegetables than the recommended daily amount. Study aimed at determining the effects of peer education intervention on the consumption of fruits and vegetable in housewives. METHODS: A quasi-experimental was conducted with 130 housewives referring to health care centers in Bandar Abbas, Iran. Sixty-five subjects were recruited in each of the intervention and the control groups. Intervention group were divided into three subgroups each receiving a seven-sessions educational programs (lecturing and group discussion) through peers about the importance of benefits of fruits and vegetables consumption. Participants were followed for two months. Data were collected using a questionnaire in two stages of pre- and post-intervention. Differences in the outcome before and after the intervention were tested using T-test and paired T-test. RESULTS: The daily servings of fruits and vegetables in the intervention group increased from 1.73 to 4.20 and in the control group from 1.96 to 2.16; a statistically significant difference was also observed between the groups (P < 0.001). After the intervention benefits and self-efficacy of fruits and vegetables consumption significantly increased and perceived barriers of fruits and vegetables consumption significantly decreased in the intervention group (P < 0.001). CONCLUSION: Peer education improves benefits and self-efficacy, reduces barriers, and increases the daily servings of fruits and vegetables in housewives.

Assessment of a Cellular Host Response Test as a Sepsis Diagnostic for Those With Suspected Infection in the Emergency Department.

OBJECTIVES: Sepsis is a common cause of morbidity and mortality. A reliable, rapid, and early indicator can help improve efficiency of care and outcomes. To assess the IntelliSep test, a novel in vitro diagnostic that quantifies the state of immune activation by measuring the biophysical properties of leukocytes, as a rapid diagnostic for sepsis and a measure of severity of illness, as defined by Sequential Organ Failure Assessment and Acute Physiology and Chronic Health Evaluation-II scores and the need for hospitalization. DESIGN SETTING SUBJECTS: Adult patients presenting to two emergency departments in Baton Rouge, LA, with signs of infection (two of four systemic inflammatory response syndrome criteria, with at least one being aberration of temperature or WBC count) or suspicion of infection (a clinician order for culture of a body fluid), were prospectively enrolled. Sepsis status, per Sepsis-3 criteria, was determined through a 3-tiered retrospective and blinded adjudication process consisting of objective review, site-level clinician review, and final determination by independent physician adjudicators. MEASUREMENTS AND MAIN RESULTS: Of 266 patients in the final analysis, those with sepsis had higher IntelliSep Index (median = 6.9; interquartile range, 6.1-7.6) than those adjudicated as not septic (median = 4.7; interquartile range, 3.7-5.9; p < 0.001), with an area under the receiver operating characteristic curve of 0.89 and 0.83 when compared with unanimous and forced adjudication standards, respectively. Patients with higher IntelliSep Index had higher Sequential Organ Failure Assessment (3 [interquartile range, 1-5] vs 1 [interquartile range, 0-2]; p < 0.001) and Acute Physiology and Chronic Health Evaluation-II (7 [interquartile range, 3.5-11.5] vs 5 [interquartile range, 2-9]; p < 0.05) and were more likely to be admitted to the hospital (83.6% vs 48.3%; p < 0.001) compared with those with lower IntelliSep Index. CONCLUSIONS: In patients presenting to the emergency department with signs or suspicion of infection, the IntelliSep Index is a promising tool for the rapid diagnosis and risk stratification for sepsis.

Development and validation of a cellular host response test as an early diagnostic for sepsis.

Sepsis must be diagnosed quickly to avoid morbidity and mortality. However, the clinical manifestations of sepsis are highly variable and emergency department (ED) clinicians often must make rapid, impactful decisions before laboratory results are known. We previously developed a technique that allows the measurement of the biophysical properties of white blood cells as they are stretched through a microfluidic channel. In this study we describe and validate the resultant output as a model and score-the IntelliSep Index (ISI)-that aids in the diagnosis of sepsis in patients with suspected or confirmed infection from a single blood draw performed at the time of ED presentation. By applying this technique to a high acuity cohort with a 23.5% sepsis incidence (n = 307), we defined specific metrics-the aspect ratio and visco-elastic inertial response-that are more sensitive than cell size or cell count in predicting disease severity. The final model was trained and cross-validated on the high acuity cohort, and the performance and generalizability of the model was evaluated on a separate low acuity cohort with a 6.4% sepsis incidence (n = 94) and healthy donors (n = 72). For easier clinical interpretation, the ISI is divided into three interpretation bands of Green, Yellow, and Red that correspond to increasing disease severity. The ISI agreed with the diagnosis established by retrospective physician adjudication, and accurately identified subjects with severe illness as measured by SOFA, APACHE-II, hospital-free days, and intensive care unit admission. Measured using routinely collected blood samples, with a short run-time and no requirement for patient or laboratory information, the ISI is well suited to aid ED clinicians in rapidly diagnosing sepsis.

Highly sensitive label-free dual sensor array for rapid detection of wound bacteria.

Wound infections are a critical healthcare concern worldwide. Rapid and effective antibiotic treatments that can mitigate infection severity and prevent the spread of antibiotic resistance are contingent upon timely infection detection. In this work, dual electrochemical pH and cell-attachment sensor arrays were developed for the real-time spatial and temporal monitoring of potential wound infections. Biocompatible polymeric device coatings were integrated to stabilize the sensors and promote bacteria attachment while preventing non-specific cell and protein fouling. High sensitivity (bacteria concentration of 102 colony forming units (CFU)/mL and -88.1±6.3mV/pH over a pH range of 1-13) and stability over 14 days were achieved without the addition of biological recognition elements. The dual sensor array was demonstrated to successfully monitor the growth of both gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) over time through lag and log growth phases and following antibiotic administration and in simulated shallow wounds conditions. The versatile fabrication methods utilized in sensor development, superior sensitivity, prolonged stability, and lack of non-specific sensor fouling may enable long-term in situ sensor array operation in low resource settings.

A Wireless Implantable Micropump for Chronic Drug Infusion Against Cancer.

We present an implantable micropump with a miniature form factor and completely wireless operation that enables chronic drug administration intended for evaluation and development of cancer therapies in freely moving small research animals such as rodents. The low power electrolysis actuator avoids the need for heavy implantable batteries. The infusion system features a class E inductive powering system that provides on-demand activation of the pump as well as remote adjustment of the delivery regimen without animal handling. Micropump performance was demonstrated using a model anti-cancer application in which daily doses of 30 µL were supplied for several weeks with less than 6% variation in flow rate within a single pump and less than 8% variation across different pumps. Pumping under different back pressure, viscosity, and temperature conditions were investigated; parameters were chosen so as to mimic in vivo conditions. In benchtop tests under simulated in vivo conditions, micropumps provided consistent and reliable performance over a period of 30 days with less than 4% flow rate variation. The demonstrated prototype has potential to provide a practical solution for remote chronic administration of drugs to ambulatory small animals for research as well as drug discovery and development applications.

Complementary sensors for rapid and sensitive detection of wound bacteria.

Dual sensors for timely wound bacterial infection detection through the measurement of pH and bacterial cell attachment were developed. A high sensitivity of -57.98 ± 7.08 mV/pH (pH 1-13; over 14 days) and a minimum detectable bacteria concentration of 103 CFU/mL was achieved for the pH and cell-based sensors, respectively. Sensors were capable of successfully monitoring growth of bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) over time with and without antibiotics in simulated would fluid.

Acceleration Techniques for Recombination of Gases in Electrolysis Microactuators with Nafion®-Coated Electrocatalyst.

Recombination of electrolysis gases (oxidation of hydrogen and reduction of oxygen) is an important factor in operation efficiency of devices employing electrolysis such as actuators and also unitized regenerative fuel cells. Several methods of improving recombination speed and repeatability were developed for application to electrolysis microactuators with Nafion®-coated catalytic electrodes. Decreasing the electrolysis chamber volume increased the speed, consistency, and repeatability of the gas recombination rate. To further improve recombination performance, methods to increase the catalyst surface area, hydrophobicity, and availability were developed and evaluated. Of these, including in the electrolyte pyrolyzed-Nafion®-coated Pt segments contained in the actuator chamber accelerated recombination by increasing the catalyst surface area and decreasing the gas transport diffusion path. This approach also reduced variability in recombination encountered under varying actuator orientation (resulting in differing catalyst/gas bubble proximity) and increased the rate of recombination by 2.3 times across all actuator orientations. Repeatability of complete recombination for different generated gas volumes was studied through cycling.

Wireless programmable electrochemical drug delivery micropump with fully integrated electrochemical dosing sensors.

We present a fully integrated implantable electrolysis-based micropump with incorporated EI dosing sensors. Wireless powering and data telemetry (through amplitude and frequency modulation) were utilized to achieve variable flow control and a bi-directional data link with the sensors. Wireless infusion rate control (0.14-1.04 µL/min) and dose sensing (bolus resolution of 0.55-2 µL) were each calibrated separately with the final circuit architecture and then simultaneous wireless flow control and dose sensing were demonstrated. Recombination detection using the dosing system, as well as, effects of coil separation distance and misalignment in wireless power and data transfer were studied. A custom-made normally closed spring-loaded ball check valve was designed and incorporated at the reservoir outlet to prevent backflow of fluids as a result of the reverse pressure gradient caused by recombination of electrolysis gases. Successful delivery, infusion rate control, and dose sensing were achieved in simulated brain tissue.

MEMS: Enabled Drug Delivery Systems.

Drug delivery systems play a crucial role in the treatment and management of medical conditions. Microelectromechanical systems (MEMS) technologies have allowed the development of advanced miniaturized devices for medical and biological applications. This Review presents the use of MEMS technologies to produce drug delivery devices detailing the delivery mechanisms, device formats employed, and various biomedical applications. The integration of dosing control systems, examples of commercially available microtechnology-enabled drug delivery devices, remaining challenges, and future outlook are also discussed.

On-demand wireless infusion rate control in an implantable micropump for patient-tailored treatment of chronic conditions.

Wireless infusion rate control and programmability for an implantable, low power, electrochemical micropump is presented. Flow rate control was achieved through adjustment of the wiper position of a current potentiometer in the wireless receiver (0.6-3.2 mA output current with a resolution of 0.2 mA per step). An off-the-shelf Bluetooth module and Basic Stamp microcontroller kit was used to initiate amplitude-shift keying (ASK) modulation of the inductive power signal. Accurate flow control of two model regimens was achieved on benchtop. Wireless transmission (power transfer and control) was not affected by simulated tissue material placed between the transmitter and receiver.

A MEMS electrochemical bellows actuator for fluid metering applications.

We present a high efficiency wireless MEMS electrochemical bellows actuator capable of rapid and repeatable delivery of boluses for fluid metering and drug delivery applications. Nafion®-coated Pt electrodes were combined with Parylene bellows filled with DI water to form the electrolysis-based actuator. The performance of actuators with several bellows configurations was compared for a range of applied currents (1-10 mA). Up to 75 boluses were delivered with an average pumping flow rate of 114.40 ± 1.63 µL/min. Recombination of gases into water, an important factor in repeatable and reliable actuation, was studied for uncoated and Nafion®-coated actuators. Real-time pressure measurements were conducted and the effects of temperature, physiological back pressure, and drug viscosity on delivery performance were investigated. Lastly, we present wireless powering of the actuator using a class D inductive powering system that allowed for repeatable delivery with less than 2 % variation in flow rate values.

An implantable MEMS micropump system for drug delivery in small animals.

We present the first implantable drug delivery system for controlled timing and location of dosing in small animals. Current implantable drug delivery devices do not provide control over these factors nor are they feasible for implantation in research animals as small as mice. Our system utilizes an integrated electrolysis micropump, is refillable, has an inert drug reservoir for broad drug compatibility, and is capable of adjustment to the delivery regimen while implanted. Electrochemical impedance spectroscopy (EIS) was used for characterization of electrodes on glass substrate and a flexible Parylene substrate. Benchtop testing of the electrolysis actuator resulted in flow rates from 1 µL/min to 34 µL/min on glass substrate and up to 6.8 µL/min on Parylene substrate. The fully integrated system generated a flow rate of 4.72 ± 0.35 µL/min under applied constant current of 1.0 mA while maintaining a power consumption of only ~3 mW. Finally, we demonstrated in vivo application of the system for anti-cancer drug delivery in mice.

Design, fabrication, and characterization of an electrochemically-based dose tracking system for closed-loop drug delivery.

A real-time integrated electrochemically-based dose tracking system for closed-loop drug delivery is presented. Thin film Pt sensors were integrated in an electrolytic MEMS drug delivery pump to allow dose tracking via electrochemical impedance measurement. Measurement electrode placement and composition were investigated. A bolus resolution of 230 nL was demonstrated. The sensor was calibrated for use with water (low conductivity) and 1 × PBS (high conductivity), the selected model aqueous drugs. The impedance response is dependent on delivered volume and not affected by actuation parameters. A graphical user interface was created for real-time impedance based dose tracking and leakage/blockage detection in the system. Drift in the impedance response of an idle system after perturbation (actuation) were investigated and mitigated through the use of Pt wire electrodes as opposed to thin film electrodes.

A Parylene Bellows Electrochemical Actuator.

We present the first electrochemical actuator with Parylene bellows for large-deflection operation. The bellows diaphragm was fabricated using a polyethylene-glycol-based sacrificial molding technique followed by coating in Parylene C. Bellows were mechanically characterized and integrated with a pair of interdigitated electrodes to form an electrochemical actuator that is suitable for low-power pumping of fluids. Pump performance (gas generation rate and pump efficiency) was optimized through a careful examination of geometrical factors. Overall, a maximum pump efficiency of 90% was achieved in the case of electroplated electrodes, and a deflection of over 1.5 mm was demonstrated. Real-time wireless operation was achieved. The complete fabrication process and the materials used in this actuator are bio-compatible, which makes it suitable for biological and medical applications.

A low power, on demand electrothermal valve for wireless drug delivery applications.

We present a low power, on demand Parylene MEMS electrothermal valve. A novel Omega-shaped thermal resistive element requires low power (approximately mW) and enables rapid valve opening (approximately ms). Using both finite element analysis and valve opening experiments, a robust resistive element design for improved valve opening performance in water was obtained. In addition, a thermistor, as an inrush current limiter, was added into the valve circuit to provide variable current ramping. Wireless activation of the valve using RF inductive power transfer was demonstrated.