Trends in COVID-19 Testing and Positivity Rates from a Mobile Testing Program in the Phoenix Metropolitan Area.

The coronavirus (COVID-19) pandemic continues to be a global concern, with over 150 million cases worldwide. Arizona, which was recently a hotspot for COVID-19, has over 860 thousand cases. Reviewing the COVID-19 trends over time is crucial in understanding the pandemic and evaluating the impact of mitigation techniques. This current study analyzes the trends in COVID-19 testing and positivity rates from a mobile testing program in the Phoenix metropolitan area between December 2020 and April 2021. Of the 32,234 tests performed there was a total of 3654 COVID positive cases, yielding an overall positivity rate of 11.3%. COVID-19 positivity rates were significantly higher in December (12.9%) and January (12.7%), compared to February (7.5%), March (4.9%), and April (6.7%), p < 0.05. The peak of COVID-19 cases is likely attributable to the holiday season and family gatherings, followed by a steady decline, likely due to fewer gatherings and an increase in individuals receiving the COVID-19 vaccines. Continued public health measures, including vaccinations, are critical in reducing COVID-19 transmission.

Systolic Blood Pressure Threshold for HEMS-Witnessed Arrests.

OBJECTIVE: Defining vital sign thresholds has focused on mortality, which may be delayed for hours, days, or weeks after injury. This limits the immediate clinical significance in guiding therapy to avoid arrest. The aim of this study was to identify a systolic blood pressure (SBP) threshold indicating imminent cardiopulmonary arrest. METHODS: This was a retrospective, observational study analyzing physiological data from air medical patients suffering witnessed arrest. We limited the analysis to a subgroup of adult (> 14 years) patients with hypoperfusion-related arrest. Prearrest SBP values were plotted over time, with arrest defined as "time zero." Multiple linear regression was used to define a best fit curve to identify an inflection point beyond which arrest was imminent. RESULTS: A total of 53 eligible patients were identified; 33 (62%) were trauma victims. A fifth-degree equation showed appropriate goodness of fit (r = -.66, P < .0001). An inflection point was identified at an SBP of 78 mm Hg, with arrest occurring approximately 3 minutes later. CONCLUSION: An inflection point below SBP 80 mm Hg was identified, suggesting a predictable physiological pattern for perfusion-related deterioration. This may help guide therapy to reverse deterioration and prevent arrest.

Electrochemical Detection of Fertility Hormones.

Fertility hormone levels are constantly changing, but it is crucial for a woman to be able to monitor her fertility levels if she is interested in conceiving. Women and physicians often have a difficult time determining ovulation windows due to fluctuating menstrual cycles and inaccurate interpretations of hormone levels. Current methods of fertility monitoring include physical or vaginal exams, laparoscopy, ultrasound scans, as well as evaluation of hormone levels. A rapid, at-home fertility monitoring tool can help alleviate the apprehensiveness associated with routine screenings and give women the privacy desired when trying to conceive. Herein, we discuss the development of an electrochemical biosensor for quantification of three fertility hormones: beta-estradiol, progesterone, and FSH. Each biomarker's MRE was immobilized onto a gold disk electrode through the use of self-assembled monolayer linking chemistry. Using electrochemical impedance spectroscopy (EIS), the biomarker concentration was correlated to impedance magnitude. An optimal binding frequency was identified for each biomarker, permitting simplistic hardware requirements and investigation into multimarker detection. Analytes were tested in both purified solutions and 1%-90% whole blood. Each biomarker exhibited a unique imaginary impedance peak and optimal binding frequency. The determination was made by assessing the response parameters including the linear fit correlation across the physiological hormone ranges. The existence of unique optimal frequencies permits for simultaneous detection of multiple hormones in a single test. Additionally, the identified frequency was robust across purified and complex solutions. Response characteristics were negatively impacted by the introduction of blood-based contaminants. However, the introduction of Nafion membranes, similar to ones used in commercial glucose sensors, is both feasible and beneficial.

Vital sign patterns before shock-related cardiopulmonary arrest.

OBJECTIVE: Traditional vital sign thresholds reflect an increased risk of mortality, which may occur hours, days, or weeks following illness/injury, limiting immediate clinical significance to guide rescue therapy to avoid arrest. Our objective is to explore vital sign patterns prior to arrest due to shock. DESIGN: This retrospective observational analysis utilized physiological data from adult helicopter patients suffering provider-witnessed arrest. Pre-arrest values for systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR), shock index, and end-tidal carbon dioxide (EtCO2) were modeled against time using polynomial linear regression. The "terminal inflection point" beyond which arrest was imminent was identified where slope equals 1.0 (shock index) or -1.0 (SBP, MAP, HR, EtCO2) and was then compared to initial values. SETTING: Air ambulance services. PATIENTS: 70 helicopter patients over age fourteen suffering cardiac arrest. RESULTS: SBP and MAP demonstrated a gentle decline followed by acceleration beyond the inflection point (SBP 80.7 mmHg, MAP 61.9 mmHg). HR demonstrated an increase followed by a terminal drop, but inflection point values fell within normal range. Shock index increased gradually from a mean of 0.9 to the inflection point of 1.1. Initial EtCO2 values declined gradually from normal (34.4 mmHg) to the inflection point (24.7 mmHg), then dropped precipitously into arrest. All inflection points occurred 2-5 min prior to arrest. CONCLUSIONS: Vital sign patterns were defined for SBP, MAP, HR, shock index, and EtCO2 with clear inflection points identified 2-5 min prior to arrest. These patterns may help guide therapy to reverse deterioration and prevent arrest.

A Disposable Tear Glucose Biosensor-Part 5: Improvements in Reagents and Tear Sampling Component.

A tear glucose (TG) sensor with an integrated tear sampler can provide a noninvasive method for calibrating the continuous TG contact lens and monitoring glucose. Expanding from previous work, an improved TG sensor that implements dried reagents, genetically modified glucose dehydrogenase (GDH), and a tear sampler was developed and compared against the TG sensor prepared with commercial GDH. It was found that neither sensor was affected by the tear interferents: ascorbic acid, acetaminophen, and uric acid. The sensor prepared with commercial GDH generated higher current. This suggests that using enzymes with lower Km may be advantageous when operating in low glucose environments like tears. The improved TG sensor also demonstrated the potential of integrating Schirmer's test strip as a tear sampler for self-monitoring of TG.