COVID-19 and the cardiovascular system: A review of current data, summary of best practices, outline of controversies, and illustrative case reports.

As the severe acute respiratory syndrome coronavirus 2 virus pandemic continues to grow globally, an association is apparent between patients with underlying cardiovascular disease comorbidities and the risk of developing severe COVID-19. Furthermore, there are potential cardiac manifestations of severe acute respiratory syndrome coronavirus 2 including myocyte injury, ventricular dysfunction, coagulopathy, and electrophysiologic abnormalities. Balancing management of the infection and treatment of underlying cardiovascular disease requires further study. Addressing the increasing reports of health care worker exposure and deaths remains paramount. This review summarizes the most contemporary literature on the relationship of the cardiovascular system and COVID-19 and society statements with relevance to protection of health care workers, and provides illustrative case reports in this context.

The effect of continuous positive airway pressure on inferior vena cava collapsibility as measured by bedside ultrasound.

Objectives: The purpose of this study was to determine the impact of progressively increasing continuous positive airway pressure (CPAP) on measurements of the caval index (CI) using bedside ultrasound at the 3 common inferior vena cava (IVC) evaluation sites. Methods: This was a prospective, observational trial that included 165 healthy adults over 18 years old enrolled between February 2015 and May 2018. Measurements of the IVC were obtained during normal tidal respirations from the subxiphoid area in the long and short axis and from the right mid-axillary line in the long axis. Measurements were obtained in each of these locations at atmospheric pressure and with CPAP at 5, 10, and 15 cmH2O. The CI was then calculated for each of the 3 selected locations at each level of pressure. Results: As CPAP pressures increased from 0 to 15 cmH2O the CI measurements obtained at the lateral mid-axillary line did not show any statistically significant variation. There was a statistically significant difference (P < 0.001) when comparing measurements of the CI from the lateral mid-axillary line location to both anterior locations. As CPAP pressures increased, the CI calculated from the subxiphoid area in both the anterior short and anterior long axis orientations initially trended upwards at 5 cmH2O, then began to downtrend as the pressures increased to 10 and 15 cmH2O. Comparing the CI measurements from the anterior long and anterior short axis at 0, 5, 10, and 15 cmH2O, there was no statistically significant difference at any pressure (P > 0.05). Conclusion: When evaluating the IVC in a spontaneously breathing patient, measurements from an anterior orientation are preferred as the lateral mid-axillary view can underestimate CI calculations.

Comparison of four handheld point-of-care ultrasound devices by expert users.

BACKGROUND: Point-of-care ultrasound (POCUS) is rapidly becoming ubiquitous across healthcare specialties. This is due to several factors including its portability, immediacy of results to guide clinical decision-making, and lack of radiation exposure to patients. The recent growth of handheld ultrasound devices has improved access to ultrasound for many clinicians. Few studies have directly compared different handheld ultrasound devices among themselves or to cart-based ultrasound machines. We conducted a prospective observational study comparing four common handheld ultrasound devices for ease of use, image quality, and overall satisfaction. Twenty-four POCUS experts utilized four handheld devices (Butterfly iQ+™ by Butterfly Network Inc., Kosmos™ by EchoNous, Vscan Air™ by General Electric, and Lumify™ by Philips Healthcare) to obtain three ultrasound views on the same standardized patients using high- and low-frequency probes. RESULTS: Data were collected from 24 POCUS experts using all 4 handheld devices. No single ultrasound device was superior in all categories. For overall ease of use, the Vscan Air™ was rated highest, followed by the Lumify™. For overall image quality, Lumify™ was rated highest, followed by Kosmos™. The Lumify™ device was rated highest for overall satisfaction, while the Vscan Air™ was rated as the most likely to be purchased personally and carried in one's coat pocket. The top 5 characteristics of handheld ultrasound devices rated as being "very important" were image quality, ease of use, portability, total costs, and availability of different probes. CONCLUSIONS: In a comparison of four common handheld ultrasound devices in the United States, no single handheld ultrasound device was perceived to have all desired characteristics. POCUS experts rated the Lumify™ highest for image quality and Vscan Air™ highest for ease of use. Overall satisfaction was highest with the Lumify™ device, while the most likely to be purchased as a pocket device was the Vscan Air™. Image quality was felt to be the most important characteristic in evaluating handheld ultrasound devices.

Emergency department bedside ultrasonographic measurement of the caval index for noninvasive determination of low central venous pressure.

STUDY OBJECTIVE: Among adult emergency department (ED) patients undergoing central venous catheterization, we determine whether a greater than or equal to 50% decrease in inferior vena cava diameter is associated with a central venous pressure of less than 8 mm Hg. METHODS: Adult patients undergoing central venous catheterization were enrolled in a prospective, observational study. Inferior vena cava inspiratory and expiratory diameters were measured by 2-dimensional bedside ultrasonography. The caval index was calculated as the relative decrease in inferior vena cava diameter during 1 respiratory cycle. The correlation of central venous pressure and caval index was calculated. The sensitivity, specificity, and positive and negative predictive values of a caval index greater than or equal to 50% that was associated with a central venous pressure less than 8 mm Hg were estimated. RESULTS: Of 73 patients, the median age was 63 years and 60% were women. Mean time and fluid administered from ultrasonographic measurement to central venous pressure determination were 6.5 minutes and 45 mL, respectively. Of the 73 participants, 32% had a central venous pressure less than 8 mm Hg. The correlation between caval index and central venous pressure was -0.74 (95% confidence interval [CI] -0.82 to -0.63). The sensitivity of caval index greater than or equal to 50% to predict a central venous pressure less than 8 mm Hg was 91% (95% CI 71% to 99%), the specificity was 94% (95% CI 84% to 99%), the positive predictive value was 87% (95% CI 66% to 97%), and the negative predictive value was 96% (95% CI 86% to 99%). CONCLUSION: Bedside ultrasonographic measurement of caval index greater than or equal to 50% is strongly associated with a low central venous pressure. Bedside measurements of caval index could be a useful noninvasive tool to determine central venous pressure during the initial evaluation of the ED patient.

Ultrasound detection of guidewire position during central venous catheterization.

INTRODUCTION: Ultrasound guidance decreases complications of central venous catheter (CVC) placement, but risks of arterial puncture and inadvertent arterial catheter placement exist. Ultrasound-assisted detection of guidewire position in the internal jugular vein could predict correct catheter position before dilation and catheter placement. METHODS: Ultrasound examinations were performed in an attempt to identify the guidewire before dilation and catheter insertion in 20 adult patients requiring CVC placement. Central venous pressures were measured after completion of the procedure. RESULTS: Guidewires were visible within the lumen of the internal jugular vein in all subjects. Central venous pressures confirmed venous placement of catheters. Ultrasound visualization of the guidewire predicted venous CVC placement with 100% sensitivity (95% confidence interval 80-100%) and 100% specificity (95% confidence interval 80%-100%). CONCLUSIONS: Ultrasound reliably detects the guidewire during CVC placement and visualization of the wire before dilation and catheter insertion may provide an additional measure of safety during ultrasound-guided CVC placement.

Bedside ultrasound for the detection of diabetic myonecrosis.

Diabetic myonecrosis is an uncommon complication of diabetes mellitus. There are fewer than 50 cases reported in the general medical literature. Patients classically complain of the abrupt onset of diffuse anterior thigh pain with no signs of overlying infection or signs of systemic toxicity.Because of the difficulty in diagnosis, most patients endure multiple medical visits until appropriate imaging modalities are obtained. Currently, magnetic resonance imaging (MRI) or tissue biopsy is considered the gold standard for diagnosis. This is the first case reported in the literature of diabetic myonecrosis detected in the ED by bedside ultrasound. We hope that with the continued use of bedside ultrasound, more physicians will be able to determine abnormal tissue architecture allowing for the early detection of diabetic myonecrosis.

The Impact of a Location-Sensing Electronic Health Record on Clinician Efficiency and Accuracy: A Pilot Simulation Study.

BACKGROUND: Through the Health Information Technology for Economic and Clinical Health Act of 2009, the federal government invested $26 billion in electronic health records (EHRs) to improve physician performance and patient safety; however, these systems have not met expectations. One of the cited issues with EHRs is the human-computer interaction, as exhibited by the excessive number of interactions with the interface, which reduces clinician efficiency. In contrast, real-time location systems (RTLS)-technologies that can track the location of people and objects-have been shown to increase clinician efficiency. RTLS can improve patient flow in part through the optimization of patient verification activities. However, the data collected by RTLS have not been effectively applied to optimize interaction with EHR systems. OBJECTIVES: We conducted a pilot study with the intention of improving the human-computer interaction of EHR systems by incorporating a RTLS. The aim of this study is to determine the impact of RTLS on process metrics (i.e., provider time, number of rooms searched to find a patient, and the number of interactions with the computer interface), and the outcome metric of patient identification accuracy METHODS: A pilot study was conducted in a simulated emergency department using a locally developed camera-based RTLS-equipped EHR that detected the proximity of subjects to simulated patients and displayed patient information when subjects entered the exam rooms. Ten volunteers participated in 10 patient encounters with the RTLS activated (RTLS-A) and then deactivated (RTLS-D). Each volunteer was monitored and actions recorded by trained observers. We sought a 50% improvement in time to locate patients, number of rooms searched to locate patients, and the number of mouse clicks necessary to perform those tasks. RESULTS: The time required to locate patients (RTLS-A = 11.9 ± 2.0 seconds vs. RTLS-D = 36.0 ± 5.7 seconds, p < 0.001), rooms searched to find patient (RTLS-A = 1.0 ± 1.06 vs. RTLS-D = 3.8 ± 0.5, p < 0.001), and number of clicks to access patient data (RTLS-A = 1.0 ± 0.06 vs. RTLS-D = 4.1 ± 0.13, p < 0.001) were significantly reduced with RTLS-A relative to RTLS-D. There was no significant difference between RTLS-A and RTLS-D for patient identification accuracy. CONCLUSION: This pilot demonstrated in simulation that an EHR equipped with real-time location services improved performance in locating patients and reduced error compared with an EHR without RTLS. Furthermore, RTLS decreased the number of mouse clicks required to access information. This study suggests EHRs equipped with real-time location services that automates patient location and other repetitive tasks may improve physician efficiency, and ultimately, patient safety.