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OBJECTIVES: To overcome the shortage of personal protective equipment and airborne infection isolation rooms (AIIRs) in the COVID-19 pandemic, a collaborative team of research engineers and clinical physicians worked to build a novel negative pressure environment in the hopes of improving healthcare worker and patient safety. The team then sought to test the device's efficacy in generating and maintaining negative pressure. The goal proved prescient as the US Food and Drug Administration (FDA) later recommended that all barrier devices use negative pressure. METHODS: Initially, engineers observed simulations of various aerosol- and droplet-generating procedures using hospital beds and stretchers to determine the optimal working dimensions of the containment device. Several prototypes were made based on these dimensions which were combined with filters and various flow-generating devices. Then, the airflow generated and the pressure differential within the device during simulated patient care were measured, specifically assessing its ability to create a negative pressure environment consistent with standards published by the Centers for Disease Control and Prevention (CDC). RESULTS: The portable fans were unable to generate any airflow and were dropped from further testing. The vacuums tested were all able to generate a negative pressure environment with the magnitude of pressure differential increasing with the vacuum horsepower. Only the 3.5-horsepower Shop-Vac, however, generated a -3.0 pascal (Pa) pressure gradient, exceeding the CDC-recommended minimum of -2.5 Pa for AIIRs. CONCLUSION: A collaborative team of physicians and engineers demonstrated the efficacy of a prototype portable negative pressure environment, surpassing the negative pressure differential recommended by the CDC.
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The emergence of the SARS-CoV-2 pandemic has imposed a multitude of complications on healthcare facilities. Healthcare professionals had to develop creative solutions to deal with resource shortages and isolation spaces when caring for COVID positive patients. Among many other solutions, facilities have utilized engineering strategies to mitigate the spread of viral contamination within the hospital environment. One of the standard solutions has been the use of whole room negative pressurization (WRNP) to turn a general patient room into an infection isolation space. However, this has not always been easy due to many limitations, such as direct access to the outdoors and the availability of WRNP units. In operating rooms where a patient is likely to go through aerosol-generating procedures, other solutions must be considered because most operating rooms use positive pressure ventilation to maintain sterility. The research team has designed, built, and tested a Covering for Operations during Viral Emergency Response (COVER), a low-cost, portable isolation chamber that fits over a patient's torso on a hospital bed to contain and remove the pathogenic agents at the source (i.e., patient's mouth and nose). This study tests the performance of the COVER system under various design and performance scenarios using particle tracing techniques and compares its efficiency with WRNP units. The results show that COVER can dramatically reduce the concentration of particles within the room, while WRNP is only effective in preventing the room-induced particles from migrating to adjacent spaces.
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BACKGROUND: Diltiazem in its extended-release formulation is widely prescribed and is generally well-tolerated. Currently, there are no published case reports of localized inflammation related to extended-release diltiazem causing either significant pill esophagitis or airway inflammation when swallowed incompletely. CASE REPORT: We present a case of an 85-year-old female who reported difficulty swallowing roughly 18 h after incomplete ingestion of an extended-release diltiazem tablet. She had mild stridor and visible right-sided neck swelling on examination. Imaging revealed a large inflammatory mass, which was believed to be a subacute to chronic neoplastic process when reviewed both by radiology and otolaryngology. Two days after presentation, however, the patient's symptoms and the inflammatory mass had resolved entirely. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Extended-release diltiazem can cause an inflammatory mass when ingested incompletely, leading to possible acute airway compromise. Any invasive airway intervention should be approached with caution, given the degree of acute inflammation. Even in patients who do not require intervention, close observation until clinical improvement is warranted in symptomatic patients with a history of recent incomplete ingestion of extended-release diltiazem.
