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Open Access Publications from the University of California

Open Access Policy Deposits

This series is automatically populated with publications deposited by UC Irvine Department of Emergency Medicine researchers in accordance with the University of California’s open access policies. For more information see Open Access Policy Deposits and the UC Publication Management System.

Cover page of A randomized study to compare oral potassium binders in the treatment of acute hyperkalemia.

A randomized study to compare oral potassium binders in the treatment of acute hyperkalemia.



The KBindER (K+ Binders in Emergency Room and hospitalized patients) clinical trial is the first head-to-head evaluation of oral potassium binders (cation-exchange resins) for acute hyperkalemia therapy.


Emergency room and hospitalized patients with a blood potassium level ≥ 5.5 mEq/L are randomized to one of four study groups: potassium binder drug (sodium polystyrene sulfonate, patiromer, or sodium zirconium cyclosilicate) or nonspecific laxative (polyethylene glycol). Exclusion criteria include recent bowel surgery, ileus, diabetic ketoacidosis, or anticipated dialysis treatment within 4 h of treatment drug. Primary endpoints include change in potassium level at 2 and 4 h after treatment drug. Length of hospital stay, next-morning potassium level, gastrointestinal side effects and palatability will also be analyzed. We are aiming for a final cohort of 80 patients with complete data endpoints (20 per group) for comparative statistics including multivariate adjustment for kidney function, diabetes mellitus, congestive heart failure, metabolic acidosis, renin-angiotensin-aldosterone system inhibitor prescription, and treatment with other agents to lower potassium (insulin, albuterol, loop diuretics).


The findings from our study will inform decision-making guidelines on the role of oral potassium binders in the treatment of acute hyperkalemia.

Trial registration Identifier: NCT04585542 . Registered 14 October 2020.

Cover page of Potential application of conversational agents in HIV testing uptake among high-risk populations.

Potential application of conversational agents in HIV testing uptake among high-risk populations.


Human Immunodeficiency Virus (HIV) continues to be a significant public health problem, with ~1.2 million Americans living with HIV and ~14% unaware of their infection. The Centers for Disease Control and Prevention recommends that patients 13 to 64 years of age get screened for HIV at least once, and those with higher risk profiles screen at least annually. Unfortunately, screening rates are below recommendations for high-risk populations, leading to problems of delayed diagnosis. Novel technologies have been applied in HIV research to increase prevention, testing and treatment. Conversational agents, with potential for integrating artificial intelligence and natural language processing, may offer an opportunity to improve outreach to these high-risk populations. The feasibility, accessibility and acceptance of using conversational agents for HIV testing outreach is important to evaluate, especially amidst a global coronavirus disease 2019 pandemic when clinical services have been drastically affected. This viewpoint explores the application of a conversational agent in increasing HIV testing among high-risk populations.

Cover page of Monkeypox 2022 Identify-Isolate-Inform: A 3I Tool for frontline clinicians for a zoonosis with escalating human community transmission.

Monkeypox 2022 Identify-Isolate-Inform: A 3I Tool for frontline clinicians for a zoonosis with escalating human community transmission.


Monkeypox 2022, a zoonotic virus similar to smallpox, presented as a rapidly escalating human outbreak with community transmission outside endemic regions of Africa. In just over one month of detection, confirmed cases escalated to over 3300, with reports of patients in at least 43 non-African nations. Mechanisms of transmission in animals and the reservoir host remain uncertain; spread from humans to wild or domestic animals risks the creation of new endemic zones. While initial cases were reported in men who have sex with men (MSM), monkeypox is not considered a sexually transmitted infection. Anyone with close contact with an infected person, aerosolized infectious material (e.g., from shaken bedsheets), or contact with fomites or infected animals is at risk. In humans, monkeypox typically presents with a non-specific prodromal phase followed by a classic rash with an incubation period of 5-21 days (usually 6-13 days). The prodrome may be subclinical, and the monkeypox virus may be transmissible from person-to-person before observed symptom onset. Most clinicians are unfamiliar with monkeypox. Information is rapidly evolving, producing an urgent need for immediate access to clear, concise, fact-based, and actionable information for frontline healthcare workers in prehospital, emergency departments/hospitals, and acute care/sexual transmitted infection clinics. This paper provides a novel Identify-Isolate-Inform (3I) Tool for the early detection and management of patients under investigation for monkeypox 2022. Patients are identified as potentially exposed or infected after an initial assessment of risk factors and signs/symptoms. Management of exposed patients includes consideration of quarantine and post-exposure prophylaxis with a smallpox vaccine. For infectious patients, providers must immediately don personal protective equipment and isolate patients. Healthcare workers must report suspected and confirmed cases in humans or animals to public health authorities. This innovative 3I Tool will assist emergency, primary care, and prehospital clinicians in effectively managing persons with suspected or confirmed monkeypox.

Cover page of Monkeypox 2022: A Primer and Identify-Isolate-Inform (3I) Tool for Emergency Medical Services Professionals.

Monkeypox 2022: A Primer and Identify-Isolate-Inform (3I) Tool for Emergency Medical Services Professionals.


Monkeypox 2022 exhibits unprecedented human-to-human transmission and presents with different clinical features than those observed in prior outbreaks. Previously endemic only to West and Central Africa, the monkeypox virus spread rapidly world-wide following confirmation of a case in the United Kingdom on May 7, 2022 of an individual that had traveled to Nigeria. Detection of cases with no travel history confirms on-going community spread. Emergency Medical Services (EMS) professionals will likely encounter patients suspected or confirmed to have monkeypox, previously a rare disease and therefore unfamiliar to most clinicians. Consequently, it is critical for EMS medical directors to immediately implement policies and procedures for EMS teams - including emergency medical dispatchers - to identify potential monkeypox cases. These must include direction on actions EMS professionals should take to protect themselves and others from virus transmission. Monkeypox 2022 may manifest more subtly than it has historically. Presentations include a subclinical prodrome and less dramatic skin lesions - potentially limited to genital or anal body regions - which can be easily confused with dermatologic manifestations of common sexually transmitted infections (STIs). While most readily spread by close contact with infectious skin lesions on a patient, it is also transmissible from fomites, such as bed sheets. Additionally, droplet transmission can occur, and the virus can be spread by aerosolization under certain conditions. The long incubation period could have profound negative consequences on EMS staffing if clinicians are exposed to monkeypox. This report summarizes crucial information needed for EMS professionals to understand and manage the monkeypox 2022 outbreak. It presents an innovative Identify-Isolate-Inform (3I) Tool for use by EMS policymakers, educators, and clinicians on the frontlines who may encounter monkeypox patients. Patients are identified as potentially exposed or infected after an initial assessment of risk factors with associated signs and symptoms. Prehospital workers must immediately don personal protective equipment (PPE) and isolate infectious patients. Also, EMS professionals must report exposures to their agency infection control officer and alert health authorities for non-transported patients. Prehospital professionals play a crucial role in emerging and re-emerging infectious disease mitigation. The monkeypox 2022 3I Tool includes knowledge essential for all clinicians, plus specific information to guide critical actions in the prehospital environment.

Cover page of Escape box and puzzle design as educational methods for engagement and satisfaction of medical student learners in emergency medicine: survey study.

Escape box and puzzle design as educational methods for engagement and satisfaction of medical student learners in emergency medicine: survey study.



Gamification in medical education has gained popularity over the past several years. We describe a virtual escape box in emergency medicine clerkship didactics to teach chest pain and abdominal pain and compare this instructional method to a traditional flipped classroom format.


A virtual escape box was designed at our institution and incorporated into the mandatory two-week emergency medicine clerkship. The game consisted of a PDF with four cases containing puzzles to unlock a final clue. Likert scale surveys were administered to assess participants' perceptions of the escape box format; of clerkship didactics as a whole; and of the clerkship overall. These responses were compared to the prior year's evaluations on flipped classroom didactics and clerkship.


One hundred thirty-four learners participated in the escape box and completed the survey. Eighty-six percent strongly agreed with feeling more engaged with the escape box, 84% strongly agreed with learning something new, 81% strongly agreed with finding the escape box to be satisfying, 78% strongly agreed with being able to apply knowledge gained, and 74% strongly agreed with wanting more escape boxes incorporated into medical education. The escape box showed a higher average score (3.6 ± 0.63) compared to chest pain (3.5 ± 0.67) and abdominal pain (3.2 ± 0.77) flipped classroom sessions (p = 0.0491) for the category of "lecturer explaining content clearly and at the proper level of complexity." For the category of "lecturer provided effective instructional materials," the escape box showed higher scores (3.6 ± 0.63) compared to flipped classroom for chest pain (3.4 ± 0.77) and abdominal pain (3.1 ± 0.80) (p < 0.001).


Escape boxes are adaptable to a virtual format and can teach abstract concepts such as teamwork and communication in addition to traditional lecture content. Ratings of didactics were higher for the escape box compared to the flipped classroom, while ratings of overall clerkship experience were not found to change significantly.

Cover page of Antifragile Behavior Change Through Digital Health Behavior Change Interventions.

Antifragile Behavior Change Through Digital Health Behavior Change Interventions.


Digital health behavior change interventions (DHBCIs) offer users accessible support, yet their promise to improve health behaviors at scale has not been met. One reason for this unmet potential may be a failure to offer users support that is tailored to their personal characteristics and goals. We apply the concept of antifragility to propose how DHBCIs could be better designed to support diverse users' behavior change journeys. We first define antifragility as a feature of an individual's relationship to a particular challenge such that if one is antifragile to a challenge, one is well positioned to benefit from facing that challenge. Second, we introduce antifragile behavior change to describe behavior change processes that leverage person-specific antifragilities to maximize benefits and minimize risk in the behavior change process. While most existing behavior change models focus on improving one's motivation and ability to face challenges, antifragile behavior change complements these models by helping to select challenges that are most likely to produce desired outcomes. Next, we propose three principles by which DHBCIs can help users to develop antifragile behavior change strategies: providing personalized guidance, embracing variance and exploration in choosing behaviors, and prioritizing user agency. Finally, we offer an example of how a DHBCI could be designed to support antifragile behavior change.

Facial Fractures Have Similar Outcomes When Managed by Either Otolaryngology or Plastic Surgery: Encounters From a Single Level I Trauma Center.


Study design

Retrospective cohort.


Traumatic facial fractures (FFs) often require specialty consultation with Plastic Surgery (PS) or Otolaryngology (ENT); however, referral patterns are often non-standardized and institution specific. Therefore, we sought to compare management patterns and outcomes between PS and ENT, hypothesizing no difference in operative rates, complications, or mortality.


We performed a retrospective analysis of patients with FFs at a single Level I trauma center from 2014 to 2017. Patients were compared by consulting service: PS vs. ENT. Chi-square and Mann-Whitney-U tests were performed.


Of the 755 patients with FFs, 378 were consulted by PS and 377 by ENT. There was no difference in demographic data (P > 0.05). Patients managed by ENT received a longer mean course of antibiotics (9.4 vs 7.0 days, P = 0.008) and had a lower rate of open reduction internal fixation (ORIF) (9.8% vs. 15.3%, P = 0.017), compared to PS patients. No difference was observed in overall operative rate (15.1% vs. 19.8%), use of computed tomography (CT) imaging (99% vs. 99%), time to surgery (65 vs. 55 hours, P = 0.198), length of stay (LOS) (4 vs. 4 days), 30-day complication rate (10.6% vs. 7.1%), or mortality (4.5% vs. 2.6%) (all P > 0.05).


Our study demonstrated similar baseline characteristics, operative rates, complications, and mortality between FFs patients who had consultation by ENT and PS. This supports the practice of allowing both ENT and PS to care for trauma FFs patients, as there appears to be similar standardized care and outcomes. Future studies are needed to evaluate the generalizability of our findings.

Cover page of The Natural History of Stingray Injuries.

The Natural History of Stingray Injuries.



Stingray envenomation is a marine injury suffered by ocean goers throughout the world. No prospective studies exist on the various outcomes associated with these injuries.

Study objective

The aim of this study was to perform a prospective, observational study of human stingray injuries to determine the natural history, acute and subacute complications, prevalence of medical evaluation, and categories of medical treatment.


This study prospectively studied a population of subjects who were injured by stingrays at Seal Beach, California (USA) from July 2012 through September 2016 and did not immediately seek emergency department evaluation. Subjects described their initial injury and provided information on their symptoms, medical evaluations, and medical treatment for the injury at one week and one month after the injury. This information was reported as descriptive statistics.


A total of 393 participants were enrolled in the study; 313 (80%) of those completed the one-week follow-up interview and 279 (71%) participants completed both the one-week and one-month follow-up interviews. Overall, 234 (75%) injuries occurred to the foot. One hundred sixty-three (52%) patients had complete resolution of their pain within one week and 261 (94%) had either complete resolution or improvement of pain by one month. Sixty-eight (22%) subjects reported being evaluated by a physician and a total of 49 (17%) subjects reported antibiotic treatment for their wound. None of the subjects required parenteral antibiotics or hospital admission.


The majority of stingray victims recover from stingray injury without requiring antibiotics. A subset of subjects will have on-going wound pain after one month. The need for parenteral antibiotics or hospital admission is rare.

Cover page of Potential Role of Conversational Agents in Encouraging PrEP Uptake.

Potential Role of Conversational Agents in Encouraging PrEP Uptake.


Approximately 1.2 million people are living with HIV, with many of them unaware of their infection. Pre-exposure prophylaxis (PrEP) is available to minimize transmission among those at high risk for infection, including men who have sex with men, people who inject drugs, and female sex workers. Despite its availability, there is low usage of PrEP. To address this problem, various digital tools have been examined in HIV research. Among those, conversational agents are still underused and their capacity warrants examination to reach at-risk populations. In this paper, we discuss the potential of conversational agents in increasing uptake of PrEP by addressing barriers experienced among those at high risk for infection.

Cover page of Dose- and Sex-Dependent Bidirectional Relationship between Intravenous Fentanyl Self-Administration and Gut Microbiota.

Dose- and Sex-Dependent Bidirectional Relationship between Intravenous Fentanyl Self-Administration and Gut Microbiota.


Gut bacteria influence neural circuits in addiction-related behaviors. Given the association between opioid use, gastrointestinal distress, and microbial dysbiosis in humans and mice, we test the hypothesis that interactions between gut bacteria and the brain mediate the rewarding and reinforcing properties of fentanyl. We implant rats with intravenous catheters in preparation for fentanyl intravenous self-administration (IVSA) on an escalating schedule of reinforcement to determine factors that influence fentanyl intake, including sex, dose, and gut microbiota. Our data show the impact of fentanyl IVSA on gut microbiota diversity, as well as the role of gut microbiota on fentanyl IVSA, in Sprague Dawley rats in a sex- and dose-dependent manner (n = 10-16/group). We found that the diversity of gut microbiota within females dose-dependently predicts progressive but not fixed ratio schedules of fentanyl IVSA. Depending on sex and fentanyl dose, alpha diversity (richness and evenness measured with Shannon index) is either increased or decreased following fentanyl IVSA and predicts progressive ratio breakpoint. Our findings collectively suggest a role of gut bacteria in drug-related behavior, including motivation and reinforcement. This work provides feasibility for an intravenous fentanyl self-administration model and uncovers potential factors mediating drug use, which may lead to the development of effective addiction interventions.