Predictors of Bradycardia with Dexmedetomidine Use

INTRODUCTION: Although dexmedetomidine is a widely used sedative in the ICU, risk factors for bradycardia associated with dexmedetomidine use are not well characterized. Identifying factors that place a patient at increased risk for bradycardia with dexmedetomidine use may help guide interventions or limit complications associated with the medication's negative chronotropic effects. The aim of this analysis is to determine risk factors for development of bradycardia with dexmedetomidine use. METHOD(S): This single center, retrospective nested casecontrol included adult patients in cardiac and non-cardiac intensive care units with an intravenous dexmedetomidine duration of at least 1 hour. A univariate analysis was used to compare patients with and without bradycardia with dexmedetomidine use, and a predictive model was used to evaluate factors associated with bradycardia. Step-down backward variable selection was used based on Akaike's Information Criterion (AIC) and Bayesian Information Criteria (BIC) to identify the final model. The discriminatory power and absolute predictive ability of the final model was evaluated by the concordance index (c-index), which was internal validated by bootstrapping. Multiple imputation was performed before model selection to fill in missing values in pulse at initiation and Child Pugh Score before modeling. RESULT(S): Of the 1,838 patients receiving dexmedetomidine, 110 patients (6.0%) developed bradycardia within 72 hours of initiation. In patients that experienced bradycardia, 31 (28.1%) required an intervention. The initial full predictive model for bradycardia included age, sex, BMI, COVID19 positive test, hypothermia, pulse at initiation, ICU location (Cardiac vs non-cardiac), Child Pugh Score, use of fentanyl and propofol. Step-down backward variable selection identified 4 predictors in the final model, including COVID positive test, hypothermia, pulse at initiation, and ICU location. The final model achieved a good performance in discriminatory capability (c-index: 0.758, 95%CI 0.713-0.806) using the smallest number of predictors. CONCLUSION(S): Patients with COVID-19, hypothermia, non-cardiac ICU locations and lower pulse at initiation are at increased odds of developing bradycardia. Recognition of risk may be used to guide monitoring or alternative sedation strategies.

Influence of COVID-19 confinement on students' performance in higher education.

This study analyzes the effects of COVID-19 confinement on the autonomous learning performance of students in higher education. Using a field experiment with 458 students from three different subjects at Universidad Autónoma de Madrid (Spain), we study the differences in assessments by dividing students into two groups. The first group (control) corresponds to academic years 2017/2018 and 2018/2019. The second group (experimental) corresponds to students from 2019/2020, which is the group of students that had their face-to-face activities interrupted because of the confinement. The results show that there is a significant positive effect of the COVID-19 confinement on students' performance. This effect is also significant in activities that did not change their format when performed after the confinement. We find that this effect is significant both in subjects that increased the number of assessment activities and subjects that did not change the student workload. Additionally, an analysis of students' learning strategies before confinement shows that students did not study on a continuous basis. Based on these results, we conclude that COVID-19 confinement changed students' learning strategies to a more continuous habit, improving their efficiency. For these reasons, better scores in students' assessment are expected due to COVID-19 confinement that can be explained by an improvement in their learning performance.

Antivirals for COVID-19

Drugs targeting RNA respiratory viruses has resulted in few effective therapies, highlighting challenges for antivirals to treat COVID-19. Several antivirals are being investigated for symptomatic COVID-19 but no definitive data support their clinical use. Remdesivir, with good in vitro activity against SARS-CoV2, appeared to result in favorable outcomes for hospitalized patients in a compassionate use series with shortened time to recovery and a modest decrease in mortality. Currently, remdesivir is available in phase III clinical trials, the compassionate use program, and eventually through the emergency use authorization. A randomized controlled trial of lopinavir/ritonavir demonstrated no apparent clinical or virologic benefit and drug-drug interactions and side effects further limit its utility. Antivirals to treat influenza (oseltamivir) have limited activity against SARS-CoV-2, but favipiravir and umifenovir, influenza antivirals available internationally, have distinct viral targets and require further investigation. Antivirals with evidence of clinical activity must be studied as treatment and prophylaxis for those at high risk for severe COVID-19.