Elimination of Emergency Department Ambulance Divert during the COVID-19 Pandemic Was Not Associated with an Increase in the Average Number of Ambulance Arrivals per Day.

INTRODUCTION: During the COVID-19 pandemic, ambulance divert in our EMS system reached critical levels. We hypothesized that eliminating ambulance divert would not be associated with an increase in the average number of daily ambulance arrivals. Our study objective was to quantify the EMS and emergency department (ED) effects of eliminating ambulance divert during the COVID-19 pandemic. METHODS: Regional hospital divert data were obtained for the 10-county Twin Cities metro from MNTrac, a state-supported online system designed to allow hospitals to indicate their divert status to EMS. ED metrics are reported for a single Level I trauma center and were obtained by a deidentified data pull from our electronic medical record covering the 12 months prior to the elimination of divert (2021) and the 12 months after divert elimination (2022). The decision to eliminate divert occurred in November 2021, based on data available through October, with an implementation date of January 2022. The primary study outcome was to quantify the effect of the elimination of divert on the number of ambulances arriving per day at the study hospital. RESULTS: Regional utilization of ambulance divert increased steadily by 859% from January to October 2021 when 355 individual divert events occurred, totaling 809 h (34 days). There was no significant difference in the number of ambulances that arrived to the study hospital in 2021 (30,774) vs 2022 (30,421) p = 0.15. As compared to 2021, in 2022 there was no significant increase in mean ambulance arrivals per day (84/day vs 83/day, p = 0.08), time to room Emergency Severity Index level 2 (ESI) patients (28 min vs 28 min, p = 0.90), or time to obtain emergent head CT in acute "code stroke" patients (12 min vs 12 min, p = 0.15). Ambulance turnaround interval in the ED did not appreciably increase (16 min vs 17 min, p = 0.15). CONCLUSION: Elimination of ambulance divert was not associated with increases in the number of mean daily ambulance arrivals or EMS turnaround intervals, delays in ESI 2 patients being placed in beds, or prolonged time to head CT in stroke code patients.

Combined use of conventional and second-derivative data in the SIMPLISMA self-modeling mixture analysis approach.

Simple-to-use interactive self-modeling mixture analysis (SIMPLISMA) is a successful pure variable approach to resolve spectral mixture data. A pure variable (e.g., wavenumber, frequency number, etc.) is defined as a variable that has significant contributions from only one of the pure components in the mixture data set. For spectral data with highly overlapping pure components or significant baselines, the pure variable approach has limitations; however, in this case, second-derivative spectra can be used. In some spectroscopies, very wide peaks of components of interest are overlapping with narrow peaks of interest. In these cases, the use of conventional data in SIMPLISMA will not result in proper pure variables. The use of second-derivative data will not be successful, since the wide peaks are lost. This paper describes a new SIMPLISMA approach in which both the conventional spectra (for pure variables of wide peaks) and second-derivative spectra (for pure variables of narrow peaks, overlapping with the wide peaks) are used. This new approach is able to properly resolve spectra with wide and narrow peaks and minimizes baseline problems by resolving them as separate components. Examples will be given of NMR spectra of surfactants and Raman imaging data of dust particle samples taken from a lead and zinc factory's ore stocks that were stored outdoors.