The Correlation between COVID-19 Hospitalizations and Emergency Medical Services Responses for Time-Sensitive Emergencies during the COVID-19 Pandemic.

OBJECTIVE: COVID-19 has had significant secondary effects on health care systems, including effects on emergency medical services (EMS) responses for time-sensitive emergencies. We evaluated the correlation between COVID-19 hospitalizations and EMS responses for time-sensitive emergencies in a large EMS system. METHODS: This was a retrospective study using data from the Los Angeles County EMS Agency. We abstracted data on EMS encounters for stroke, ST-elevation myocardial infarction (STEMI), out-of-hospital cardiac arrest (OHCA), and trauma from April 5, 2020 to March 6, 2021 and for the same time period in the preceding year. We also abstracted daily hospital admissions and censuses (total and intensive care unit [ICU]) for COVID-19 patients. We designated November 29, 2020 to February 27, 2021 as the period of surge. We calculated Spearman's correlations between the weekly averages of daily hospital admissions and census and EMS responses overall and for stroke, STEMI, OHCA, and trauma. RESULTS: During the study period, there were 70,616 patients admitted for confirmed COVID-19, including 12,467 (17.7%) patients admitted to the ICU. EMS responded to 899,794 calls, including 9,944 (1.1%) responses for stroke, 3,325 (0.4%) for STEMI, 11,207 (1.2%) for OHCA, and 114,846 (12.8%) for trauma. There was a significant correlation between total hospital COVID-19 positive patient admissions and EMS responses for all time-sensitive emergencies, including a positive correlation with stroke (0.41), STEMI (0.37), OHCA (0.78), and overall EMS responses (0.37); and a negative correlation with EMS responses for trauma (-0.48). ICU COVID-19 positive patient admissions also correlated with increases in EMS responses for stroke (0.39), STEMI (0.39), and OHCA (0.81); and decreased for trauma (-0.53). Similar though slightly weaker correlations were found when evaluating inpatient census. During the period of surge, the correlation with overall EMS responses increased substantially (0.88) and was very strong with OHCA (0.95). CONCLUSION: We found significant correlation between COVID-19 hospitalizations and the frequency of EMS responses for time-sensitive emergencies in this regional EMS system. EMS systems should consider the potential effects of this and future pandemics on EMS responses and prepare to meet non-pandemic resource needs during periods of surge, particularly for time-sensitive conditions.

Increased Access to and Use of Endovascular Therapy Following Implementation of a 2-Tiered Regional Stroke System.

Background and Purpose- We quantified population access to endovascular-capable centers, timing, and rates of thrombectomy in Los Angeles County before and after implementing 2-tiered routing in a regional stroke system of care. Methods- In 2018, the Los Angeles County Emergency Medical Services Agency implemented transport of patients with suspected large vessel occlusions identified by Los Angeles Motor Scale ≥4 directly to designated endovascular-capable centers. We calculated population access to a designated endovascular-capable center within 30 minutes comparing 2016, before 2-tiered system planning began, to 2018 after implementation. We analyzed data from stroke centers in the region from 1 year before and after implementation to delineate changes in rates and speed of administration of tPA (tissue-type plasminogen activator) and thrombectomy and frequency of interfacility transfer. Results- With implementation of the 2-tier system, certified endovascular-capable hospitals increased from 4 to 19 centers, and within 30-minute access to endovascular care for the public in Los Angeles County, from 40% in 2016 to 93% in 2018. Comparing Emergency Medical Services-transported stroke patients in the first post-implementation year (N=3303) with those transported in the last pre-implementation year (N=3008), age, sex, and presenting deficit severity were similar. The frequency of thrombolytic therapy increased from 23.8% to 26.9% (odds ratio, 1.2 [95% CI, 1.05-1.3]; P=0.006), and median first medical contact by paramedic-to-needle time decreased by 3 minutes ([95% CI, 0-5] P=0.03). The frequency of thrombectomy increased from 6.8% to 15.1% (odds ratio, 2.4 [95% CI, 2.0-2.9]; P<0.0001), although first medical contact-to-puncture time did not change significantly, median decrease of 8 minutes ([95% CI, -4 to 20] P=0.2). The frequency of interfacility transfers declined from 3.2% to 1.0% (odds ratio, 0.3 [95% CI, 0.2-0.5]; P<0.0001). Conclusions- After implementation of 2-tiered stroke routing in the most populous US county, thrombectomy access increased to 93% of the population, and the frequency of thrombectomy more than doubled, whereas interfacility transfers declined.

Emergency Medical Services Responses to Out-of-Hospital Cardiac Arrest and Suspected ST-Segment-Elevation Myocardial Infarction During the COVID-19 Pandemic in Los Angeles County.

Background Public health emergencies may significantly impact emergency medical services responses to cardiovascular emergencies. We compared emergency medical services responses to out-of-hospital cardiac arrest (OHCA) and ST-segment‒elevation myocardial infarction (STEMI) during the 2020 COVID-19 pandemic to 2018 to 2019 and evaluated the impact of California's March 19, 2020 stay-at-home order. Methods and Results We conducted a population-based cross-sectional study using Los Angeles County emergency medical services registry data for adult patients with paramedic provider impression (PI) of OHCA or STEMI from February through May in 2018 to 2020. After March 19, 2020, weekly counts for PI-OHCA were higher (173 versus 135; incidence rate ratios, 1.28; 95% CI, 1.19‒1.37; P<0.001) while PI-STEMI were lower (57 versus 65; incidence rate ratios, 0.87; 95% CI, 0.78‒0.97; P=0.02) compared with 2018 and 2019. After adjusting for seasonal variation in PI-OHCA and decreased PI-STEMI, the increase in PI-OHCA observed after March 19, 2020 remained significant (P=0.02). The proportion of PI-OHCA who received defibrillation (16% versus 23%; risk difference [RD], -6.91%; 95% CI, -9.55% to -4.26%; P<0.001) and had return of spontaneous circulation (17% versus 29%; RD, -11.98%; 95% CI, -14.76% to -9.18%; P<0.001) were lower after March 19 in 2020 compared with 2018 and 2019. There was also a significant increase in dead on arrival emergency medical services responses in 2020 compared with 2018 and 2019, starting around the time of the stay-at-home order (P<0.001). Conclusions Paramedics in Los Angeles County, CA responded to increased PI-OHCA and decreased PI-STEMI following the stay-at-home order. The increased PI-OHCA was not fully explained by the reduction in PI-STEMI. Field defibrillation and return of spontaneous circulation were lower. It is critical that public health messaging stress that emergency care should not be delayed.