Prehospital hypoxemia, measured by pulse oximetry, predicts hospital outcomes during the New York City COVID-19 pandemic.

OBJECTIVE: To determine if oxygen saturation (out-of-hospital SpO2), measured by New York City (NYC) 9-1-1 Emergency Medical Services (EMS), was an independent predictor of coronavirus disease 2019 (COVID-19) in-hospital mortality and length of stay, after controlling for the competing risk of death. If so, out-of-hospital SpO2 could be useful for initial triage. METHODS: A population-based longitudinal study of adult patients transported by EMS to emergency departments (ED) between March 5 and April 30, 2020 (the NYC COVID-19 peak period). Inclusion required EMS prehospital SpO2 measurement while breathing room air, transport to emergency department, and a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction test. Multivariable logistic regression modeled mortality as a function of prehospital SpO2, controlling for covariates (age, sex, race/ethnicity, and comorbidities). A competing risk model also was performed to estimate the absolute risks of out-of-hospital SpO2 on the cumulative incidence of being discharged from the hospital alive. RESULTS: In 1673 patients, out-of-hospital SpO2 and age were independent predictors of in-hospital mortality and length of stay, after controlling for the competing risk of death. Among patients ≥66 years old, the probability of death was 26% with an out-of-hospital SpO2 >90% versus 54% with an out-of-hospital SpO2 ≤90%. Among patients <66 years old, the probability of death was 11.5% with an out-of-hospital SpO2 >90% versus 31% with an out-of-hospital SpO2 ≤ 90%. An out-of-hospital SpO2 level ≤90% was associated with over 50% decreased likelihood of being discharged alive, regardless of age. CONCLUSIONS: Out-of-hospital SpO2 and age predicted in-hospital mortality and length of stay: An out-of-hospital SpO2 ≤90% strongly supports a triage decision for immediate hospital admission. For out-of-hospital SpO2 >90%, the decision to admit depends on multiple factors, including age, resource availability (outpatient vs inpatient), and the potential impact of new treatments.

Characteristics Associated With Out-of-Hospital Cardiac Arrests and Resuscitations During the Novel Coronavirus Disease 2019 Pandemic in New York City.

Importance: Risk factors for out-of-hospital death due to novel coronavirus disease 2019 (COVID-19) are poorly defined. From March 1 to April 25, 2020, New York City, New York (NYC), reported 17 118 COVID-19-related deaths. On April 6, 2020, out-of-hospital cardiac arrests peaked at 305 cases, nearly a 10-fold increase from the prior year. Objective: To describe the characteristics (race/ethnicity, comorbidities, and emergency medical services [EMS] response) associated with outpatient cardiac arrests and death during the COVID-19 pandemic in NYC. Design, Setting, and Participants: This population-based, cross-sectional study compared patients with out-of-hospital cardiac arrest receiving resuscitation by the NYC 911 EMS system from March 1 to April 25, 2020, compared with March 1 to April 25, 2019. The NYC 911 EMS system serves more than 8.4 million people. Exposures: The COVID-19 pandemic. Main Outcomes and Measures: Characteristics associated with out-of-hospital arrests and the outcomes of out-of-hospital cardiac arrests. Results: A total of 5325 patients were included in the main analysis (2935 men [56.2%]; mean [SD] age, 71 [18] years), 3989 in the COVID-19 period and 1336 in the comparison period. The incidence of nontraumatic out-of-hospital cardiac arrests in those who underwent EMS resuscitation in 2020 was 3 times the incidence in 2019 (47.5/100 000 vs 15.9/100 000). Patients with out-of-hospital cardiac arrest during 2020 were older (mean [SD] age, 72 [18] vs 68 [19] years), less likely to be white (611 of 2992 [20.4%] vs 382 of 1161 [32.9%]), and more likely to have hypertension (2134 of 3989 [53.5%] vs 611 of 1336 [45.7%]), diabetes (1424 of 3989 [35.7%] vs 348 of 1336 [26.0%]), and physical limitations (2259 of 3989 [56.6%] vs 634 of 1336 [47.5%]). Compared with 2019, the odds of asystole increased in the COVID-19 period (odds ratio [OR], 3.50; 95% CI, 2.53-4.84; P < .001), as did the odds of pulseless electrical activity (OR, 1.99; 95% CI, 1.31-3.02; P = .001). Compared with 2019, the COVID-19 period had substantial reductions in return of spontaneous circulation (ROSC) (727 of 3989 patients [18.2%] vs 463 of 1336 patients [34.7%], P < .001) and sustained ROSC (423 of 3989 patients [10.6%] vs 337 of 1336 patients [25.2%], P < .001), with fatality rates exceeding 90%. These associations remained statistically significant after adjustment for potential confounders (OR for ROSC, 0.59 [95% CI, 0.50-0.70; P < .001]; OR for sustained ROSC, 0.53 [95% CI, 0.43-0.64; P < .001]). Conclusions and Relevance: In this population-based, cross-sectional study, out-of-hospital cardiac arrests and deaths during the COVID-19 pandemic significantly increased compared with the same period the previous year and were associated with older age, nonwhite race/ethnicity, hypertension, diabetes, physical limitations, and nonshockable presenting rhythms. Identifying patients with the greatest risk for out-of-hospital cardiac arrest and death during the COVID-19 pandemic should allow for early, targeted interventions in the outpatient setting that could lead to reductions in out-of-hospital deaths.

System impacts of the COVID-19 pandemic on New York City's emergency medical services.

OBJECTIVES: To describe the impact of the COVID-19 pandemic on New York City's (NYC) 9-1-1 emergency medical services (EMS) system and assess the efficacy of pandemic planning to meet increased demands. METHODS: Longitudinal analysis of NYC 9-1-1 EMS system call volumes, call-types, and response times during the COVID-19 peak-period (March 16-April 15, 2020) and post-surge period (April 16-May 31, 2020) compared with the same 2019 periods. RESULTS: EMS system received 30,469 more calls from March 16-April 15, 2020 compared with March 16-April 15, 2019 (161,815 vs 127,962; P < 0.001). On March 30, 2020, call volume increased 60% compared with the same 2019 date. The majority were for respiratory (relative risk [RR] = 2.50; 95% confidence interval [CI] = 2.44-2.56) and cardiovascular (RR = 1.85; 95% CI = 1.82-1.89) call-types. The proportion of high-acuity, life-threatening call-types increased compared with 2019 (42.3% vs 36.4%). Planned interventions to prioritize high-acuity calls resulted in the average response time increasing by 3 minutes compared with an 11-minute increase for low low-acuity calls. Post-surge, EMS system received fewer calls compared with 2019 (154,310 vs 193,786; P < 0.001). CONCLUSIONS: COVID-19-associated NYC 9-1-1 EMS volume surge was primarily due to respiratory and cardiovascular call-types. As the pandemic stabilized, call volume declined to below pre-pandemic levels. Our results highlight the importance of EMS system-wide pandemic crisis planning.

Hypothermic maintenance of hepatocyte spheroids.

Primary hepatocytes form spheroids under some culture conditions. These spheroids exhibit many tissue-like ultrastructures and retain many liver-specific functions over a long period of time. They are attractive for many applications employing liver cells. The ability to maintain their viability and functions at a reduced temperature to allow for transportation to the site of their application will facilitate their use. Furthermore, with their structural and functional similarity, they could possibly be used as a model system for studying various liver ischemias. The effect of hypothermic treatment was assessed by oxygen consumption rate, ATP, H2O2, and caspase 8 content, as well as albumin and urea synthesis, during and posttreatment. No single outcome variable gives a superlative quantification of hypothermic damage. Taken together, the hypothermic treatment can be seen as increasingly damaging as the temperature decreases from 21 degrees C to 15 degrees C and 4 degrees C. The addition of the chemical protectants glutathione, N-acetyl-L-cystein (NAC), and tauroursodeoxycholic acid (TUDCA) decreased the damaging effect of hypothermic treatment. This protection effect was even more profound when spheroids were preincubated with the protectant for 24 h, and was most prominent at 4 degrees C. The viability of the hypothermically treated hepatocyte spheroids was confirmed by laser scanning confocal microscopy. The method reported provides a means of maintaining spheroids' viability and may allow for their distribution to application sites at a distance.

Sustaining a bioartificial liver under hypothermic conditions.

Bioartificial liver (BAL) devices employing xenogeneic hepatocytes are being developed as a temporary support of liver failure. For clinical applications, transporting such a device from the manufacturing site to the hospital is necessary. We investigated the effect of hypothermic treatment on the performance of the collagen-entrapment BAL device developed at the University of Minnesota. A number of chemical protectants were examined for their effectiveness in minimizing damage to hepatocytes. Preincubation with protectant (tauroursodeoxycholic acid, TUDCA) before hypothermic treatment improved posttreatment BAL performance. Oxygen consumption and albumin and urea synthesis all resumed at levels comparable to pretreatment levels. The method described will facilitate the application of BAL in the treatment of liver failure.