Impact of Vaccination and the Omicron Variant on COVID-19-related Chest CT Findings: A Multicenter Study.

Background The SARS-CoV-2 Omicron variant has a higher infection rate than previous variants but results in less severe disease. However, the effects of Omicron and vaccination on chest CT findings are difficult to evaluate. Purpose To investigate the effect of vaccination status and predominant variant on chest CT findings, diagnostic scores, and severity scores in a multicenter sample of consecutive patients referred to emergency departments for proven COVID-19. Materials and Methods This retrospective multicenter study included adults referred to 93 emergency departments with SARS-CoV-2 infection according to a reverse-transcriptase polymerase chain reaction test and known vaccination status between July 2021 and March 2022. Clinical data and structured chest CT reports, including semiquantitative diagnostic and severity scores following the French Society of Radiology-Thoracic Imaging Society guidelines, were extracted from a teleradiology database. Observations were divided into Delta-predominant, transition, and Omicron-predominant periods. Associations between scores and variant and vaccination status were investigated with χ2 tests and ordinal regressions. Multivariable analyses evaluated the influence of Omicron variant and vaccination status on the diagnostic and severity scores. Results Overall, 3876 patients were included (median age, 68 years [quartile 1 to quartile 3 range, 54-80]; 1695 women). Diagnostic and severity scores were associated with the predominant variant (Delta vs Omicron, χ2 = 112.4 and 33.7, respectively; both P < .001) and vaccination status (χ2 = 243.6 and 210.1; both P < .001) and their interaction (χ2 = 4.3 [P = .04] and 28.7 [P < .001], respectively). In multivariable analyses, Omicron variant was associated with lower odds of typical CT findings than was Delta variant (odds ratio [OR], 0.46; P < .001). Two and three vaccine doses were associated with lower odds of demonstrating typical CT findings (OR, 0.32 and 0.20, respectively; both P < .001) and of having high severity score (OR, 0.47 and 0.33, respectively; both P < .001), compared with unvaccinated patients. Conclusion Both the Omicron variant and vaccination were associated with less typical chest CT manifestations of COVID-19 and lesser extent of disease. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Yoon and Goo in this issue.

Lymphocyte-to-C-Reactive Protein (LCR) Ratio Is Not Accurate to Predict Severity and Mortality in Patients with COVID-19 Admitted to the ED.

Health care systems worldwide have been battling the ongoing COVID-19 pandemic. Since the beginning of the COVID-19 pandemic, Lymphocytes and CRP have been reported as markers of interest. We chose to investigate the prognostic value of the LCR ratio as a marker of severity and mortality in COVID-19 infection. Between 1 March and 30 April 2020, we conducted a multicenter, retrospective cohort study of patients with moderate and severe coronavirus disease 19 (COVID-19), all of whom were hospitalized after being admitted to the Emergency Department (ED). We conducted our study in six major hospitals of northeast France, one of the outbreak's epicenters in Europe. A total of 1035 patients with COVID-19 were included in our study. Around three-quarters of them (76.2%) presented a moderate form of the disease, while the remaining quarter (23.8%) presented a severe form requiring admission to the ICU. At ED admission, the median LCR was significantly lower in the group presenting severe disease compared to that with moderate disease (versus 6.24 (3.24-12) versus 12.63 ((6.05-31.67)), p < 0.001). However, LCR was neither associated with disease severity (OR: 0.99, CI 95% (0.99-1)), p = 0.476) nor mortality (OR: 0.99, CI 95% (0.99-1)). In the ED, LCR, although modest, with a threshold of 12.63, was a predictive marker for severe forms of COVID-19.

[White plan and the organisation of emergency response services in France]. / Plan blanc et organisation des secours en France.

The Eemergency plans for outside hospitals (ORSEC) and inside hospitals (white plan) are often linked and must be well structured in order to respond to the tensions created by exceptional health situations. They must be designed, used and updated like toolboxes. How is the chain of care organised? What is the role of the samu (emergency medical assistance service) in the preparation, activation and coordination of the white plan?

[Emergency response plans in France]. / Les plans de secours en France.

Disaster is a risk which health professionals must learn to manage without ever being sure that they will be confronted with it. A health crisis will have potentially significant repercussions within healthcare facilities. Emergency response plans as well as a shared culture enable healthcare workers to face a crisis by being organised.

Effect of the COVID-19 pandemic on acute stroke reperfusion therapy: data from the Lyon Stroke Center Network.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic would have particularly affected acute stroke care. However, its impact is clearly inherent to the local stroke network conditions. We aimed to assess the impact of COVID-19 pandemic on acute stroke care in the Lyon comprehensive stroke center during this period. METHODS: We conducted a prospective data collection of patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis (IVT) and/or mechanical thrombectomy (MT) during the COVID-19 period (from 29/02/2020 to 10/05/2020) and a control period (from 29/02/2019 to 10/05/2019). The volume of reperfusion therapies and pre and intra-hospital delays were compared during both periods. RESULTS: A total of 208 patients were included. The volume of IVT significantly decreased during the COVID-period [55 (54.5%) vs 74 (69.2%); p = 0.03]. The volume of MT remains stable over the two periods [72 (71.3%) vs 65 (60.8%); p = 0.14], but the door-to-groin puncture time increased in patients transferred for MT (237 [187-339] vs 210 [163-260]; p < 0.01). The daily number of Emergency Medical Dispatch calls considerably increased (1502 [1133-2238] vs 1023 [960-1410]; p < 0.01). CONCLUSIONS: Our study showed a decrease in the volume of IVT, whereas the volume of MT remained stable although intra-hospital delays increased for transferred patients during the COVID-19 pandemic. These results contrast in part with the national surveys and suggest that the impact of the pandemic may depend on local stroke care networks.