[en] SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has caused more tan 767 million infections and nearly 7 million deaths and has destabilized even the most advanced healthcare systems. Intensive Care Units (ICU) had to face a new disease, with no known treatment, and a number of patients much higher than their usual capacity. The objectives of this thesis were: i) Analyze the effect of a short course of low-dose corticosteroids on the inflammatory and gas exchange parameters of patients with COVID- 19 on mechanical ventilation; ii) Describe the incidence, microbiology and impact on the prognosis of bacterial coinfection upon admission to the ICU; iii) Describe how the ICUs in Spain adapted to respond during the first year of the pandemic. A retrospective observational study was carried out on adult patients admitted to the ICU of the Complexo Hospitalario Universitario de Ourense between March 2020 and December 2021. In turn, a survey was carried out among the members of the Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias who provided assistance during the first year of the pandemic. The findings show that a short course of corticosteroids improved, at least temporarily, the inflammatory parameters and gas exchange of COVID patients admitted to the ICU. Subsequently, a clinical trial demonstrated the benefit of this treatment. On the other hand, the incidence of bacterial coinfection upon admission to the ICU was high and, in addition, it negatively affects the prognosis of the patients, which is why antibiotic treatment is proposed for all patients upon admission to the ICU followed by early withdrawal if the clinical, analytical and microbiological evolution of the patient in the following 24-48 hours allows us to rule out bacterial coinfection. The survey carried out confirmed that the first waves of the pandemic exceeded the capacity of the country's ICUs. It was possible to remedy the material deficiencies, but not the human resource deficiencies. The ICU staff suffered strong emotional stress and it was necessary to create psychological support teams for workers. The pandemic was a brake on non-care activities, as well as a boost for online training and networking and large research groups.

[gl] O SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) causou mais de 767 millons de infeccions e case 7 millons de mortes e desestabilizou ata os sistemas de saude mais avanzados. As Unidades de Coidados Intensivos (UCI) tiveron que afrontar unha nova enfermidade, sen tratamento conecido, e un numero de pacientes moi superior a sua capacidade habitual. Os obxectivos desta tese foron: i) Analizar o efecto dun curso curto de corticoides en doses baixas sobre os parametros inflamatorios e de intercambio gaseoso dos pacientes con COVID-19 en ventilacion mecanica; ii) Describir a incidencia, microbioloxia e impacto no prognostico da coinfeccion bacteriana ao ingreso na UCI; iii) Describir como se adaptaron as UCI en Espana durante o primeiro ano da pandemia. Realizouse un estudo observacional retrospectivo de pacientes adultos ingresados na UCI do Complexo Hospitalario Universitario de Ourense entre marzo de 2020 e decembro de 2021. A sua vez, realizouse unha enquisa entre os membros da Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias que prestaron asistencia durante o primeiro ano da pandemia. Os resultados mostran que un curso curto de corticoides mellorou, polo menos temporalmente, os parametros inflamatorios e o intercambio de gases dos pacientes con COVID ingresados na UCI. Posteriormente, un ensaio clinico demostrou o beneficio deste tratamento. Por outra banda, a incidencia de coinfeccion bacteriana ao ingreso na UCI foi elevada e, ademais, afecta negativamente ao prognostico dos pacientes, polo que se propon un tratamento antibiotico para todos os pacientes ao ingreso na UCI e a sua retirada precoz se a evolucion clinica, analitica e microbioloxica do paciente nas seguintes 24-48 horas permite descartar a coinfeccion bacteriana. A enquisa realizada confirmou que as primeiras vagas da pandemia superaron a capacidade das UCI do pais. Foi posible subsanar as deficiencias materiais, pero non as de recursos humanos. O persoal da UCI sufriu un forte estres emocional e foi necesario crear equipos de apoio psicoloxico aos traballadores. A pandemia supuxo un freo as actividades non asistenciais, asi como un impulso a formacion a distancia, ao traballo en rede e aos grandes grupos de investigacion.