[Poor prognostic factors in patients hospitalized for COVID-19].

BACKGROUND: The clinical spectrum of COVID-19 varies from no or mild symptoms to pneumonia with fatal complications. The aim of the study was to find predictors of mortality and admission in the intensive care unit (ICU) in patients hospitalized for COVID-19. METHODS: Retrospective study of a cohort of patients admitted for COVID-19 between March 2020 and February 2021. Demographic, clinical, radiological and laboratory variables were described at admission. Independent predictors of mortality and ICU admission were identified by means of backward stepwise logistic regression and described in terms of odds ratio (OR) and 95% confidence interval (95%CI). RESULTS: A total of 883 patients were included, 51.8% men with a mean age of 68; 1.8% readmissions. 17.6% of patients died (n=154). The independent predictors of mortality were age (OR=1.071; 95%CI: 1.046-1.095), percentage of oxygen saturation (SatO2) (OR=0.938; 95%CI: 0.903-0.974), diastolic blood pressure (DBP, OR= 0.972; 95%CI: 0.955-0.989), creatinine (OR=1.516; 95%CI: 1.088-2.113), INR (OR=1.199; 95%CI: 1.012-1.419) and sodium (OR=1.082; 95%CI: 1.037-1.128). Eight percent of patients were admitted to ICU; the independent predictors were: male sex (OR=2.079; 95%CI: 1.099-3.935), age (OR=0.960; 95%CI: 0.942-0.979), SatO2 (OR=0.925; 95%CI: 0.889-0.962), creatinine (OR=1.551; 95%CI: 1.118-2.152) and C-reactive protein (CRP, OR=1.003; 95%CI: 1.000-1.007). CONCLUSION: The identification of independent predictors of mortality (age, SatO2, DBP, creatinine, INR, sodium) and ICU admission (sex, age, SatO2, creatinine, and CRP) allowed for the stratification of patients to adapt clinical care protocols to these findings, thereby improving medical decisions.

Factores de mal pronóstico en pacientes hospitalizados por COVID-19 / Poor prognostic factors in patients hospitalized for COVID-19

Fundamento: El espectro clínico de la COVID-19 varía entre sintomatología leve o ausente hasta neumonías con complicaciones mortales. El objetivo del estudio fue determinar los factores predictivos de mortalidad e ingreso en cuidados intensivos (UCI) en pacientes hospitalizados por COVID-19. Metodología: Estudio retrospectivo de una cohorte de pacientes ingresados por COVID-19 entre marzo de 2020 y febrero de 2021. Se describieron las variables demográficas, clínicas, radiológicas y analíticas al ingreso. Los predictores independientes de mortalidad e ingreso en UCI se identificaron mediante regresión logística por pasos hacia atrás y se describieron como odds ratio (OR) e intervalo de confianza al 95% (IC95%). Resultados: Se incluyeron 883 pacientes, 51,8% varones y edad media 68 años; el 1,8% reingresó. Fallecieron 154 pacientes (17,6%); los predictores independientes de mortalidad fueron: edad (OR=1,071; IC95%: 1,046-1,095), porcentaje de saturación de oxígeno (SatO2) (OR=0,938; IC95%: 0,903-0,974), tensión arterial diastólica (PAD, OR=0,972; IC95%: 0,955-0,989), creatinina (OR=1,516; IC95%: 1,088-2,113), INR (OR=1,199; IC95%: 1,012-1,419) y sodio (OR=1,082; IC95%: 1,037-1,128). El 8% de los pacientes ingresaron en UCI; las variables predictoras independientes fueron: sexo masculino (OR=2,079; IC95%: 1,099-3,935), edad (OR=0,960; IC95%: 0,942-0,979), SatO2 (OR=0,925; IC95%: 0,889-0,962), creatinina (OR=1,551; IC95%: 1,118-2,152) y proteína C reactiva (PCR, OR=1,003; IC95%: 1,000-1,007). Conclusiones: La identificación de predictores independientes de mortalidad (edad, SatO2, PAD, creatinina, INR, sodio) y de ingreso en UCI (sexo, edad, SatO2, creatinina y PCR) permite estratificar a los pacientes y adaptar los protocolos de atención clínica a estos hallazgos, mejorando las decisiones médicas.(AU)

Background: The clinical spectrum of COVID-19 varies from no or mild symptoms to pneumonia with fatal complications. The aim of the study was to find predictors of mortality and admis-sion in the intensive care unit (ICU) in patients hospitalized for COVID-19. Methods: Retrospective study of a cohort of patients admitted for COVID-19 between March 2020 and February 2021. Demographic, clinical, radiological and laboratory variables were described at admission. Independent predictors of mortality and ICU admission were identified by means of backward stepwise logistic regression and described in terms of odds ratio (OR) and 95% confidence interval (95%CI). Results: A total of 883 patients were included, 51.8% men with a mean age of 68; 1.8% readmissions. 17.6% of patients died (n=154). The independent predictors of mortality were age (OR=1.071; 95%CI: 1.046-1.095), percentage of oxygen saturation (SatO2) (OR=0.938; 95%CI: 0.903-0.974), diastolic blood pressure (DBP, OR= 0.972; 95%CI: 0.955-0.989), creatinine (OR=1.516; 95%CI: 1.088-2.113), INR (OR=1.199; 95%CI: 1.012-1.419) and sodium (OR=1.082; 95%CI: 1.037-1.128). Eight percent of patients were admitted to ICU; the independent predictors were: male sex (OR=2.079; 95%CI: 1.099-3.935), age (OR=0.960; 95%CI: 0.942-0.979), SatO2 (OR=0.925; 95%CI: 0.889-0.962), creatinine (OR=1.551; 95%CI: 1.118-2.152) and C-reactiveprotein (CRP, OR=1.003; 95%CI: 1.000-1.007). Conclusion: The identification of independent predictors of mortality (age, SatO2, DBP, creatinine, INR, sodium) and ICU admission (sex, age, SatO2, creatinine, and CRP) allowed for the stratification of patients to adapt clinical care protocols to these findings, thereby improving medical decisions.(AU)

Reduction and oxidation kinetics of NiWO4 as an oxygen carrier for hydrogen storage by a chemical looping process.

NiWO4 with a volumetric storage density (VSD) of 496 g L-1 was studied to evaluate its H2 storage potential as an oxygen carrier under a chemical looping (CL) process scheme. The material was synthesized by precipitation and calcined at 950 °C for 5 hours in air. Characterization consisted in XRD, BET surface area, SEM and EDS analysis. NiWO4 hydrogen storage reduction-oxidation evaluation was performed by TGA using 5% v H2/Ar and 2.2% v H2O/Ar at 800 °C. Global kinetics for the reduction step was studied from 730 to 870 °C using 2 to 5% v of H2/Ar. While oxidation kinetics was examined from 730 to 870 °C using 0.8 to 2.2% v H2O/Ar. A hydrogen storage multicycle stability test was performed by exposing NiWO4 to 17 consecutive redox cycles. XRD results of the synthesized material indicate NiWO4 as the only crystalline phase. Fully reduced material found only W and Ni species, while reoxidation led back to NiWO4. BET surface area of synthesized material was 4.25 m2 g-1. SEM results showed fresh NiWO4 composed of non-porous large particles (1-5 µm). After reduction, the material shown a porous coral-like morphology with particles between 50 to 100 nm. EDS analysis results confirmed the compositions of the reduced (Ni + W) and fully oxidized NiWO4 species, respectively. Oxygen carrier reaction conversions for both reduction and regeneration steps were 100%. Global kinetic studies indicate a first order reaction for the two reduction steps and during oxidation, with activation energies of 22.1, 48.4 and 53.4 kJ mol-1 for the two reduction and oxidation steps, respectively. NiWO4 multicycle stability test shown no loss of VSD and fast reduction and oxidation kinetics under the studied conditions after seventeen consecutive redox cycles, which confirms the potential of this material with respect to current oxygen carriers reported in the literature for hydrogen storage applications.