Risk models for predicting in-hospital mortality from COVID-19 pneumonia in the elderly. / Modelos de riesgo para la predicción de mortalidad hospitalaria en ancianos con neumonía por COVID-19.

OBJECTIVES: To compare the prognostic value of 3 severity scales: the Pneumonia Severity Index (PSI), the CURB-65 pneumonia severity score, and the Severity Community-Acquired Pneumonia (SCAP) score. To build a new predictive model for in-hospital mortality in patients over the age of 75 years admitted with pneumonia due to the coronavirus disease 2019 (COVID-19). MATERIAL AND METHODS: Retrospective study of patients older than 75 years admitted from the emergency department for COVID-19 pneumonia between March 12 and April 27, 2020. We recorded demographic (age, sex, living in a care facility or not), clinical (symptoms, comorbidities, Charlson Comorbidity Index [CCI]), and analytical (serum biochemistry, blood gases, blood count, and coagulation factors) variables. A risk model was constructed, and the ability of the 3 scales to predict all-cause in-hospital mortality was compared. RESULTS: We included 186 patients with a median age of 85 years (interquartile range, 80-89 years); 44.1% were men. Mortality was 47.3%. The areas under the receiver operating characteristic curves (AUCs) were as follows for each tool: PSI, 0.74 (95% CI, 0.64-0.82); CURB-65 score, 0.71 (95% CI, 0.62-0.79); and SCAP score, 0.72 (95% CI, 0.63-0.81). Risk factors included in the model were the presence or absence of symptoms (cough, dyspnea), the CCI, and analytical findings (aspartate aminotransferase, potassium, urea, and lactate dehydrogenase. The AUC for the model was 0.81 (95% CI, 0.73-0.88). CONCLUSION: This study shows that the predictive power of the PSI for mortality is moderate and perceptibly higher than the CURB-65 and SCAP scores. We propose a new predictive model for mortality that offers significantly better performance than any of the 3 scales compared. However, our model must undergo external validation.

OBJETIVO: Los objetivos son comparar la utilidad pronóstica de tres escalas de gravedad (Pneumonia Severity Index: PSI; CURB-65 scale; Severity Community Acquired Pneumonia Score: SCAP) y diseñar un nuevo modelo predictivo de mortalidad hospitalaria en pacientes mayores de 75 años ingresados por neumonía por COVID-19. METODO: Estudio retrospectivo de pacientes mayores de 75 años ingresados por neumonía por COVID-19 desde el servicio de urgencias entre el 12 de marzo y el 27 de abril de 2020. Se recogieron variables demográficas (edad, sexo, institucionalización), clínicas (síntomas, comorbilidades, índice de Charlson) y analíticas (bioquímica en suero, gasometría, hematimetría, hemostasia). Se derivó un modelo de riesgo y se compararon las escalas de gravedad PSI, CURB-65 y SCAP para predecir la mortalidad intrahospitalaria por cualquier causa. RESULTADOS: Se incluyeron 186 pacientes, con una mediana de edad de 85 años (RIC 80-89), un 44,1% varones. La mortalidad fue del 47,3%. Las escalas PSI, CURB-65 y SCAP tuvieron un área bajo la curva (ABC) de 0,74 (IC 95% 0,64-0,82), 0,71 (IC 95% 0,62-0,79) y 0,72 (IC 95% 0,63-0,81), respectivamente. El modelo predictivo compuesto por la ausencia o presencia de síntomas (tos y disnea), comorbilidad (índice de Charlson) y datos analíticos (aspartato- aminotransferasa, potasio, urea y lactato-deshidrogenasa) tuvo un ABC de 0,81 (IC 95% 0,73-0,88). CONCLUSIONES: Este estudio muestra que la escala PSI tiene una capacidad predictiva de mortalidad moderada, notablemente mejor que las escalas CURB-65 y SCAP. Se propone un nuevo modelo predictivo de mortalidad que mejora significativamente el rendimiento de estas escalas, siendo necesario verificar su validez externa.

[Variability of pulse signal frequency obtained using nocturnal pulse oximetry in patients with sleep apnoea/hypoapnoea syndrome]. / Variabilidad de la señal de frecuencia de pulso obtenida mediante pulsioximetría nocturna en pacientes con síndrome de apnea hipopnea del sueño.

INTRODUCTION: The measurement of central tendency (MCT) is a non-linear analysis technique which applied to second order differences diagrams enables the degree of variability to be quantified in a data series. In the present study an attempt is made to quantify and characterise the changes in heart rate obtained by pulse oximetry in patients with a clinical suspicion of sleep apnoea/hypoapnoea syndrome (SAHS) using the MCT and to evaluate its diagnostic use. PATIENTS AND METHODS: A total of 187 patients were included in the study, on whom a nocturnal polysomnographic and pulse oximetry study was performed. To evaluate the variability of the heart rate the MCT applied to graphs of second order differences obtained from the heart rate record. RESULT: Patients with SAHS had a higher heart rate variability than patients without SAHS (0.449 vs. 0.666, P<0.001. In the multivariate analysis, the heart rate, the minimum saturation and the desaturation index of 4% were independently associated with the heart rate variability. As a diagnostic method, the MCT of the heart rate gives a sensitivity of 69.3%, a specificity of 77.6% and a diagnostic precision of 72.7% CONCLUSIONS: Patients with SAHS have a greater variability in heart rate during the night, evaluated by applying the MCT of the heart rate to diagrams of second order differences. As a screening method, the MCT applied to the heart rate has a moderate sensitivity and specificity.