Oxidation State in Peritoneal Dialysis in Patients with Type 2 Diabetes Mellitus.

End-stage renal disease (ESRD) progression is closely related to oxidative stress (OS). The study objective was to determine the oxidant and antioxidant status in peritoneal dialysis (PD) patients with type 2 diabetes mellitus (DM). An analytical cross-sectional study from the PD program was carried out with 62 patients, 22 with and 40 without DM. Lipoperoxides (LPO) levels in patients with DM, 3.74 ± 1.09 mM/L, and without DM, 3.87 ± 0.84 mM/L were found to increase compared to healthy controls (HC) 3.05 ± 0.58 mM/L (p = 0.006). The levels of the oxidative DNA damage marker (8-OH-dG) were found to be significantly increased in patients with DM, 1.71 ng/mL (0.19-71.92) and without DM, 1.05 ng/mL (0.16-68.80) front to 0.15 ng/mL (0.15-0.1624) of HC (p = 0.001). The antioxidant enzyme superoxide dismutase (SOD) activity was found to be significantly increased in patients with DM, 0.37 ± 0.15 U/mL, and without DM, 0.37 ± 0.17 compared to HC, 0.23 ± 0.05 U/mL (p = 0.038). The activity of the enzyme glutathione peroxidase (GPx) showed a significant increase (p < 0.001) in patients with DM, 3.56 ± 2.18 nmol/min/mL, and without DM, 3.28 ± 1.46 nmol/min/mL, contrary to the activity obtained in HC, 1.55 ± 0.34 nmol/min/mL. In conclusion, we found an imbalance of oxidative status in patients undergoing PD with and without DM through the significant increase in LPO oxidants and the marker of oxidative damage in DNA. The activity of the antioxidant enzymes SOD and GPx were significantly increased in patients with and without DM undergoing PD, possibly in an attempt to compensate for the deregulation of oxidants. Antioxidant enzymes could be promising therapeutic strategies as a complement to the management of chronic kidney diseases.

Papel del ultrasonido pulmonar en la clasificación por fenotipos del SDRA por COVID-19 / Role of lung ultrasound in the classification by phenotypes of ARDS by COVID-19 / Papel da ultrassonografia pulmonar na classificação por fenótipos da SDRA por COVID-19

Resumen: Introducción: La mayoría de los pacientes con COVID-19 mecánicamente ventilados cumplen con los criterios de Berlín para síndrome de distrés respiratorio agudo (SDRA); sin embargo, se ha observado una discrepancia entre el grado de hipoxemia y la distensibilidad pulmonar. Basados en la mecánica respiratoria y hallazgos tomográficos se han propuesto dos fenotipos distintos: L y H, cada fenotipo podría beneficiarse de estrategias de ventilación distintas; sin embargo, realizar tomografías durante la pandemia resulta complicado. Objetivo: Determinar la utilidad del ultrasonido pulmonar para diferenciar los fenotipos del SDRA por COVID-19 mediante la correlación de lung ultrasound score (LUS) y la distensibilidad del sistema respiratorio. Material y métodos: Analizamos de forma prospectiva pacientes con COVID-19 bajo ventilación mecánica invasiva a su ingreso a la unidad de cuidados intensivos (UCI). Resultados: De un total de 90 pacientes, 62% hombres, mediana 60 años, SOFA siete puntos. La incidencia del fenotipo H fue 83.3%. El puntaje de aireación (LUS) tuvo una diferencia significativa entre ambos fenotipos (p = 0.001), con un área bajo la curva de 0.797 (p < 0.001). Con punto de corte para la predicción del fenotipo H: LUS > 18 puntos (sensibilidad 82.6%, especificidad 73.3%). Conclusión: El ultrasonido pulmonar valora de forma confiable el grado de aireación pulmonar y junto con la distensibilidad permite clasificar por fenotipos a los pacientes con SDRA por COVID-19.

Abstract: Introduction: Most mechanically ventilated COVID-19 patients meet the Berlin criteria for acute respiratory distress syndrome (ARDS), however, a discrepancy between the degree of hypoxemia and pulmonary distensibility has been observed. Based on respiratory mechanics and tomographic findings two distinct phenotypes have been proposed: L and H, each phenotype could benefit from distinct ventilation strategies, however, performing tomographic scans during pandemic is complicated. Objective: To determine the usefulness of lung ultrasound to differentiate ARDS phenotypes by COVID-19, by correlating LUS and respiratory system distensibility. Material and methods: We prospectively analyzed patients with COVID-19 under invasive mechanical ventilation on admission to the ICU. Results: Of a total of 90 patients, 62% men, median 60 years, SOFA 7 points. The incidence of phenotype H was 83.3%. LUS had a significant difference between both phenotypes (p = 0.001), with an area under the curve of 0.797 (p < 0.001). With cutoff point for phenotype H prediction: LUS >18 points (sensitivity 82.6%, specificity 73.3%). Conclusion: Lung ultrasound reliably assesses the degree of pulmonary aeration and, together with distensibility, allows the classification of patients with ARDS by COVID-19 phenotypes.

Resumo: Introdução: A maioria dos pacientes com COVID-19 ventilados mecanicamente atende aos critérios de Berlim para SDRA, no entanto, foi observada uma discrepância entre o grau de hipoxemia e a complacência pulmonar. Com base na mecânica respiratória e nos achados tomográficos, dois fenótipos diferentes foram propostos: L e H, cada fenótipo poderia se beneficiar de diferentes estratégias de ventilação, porém, realizar a tomografia durante a pandemia é complicado. Objetivo: Determinar a utilidade da ultrassonografia pulmonar para diferenciar os fenótipos de SDRA por COVID-19, correlacionando LUS e complacência do sistema respiratório. Material e métodos: Analisamos prospectivamente pacientes com COVID-19 sob ventilação mecânica invasiva na admissão à UTI. Resultados: De um total de 90 pacientes, 62% homens, idade média de 60 anos, SOFA 7 pontos. A incidência do fenótipo H foi de 83.3%. O LUS apresentou diferença significativa entre os dois fenótipos (p = 0.001), com área sob a curva de 0.797 (p < 0.001). Com ponto de corte para a predição do fenótipo H: LUS > 18 pontos (sensibilidade 82.6%, especificidade 73.3%). Conclusão: A ultrassonografia pulmonar avalia de forma confiável o grau de aeração pulmonar e, juntamente com a distensibilidade, permite que os pacientes com SDRA por COVID-19 sejam classificados por fenótipos.

Use of Airway Pressure Release Ventilation in Patients With Acute Respiratory Failure Due to COVID-19: Results of a Single-Center Randomized Controlled Trial.

OBJECTIVES: Airway pressure release ventilation is a ventilatory mode characterized by a mandatory inverse inspiratory:expiratory ratio with a very short expiratory phase, aimed to avoid derecruitment and allow spontaneous breathing. Recent basic and clinical evidence suggests that this mode could be associated with improved outcomes in patients with acute respiratory distress syndrome. The aim of this study was to compare the outcomes between airway pressure release ventilation and traditional ventilation targeting low tidal volume, in patients with severe coronavirus disease 2019. DESIGN: Single-center randomized controlled trial. SETTING: ICU of a Mexican referral center dedicated to care of patients with confirmed diagnosis of coronavirus disease 2019. PATIENTS: Ninety adult intubated patients with acute respiratory distress syndrome associated with severe coronavirus disease 2019. INTERVENTIONS: Within 48 hours after intubation, patients were randomized to either receive ventilatory management with airway pressure release ventilation or continue low tidal volume ventilation. MEASUREMENTS AND MAIN RESULTS: Forty-five patients in airway pressure release ventilation group and 45 in the low tidal volume group were included. Ventilator-free days were 3.7 (0-15) and 5.2 (0-19) in the airway pressure release ventilation and low tidal volume groups, respectively (p = 0.28). During the first 7 days, patients in airway pressure release ventilation had a higher Pao2/Fio2 (mean difference, 26 [95%CI, 13-38]; p < 0.001) and static compliance (mean difference, 3.7 mL/cm H2O [95% CI, 0.2-7.2]; p = 0.03), higher mean airway pressure (mean difference, 3.1 cm H2O [95% CI, 2.1-4.1]; p < 0.001), and higher tidal volume (mean difference, 0.76 mL/kg/predicted body weight [95% CI, 0.5-1.0]; p < 0.001). More patients in airway pressure release ventilation had transient severe hypercapnia, defined as an elevation of Pco2 at greater than or equal to 55 along with a pH less than 7.15 (42% vs 15%; p = 0.009); other outcomes were similar. Overall mortality was 69%, with no difference between the groups (78% in airway pressure release ventilation vs 60% in low tidal volume; p = 0.07). CONCLUSIONS: In conclusion, when compared with low tidal volume, airway pressure release ventilation was not associated with more ventilator-free days or improvement in other relevant outcomes in patients with severe coronavirus disease 2019.

Medidas de protección alveolar en pacientes con COVID-19 / Alveolar protection measures in patients with COVID-19 / Medidas de proteção alveolar em pacientes com COVID-19

Resumen: COVID-19, la enfermedad ocasionada por SARS-CoV-2, fue declarada pandemia por la OMS a principios de marzo 2020. En México, hasta noviembre 2020 habían sido confirmados más de 995,000 casos y cerca de 100,000 defunciones, situándose dentro de los 10 países con mayor tasa de infectados a nivel mundial. La gran mayoría de pacientes cursa con síntomas leves que no amerita hospitalización, pero los pacientes con cuadros severos de insuficiencia respiratoria pueden requerir ventilación mecánica invasiva, tratamiento que en México se ha asociado a una mortalidad de hasta 73.7%. La ventilación mecánica es una terapia que puede salvar vidas, pero no está exenta de riesgos y una programación inadecuada también puede ocasionar daño por diversos mecanismos denominados en conjunto VILI (Ventilator-induced lung injury). Más de 50 años de búsqueda han dictado las directrices para el manejo óptimo de la ventilación mecánica, pero esta nueva pandemia ha abierto el panorama a nuevas investigaciones. La ventilación protectora pulmonar: VT de 6-8 mL/kg, presión meseta < 30 cmH2O, ha mejorado los desenlaces clínicos en pacientes con y sin SDRA en los últimos 20 años, aunque el COVID-19 tiene particularidades la evidencia sugiere otorgar la misma estrategia.

Abstract: COVID-19, the disease spectrum caused by the new beta coronavirus SARS-CoV-2 was declared as a pandemic by the WHO in March 2020. Until November 2020 more than 995,000 cases and nearly 100,000 deaths had been confirmed have been confirmed in Mexico, being one of the 10 countries with the highest index of cases. Most patients have a mild disease not requiring hospitalization, but severe cases with respiratory failure may require mechanical ventilation with a high mortality rate up to 73.7% in some series in Mexico. Mechanical ventilation saves lives but, it is not out of risk as it may cause harm through many mechanisms named VILI on the whole (ventilator-induced lung injury). After more than 50 years since its first description, protective mechanical ventilation has become the standard of care in ARDS patients, but this pandemic has opened the gap for new research. Protective mechanical ventilation: low tidal volumes 6-8 mL/kg predicted body weight (PBW) and plateau pressure < 30 cmH2O has improved patients' outcomes in the last 20 years. Even though COVID-19 has certain differences with the «classical¼ ARDS, evidence-based medicine suggests the same strategies should be followed.

Resumo: COVID-19, a doença causada pelo SARS-CoV-2, foi declarada pandemia pela OMS no início de março de 2020. No México, até novembro de 2020 foram confirmados mais de 995,000 casos e quase 100,000 mortes, classificando-se em 10 países com a maior taxa de infectados em todo o mundo. A grande maioria dos pacientes apresenta sintomas leves que não justificam a hospitalização, mas os pacientes com insuficiência respiratória grave podem requerer ventilação mecânica invasiva, um tratamento que no México foi associado a uma taxa de mortalidade de até 73.7%. A ventilação mecânica é uma terapia que salva vidas, mas não é isenta de riscos, e uma programação inadequada também pode causar danos por vários mecanismos chamados coletivamente de VILI (Ventilator-induced lung injury). Mais de 50 anos de pesquisa ditaram as diretrizes para o gerenciamento ideal da ventilação mecânica, mas esta nova pandemia abriu o cenário para novas pesquisas. Ventilação protetora pulmonar: VT de 6-8 mL/kg, pressão de platô < 30 cmH2O, melhorou os desfechos clínicos em pacientes com e sem SDRA nos últimos 20 anos, embora COVID-19 tenha particularidades, as evidências sugerem conceder as mesmas estratégia.