Aging-related predictive factors for oxygenation improvement and mortality in COVID-19 and acute respiratory distress syndrome (ARDS) patients exposed to prone position: A multicenter cohort study

Abstract Background: Elderly patients are more susceptible to Coronavirus Disease-2019 (COVID-19) and are more likely to develop it in severe forms, (e.g., Acute Respiratory Distress Syndrome [ARDS]). Prone positioning is a treatment strategy for severe ARDS; however, its response in the elderly population remains poorly understood. The main objective was to evaluate the predictive response and mortality of elderly patients exposed to prone positioning due to ARDS-COVID-19. Methods: This retrospective multicenter cohort study involved 223 patients aged ≥ 65 years, who received prone position sessions for severe ARDS due to COVID-19, using invasive mechanical ventilation. The PaO2/FiO2 ratio was used to assess the oxygenation response. The 20-point improvement in PaO2/FiO2 after the first prone session was considered for good response. Data were collected from electronic medical records, including demographic data, laboratory/image exams, complications, comorbidities, SAPS III and SOFA scores, use of anticoagulants and vasopressors, ventilator settings, and respiratory system mechanics. Mortality was defined as deaths that occurred until hospital discharge. Results: Most patients were male, with arterial hypertension and diabetes mellitus as the most prevalent comorbidities. The non-responders group had higher SAPS III and SOFA scores, and a higher incidence of complications. There was no difference in mortality rate. A lower SAPS III score was a predictor of oxygenation response, and the male sex was a risk predictor of mortality. Conclusion: The present study suggests the oxygenation response to prone positioning in elderly patients with severe COVID-19-ARDS correlates with the SAPS III score. Furthermore, the male sex is a risk predictor of mortality.

Impact of prone positioning on patients with COVID-19 and ARDS on invasive mechanical ventilation: a multicenter cohort study / Impacto da pronação em pacientes com COVID-19 e SDRA em ventilação mecânica invasiva: estudo de coorte multicêntrico

ABSTRACT Objective: To identify factors that lead to a positive oxygenation response and predictive factors of mortality after prone positioning. Methods: This was a retrospective, multicenter, cohort study involving seven hospitals in Brazil. Inclusion criteria were being > 18 years of age with a suspected or confirmed diagnosis of COVID-19, being on invasive mechanical ventilation, having a PaO2/FIO2 ratio < 150 mmHg, and being submitted to prone positioning. After the first prone positioning session, a 20 mmHg improvement in the PaO2/FIO2 ratio was defined as a positive response. Results: The study involved 574 patients, 412 (72%) of whom responded positively to the first prone positioning session. Multiple logistic regression showed that responders had lower Simplified Acute Physiology Score III (SAPS III)/SOFA scores and lower D-dimer levels (p = 0.01; p = 0.04; and p = 0.04, respectively). It was suggested that initial SAPS III and initial PaO2/FIO2 were predictors of oxygenation response. The mortality rate was 69.3%. Increased risk of mortality was associated with age (OR = 1.04 [95 CI: 1.01-1.06]), time to first prone positioning session (OR = 1.18 [95 CI: 1.06-1.31]), number of sessions (OR = 1.31 [95% CI: 1.00-1.72]), proportion of pulmonary impairment (OR = 1.55 [95% CI: 1.02-2.35]), and immunosuppression (OR = 3.83 [95% CI: 1.35-10.86]). Conclusions: Our results show that most patients in our sample had a positive oxygenation response after the first prone positioning session. However, the mortality rate was high, probably due to the health status and the number of comorbidities of the patients, as well as the severity of their disease. Our results also suggest that SAPS III and the initial PaO2/FIO2 predict the oxygenation response; in addition, age, time to first prone positioning, number of sessions, pulmonary impairment, and immunosuppression can predict mortality.

RESUMO Objetivo: Identificar fatores que levam a uma resposta positiva da oxigenação e fatores preditivos de mortalidade após a pronação. Métodos: Estudo de coorte retrospectivo multicêntrico envolvendo sete hospitais brasileiros. Os critérios de inclusão foram idade > 18 anos com diagnóstico suspeito ou confirmado de COVID-19, ventilação mecânica invasiva, relação PaO2/FIO2 < 150 mmHg e pronação. Após a primeira sessão de pronação, uma melhora de 20 mmHg na relação PaO2/FIO2 foi definida como resposta positiva. Resultados: O estudo envolveu 574 pacientes, dos quais 412 (72%) apresentaram resposta positiva à primeira sessão de pronação. A regressão logística múltipla mostrou que os respondedores apresentaram menores pontuações no Simplified Acute Physiology Score III (SAPS III) e no SOFA e menores níveis de dímero D (p = 0,01; p = 0,04; e p = 0,04, respectivamente). Sugeriu-se que a pontuação no SAPS III e a PaO2/FIO2 iniciais seriam preditores da resposta da oxigenação. A taxa de mortalidade foi de 69,3%. Maior risco de mortalidade foi associado à idade (OR = 1,04 [IC95%: 1,01-1,06]), tempo até a primeira sessão de pronação (OR = 1,18 [IC95%: 1,06-1,31]), número de sessões (OR = 1,31 [IC95%: 1,00-1,72]), porcentagem de comprometimento pulmonar (OR = 1,55 [IC95%: 1,02-2,35]) e imunossupressão (OR = 3,83 [IC95%: 1,35-10,86]). Conclusões: Nossos resultados mostram que a maioria dos pacientes de nossa amostra apresentou resposta positiva da oxigenação após a primeira sessão de pronação. No entanto, a taxa de mortalidade foi elevada, provavelmente em virtude do estado de saúde e número de comorbidades dos pacientes e da gravidade de sua doença. Nossos resultados também sugerem que a pontuação no SAPS III e a PaO2/FIO2 inicial predizem a resposta da oxigenação; além disso, idade, tempo até a primeira sessão de pronação, número de sessões, comprometimento pulmonar e imunossupressão podem predizer mortalidade.