Infectious Diseases Department, Fondazione I.R.C.C.S Policlinico San Matteo Pavia, Italy.
Infectious Diseases Department, São João University Hospital Center.
Curr Opin Crit Care. 2019 Oct;25(5):449-457. doi: 10.1097/MCC.0000000000000638.
Overview of influenza infection, focusing on outcome and complications in critically ill patients. We also discuss relevant elements in immunopathogenesis and their role as predictors of severity.
Pandemic influenza A (H1N1) virus circulates seasonally and remains the predominant subtype among intensive care patients. Mortality in acute respiratory failure (ARF) is around 20%, independent of influenza subtypes. During severe infection, the imbalance between pro-inflammatory and anti-inflammatory molecules, such as Th1 and Th17 cytokines, is associated with complicated infections and mortality. Primary viral pneumonia presents in more than 70% of ICU influenza patients and more than 50% develop acute respiratory distress syndrome. Bacterial secondary infection occurs in 20% of severe cases and Streptococcus pneumoniae and Staphylococcus aureus remain the prevalent pathogens. Myocarditis and late-onset cardiovascular complications are associated with mortality. Antiviral therapy within 48 h after onset, avoidance of corticosteroids and rescue therapies for ARF or myocarditis, such as extracorporeal membrane oxygenation, improve survival.
The present review summarizes current knowledge on pathogenesis and clinical manifestations of severe influenza. Immunological dysfunction during viral infection correlates with severity and mortality among ICU patients. A theranostics strategy should be implemented to improve outcomes.
概述流感感染，重点关注危重症患者的结局和并发症。我们还讨论了免疫发病机制中的相关因素及其作为严重程度预测因子的作用。
季节性流行的甲型流感（H1N1）病毒仍然是重症监护患者中主要的亚型。急性呼吸衰竭（ARF）的死亡率约为 20%，与流感亚型无关。在严重感染期间，促炎和抗炎分子（如 Th1 和 Th17 细胞因子）之间的失衡与复杂感染和死亡率相关。原发性病毒性肺炎在超过 70%的 ICU 流感患者中出现，超过 50%的患者发展为急性呼吸窘迫综合征。20%的重症患者发生继发性细菌感染，肺炎链球菌和金黄色葡萄球菌仍然是主要病原体。心肌炎和迟发性心血管并发症与死亡率相关。发病后 48 小时内使用抗病毒治疗、避免使用皮质类固醇以及对 ARF 或心肌炎进行挽救性治疗（如体外膜氧合）可提高生存率。
本综述总结了严重流感的发病机制和临床表现的最新知识。病毒感染期间的免疫功能障碍与 ICU 患者的严重程度和死亡率相关。应该实施一种治疗策略来改善结局。
