Venous thromboembolism (VTE) is a leading cause of morbidity and mortality among hospitalized patients, including children. In recent years, it has become clear that hospitalization and critical illness bestow an increased VTE risk in pediatrics and relate to mortality and life-limiting comorbidities. For critically ill children, reported rates of VTE vary by study sampling techniques, presence of inherited or acquired thrombophilia, acute and chronic immobility, underlying illness prompting hospitalization, and clinical factors related to illness severity such as central venous catheterization, length of stay, mechanical ventilation, and patient age. Accordingly, critically ill children with new signs of venous congestion, acute inflammation, or unexplained acute organ dysfunction should be routinely evaluated for VTE. This narrative review summarizes recent and historical literature regarding risk factors, prevention, presentation, treatment, and outcomes of VTE in critically ill children. In addition, we identify knowledge gaps and priorities for future collaborative research on this vital condition. Special attention is given to the clinical trial opportunities, challenges, and ongoing efforts in thromboprophylaxis in critically ill children, including those hospitalized for disease related to novel coronavirus (COVID-19) and multisystem inflammatory disease in children.

静脉血栓栓塞 (VTE) 是住院患者（包括儿童）发病率和死亡率的主要原因。近年来，很明显，住院和危重病会增加儿科的 VTE 风险，并与死亡率和限制生命的合并症有关。对于危重儿童，报告的 VTE 发生率因研究采样技术、遗传性或获得性血栓形成倾向的存在、急性和慢性不动、导致住院的潜在疾病以及与疾病严重程度相关的临床因素（如中心静脉导管插入术、住院时间长短、机械通气量和患者年龄。因此，对于出现静脉充血、急性炎症或无法解释的急性器官功能障碍的新体征的危重儿童，应常规评估 VTE。这篇叙述性综述总结了关于危重儿童 VTE 的危险因素、预防、表现、治疗和结果的近期和历史文献。此外，我们确定了未来关于这一重要条件的合作研究的知识差距和优先事项。特别关注重症儿童血栓预防的临床试验机会、挑战和正在进行的努力，包括因新型冠状病毒 (COVID-19) 相关疾病和儿童多系统炎症疾病住院的儿童。