Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI.
Division of Pulmonary and Critical Care, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL.
Chest. 2024 Apr;165(4):881-891. doi: 10.1016/j.chest.2023.12.014. Epub 2023 Dec 13.
Since the 1990s, time-limited trials have been described as an approach to navigate uncertain benefits and limits of life-sustaining therapies in patients with critical illness. In this review, we aim to synthesize the evidence on time-limited trials in critical care, establish what is known, and highlight important knowledge gaps.
We identified 18 empirical studies and 15 ethical analyses about time-limited trials in patients with critical illness. Observational studies suggest time-limited trials are part of current practice in ICUs in the United States, but their use varies according to unit and physician factors. Some ICU physicians are familiar with, endorse, and have participated in time-limited trials, and some older adults appear to favor time-limited trial strategies over indefinite life-sustaining therapy or care immediately focused on comfort. When time-limited trials are used, they are often implemented incompletely and challenged by systematic barriers (eg, continually rotating ICU staff). Predictive modeling studies support prevailing clinical wisdom that prognostic uncertainty decreases over time in the ICU for some patients. One study prospectively comparing usual ICU care with an intervention designed to support time-limited trials yielded promising preliminary results. Ethical analyses describe time-limited trials as a pragmatic approach within the longstanding discussion about withholding and withdrawing life-sustaining therapies.
Time-limited trials are endorsed by physicians, align with the priorities of some older adults, and are part of current practice. Substantial efforts are needed to test their impact on patient-centered outcomes, improve their implementation, and maximize their potential benefit.
主题重要性：自 20 世纪 90 年代以来，限时试验被描述为一种在危重病患者中探索生命支持治疗的不确定益处和限制的方法。在本综述中，我们旨在综合危重病限时试验的证据，确定已知内容，并强调重要的知识空白。
综述发现：我们确定了 18 项关于危重病患者限时试验的实证研究和 15 项伦理分析。观察性研究表明，限时试验是美国 ICU 目前实践的一部分，但它们的使用因单位和医生因素而异。一些 ICU 医生熟悉、支持并参与了限时试验，一些老年患者似乎更喜欢限时试验策略而不是无限期的生命支持治疗或立即专注于舒适的治疗。当使用限时试验时，它们通常执行不完整，并受到系统障碍的挑战（例如，不断轮换的 ICU 工作人员）。预测建模研究支持了普遍的临床观点，即对于某些患者，在 ICU 中，预后的不确定性随着时间的推移而降低。一项前瞻性比较常规 ICU 护理与旨在支持限时试验的干预措施的研究取得了有希望的初步结果。伦理分析将限时试验描述为在长期关于 withholding 和 withdrawing 生命支持治疗的讨论中的一种实用方法。
总结：限时试验得到了医生的认可，与一些老年患者的优先事项一致，并且是当前实践的一部分。需要做出大量努力来测试它们对以患者为中心的结果的影响，改善它们的实施，并最大限度地发挥它们的潜在益处。
