Dept. of Medical Intensive Care, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
Dept. of Anaesthesia and Intensive Care Medicine, Haukeland University Hospital, Bergen, Norway.
J Crit Care. 2022 Oct;71:154067. doi: 10.1016/j.jcrc.2022.154067. Epub 2022 May 25.
Prognostication for patients with critical conditions remains challenging, especially for very old individuals. Time-limited trials (TLT) are used to decrease prognostic uncertainty in the individual patient by monitoring the response to treatment over a pre-determined period of time. However, there are substantial difficulties with determining the length of that period. This study presents a probabilistic method to estimate a suitable duration of a TLT based on temporal profiles of uncertainty about critical care and outcome.
The study included very old patients (age ≥ 80 years, n = 1209) from the VIP2 study cohort who were admitted to the ICU for between 2 and 14 days, with respiratory or circulatory support from day 1 and with either no limitations of life-sustaining treatment or a decision to withdraw that treatment, as well as with complete data. Multi-state modelling of critical care trajectories to obtain time-dependent probabilities for transitions between distinct levels of organ support and to outcome states. The extent of uncertainty is quantified by Shannon's entropy of probability distributions at discrete points in time.
We detected periods of enhanced prognostic uncertainty of up to 7 days after admission. The duration of these periods depends on patient characteristics at baseline (frailty, severity of critical illness) and the extent of organ support.
Time-dependent patterns of uncertainty concerning the response to critical care can inform decisions about the duration of TLTs which may last up to a week in very old patients.
对于危重症患者的预后仍然具有挑战性，尤其是非常高龄的个体。限时试验（TLT）用于通过在预定时间段内监测对治疗的反应来减少个体患者的预后不确定性。然而，确定该时间段的长度存在很大的困难。本研究提出了一种基于危重病和结局不确定性的时间分布来估计 TLT 合适持续时间的概率方法。
该研究纳入了 VIP2 研究队列中的非常高龄患者（年龄≥80 岁，n=1209），他们在 ICU 住院 2 至 14 天，从第 1 天开始接受呼吸或循环支持，并且要么没有限制生命支持治疗，要么决定停止该治疗，同时还具有完整的数据。采用多状态模型对危重病轨迹进行建模，以获得器官支持和结局状态之间不同水平之间转换的时变概率。通过在离散时间点的概率分布的香农熵来量化不确定性的程度。
我们发现入院后长达 7 天的预后不确定性增加期。这些时期的持续时间取决于患者的基线特征（脆弱性、危重病的严重程度）和器官支持的程度。
关于对危重病反应的不确定性的时变模式可以为 TLT 的持续时间提供信息，对于非常高龄的患者，TLT 可能持续长达一周。
