Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
J Heart Lung Transplant. 2021 Jan;40(1):4-11. doi: 10.1016/j.healun.2020.10.003. Epub 2020 Oct 13.
Currently, the primary graft dysfunction (PGD) score is used to measure allograft function in the early post-lung transplant period. Although PGD grades at later time points (T48 hours and T72 hours) are useful to predict mid- and long-term outcomes, their predictive value is less relevant within the first 24 hours after transplantation. This study aimed to evaluate the capability of PGD grades to predict prolonged mechanical ventilation (MV) and compare it with a model derived from ventilation parameters measured on arrival at the intensive care unit (ICU).
A retrospective single-center analysis of 422 double lung transplantations (LTxs) was performed. PGD was assessed 2 hours after arrival at ICU, and grades were associated with length of MV (LMV). In addition, peak inspiratory pressure (P), ratio of the arterial partial pressure of oxygen to fraction of inspired oxygen (P/F ratio), and dynamic compliance (cDyn) were collected, and a logistic regression model was created. The predictive capability for prolonged MV was calculated for both (the PGD score and the model). In a second step, the created model was externally validated using a prospective, international multicenter cohort including 102 patients from the lung transplant centers of Vienna, Toronto, and Budapest.
In the retrospective cohort, a high percentage of extubated patients was reported at 24 hours (35.1%), 48 hours (68.0%), and 72 hours (80.3%) after transplantation. At T0 (time point defined as 2 hours after arrival at the ICU), patients with PGD grade 0 had a shorter LMV with a median of 26 hours (interquartile range [IQR]: 16-47 hours) than those with PGD grade 1 (median: 42 hours, IQR: 27-50 hours), PGD grade 2 (median: 37.5 hours, IQR: 15.5-78.5 hours), and PGD grade 3 (median: 46 hours, IQR: 27-86 hours). However, IQRs largely overlapped for all grades, and the value of PGD to predict prolonged MV was poor. A total of 3 ventilation parameters (P, cDyn, and P/F ratio), determined at T0, were chosen on the basis of clinical reasoning. A logistic regression model including these parameters predicted prolonged MV (>72 hours) with an optimism-corrected area under the curve (AUC) of 0.727. In the prospective validation cohort, the model proved to be stable and achieved an AUC of 0.679.
The prediction model reported in this study combines 3 easily obtainable variables. It can be employed immediately after LTx to quantify the risk of prolonged MV, an important early outcome parameter.
目前，主要移植物功能障碍（PGD）评分用于衡量肺移植后早期的同种异体移植物功能。尽管在稍后时间点（T48 小时和 T72 小时）的 PGD 分级有助于预测中期和长期结局，但在移植后 24 小时内，其预测价值相关性较低。本研究旨在评估 PGD 分级预测延长机械通气（MV）的能力，并与基于到达重症监护病房（ICU）时测量的通气参数得出的模型进行比较。
对 422 例双肺移植（LTx）进行回顾性单中心分析。在 ICU 到达后 2 小时评估 PGD，并将分级与 MV 延长时间（LMV）相关联。此外，还收集了吸气峰压（P）、动脉血氧分压与吸入氧分数比（P/F 比）和动态顺应性（cDyn）的比值，并建立了逻辑回归模型。计算了这两种方法（PGD 评分和模型）对延长 MV 的预测能力。在第二步中，使用来自维也纳、多伦多和布达佩斯肺移植中心的前瞻性国际多中心队列对所创建的模型进行外部验证，该队列包括 102 例患者。
在回顾性队列中，报告了在移植后 24 小时（35.1%）、48 小时（68.0%）和 72 小时（80.3%）时较高比例的患者拔管。在 T0 时（定义为到达 ICU 后 2 小时），PGD 分级为 0 的患者 LMV 较短，中位数为 26 小时（四分位距 [IQR]：16-47 小时），而 PGD 分级为 1（中位数：42 小时，IQR：27-50 小时）、PGD 分级为 2（中位数：37.5 小时，IQR：15.5-78.5 小时）和 PGD 分级为 3（中位数：46 小时，IQR：27-86 小时）的患者。然而，所有分级的 IQR 均大量重叠，PGD 预测 MV 延长的价值较差。总共选择了 3 个通气参数（P、cDyn 和 P/F 比），这是基于临床推理确定的。包含这些参数的逻辑回归模型以校正后的曲线下面积（AUC）0.727 预测了 MV 延长（>72 小时）。在前瞻性验证队列中，该模型被证明是稳定的，AUC 为 0.679。
本研究报告的预测模型结合了 3 个易于获得的变量。它可以在 LTx 后立即使用，以量化延长 MV 的风险，这是一个重要的早期结局参数。
