Long Beach Memorial Medical Center, Long Beach, California, USA
Division of Pulmonary and Critical Care Medicine, University of California Irvine, Irvine, California, USA.
BMJ Open Respir Res. 2024 Oct 1;11(1):e002439. doi: 10.1136/bmjresp-2024-002439.
An association between driving pressure (∆P) and the outcomes of invasive mechanical ventilation (IMV) may exist. However, the effect of a sustained limitation of ∆P on mortality in patients with acute respiratory distress syndrome (ARDS), including patients with COVID-19 (COVID-19-related acute respiratory distress syndrome (C-ARDS)) undergoing IMV, has not been rigorously evaluated. The use of emulations of a target trial in intensive care unit research remains in its infancy. To inform future, large ARDS target trials, we explored using a target trial emulation approach to analyse data from a cohort of IMV adults with C-ARDS to determine whether maintaining daily ∆p<15 cm HO (in addition to traditional low tidal volume ventilation (LTVV) (tidal volume 5-7 cc/PBW+plateau pressure (P) ≤30 cm HO), compared with LTVV alone, affects the 28-day mortality.
To emulate a target trial, adults with C-ARDS requiring >24 hours of IMV were considered to be assigned to limited ∆P or LTVV. Lung mechanics were measured twice daily after ventilator setting adjustments were made. To evaluate the effect of each lung-protective ventilation (LPV) strategy on the 28-day mortality, we fit a stabilised inverse probability weighted marginal structural model that adjusted for baseline and time-varying confounders known to affect protection strategy use/adherence or survival.
Among the 92 patients included, 27 (29.3%) followed limited ∆P ventilation, 23 (25.0%) the LTVV strategy and 42 (45.7%) received no LPV strategy. The adjusted estimated 28-day survival was 47.0% (95% CI 23%, 76%) in the limited ∆P group, 70.3% in the LTVV group (95% CI 37.6%, 100%) and 37.6% (95% CI 20.8%, 58.0%) in the no LPV strategy group.
Limiting ∆P may not provide additional survival benefits for patients with C-ARDS over LTVV. Our results help inform the development of future target trial emulations focused on evaluating LPV strategies, including reduced ∆P, in adults with ARDS.
驱动压（∆P）与有创机械通气（IMV）结果之间可能存在关联。然而，在接受 IMV 的急性呼吸窘迫综合征（ARDS）患者（包括 COVID-19 相关急性呼吸窘迫综合征（C-ARDS）患者）中，持续限制 ∆P 对死亡率的影响尚未得到严格评估。在重症监护病房研究中模拟目标试验的应用仍处于起步阶段。为了为未来的大型 ARDS 目标试验提供信息，我们探索了使用目标试验模拟方法来分析接受 IMV 的 C-ARDS 成人队列的数据，以确定与单独使用低潮气量通气（LTVV）（潮气量 5-7 cc/PBW+平台压（P）≤30 cmHO）相比，每天维持 ∆p<15 cmHO（外加）是否会影响 28 天死亡率。
为了模拟目标试验，需要接受 >24 小时 IMV 的 C-ARDS 成人被认为被分配到限制 ∆P 或 LTVV。在调整呼吸机设置后，每天测量两次肺力学。为了评估每种肺保护性通气（LPV）策略对 28 天死亡率的影响，我们拟合了一个稳定的逆概率加权边缘结构模型，该模型调整了已知影响保护策略使用/依从性或生存的基线和时变混杂因素。
在纳入的 92 名患者中，27 名（29.3%）接受了限制 ∆P 通气，23 名（25.0%）接受了 LTVV 策略，42 名（45.7%）未接受 LPV 策略。在限制 ∆P 组中，调整后的估计 28 天生存率为 47.0%（95%CI 23%，76%），LTVV 组为 70.3%（95%CI 37.6%，100%），无 LPV 策略组为 37.6%（95%CI 20.8%，58.0%）。
在接受 LTVV 的 C-ARDS 患者中，限制 ∆P 可能不会带来额外的生存获益。我们的结果有助于为未来的目标试验模拟提供信息，重点是评估 ARDS 成人的 LPV 策略，包括降低 ∆P。
