From the Division of Trauma and General Surgery, Department of Surgery (S.P.C., J.L.S., J.B.B.), University of Pittsburgh Medical Center, Pittsburgh; Department of Surgery (W.L.), University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery (B.J.D.), University of Tennessee Health Science Center, Knoxville, Tennessee; Department of Surgery (R.S.M.), John Peter Smith Health Network, Fort Worth, Texas; Department of Surgery (B.G.H.), University of Louisville, Louisville, Kentucky; Department of Surgery (J.A.C.), MetroHealth Medical Center/Case Western Reserve University, Cleveland, Ohio; Department of Surgery (H.A.P.), Louisiana State University Health Sciences Center-New Orleans, New Orleans, Los Angeles; and Department of Emergency Medicine (F.X.G.), University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
J Trauma Acute Care Surg. 2021 Jul 1;91(1):186-191. doi: 10.1097/TA.0000000000003173.
Prehospital plasma transfusion in trauma reduces mortality. However, the underlying mechanism remains unclear. Reduction in shock severity may play a role. Lactate correlates with physiologic shock severity and mortality after injury. Our objective was to determine if prehospital plasma reduces lactate and if this contributes to the mortality benefit of plasma.
Patients in the Prehospital Air Medical Plasma trial in the upper quartile of injury severity (Injury Severity Score, >30) were included to capture severe shock. Trial patients were randomized to prehospital plasma or standard care resuscitation (crystalloid ± packed red blood cells). Regression determined the associations between admission lactate, 30-day mortality, and plasma while adjusting for demographics, prehospital crystalloid, time, mechanism, and injury characteristics. Causal mediation analysis determined what proportion of the effect of plasma on mortality is mediated by lactate reduction.
A total of 125 patients were included. The plasma group had a lower adjusted admission lactate than standard of care group (coefficient, -1.64; 95% confidence interval [CI], -2.96 to -0.31; p = 0.02). Plasma was associated with lower odds of 30-day mortality (odds ratio [OR], 0.27; 95% CI, 0.08-0.90; p = 0.03). When adding lactate to this model, the effect of plasma on 30-day mortality was no longer significant (OR, 0.36; 95% CI, 0.07-1.88; p = 0.23), while lactate was associated with mortality (OR, 1.74 per 1 mmol/L increase; 95% CI, 1.10-2.73; p = 0.01). Causal mediation demonstrated 35.1% of the total effect of plasma on 30-day mortality was mediated by the reduction in lactate among plasma patients.
Prehospital plasma is associated with reduced 30-day mortality and lactate in severely injured patients. More than one third of the effect of plasma on mortality is mediated by a reduction in lactate. Thus, reducing the severity of hemorrhagic shock appears to be one mechanism of prehospital plasma benefit. Further study should elucidate other mechanisms and if a dose response exists.
Therapeutic, level II.
创伤前的血浆输注可降低死亡率。然而，其潜在机制尚不清楚。休克严重程度的降低可能起作用。乳酸与生理休克严重程度和受伤后的死亡率相关。我们的目的是确定院前血浆是否可降低乳酸水平，以及这是否有助于血浆带来的死亡率益处。
纳入了严重程度（损伤严重程度评分，>30）处于前四分位数的 Prehospital Air Medical Plasma 试验中的患者，以捕获严重休克。试验患者被随机分配至院前血浆或标准复苏（晶体液+浓缩红细胞）。回归确定了入院时的乳酸值、30 天死亡率和血浆之间的关联，同时调整了人口统计学因素、院前晶体液、时间、机制和损伤特征。因果中介分析确定了血浆对死亡率的影响中有多少是由乳酸降低介导的。
共纳入 125 例患者。与标准治疗组相比，血浆组的入院时乳酸值较低（校正系数，-1.64；95%置信区间，-2.96 至 -0.31；p=0.02）。血浆与较低的 30 天死亡率相关（比值比[OR]，0.27；95%置信区间，0.08-0.90；p=0.03）。当将乳酸添加到该模型中时，血浆对 30 天死亡率的影响不再显著（OR，0.36；95%置信区间，0.07-1.88；p=0.23），而乳酸与死亡率相关（OR，每增加 1mmol/L 增加 1.74；95%置信区间，1.10-2.73；p=0.01）。因果中介表明，血浆对 30 天死亡率的总影响有 35.1%是通过血浆患者乳酸降低来介导的。
院前血浆与严重受伤患者的 30 天死亡率和乳酸降低相关。血浆对死亡率影响的三分之一以上是通过降低乳酸来介导的。因此，降低失血性休克的严重程度似乎是院前血浆获益的一个机制。应进一步研究是否存在其他机制和剂量反应。
治疗性，二级。
