From the Department of Surgery (D.S.G., J.B.B., M.D.N., B.S.Z., J.L.S.), University of Pittsburgh; Division of Trauma and Acute Care Surgery (D.S.G., J.B.B., M.D.N., B.S.Z., J.L.S.), Pittsburgh Trauma Research Center; Department of Emergency Medicine (F.X.G.), University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Surgery (B.J.D.), University of Tennessee Health Science Center, Knoxville; Department of Surgery (R.S.M.), Vanderbilt University Medical Center, Nashville, Tennessee; University of Louisville (B.G.H.), Louisville, Kentucky; MetroHealth Medical Center (J.A.C.), Case Western Reserve University, Cleveland, Ohio; Department of Surgery (H.A.P.), University of Texas Southwestern, Parkland Memorial Hospital, Dallas, Texas; and Department of Pathology (M.H.Y.), University of Pittsburgh, Pittsburgh, Pennsylvania.
J Trauma Acute Care Surg. 2020 Nov;89(5):908-914. doi: 10.1097/TA.0000000000002816.
Prehospital plasma improves survival for severely injured trauma patients transported by air ambulance. We sought to characterize the unexpected survivors, patients who survived despite having high predicted mortality after traumatic injury.
The Prehospital Air Medical Plasma trial randomized severely injured patients (n = 501) to receive either standard care (crystalloid) or two units of prehospital plasma followed by standard care fluid resuscitation. We built a generalized linear model to estimate patient mortality. Area under the receiver operating characteristic curve was used to evaluate model performance. We defined unexpected survivors as patients who had a predicted mortality greater than 50% and survived to 30 days. We characterized patient demographics, clinical features, and outcomes of the unexpected survivors. Observed to expected (O/E) ratios and Z-statistics were calculated using model-estimated mortality for each cohort.
Our model predicted mortality better than Injury Severity Score or Revised Trauma Score parameters and identified 36 unexpected survivors. Compared with expected survivors, unexpected survivors were younger (33 years [24, 52 years] vs. 47 years [32, 59 years], p = 0.013), were more severely injured (Injury Severity Score 34 [22, 50] vs. 18 [10, 27], p < 0.001), had worse organ dysfunction and hospital resource outcomes (multiple organ failure, intensive care unit, hospital length of stay, and ventilator days), and were more likely to receive prehospital plasma (67 vs. 46%, p = 0.031). Nonsurvivors with high predicted mortality were more likely to receive standard care resuscitation (p < 0.001). Unexpected survivors who received prehospital plasma had a lower observed to expected mortality than those that received standard care resuscitation (O/E 0.56 [0.33-0.84] vs. 1.0 [0.73-1.32]). The number of prehospital plasma survivors (24) exceeded the number of predicted survivors (n = 10) estimated by our model (p < 0.001).
Prehospital plasma is associated with an increase in the number of unexpected survivors following severe traumatic injury. Prehospital interventions may improve the probability of survival for injured patients with high predicted mortality based on early injury characteristics, vital signs, and resuscitation measures.
Therapeutic Level III.
院前输注血浆可提高空运创伤患者的存活率。我们旨在描述那些意外存活的患者，这些患者尽管创伤后预测死亡率高，但仍存活下来。
在 Prehospital Air Medical Plasma 试验中，我们将 501 例严重创伤患者随机分为接受标准治疗（晶体液）或院前输注 2 单位血浆加标准治疗液体复苏组。我们构建了一个广义线性模型来估计患者的死亡率。采用受试者工作特征曲线下面积来评估模型性能。我们将预测死亡率>50%且存活至 30 天的患者定义为意外存活者。我们对意外存活者的患者人口统计学、临床特征和结局进行了描述。使用模型估计的死亡率计算每个队列的观察到的与预期的（O/E）比值和 Z 统计量。
我们的模型预测死亡率优于损伤严重程度评分或修订创伤评分参数，并确定了 36 例意外存活者。与预期存活者相比，意外存活者更年轻（33 岁[24，52 岁] vs. 47 岁[32，59 岁]，p=0.013），损伤更严重（损伤严重程度评分 34[22，50] vs. 18[10，27]，p<0.001），器官功能障碍和医院资源结局更差（多器官衰竭、重症监护病房、住院时间和呼吸机天数），更有可能接受院前输注血浆（67% vs. 46%，p=0.031）。高预测死亡率的非幸存者更可能接受标准治疗复苏（p<0.001）。接受院前输注血浆的意外存活者的观察到的与预期的死亡率低于接受标准治疗复苏的存活者（O/E 0.56[0.33-0.84] vs. 1.0[0.73-1.32]）。接受院前输注血浆的存活者（24 例）超过了我们模型估计的预测存活者（n=10 例）的数量（p<0.001）。
院前输注血浆与严重创伤后意外存活者数量的增加有关。基于早期损伤特征、生命体征和复苏措施，院前干预可能会提高高预测死亡率创伤患者的生存概率。
治疗性三级。
