Prehosp Emerg Care. 2019 Nov-Dec;23(6):764-771. doi: 10.1080/10903127.2019.1593564. Epub 2019 Apr 9.
Hypotension in the prehospital environment is common and linked to dose-dependent mortality. Bolus dose epinephrine (BDE) may reverse hypotension. We tested if BDE use to treat profound hypotension is associated with 24-hour survival. We performed a retrospective case-cohort study of critical care transport patients with systolic blood pressure (SBP) <70 mmHg from January 2011 to January 2017. To account for baseline differences between treated and untreated patients, we used nearest neighbor matching to estimate the average treatment effect of BDE on 24-hour survival. Included covariates were age, gender, shock type (cardiogenic, distributive, obstructive or hypovolemic), weight, type of service, vitals (heart rate, SBP and diastolic blood pressure, respiratory rate, oxygen saturation, end-tidal carbon dioxide, and Glasgow Coma Scale score) at the time of the first hypotensive episode, as well as pretreatment characteristics including cardiopulmonary resuscitation, defibrillation, transcutaneous pacing, needle thoracostomy, vasopressors, intubation, or arrhythmias. After statistical analysis, we assessed for residual bias by selecting random matched patient records and asking 2 blinded physicians to rate overall illness severity on a Likert scale. We compared perceived illness severity between cases and matched controls using a rank-sum test. There were 6,992 patients transported with SBP <70 mmHg at least once and 4,374 meet inclusion criteria. Of the 1,620 patients transported after protocol implementation, 574 (35%) received BDE. Overall 24-hour survival, survival to discharge and 30-day survival were 80, 57, and 54%, respectively. Survival at 24 hours differed between the BDE group (66%) and controls (82%). These differences persisted at both discharge and 30 days. Administration of BDE was associated with increased post-treatment SBP. BDE treated patients were also more likely to receive cardiopulmonary resuscitation and vasopressors after treatment than untreated hypotensive patients, but there was no association with tachydysrhythmias requiring defibrillation. Bolus dose epinephrine increases blood pressure in the prehospital setting. Despite robust efforts to control for confounding, BDE remained associated with increased mortality in this observational cohort. This association may be due to unmeasured confounding and a randomized controlled trial is necessary to establish a causal relationship between bolus dose vasopressors and mortality.
在院前环境中，低血压很常见，并且与剂量相关的死亡率有关。弹丸剂量肾上腺素（BDE）可能逆转低血压。我们测试了 BDE 治疗严重低血压是否与 24 小时生存率相关。我们对 2011 年 1 月至 2017 年 1 月期间接受 SBP <70mmHg 的重症监护转运患者进行了回顾性病例对照研究。为了考虑治疗组和未治疗组之间的基线差异，我们使用最近邻匹配来估计 BDE 对 24 小时生存率的平均治疗效果。纳入的协变量包括年龄、性别、休克类型（心源性、分布性、阻塞性或低血容量性）、体重、服务类型、第一次低血压发作时的生命体征（心率、SBP 和舒张压、呼吸频率、血氧饱和度、呼气末二氧化碳分压和格拉斯哥昏迷评分），以及预处理特征，包括心肺复苏、除颤、经皮起搏、胸腔穿刺、血管加压药、插管或心律失常。经过统计分析，我们通过选择随机匹配的患者记录并要求 2 名盲法医生对整体疾病严重程度进行李克特量表评分，评估残余偏倚。我们使用秩和检验比较病例和匹配对照组之间的感知疾病严重程度。共有 6992 名患者至少一次转运时 SBP <70mmHg，其中 4374 名符合纳入标准。在方案实施后转运的 1620 名患者中，574 名（35%）接受了 BDE。总体 24 小时生存率、出院生存率和 30 天生存率分别为 80%、57%和 54%。BDE 组（66%）与对照组（82%）之间 24 小时生存率存在差异。这些差异在出院和 30 天后仍然存在。BDE 的给药与治疗后 SBP 的升高有关。与未治疗的低血压患者相比，接受 BDE 治疗的患者在治疗后更有可能接受心肺复苏和血管加压药治疗，但与需要除颤的心动过速无关联。弹丸剂量肾上腺素可增加院前环境中的血压。尽管进行了强有力的努力来控制混杂因素，但在这个观察性队列中，BDE 仍与死亡率增加相关。这种关联可能是由于未测量的混杂因素造成的，需要进行随机对照试验来确定弹丸剂量血管加压药与死亡率之间的因果关系。
