Mosier Jarrod M, Fisher Julia M, Hypes Cameron D, Bedrick Edward J, Campbell Elizabeth Salvagio, Lutrick Karen, Cairns Charles B
Department of Emergency Medicine, College of Medicine, University of Arizona, Tucson, AZ 85724, USA.
Division of Pulmonary, Allergy, Critical Care and Sleep, Department of Medicine, College of Medicine, University of Arizona, Tucson, AZ 85724, USA.
J Clin Med. 2021 Sep 2;10(17):3971. doi: 10.3390/jcm10173971.
Emergency medicine is acuity-based and focuses on time-sensitive treatments for life-threatening diseases. Prolonged time in the emergency department, however, is associated with higher mortality in critically ill patients. Thus, we explored management after an acuity-based intervention, which we call perpetuity, as a potential mechanism for increased risk. To explore this concept, we evaluated the impact of each hour above a lung-protective tidal volume on risk of mortality.
This cohort analysis includes all critically ill, non-trauma, adult patients admitted to two academic EDs between 1 November 2013 and 30 April 2017. Cox models with time-varying covariates were developed with time in perpetuity as a time-varying covariate, defined as hours above 8 mL/kg ideal body weight, adjusted for covariates. The primary outcome was the time to in-hospital death.
Our analysis included 2025 patients, 321 (16%) of whom had at least 1 h of perpetuity time. A partial likelihood-ratio test comparing models with and without hours in perpetuity was statistically significant (χ(3) = 13.83, = 0.0031). There was an interaction between age and perpetuity (Relative risk (RR) 0.9995; 95% Confidence interval (CI): 0.9991-0.9998). For example, for each hour above 8 mL/kg ideal body weight, a 20-year-old with 90% oxygen saturation has a relative risk of death of 1.02, but a 40-year-old with 90% oxygen saturation has a relative risk of 1.01.
Perpetuity, illustrated through the lens of mechanical ventilation, may represent a target for improving outcomes in critically ill patients, starting in the emergency department. Research is needed to evaluate the types of patients and interventions in which perpetuity plays a role.
急诊医学以急症为基础，专注于对危及生命的疾病进行时间敏感型治疗。然而，在急诊科停留时间过长与危重症患者的较高死亡率相关。因此，我们探讨了一种基于急症的干预措施（我们称之为“持续时间”）后的管理情况，将其作为风险增加的一种潜在机制。为了探究这一概念，我们评估了高于肺保护性潮气量的每一小时对死亡风险的影响。
这项队列分析纳入了2013年11月1日至2017年4月30日期间入住两家学术性急诊科的所有成年危重症非创伤患者。构建了具有随时间变化协变量的Cox模型，将“持续时间”作为随时间变化的协变量，定义为高于理想体重8 mL/kg的小时数，并对协变量进行了调整。主要结局是院内死亡时间。
我们的分析纳入了2025例患者，其中321例（16%）至少有1小时的“持续时间”。比较有和没有“持续时间”小时数的模型的部分似然比检验具有统计学意义（χ(3)=13.83，P = 0.0031）。年龄与“持续时间”之间存在交互作用（相对风险（RR）0.9995；95%置信区间（CI）：0.9991 - 0.9998）。例如，对于高于理想体重8 mL/kg的每一小时，氧饱和度为90%的20岁患者的死亡相对风险为1.02，而氧饱和度为90%的40岁患者的死亡相对风险为1.01。
从机械通气的角度来看，“持续时间”可能代表了改善危重症患者结局的一个靶点，从急诊科就开始。需要开展研究来评估“持续时间”发挥作用的患者类型和干预措施。
