Department of Neurology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria.
Institute of Medical Informatics, UMIT, University for Health Sciences, Medical Informatics and Technology, Eduard Wallnoefer-Zentrum 1, 6060, Hall, Austria.
Crit Care. 2020 Jul 14;24(1):432. doi: 10.1186/s13054-020-03089-w.
Endotracheal suctioning (ES) provokes a cumulative hemodynamic response by activation of sympathetic and parasympathetic circuits in the central nervous system. In this proof-of-concept study, we aimed to analyze hemodynamic changes during ES in ventilated subarachnoid hemorrhage (SAH) patients and investigated whether the associated hemodynamic changes relate to the time to arousal and functional outcome.
For the current observational study, 191 SAH patients admitted to the neurological intensive care unit of a tertiary hospital requiring mechanical ventilation were included. One thousand eighty ES episodes during the first 72 h of admission were analyzed. Baseline median heart rate (HR) and mean arterial pressure (MAP) were compared to peak HR and MAP during ES based on 5-min averaged data (ΔHR and ΔMAP). Multivariable analysis to assess associations between ΔHR and ΔMAP and time to arousal (time to Richmond Agitation Sedation Scale ≥ 0, RASS) and poor functional outcome (modified Rankin Scale Score > 2, mRS) was performed using generalized estimating equations.
Patients were 59 (IQR, 50-70) years old and presented with a median admission H&H grade of 4 (IQR, 3-5). In-hospital mortality was 22% (25% at 3 months) and median time to arousal was 13 (IQR, 4-21) days. HR increased by 2.3 ± 7.1 beats per minute (bpm) from 75.1 ± 14.8 bpm at baseline. MAP increased by 3.2 ± 7.8 mmHg from baseline 80.9 ± 9.8 mmHg. In multivariable analysis, ΔHR (p < 0.001) was significantly lower in patients who regained consciousness at a later time point and a lower ΔHR was associated with poor functional 3-month outcome independent of RASS (adjOR = 0.95; 95% CI = 0.93-0.98) or midazolam dose (adjOR = 0.96; 95% CI = 0.94-0.98). ΔMAP was neither associated with the time to regain consciousness (p = 0.087) nor with functional outcome (p = 0.263).
Augmentation in heart rate may quantify the hemodynamic response during endotracheal suctioning in brain-injured patients. The value as a biomarker to early discriminate the time to arousal and functional outcome in acutely brain-injured patients needs prospective confirmation.
气管内吸引（ES）通过激活中枢神经系统中的交感和副交感神经回路引起累积的血流动力学反应。 在这项概念验证研究中，我们旨在分析机械通气的蛛网膜下腔出血（SAH）患者在 ES 期间的血流动力学变化，并研究相关的血流动力学变化是否与觉醒时间和功能结局有关。
对于当前的观察性研究，共纳入了 191 名需要机械通气的入住我院神经重症监护病房的 SAH 患者。 对入院后 72 小时内的 1080 次 ES 发作进行了分析。 基于 5 分钟平均数据（ΔHR 和 ΔMAP），比较基线时的中位心率（HR）和平均动脉压（MAP）与 ES 期间的峰值 HR 和 MAP（ΔHR 和 ΔMAP）。 使用广义估计方程对 ΔHR 和 ΔMAP 与觉醒时间（Richmond 躁动镇静量表评分≥0，RASS）和不良功能结局（改良 Rankin 量表评分>2，mRS）之间的相关性进行多变量分析。
患者年龄为 59 岁（IQR，50-70），入院时 H&H 分级中位数为 4 级（IQR，3-5）。住院死亡率为 22%（3 个月时为 25%），平均觉醒时间为 13 天（IQR，4-21）。 HR 从基线时的 75.1±14.8 bpm 增加了 2.3±7.1 bpm。 MAP 从基线时的 80.9±9.8 mmHg 增加了 3.2±7.8 mmHg。 多变量分析显示，在觉醒时间较晚的患者中，ΔHR（p<0.001）显著降低，且较低的 ΔHR 与 3 个月时的不良功能结局独立于 RASS（调整 OR=0.95；95%CI=0.93-0.98）或咪达唑仑剂量（调整 OR=0.96；95%CI=0.94-0.98）相关。 ΔMAP 与觉醒时间（p=0.087）或功能结局（p=0.263）均无相关性。
心率的增加可能可以量化脑损伤患者气管内吸引时的血流动力学反应。 作为一种生物标志物，它的值可用于早期区分急性脑损伤患者的觉醒时间和功能结局，需要前瞻性确认。
