Department of Anesthesiology and Intensive Care, Copenhagen University Hospital, Hvidovre Hospital, Kettegård Alle 30, Hvidovre, 2650, Copenhagen, Denmark.
Department of Surgical Pathophysiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Can J Anaesth. 2023 Oct;70(10):1587-1599. doi: 10.1007/s12630-023-02556-6. Epub 2023 Sep 26.
Early postoperative mobilization can be hindered by orthostatic intolerance (OI). Postoperative OI has multifactorial pathogenesis, possibly involving both postoperative hypovolemia and autonomic dysfunction. We aimed to investigate the effect of mild acute blood loss from blood donation simulating postoperative hypovolemia, on both autonomic function and OI, thus eliminating confounding perioperative factors such as inflammation, residual anesthesia, pain, and opioids.
This prospective observational cohort study included 26 blood donors. Continuous electrocardiogram data were collected during mobilization and night sleep, both before and after blood donation. A Valsalva maneuver and a standardized mobilization procedure were performed immediately before and after blood donation, during which cardiovascular and tissue oxygenation variables were continuously measured by LiDCOrapid™ and Massimo Root™, respectively. The incidence of OI, hemodynamic responses during mobilization and Valsalva maneuver, as well as heart rate variability (HRV) responses during mobilization and sleep were compared before and 15 min after blood donation.
Prior to blood donation, no donors experienced OI during mobilization. After blood donation, 6/26 (23%; 95% CI, 9 to 44) donors experienced at least one OI symptom. Three out of 26 donors (12%; 95% CI, 2 to 30) terminated the mobilization procedure prematurely because of severe OI symptoms. Cardiovascular and cerebral tissue oxygenation responses were reduced in patients with severe OI. After blood loss, HRV indices of total autonomic power remained unchanged but increased sympathetic and decreased parasympathetic outflow was observed during mobilization, but also during sleep, indicating a prolonged autonomic effect of hypovolemia.
We describe a specific hypovolemic component of postoperative OI, independent of postoperative autonomic dysfunction, inflammation, opioids, and pain.
ClinicalTrials.gov (NCT04499664); registered 5 August 2020.
术后早期活动可能会受到直立不耐受（OI）的阻碍。术后 OI 的发病机制具有多因素性，可能涉及术后血容量减少和自主神经功能障碍。我们旨在研究模拟术后血容量减少的轻度急性失血对自主神经功能和 OI 的影响，从而消除围手术期的混杂因素，如炎症、残留麻醉、疼痛和阿片类药物。
这项前瞻性观察性队列研究纳入了 26 名献血者。在献血前后，连续采集移动和夜间睡眠时的心电图数据。在献血前后，立即进行瓦尔萨尔瓦动作和标准化移动程序，在此过程中，通过 LiDCOrapid™和 Massimo Root™连续测量心血管和组织氧合变量。比较献血前后移动和瓦尔萨尔瓦动作期间 OI 的发生率、血液动力学反应以及移动和睡眠期间心率变异性（HRV）反应。
在献血之前，没有献血者在移动期间出现 OI。献血后，26 名献血者中有 6 名（23%；95%置信区间，9 至 44）至少出现一次 OI 症状。26 名献血者中有 3 名（12%；95%置信区间，2 至 30）因严重 OI 症状而提前终止移动程序。患有严重 OI 的患者心血管和脑组织氧合反应降低。失血后，总自主功率的 HRV 指数保持不变，但在移动期间观察到交感神经增加和副交感神经减少，而在睡眠期间也观察到，这表明血容量减少的自主神经效应延长。
我们描述了术后 OI 的一种特定的血容量减少成分，独立于术后自主神经功能障碍、炎症、阿片类药物和疼痛。
ClinicalTrials.gov（NCT04499664）；2020 年 8 月 5 日注册。
