Andrei Stefan, Bar Stéphane, Nguyen Maxime, Bouhemad Bélaid, Guinot Pierre-Grégoire
Anaesthesiology and Critical Care Department, Dijon Bourgogne University Hospital, 2 Bd Maréchal de Lattre de Tassigny, 21000, Dijon, France.
Anaesthesiology and Critical Care Department, Carol Davila University of Medicine, Eroii Sanitari Bvd, no. 8, sector 5, Bucharest, Romania.
Intensive Care Med Exp. 2023 Aug 21;11(1):52. doi: 10.1186/s40635-023-00539-x.
Norepinephrine is a commonly used drug for treating vasoplegic acute circulatory failure in ICU. The prediction of norepinephrine macro- and micro-circulatory response is complicated by its uneven receptors' distribution between the arterial and the venous structures, and by the presence of a physiological vascular waterfall (VW) that disconnects the arterial and the venous circulation in two pressure systems. The objectives of this study were to describe the VW in patients with arterial hypotension due to vasodilatory circulatory shock, and its behavior according to its response to norepinephrine infusion.
A prospective, observational, bi-centric study has included adult patients, for whom the physician decided to initiate norepinephrine during the six first hours following admission to the ICU after cardiac surgery, and unresponsive to a fluid challenge. The mean systemic pressure (MSP) and the critical closing pressure (CCP) were measured at inclusion and after norepinephrine infusion.
Thirty patients were included. Norepinephrine increased arterial pressure and total peripheral resistances in all cohort. The cohort was dichotomized as VW responders (patients with a change of VW over the least significant change (≥ 93% increase in VW)), and as VW non-responders. In 19 (63%) of the 30 patients, VW increased from 3.47 [- 14.43;7.71] mmHg to 43.6 [25.8;48.1] mmHg, p < 0.001) with norepinephrine infusion, being classified as VW responders. The VW responders improved cardiac index (from 1.8 (0.6) L min m to 2.2 (0.5) L min m, p = 0.002), capillary refill time (from to 4.2 (1.1) s to 3.1 (1) s, p = 0.006), and pCO gap (from 9 [7;10] mmHg to 6 [4;8] mmHg, p = 0.04). No baseline parameters were able to predict the VW response to norepinephrine. In comparison, VW non-responders did not significantly change the VW (from 5 [-5;16] mmHg to -2 [-12;15] mmHg, p = 0.17), cardiac index (from 1.6 (0.3) L min m to 1.8 (0.4) L min m, p = 0.09) and capillary refill time (from 4.1 (1) s to 3.7 (1.4), p = 0.44).
In post-cardiac surgery patients with vasoplegic arterial hypotension, the vascular waterfall is low. Norepinephrine did not systematically restore the vascular waterfall. Increase of the vascular waterfall was associated with an improvement of laboratory and clinical parameters of tissue perfusion.
去甲肾上腺素是重症监护病房（ICU）中治疗血管麻痹性急性循环衰竭的常用药物。去甲肾上腺素对宏观和微观循环反应的预测较为复杂，这是由于其受体在动脉和静脉结构中的分布不均，以及存在生理性血管瀑布（VW），该瀑布将动脉和静脉循环分隔在两个压力系统中。本研究的目的是描述血管扩张性循环休克所致动脉低血压患者的血管瀑布情况，以及其对去甲肾上腺素输注反应的行为表现。
一项前瞻性、观察性、双中心研究纳入了成年患者，这些患者在心脏手术后入住ICU的最初6小时内，医生决定开始使用去甲肾上腺素，且对液体冲击无反应。在纳入时和去甲肾上腺素输注后测量平均体循环压力（MSP）和临界关闭压力（CCP）。
共纳入30例患者。去甲肾上腺素使所有队列患者的动脉压和总外周阻力升高。该队列被分为血管瀑布反应者（血管瀑布变化超过最小显著变化（血管瀑布增加≥93%）的患者）和血管瀑布无反应者。在30例患者中的19例（63%）中，去甲肾上腺素输注后血管瀑布从3.47[-14.43；7.71]mmHg升高至43.6[25.8；48.1]mmHg，p<0.001），被归类为血管瀑布反应者。血管瀑布反应者的心脏指数有所改善（从1.8（0.6）L·min·m²升至2.2（0.5）L·min·m²，p = 0.002），毛细血管再充盈时间（从4.2（1.1）秒降至3.1（1）秒，p = 0.006），以及pCO₂差值（从9[7；10]mmHg降至6[4；8]mmHg，p = 0.04）。没有基线参数能够预测血管瀑布对去甲肾上腺素的反应。相比之下，血管瀑布无反应者的血管瀑布没有显著变化（从5[-5；16]mmHg降至-2[-12；15]mmHg，p = 0.17），心脏指数（从1.6（0.3）L·min·m²升至1.8（0.4）L·min·m²，p = 0.09）和毛细血管再充盈时间（从4.1（1）秒降至3.7（1.4）秒，p = 0.44）。
在心脏手术后出现血管麻痹性动脉低血压的患者中，血管瀑布较低。去甲肾上腺素并非总能恢复血管瀑布。血管瀑布的增加与组织灌注的实验室和临床参数改善相关。
