AP-HP, Hôpital de Bicêtre, Service de Réanimation Médicale, Le Kremlin-Bicêtre, France.
Crit Care Med. 2011 Apr;39(4):689-94. doi: 10.1097/CCM.0b013e318206d2a3.
To assess the effects of norepinephrine on cardiac preload, cardiac index, and preload dependency during septic shock.
Prospective interventional study.
Medical Intensive Care Unit.
We included 25 septic shock patients (62 ± 13 yrs old, Simplified Acute Physiology Score II 53 ± 12, lactate 3.5 ± 2.1 mmol/L, all receiving norepinephrine at baseline at 0.24 [25%-75% interquartile range: 0.12-0.48] μg/kg/min) with a positive passive leg raising test (defined by an increase in cardiac index ≥ 10%) and a diastolic arterial pressure ≤ 40 mm Hg.
We performed a passive leg raising test (during 1 min) at baseline. Immediately after, we increased the dose of norepinephrine (to 0.48 [0.36-0.71] μg/kg/min) and, when the hemodynamic status was stabilized, we performed a second passive leg raising test (during 1 min). We finally infused 500 mL saline.
Increasing the dose of norepinephrine significantly increased central venous pressure (+23% ± 12%), left ventricular end-diastolic area (+9% ± 6%), E mitral wave (+19% ± 23%), and global end-diastolic volume (+9% ± 6%). Simultaneously, cardiac index significantly increased by 11% ± 7%, suggesting that norepinephrine had recruited some cardiac preload reserve. The second passive leg raising test increased cardiac index to a lesser extent than the baseline test (13% ± 8% vs. + 19% ± 6%, p < .05), suggesting that norepinephrine had decreased the degree of preload dependency. Volume infusion significantly increased cardiac index by 26% ± 15%. However, cardiac index increased by <15% in four patients (fluid unresponsive patients) while the baseline passive leg raising test was positive in these patients. In three of these four patients, the second passive leg raising test was also negative, i.e., the second passive leg raising test (after norepinephrine increase) predicted fluid responsiveness with a sensitivity of 95 [76-99]% and a specificity of 100 [30-100]%.
In septic patients with a positive passive leg raising test at baseline suggesting the presence of preload dependency, norepinephrine increased cardiac preload and cardiac index and reduced the degree of preload dependency.
评估去甲肾上腺素对脓毒性休克时心脏前负荷、心指数和前负荷依赖性的影响。
前瞻性干预研究。
重症监护病房。
我们纳入了 25 例脓毒性休克患者（62 ± 13 岁，简化急性生理学评分 II 53 ± 12，乳酸 3.5 ± 2.1 mmol/L，所有患者在基线时均接受去甲肾上腺素治疗，起始剂量为 0.24 [25%-75% 四分位间距：0.12-0.48] μg/kg/min），其被动抬腿试验阳性（定义为心指数增加≥10%）且舒张压≤40 mmHg。
我们在基线时进行了 1 分钟的被动抬腿试验。立即在该试验后增加去甲肾上腺素剂量（增至 0.48 [0.36-0.71] μg/kg/min），当血流动力学状态稳定后，我们进行了第二次 1 分钟的被动抬腿试验。最后我们输注 500 mL 生理盐水。
增加去甲肾上腺素剂量可显著增加中心静脉压（+23% ± 12%）、左心室舒张末期面积（+9% ± 6%）、E 尖瓣波（+19% ± 23%）和全心舒张末期容积（+9% ± 6%）。同时，心指数显著增加了 11% ± 7%，提示去甲肾上腺素已募集了部分心脏前负荷储备。第二次被动抬腿试验增加心指数的程度小于基线试验（13% ± 8%比+ 19% ± 6%，p <.05），提示去甲肾上腺素降低了前负荷依赖性的程度。容量输注可使心指数显著增加 26% ± 15%。然而，在 4 名患者（对液体无反应的患者）中，心指数增加幅度＜15%，而这些患者的基线被动抬腿试验为阳性。在这 4 名患者中的 3 名中，第二次被动抬腿试验也是阴性的，即第二次被动抬腿试验（在增加去甲肾上腺素后）预测液体反应性的敏感性为 95 [76-99]%，特异性为 100 [30-100]%。
在基线时被动抬腿试验阳性提示存在前负荷依赖性的脓毒性休克患者中，去甲肾上腺素增加了心脏前负荷和心指数，并降低了前负荷依赖性的程度。
