Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, University of Rome, La Sapienza, Italy. andrea.morelli@uniroma1
Crit Care Med. 2013 Sep;41(9):2162-8. doi: 10.1097/CCM.0b013e31828a678d.
β-blocker therapy may control heart rate and attenuate the deleterious effects of β-stimulating catecholamines in septic shock. However, their negative chronotropy and inotropy may potentially lead to an inappropriately low cardiac output, with a subsequent compromise of microvascular blood flow. The purpose of the present pilot study was to investigate the effects of reducing heart rate to less than 95 beats per minute in patients with septic shock using the β-1 adrenoceptor blocker, esmolol, with specific focus on systemic hemodynamics and the microcirculation.
Prospective, observational clinical study.
Multidisciplinary ICU at a university hospital.
After 24 hours of initial hemodynamic optimization, 25 septic shock patients with a heart rate greater than or equal to 95 beats per minute and requiring norepinephrine to maintain mean arterial pressure greater than or equal to 65 mm Hg received a titrated esmolol infusion to maintain heart rate less than 95 beats per minute. Sublingual microcirculatory blood flow was assessed by sidestream dark-field imaging. All measurements, including data from right heart catheterization and norepinephrine requirements, were obtained at baseline and 24 hours after esmolol administration. Heart rates targeted between 80 and 94 beats per minute were achieved in all patients. Whereas cardiac index decreased (4.0 [3.5; 5.3] vs 3.1 [2.6; 3.9] L/min/m; p<0.001), stroke volume remained unchanged (34 [37; 47] vs 40 [31; 46] mL/beat/m; p=0.32). Microcirculatory blood flow in small vessels increased (2.8 [2.6; 3.0] vs 3.0 [3.0; 3.0]; p=0.002), while the heterogeneity index decreased (median 0.06 [interquartile range 0; 0.21] vs 0 [0; 0]; p=0.002). PaO2 and pH increased while PaCO2 decreased (all p<0.05). Of note, norepinephrine requirements were significantly reduced by selective β-1 blocker therapy (0.53 [0.29; 0.96] vs 0.41 [0.22; 0.79] µg/kg/min; p=0.03).
This pilot study demonstrated that heart rate control by a titrated esmolol infusion in septic shock patients was associated with maintenance of stroke volume, preserved microvascular blood flow, and a reduction in norepinephrine requirements.
β-受体阻滞剂治疗可控制心率并减轻脓毒性休克中β-刺激儿茶酚胺的有害作用。然而，其负性变时性和变力性可能导致心输出量过低，随后微血管血流受到影响。本前瞻性观察性临床研究的目的是通过β-1 肾上腺素受体阻滞剂艾司洛尔，将心率降低至 95 次/分钟以下，以观察其对脓毒性休克患者的影响，重点关注全身血流动力学和微循环。
前瞻性、观察性临床研究。
大学医院多学科 ICU。
在初始血流动力学优化 24 小时后，25 例心率大于或等于 95 次/分钟且需要去甲肾上腺素维持平均动脉压大于或等于 65mmHg 的脓毒性休克患者，接受艾司洛尔滴定输注以维持心率小于 95 次/分钟。通过侧流暗场成像评估舌下微循环血流。所有测量值，包括右心导管检查和去甲肾上腺素需求的数据，均在艾司洛尔给药前和给药后 24 小时获得。所有患者的目标心率均在 80-94 次/分钟之间。心指数降低（4.0[3.5;5.3]vs3.1[2.6;3.9]L/min/m；p<0.001），而每搏量不变（34[37;47]vs40[31;46]mL/beat/m；p=0.32）。小血管中的微循环血流增加（2.8[2.6;3.0]vs3.0[3.0;3.0]；p=0.002），而异质性指数降低（中位数 0.06[四分位距 0;0.21]vs0[0;0]；p=0.002）。PaO2 和 pH 值升高，而 PaCO2 降低（均 p<0.05）。值得注意的是，通过选择性β-1 阻滞剂治疗，去甲肾上腺素的需求显著降低（0.53[0.29;0.96]vs0.41[0.22;0.79]μg/kg/min；p=0.03）。
本研究表明，脓毒性休克患者通过艾司洛尔输注进行心率控制与维持每搏量、保留微血管血流和减少去甲肾上腺素需求有关。
