Wajima Zen'ichiro, Shiga Toshiya, Imanaga Kazuyuki, Inoue Tetsuo
Department of Anesthesiology, Shioya Hospital, International University of Health and Welfare, 77 Tomita, Yaita, Tochigi, 329-2145, Japan,
J Anesth. 2013 Dec;27(6):890-4. doi: 10.1007/s00540-013-1622-8. Epub 2013 May 8.
There are no reports about the effect of bradycardia on stroke volume variation (SVV), and we hypothesized that induced bradycardia alters the value of SVV. Landiolol, an ultra-short-acting adrenergic β1-receptor blocking agent, was reported to induce bradycardia without decreasing blood pressure. The initial aim of this prospective study was to investigate changes in SVV values by induced bradycardia in patients with good cardiac function.
At 30 min after anesthesia induction, if heart rate (HR) was >80 bpm, the patient was chosen as a subject. Ten ASA physical status I-II patients aged 38-75 years who were scheduled for elective abdominal surgery were included in this study. Baseline values were recorded, and then administration of landiolol was started at 125 μg/kg/min for 1 min and then continued at 40 μg/kg/min. SVV and other parameters were recorded at baseline and 3 min after continuous landiolol injection.
Landiolol significantly decreased systolic arterial pressure, and diastolic arterial pressure, contrary to our expectations, and also HR, SVV, cardiac output, stroke volume index, and pressure of end-tidal CO(2), whereas systemic vascular resistance values increased significantly.
SVV decreased after continuous administration of a β1-adrenergic blocker, probably because of a decrease in the difference of maximum stroke volume (SV) and minimum SV, or the downward shift of the Frank-Starling curve that occurred after landiolol administration. We believe that SVV values might be overestimated or misinterpreted when HR is decreased by landiolol and might not necessarily indicate that the patient is hypervolemic or normovolemic.
目前尚无关于心动过缓对每搏量变异度（SVV）影响的报道，我们推测诱发的心动过缓会改变SVV值。据报道，超短效肾上腺素能β1受体阻滞剂兰地洛尔可诱发心动过缓而不降低血压。这项前瞻性研究的最初目的是调查心功能良好患者因诱发心动过缓导致的SVV值变化。
麻醉诱导后30分钟，若心率（HR）>80次/分钟，则将患者选为研究对象。本研究纳入了10例年龄在38 - 75岁、美国麻醉医师协会（ASA）身体状况分级为I - II级、计划进行择期腹部手术的患者。记录基线值，然后以125μg/kg/分钟的速度静脉输注兰地洛尔1分钟，之后以40μg/kg/分钟的速度持续输注。在基线以及持续输注兰地洛尔3分钟后记录SVV和其他参数。
与我们的预期相反，兰地洛尔显著降低了收缩压、舒张压、HR、SVV、心输出量、每搏量指数和呼气末二氧化碳分压，而全身血管阻力值显著增加。
持续给予β1肾上腺素能阻滞剂后SVV降低，可能是因为最大每搏量（SV）与最小SV之差减小，或者是兰地洛尔给药后Frank - Starling曲线向下移位。我们认为，当使用兰地洛尔使HR降低时，SVV值可能会被高估或误解，不一定表明患者是高血容量或血容量正常。
