Kinsky Michael P, Vaid Sumreen U, Vane Luiz A, Prough Donald S, Kramer George C
Resuscitation Research Laboratory, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas 77555-0801, USA.
Shock. 2008 Jul;30(1):55-63. doi: 10.1097/SHK.0b013e31815d1a85.
beta-Adrenergic agonists can enhance vascular volume expansion after a fluid bolus. The present study addresses how the beta-adrenergic antagonist esmolol influences volume expansion and fluid balance during normovolemia (series 1) and hypovolemia (series 2). Sheep were instrumented, and the spleen was removed. For series 1, continuous infusion of 50 to 100 microg.kg(-1).min(-1) esmolol (n = 6) or control (no drug; n = 6) was begun 30 min before administration of a 24-mL kg(-1) 20-min bolus of 0.9% NaCl. For series 2, anesthetized sheep were infused with 50 to 100 microg.kg(-1).min(-1) esmolol (n = 6) or control (no drug; n = 6) 30 min before a-20 mL kg(-1) hemorrhage. Fluid resuscitation (0.9% NaCl) was begun 30 min after hemorrhage. The 24-mL kg(-1) 20-min bolus was followed by titrated fluid therapy. Hemoglobin, fluid in, and urinary output were used to calculate changes in plasma volume (DeltaPV), extravascular volume (DeltaEVV = fluid in - urinary output - DeltaPV), volume expansion efficiency (VEE = fluid in / DeltaPV), and fluid distribution ratio (DeltaPV/DeltaEVV). Hemodynamics for both series were similar with the exception of heart rate. In series 1, peak DeltaPV was 9.1 +/- 1.0 mL kg(-1) in control and 3.7 +/- 1.0 mL kg(-1) at study end. Esmolol resulted in a lower peak DeltaPV (6.4 +/- 2.0 mL kg(-1)) and a negative DeltaPV (-0.4 +/- 0.6 mL kg(-1)) at study's end. Urinary output was lower, and EVV was greater with esmolol. In series 2, esmolol increased fluid requirements (67 +/- 7 mL kg(-1)) compared with control (54 +/- 5 mL kg(-1)). Esmolol reduced DeltaPV/DeltaEVV. These data suggest that esmolol impairs the vascular retention of fluid and may increase the amount of volume support during fluid resuscitation.
β-肾上腺素能激动剂可增强快速推注液体后的血管容量扩充。本研究探讨β-肾上腺素能拮抗剂艾司洛尔在血容量正常（系列1）和血容量不足（系列2）时如何影响容量扩充和液体平衡。对绵羊进行仪器植入，并切除脾脏。对于系列1，在给予24 mL/kg、持续20分钟的0.9%氯化钠推注前30分钟，开始持续输注50至100 μg·kg⁻¹·min⁻¹的艾司洛尔（n = 6）或对照（无药物；n = 6）。对于系列2，在麻醉的绵羊进行20 mL/kg出血前30分钟，输注50至100 μg·kg⁻¹·min⁻¹的艾司洛尔（n = 6）或对照（无药物；n = 6）。出血后30分钟开始液体复苏（0.9%氯化钠）。在24 mL/kg、持续20分钟的推注后进行滴定式液体治疗。使用血红蛋白、输入液体量和尿量来计算血浆容量变化（ΔPV）、血管外容量（ΔEVV = 输入液体量 - 尿量 - ΔPV）、容量扩充效率（VEE = 输入液体量 / ΔPV）和液体分布比（ΔPV/ΔEVV）。除心率外，两个系列的血流动力学相似。在系列1中，对照的峰值ΔPV为9.1±1.0 mL/kg，研究结束时为3.7±1.0 mL/kg。艾司洛尔导致峰值ΔPV较低（6.4±2.0 mL/kg），研究结束时ΔPV为负值（-0.4±0.6 mL/kg）。艾司洛尔组的尿量较低，血管外容量较高。在系列2中，与对照（54±5 mL/kg）相比，艾司洛尔增加了液体需求量（67±7 mL/kg）。艾司洛尔降低了ΔPV/ΔEVV。这些数据表明，艾司洛尔会损害液体在血管内的潴留，并可能增加液体复苏期间的容量支持量。
