Bryan A G, Bolsin S N, Vianna P T, Haloush H
Sir Humphrey Davy Department of Anaesthesia, Bristol Royal Infirmary, England.
J Cardiothorac Vasc Anesth. 1995 Apr;9(2):158-63. doi: 10.1016/S1053-0770(05)80187-9.
An intravenous infusion of dopamine at 2.5 microgram/kg/min was administered for 40 minutes to anesthetized cardiac surgical patients, and their renal function was measured. Five patients had the usual preoperative regimen of reduced fluid intake for the night and morning before surgery (nonhydrated), and five patients received normal saline, 2 mL/kg/hr intravenously, for 6 hours before anesthesia (hydrated). Renal function (measured by urine output, sodium excretion, free water clearance, and fractional excretion of sodium) was similar immediately before starting the dopamine infusion. All four variables were significantly higher in the hydrated group after 10 minutes; this difference becoming maximal after 40 minutes. Twenty minutes after stopping the dopamine infusion, renal function was similar in the two groups. This study indicates that preoperatively fluid-restricted patients demonstrate powerful salt and water conservation with reduced natriuretic and diuretic responses to a low-dose dopamine infusion when compared with hydrated patients. Patients with adequate fluid loading and intravascular volume will demonstrate a marked natriuresis and diuresis in response to low-dose dopamine infusion.
对麻醉的心脏手术患者静脉输注多巴胺，剂量为2.5微克/千克/分钟，持续40分钟，然后测量其肾功能。五名患者在手术前一晚和手术当天早晨遵循常规的术前方案，减少液体摄入量（未水化），另外五名患者在麻醉前6小时静脉输注生理盐水，速度为2毫升/千克/小时（水化）。在开始多巴胺输注前，两组患者的肾功能（通过尿量、钠排泄、自由水清除率和钠分数排泄来测量）相似。10分钟后，水化组的所有四项指标均显著更高；40分钟后这种差异达到最大。停止多巴胺输注20分钟后，两组患者的肾功能相似。这项研究表明，与水化患者相比，术前限制液体摄入的患者在低剂量多巴胺输注时，表现出强大的盐和水潴留能力，利钠和利尿反应减弱。液体负荷和血管内容量充足的患者对低剂量多巴胺输注会表现出明显的利钠和利尿作用。
