Department of Cardiothoracic Anesthesia and Intensive Care, Sahlgrenska University Hospital, Göteborg, Sweden.
Acta Anaesthesiol Scand. 2010 Feb;54(2):183-90. doi: 10.1111/j.1399-6576.2009.02121.x. Epub 2009 Sep 17.
Imbalance of the renal medullary oxygen supply/demand relationship can cause ischaemic acute renal failure (ARF). The use of dopamine for prevention/treatment of ischaemic ARF has been questioned. It has been suggested that dopamine may increase renal oxygen consumption (RVO(2)) due to increased solute delivery to tubular cells, which may jeopardize renal oxygenation. Information on the effects of dopamine on renal perfusion, filtration and oxygenation in man is, however, lacking. We evaluated the effects of dopamine on renal blood flow (RBF), glomerular filtration rate (GFR), RVO(2) and renal O(2) demand/supply relationship, i.e. renal oxygen extraction (RO(2)Ex).
Twelve uncomplicated, mechanically ventilated and sedated post-cardiac surgery patients with pre-operatively normal renal function were studied. Dopamine was sequentially infused at 2 and 4 ug/kg/min. Systemic haemodynamics were evaluated by a pulmonary artery catheter. Absolute RBF was measured using two independent techniques: by the renal vein thermodilution technique and by infusion clearance of paraaminohippuric acid (PAH), with a correction for renal extraction of PAH. The filtration fraction (FF) was measured by the renal extraction of (51)Cr-EDTA.
Neither GFR, tubular sodium reabsorption nor RVO(2) was affected by dopamine, which increased RBF (45-55%) with both methods, decreased renal vascular resistance (30-35%), FF (21-26%) and RO(2)Ex (28-34%). The RBF/CI ratio increased with dopamine. Dopamine decreased renal PAH extraction, suggestive of a flow distribution to the medulla.
In post-cardiac surgery patients, dopamine increases the renal oxygenation by a pronounced renal pre-and post-glomerular vasodilation with no increases in GFR, tubular sodium reabsorption or renal oxygen consumption.
肾脏髓质供氧/需氧平衡失调可导致缺血性急性肾衰竭（ARF）。多巴胺用于预防/治疗缺血性 ARF 的作用受到质疑。有人认为，多巴胺可能会增加肾氧耗（RVO₂），因为溶质输送到肾小管细胞会增加，这可能会危及肾脏氧合。然而，关于多巴胺对人类肾脏灌注、过滤和氧合作用的信息却很少。我们评估了多巴胺对肾血流量（RBF）、肾小球滤过率（GFR）、RVO₂和肾氧供需关系（即肾氧摄取率[RO₂Ex]）的影响。
我们对 12 例心脏手术后无并发症、机械通气和镇静的患者进行了研究，这些患者术前肾功能正常。多巴胺以 2 和 4ug/kg/min 的剂量顺序输注。通过肺动脉导管评估全身血液动力学。绝对 RBF 采用两种独立技术测量：通过肾静脉热稀释技术和对氨基马尿酸（PAH）的输注清除率测量，并对 PAH 的肾摄取进行校正。滤过分数（FF）通过（51）Cr-EDTA 的肾摄取来测量。
多巴胺对 GFR、肾小管钠重吸收或 RVO₂均无影响，用两种方法均可增加 RBF（45-55%），降低肾血管阻力（30-35%）、FF（21-26%）和 RO₂Ex（28-34%）。多巴胺增加了 RBF/CI 比值。多巴胺降低了肾 PAH 摄取，提示血流分布到髓质。
在心脏手术后患者中，多巴胺通过明显的肾小球前和肾小球后肾血管舒张增加了肾脏氧合，而不会增加 GFR、肾小管钠重吸收或肾氧耗。
