Department of Anaesthesiology and Intensive Care Medicine, Institution of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
Acta Anaesthesiol Scand. 2018 Oct;62(9):1229-1236. doi: 10.1111/aas.13156. Epub 2018 Jun 12.
Acute kidney injury is commonly seen after liver transplantation. The optimal perioperative target mean arterial pressure (MAP) for renal filtration, perfusion and oxygenation in liver recipients is not known. The effects of norepinephrine-induced changes in MAP on renal blood flow (RBF), oxygen delivery (RDO ), glomerular filtration rate (GFR) and renal oxygenation (=renal oxygen extraction, RO Ex) were therefore studied early after liver transplantation.
Ten patients with an intra- and post-operative vasopressor-dependent systemic vasodilation were studied early after liver transplantation during sedation and mechanical ventilation. To achieve target MAP levels of 60, 75 and 90 mm Hg, the norepinephrine infusion rate was randomly and sequentially titrated. At each target MAP, data on cardiac index (CI), RBF and GFR were obtained by transpulmonary thermodilution (PiCCO), the renal vein thermodilution technique and renal extraction of chromium ethylenediaminetetraaceticacid ( Cr-EDTA), respectively. Renal oxygen consumption (RVO ) and extraction (RO Ex) were calculated according to standard formulas.
At a target MAP of 75 mm Hg, CI (13%), RBF (18%), RDO (24%), GFR (31%) and RVO (20%) were higher while RO Ex was unchanged compared to a target MAP of 60 mm Hg. Increasing MAP from 75 up to 90 mm Hg increased RVR by 38% but had no further effects on CI, RBF, RDO or GFR.
In patients undergoing liver transplantation, RBF and GFR are pressure-dependent at MAP levels below 75 mm Hg. Our results suggest that MAP should probably be targeted to approximately 75 mm Hg for optimal perioperative renal filtration, perfusion and oxygenation in patients undergoing liver transplantation.
肝移植后常发生急性肾损伤。肝移植受者肾滤过、灌注和氧合的最佳围手术期平均动脉压（MAP）尚不清楚。因此，本研究旨在探讨肝移植后早期去甲肾上腺素诱导的 MAP 变化对肾血流量（RBF）、氧输送（RDO）、肾小球滤过率（GFR）和肾氧合（=肾氧摄取，RO Ex）的影响。
本研究纳入 10 例肝移植术后血管加压素依赖性全身血管扩张的患者，在镇静和机械通气期间进行研究。为达到目标 MAP 水平 60、75 和 90 mmHg，分别随机和连续滴定去甲肾上腺素输注率。在每个目标 MAP 下，通过经肺热稀释（PiCCO）、肾静脉热稀释技术和肾摄取铬乙二胺四乙酸（Cr-EDTA）分别获得心指数（CI）、RBF 和 GFR 数据。根据标准公式计算肾耗氧量（RVO）和摄取量（RO Ex）。
与目标 MAP 为 60 mmHg 相比，目标 MAP 为 75 mmHg 时 CI（13%）、RBF（18%）、RDO（24%）、GFR（31%）和 RVO（20%）更高，而 RO Ex 无变化。将 MAP 从 75 mmHg 增加到 90 mmHg 可使 RVR 增加 38%，但对 CI、RBF、RDO 或 GFR 无进一步影响。
在肝移植患者中，MAP 低于 75 mmHg 时 RBF 和 GFR 与压力有关。我们的研究结果表明，肝移植患者的 MAP 可能应靶向至约 75 mmHg，以实现最佳围手术期肾滤过、灌注和氧合。
