Raghavan Murugan, Marik Paul E
Liver Transplant ICU, Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Neurocrit Care. 2006;4(2):179-89. doi: 10.1385/NCC:4:2:179.
Severe intracranial hypertension (IH) in the setting of fulminant hepatic failure (FHF) carries a high mortality and is a challenging disease for the critical care provider. Despite considerable improvements in the understanding of the pathophysiology of cerebral edema during liver failure, therapeutic maneuvers that are currently available to treat this disease are limited. Orthotopic liver transplantation is currently the only definitive therapeutic strategy that improves outcomes in patients with FHF. However, many patients die prior to the availability of donor organs, often because of cerebral herniation. Currently, two important theories prevail in the understanding of the pathophysiology of IH during FHF. Ammonia and glutamine causes cytotoxic cerebral injury while cerebral vasodilation caused by loss of autoregulation increases intracranial pressure (ICP) and predisposes to herniation. Although ammonia-reducing strategies are limited in humans, modulation of cerebral blood flow seems promising, at least during the early stages of hepatic encephalopathy. ICP monitoring, transcranial Doppler, and jugular venous oximetry offer valuable information regarding intracranial dynamics. Induced hypothermia, hypertonic saline, propofol sedation, and indomethacin are some of the newer therapies that have been shown to improve survival in patients with severe IH. In this article, we review the pathophysiology of IH in patients with FHF and outline various therapeutic strategies currently available in managing these patients in the critical care setting.
暴发性肝衰竭(FHF)背景下的严重颅内高压(IH)死亡率很高,对重症监护人员来说是一种具有挑战性的疾病。尽管在理解肝衰竭期间脑水肿的病理生理学方面有了相当大的进展,但目前可用于治疗这种疾病的治疗手段仍然有限。原位肝移植是目前唯一能改善FHF患者预后的确定性治疗策略。然而,许多患者在获得供体器官之前就死亡了,通常是因为脑疝。目前,在理解FHF期间IH的病理生理学方面有两种重要的理论。氨和谷氨酰胺会导致细胞毒性脑损伤,而自动调节功能丧失引起的脑血管扩张会增加颅内压(ICP)并易发生脑疝。尽管在人类中降低氨的策略有限,但调节脑血流量似乎很有前景,至少在肝性脑病的早期阶段是这样。ICP监测、经颅多普勒和颈静脉血氧饱和度测定提供了有关颅内动力学的有价值信息。诱导性低温、高渗盐水、丙泊酚镇静和吲哚美辛是一些已被证明能提高严重IH患者生存率的新疗法。在本文中,我们回顾了FHF患者IH的病理生理学,并概述了目前在重症监护环境中管理这些患者可用的各种治疗策略。