Mukherjee K K, Chhabra R, Khosla V K
Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh 160 012.
Indian J Gastroenterol. 2003 Dec;22 Suppl 2:S62-5.
Intracranial hypertension secondary to cerebral edema is the cause of death in 50%-80% of patients with fulminant hepatic failure (FHF). This is rarely seen in chronic hepatic failure. The genesis of cerebral edema in FHF is poorly understood. The grade of encephalopathy and coagulopathy are the most important predictors of outcome in FHF. However, it is important to emphasize that intracranial pressure (ICP) may not reflect clinical course. Decerebrate posturing may be seen with ICP recording of 16 mmHg, while a quarter of the patients may have brain damage without clinical signs of raised ICP. ICP monitoring is therefore vital. The gold standard for ICP monitoring is the intraventricular method. Non-invasive methods like computerized tomography scan and magnetic resonance imaging have poor correlation with ICP. Other methods like transcranial Doppler and jugular venous oximetry measurement of brain metabolites need evaluation. The main indications for ICP monitoring in FHF are (a) patients in grade III or IV encephalopathy and (b) patients undergoing liver transplantation. Generally, patients with an ICP >40 mmHg with cerebral perfusion pressure <50 mmHg for over 2 hours are poor subjects for liver transplant.
继发于脑水肿的颅内高压是暴发性肝衰竭（FHF）患者50%-80%的死亡原因。这在慢性肝衰竭中很少见。FHF中脑水肿的发病机制尚不清楚。肝性脑病分级和凝血功能障碍是FHF预后的最重要预测指标。然而，必须强调的是，颅内压（ICP）可能无法反映临床病程。当ICP记录为16 mmHg时可能会出现去大脑强直姿势，而四分之一的患者可能有脑损伤但无ICP升高的临床体征。因此，ICP监测至关重要。ICP监测的金标准是脑室内方法。计算机断层扫描和磁共振成像等非侵入性方法与ICP的相关性较差。经颅多普勒和颈静脉血氧饱和度测量脑代谢物等其他方法需要评估。FHF中ICP监测的主要指征是：（a）III级或IV级肝性脑病患者；（b）接受肝移植的患者。一般来说，ICP>40 mmHg且脑灌注压<50 mmHg持续超过2小时的患者不是肝移植的合适对象。
