Warrillow S J, Bellomo R
Department of Intensive Care, Austin Health, Victoria, Australia.
Anaesth Intensive Care. 2014 Jan;42(1):78-88. doi: 10.1177/0310057X1404200114.
Severe cerebral oedema is a life-threatening complication of acute liver failure. Hyperammonaemia and cerebral hyperaemia are major contributing factors. A multimodal approach, which incorporates hyperventilation, haemodiafiltration, hypernatraemia and hypothermia (quadruple-H therapy), may prevent or attenuate severe cerebral oedema. This approach is readily administered by critical care clinicians and is likely to be more effective than the use of single therapies. Targeting of PaCO2 in the mild hyperventilation range, as seen in acute liver failure patients before intubation, aims to minimise hyperaemic cerebral oedema. Haemodiafiltration aims to achieve the rapid control of elevated blood ammonia concentrations by its removal and to reduce production via the lowering of core temperature. The administration of concentrated saline increases serum tonicity and further reduces cerebral swelling. In addition, the pathologically increased cerebral blood-flow is further attenuated by therapeutic hypothermia. The combination of all four treatments in a multimodal approach may be a safe and effective means of attenuating or treating the cerebral oedema of acute liver failure and preventing death from neurological complications.
严重脑水肿是急性肝衰竭的一种危及生命的并发症。高氨血症和脑充血是主要促成因素。一种多模式方法，包括过度通气、血液透析滤过、高钠血症和低温（四联-H疗法），可能预防或减轻严重脑水肿。这种方法由重症监护临床医生易于实施，并且可能比使用单一疗法更有效。将动脉血二氧化碳分压（PaCO2）靶向轻度过度通气范围，如在急性肝衰竭患者插管前所见，旨在将充血性脑水肿降至最低。血液透析滤过旨在通过去除升高的血氨浓度并通过降低核心温度来减少其产生，从而实现快速控制。给予浓盐水可增加血清张力并进一步减轻脑肿胀。此外，治疗性低温可进一步减轻病理性增加的脑血流量。以多模式方法联合所有四种治疗可能是减轻或治疗急性肝衰竭脑水肿并预防神经并发症导致死亡的一种安全有效的方法。
