How should this patient be managed to reduce the risk from cerebral oedema and intracranial hypertension?
- Strict adherence to neuro-protective ventilation
- Deep sedation and mandatory ventilation with no sedation holds. Note the risk of cerebral oedema in fulminant liver failure can lasts for many days to weeks.
- Aggressive renal replacement therapy (RRT) with high volume exchanges 60-70mls/kg (4.8Litres) with no anticoagulation including no citrate. RRT is utilised in this scenario solely in view of the risk of cerebral oedema and not for the classical indications of metabolic acidosis or renal failure. High dose RRT in intubated fulminant patients is common place in the 7 UK liver transplant centres in patients with risk factors for cerebral oedema (see earlier) even in the absence of significant renal dysfunction. The mechanism of action is not completely understood but significant amounts of ammonia are removed during the process which is a surrogate marker of the risk of cerebral oedema
- Hypertonic saline to maintain sodium 145-150 mmol/L
- Hourly pupillary checks – and treatment with hypertonic saline as required
- MAP >80 mmHg (assuming ICP >20 mmHg)
- Daily ammonia
- ICP blots were previously utilised but in view of the risk of morbidity/mortality from these in patients with refractory coagulopathy and a national move away from them by other transplant centres, there use is no longer supported
The patient is reviewed by the transplant team, no psychiatric contraindications are identified and the patient meets Kings College Criteria for listing and is placed on the national super urgent transplant list.
Vasoplegic shock worsens and is commenced on vasopressin in addition to high dose noradrenaline. A liver transplant becomes available after 26 hours on the transplant list and the patients is deemed just stable enough to proceed to transplantation, which is ultimately successful. The patient is kept deeply sedated for 48 hours after transplantation as the risk of cerebral oedema can persist for some days following transplantation.