Editing Acute liver failure

"Sudden loss of hepatic function in a person without pre-existing liver disease"

== Classification ==

* Fulminant - development of encephalopathy within 8/52 of development of symptoms
* Subfulminant - have had liver disease for up to 26 weeks before encephalopathy

== Causes ==

* Drugs - paracetamol, flucloxacillin, anaesthetic agents
* Budd-Chiari
* Malignancy
* Fatty liver disease of pregnancy
* Wilson's disease
* HAV
* Autoimmune hepatitis
* Ischaemic hepatitis
* HBV

* Clinical course
** Sudden loss of functional hepatocyte mass
** Portal HTN
** Encephalopathy, coagulopathy, renal failure, sepsis
** MODS often occurs
** Death occurs from cerebral oedema of infection

== Complications ==

* Encephalopathy

{| class="wikitable"
|'''Grade'''
|'''Mental status'''
|'''Asterixis'''
|'''EEG'''
|-
|I
|Euphoria/depression
|Yes/no
|Usually normal
|-
|
|Mild confusion
|
|
|-
|
|Slurred speech
|
|
|-
|
|Disordered sleep
|
|
|-
|II
|Lethargy
|Yes
|Abnormal
|-
|
|Moderate confusion
|
|
|-
|III
|Marked confusion 
|Yes
|Abnormal
|-
|
|Incoherent
|
|
|-
|
|Sleeping but arousable
|
|
|-
|IV
|Coma
|No
|Abnormal
|}

* Cerebral oedema - common cause of death - secondary to ammonia, however lactulose doesn't help
** Decrease ICP to below 20-25mmHg - elevate head of bed, minimise stimulation, mannitol, hyperventilation
** Maintain cerebral perfusion pressure >50-60mmHg
** Once increased ICP develops, ominous sign. If it's visible on CT, likely irreversible damage, and transplant contraindicated.
** ICP monitors may or may not stack up - risk of haemorrhage.
* Coagulopathy
* Metabolic abnormalities
** Hypokalaemia
** Hyponatraemia
** Hypophosphataemia - paracetamol-induced liver failure
** Hypoglycaemia
* Renal failure
* Pulmonary dysfunction - oedema and pnuemonia
* Seizures
** Treat with phenytoin

== Determining need for transplant ==

* Kings College criteria
** Attempts to define those patients who are going to die without transplant
** '''Paracetamol overdose criteria:''' ''a bit too inclusive for paracetamol overdose - many patients meeting these criteria do not go on to need transplant''
*** pH <7.3 or
*** INR >6.5 and serum creatinine >300
** ''The'' '''non-paracetamol criteria''' ''are still valid though''
*** INR >6.5 ''or three of:''
*** INR >3.5
*** Bilirubin >301
*** Age <=10 or >40
*** Cause of drug toxicity
*** Time from onset of jaundice to encephalopathy >7 days


See also separate topic 'liver transplant'
[[Category:Liver]]