Acute Liver Failure Flashcards
What is the most common cause of fulminant liver failure in the UK?
Paracetamol poisoning
What percentage of fulminant liver failure is attributed to drugs?(paracetamol, NSAIDs, antidepressants, halothane, rifimpacin)
70-80%
Name some of the other causes of liver failure…(name 7)
Hepatitis, herpes simplex, ecstasy, mushrooms, herbal remedies, ischeamic hepatitis, budd-chiari syndrome, surgical shock, Wilson’s disease, Reye’s syndrome, malignant infiltration and massive bacterial infection
Those who a cause cannot be found are labeled as having what?
Hepatitis caused by an unidentified virus
Acute liver failure is most commonly caused by what?
Decompensation of pre existing chronic liver disease
What is this chronic decompensation called?
Acute-on-chronic hepatic failure
How is fulminant liver failure different I.e. The one caused by paracetamol poisoning etc
Fulminant hepatic failure is a clinical syndrome resulting from massive necrosis of hepatocytes leading to a severe drop in liver function
What are the classifications of fulminant liver failure?
Hyper-acute = encephalopathy within 7d of jaundice onset Acute = encephalopathy within 8-28d of jaundice onset Sub-acute = encephalopathy within 5-26 weeks of jaundice onset
The risk of dangerous cerebral oedema decreases with what?
The longer it takes for encephalopathy to develop
Signs of liver failure include…
Jaundice, hepatic encephalopathy, fetor hepaticus (pear drops smell on breath), asterixis (liver flap), constructional apraxia (e.g. cannot copy a 5 pointed star)
Signs of chronic liver failure - acute on chronic failure
What blood tests would you do for liver failure?
FBC, U+E, LFT, clotting (increase PTT/INR), glucose, paracetamol levels, hepatitis and CMV/EBV serology, ferritin, alpha trypsin, caeruloplasmin antibodies
What microbiology tests would you do?
Blood culture, urine culture, ascetic tap
What radiology would you do to investigate?
CXR, abdominal USS, Doppler flow studies of portal vein (and hepatic vein of buds chiari suspected)
What 4 complications should you be wary of when managing liver failure?
Sepsis, hypoglycaemia, GI bleeds/varies, encephalopathy
What is the management of liver failure?
Surpportive - ITU, 20 degree head tilt, NG tube feeding to prevent aspiration infections, insert venous+urinary catheters, monitor closely with reg tests, high carb diet, give thiamine and folate supplements
Why is high carb diet used?
To prevent hypoglycaemia
Why are central venous and urinary catheters inserted?
To allow hourly fluid status checks to make sure the patient isn’t developing Hepatocytes renal syndrome especially
What is hepatorenal syndrome?
Cirrhosis+ascites+renal failure when other renal impairment causes have been excluded
What is the pathophysiology of HRS
Abnormal haemodynamics causes splanchic and systemic vasodilation but renal vasoconstriction! This causes pre renal kidney failure
HRS is split into two types, what occurs in type 1 and what is the prognosis?
Rapid circulatory and renal dysfunction
Median survival is just 2 weeks
Type 2 HRS, what occurs and what is the prognosis?
Circulatory and renal dysfunction but at a much slower and steadier rate
Median survival of 6 months
What treatments may be used in HRS?
Dialysis and combined liver and kidney transplant
What is done to treat the seizures due to encephalopathy in liver failure?
Lorazepam
What drugs should be avoided?
Sedatives and any others that require hepatic metabolism
How is the following complication treated?
Cerebral oedema
IV mannitol (20%) (osmotic balance agent for reducing fluid buildup in the brain) and hyperventilate
How is the following complication treated?
Ascites
Restrict fluid and salt intake, weigh daily, diuretics
How is the following complication treated?
Bleeding
Vitamin K and platelets. FFP, blood and endoscopy as required
How is the following complication treated?
Infection (blind treatment)
Ceftriaxone NEVER gentamicin as it contributes to renal failure
How is the following complication treated?
Hypoglycaemia
Give glucose
How is the following complication treated?
Encephalopathy
ITU, 20 degree head tilt, lactulose and regular enemas to prevent buildup of nitrogen forming bacteria
When is prognosis worst?
If patient has grade 3/4 encephalopathy, >40yrs old, albumin below 30g/L, high INR/PTT, drug induced, chronic decompensation worse than fulminant
What are the grades of hepatic encephalopathy?
1: altered mood/behaviour, sleep disturbance, dyspraxia, poor arithmetic but NO liver flap
2: drowsiness, confusion, slurred speech, inappropriate behaviour (collateral history) may have liver flap
3: incoherent, restless, liver flap, stupor
4: COMA
What drug’s effects will be amplified by liver failure?
Warfarin so monitor and adapt levels as required
What is the definition of acute liver failure?
Onset of hepatic decompensation with encephalopathy, coagulation disturbance and jaundice within 6 months of onset of symptoms (which will have been jaundice)