liver acute liver failure 15 01 14

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Acute liver failure Hepatic encephalopathy and coagulopathy within 12 to 26 wks of jaundice in a patient without preexisting liver disease

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Acute viral hepatitis

Most common cause – 70 %


Other causes

Amanita phalloides (mushroom) poisoning

Paracetamol toxicity – common in Europe and North America

Reye's syndrome Acute fatty liver of pregnancy Wilson's disease Shock Malignant disease of the liver


HELLP Syndrome Hemolysis, Elevated Liver

enzymes, Low Platelets Severe, life-threatening

complication of PET Delivery - only known

treatment


INVESTIGATIONS - cause

IgM anti-HBc IgM anti-HAV Anti-HCV, cytomegalovirus, herpes

simplex, Epstein-Barr virus Caeruloplasmin, serum copper, urinary

copper, slit-lamp eye examination Autoantibodies: ANA, ASMA, LKM Doppler ultrasound of liver


COMPLICATIONS Encephalopathy and cerebral edema Hypoglycemia Metabolic acidosis Infection (bacterial, fungal) Renal failure Multi-organ failure (hypotension and

respiratory failure)


Hepatic encephalopathy

Cerebral disturbance›Cardinal manifestation


Ammonia Synthesized predominantly

› Gut microorganisms Detoxified in astrocytes to

osmotically active glutamine Contribute to

› Hepatic encephalopathy› Cerebral edema


Hyperammonemia treatment

Lactulose Nonabsorbable oral antibiotics


Cerebral edema

Causes intracranial hypertension


Cytotoxic cerebral edema

Results from astrocyte swelling rather than a leaky blood brain barrier (vasogenic cerebral edema)

Corticosteroids are not recommended


Manifestations

Decreasing consciousness Hyperventilation Systemic hypertension Pupillary abnormalities Decerebrate posturing, Uncal herniation and death


ICP monitoring

Gold standard for measuring and monitoring ICH› < 25 mm Hg

Neuroimaging - not reliable in diagnosing early ICH› To exclude other problems (e.g.,

intracranial bleeding or stroke)


ICP transducer

Requires correction of underlying coagulopathy

Portal of entry for infectious organisms

Can precipitate intracranial hemorrhage


Mannitol First-line therapy for intracranial hypertension

Elevate head of the bed to 30 degrees


Refractory cerebral edema

IV hypertonic saline

IV thiopental


Hypothermia (e.g., 32° to 33°C)

External cooling blankets

In refractory cerebral edema

Require an ICP monitor


Infection

Main cause of death in ALF

Signs - frequently absent


Most common sites

Lung Urinary tract Blood


Most common organisms

Gram-positive cocciStaphylococciStreptococci

Enteric GNB Candida


Sedation Propofol and benzodiazepines

are most commonly used Propofol decreases cerebral

blood flow and lowers intracranial pressure


Parenteral vitamin K

Recommended empirically in all patients


Cryoprecipitate In patients who have significant hypofibrinogenemia (100 mg/dL)


Antifibrinolytic agents

Aminocaproic acid in hyperfibrinolytic state › Diffuse mucosal and puncture wound oozing

› Increased clot lysis time


rFVIIa Recombinant factor VIIa

› when FFP has failed to correct PT/INR

› Volume overloaded Given before invasive

procedures with a high risk of bleeding


H2 receptor antagonists/PPI

Incidence of upper GI bleeding decreased


Blood glucose

Checked every 1–2 hrs High risk for hypoglycemia Hyperglycemia exacerbate

intracranial hypertension Insulin infusions - glucose

levels < 50 mg/dL


Maintain CPP of 50–80 mm Hg

CPP = Mean arterial pressure – ICP Correct hypovolemia before

vasopressors › Norepinephrine preferred to

dopamine› Hydrocortisone improve the

vasopressor response to norepinephrine


Fever

Exacerbates ICP Treat aggressively with cooling

blankets, fans, or other noninvasive devices

NSAIDs and acetaminophen are not recommended


Renal function Urine sodium

› low (10 mEq/L) in prerenal azotemia and functional renal failure (hepatorenal syndrome)

› high in acute tubular necrosis Casts and renal tubular cells in the

urine suggest ATN IV fluid challenge (1L) to exclude

prerenal azotemia


Serum electrolytes

Monitor once or twice daily

Hyponatremia ›Exacerbate edema›Avoided strictly

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Mechanical Ventilation

May be needed

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Etiology-specific therapy

Paracetamol poisoning - NAC Amanita - Penicillin G and NAC HSV – Acyclovir AIH - Methylprednisolone HBV - Lamivudine AFLP/HELLP - Delivery of fetus


Amanita mushroom poisoning

Reduce the toxin load› Gastric lavage› Instillation of charcoal

Hemodialysis - remove toxins from the serum

Lower entero-hepatic toxin load - Uncertain › pencillin, cytochrome c, and silymarin


Liver transplantation

Life-saving

liver acute liver failure 15 01 14

Health & Medicine

intracranial bleeding

refractory cerebral

intracranial pressurewww

intracranial hemorrhage

cerebral blood flow

serum copper

elevated liver enzymes

hrs high risk