hepatic failure

Fulminant hepatic failure_
a syndrome is characterised by hepatic encephalopathy resuling frm sudden severe impairement of hepatic function,occuring within 4 wks of onset of symptoms in a absence of any evidence of pre existing liver disease.
Onset of encephalopathy within 7 days of symptoms is known as hyperacute hepatic failure.
Atiology-
1 acute viral hepatitis B n E
2 hepatotoxic drugs like cyclosporhin,methotrexate,valproic acid.
3 pregnancy
4 autoimmune hepatitis
5 wilson's disease
6 shock 7 poisoing.
Pathogenesis_elevated ammonia in the blood apparently play a role in the pathogenesis of hepatic encephalopathy.

Clinical features_
general features-weakness,nausea vomitting.Jaundice,rt hypochondriac pain.
Liver may enlarge initially but later shrinks.
Live dullness absent on percussion.Ascites n oedema develop later.
Featurs of hepatic encepalopathy_ reduce alertness,poor cöncentration,restlessness,manic episode,drausiness n coma.
Confusion,disoriantation,inversion of sleep rhythm,slurred speech,convulsion,foetor hepaticus n flapping tremor.
Featurs of cerebral oedema_bradycardia,hypertensiön,irregular respiration.
Unequal or abnormally reacting pupil,fixed pupil n spontaneous respiration.
Investigation_
1 urine contains proteion,bilirubin n urobilirubin.
2 leucocytosis
3 serum bilirubin is raised
4 hypoalbumineamia
5 prothrombin time is prolonged
6blood ammonia level r elevated.
7 plasma n urine amino acid increased
8 USG-shrunken liver 9 ICT raisd.
Complication_
encephalopathy,cerebral oedema,respiratory failure,bleeding n hypotension,hypothermia,ifections,pancreatitis,renal failure.
Management_
general-
monitor vital signs,hrly urine output.,central venous pressure,renal functions n electrolytes.
Fluid n electrolyte therapy.
Calories r supplied as glucose 300g/day orally or by nesogastric tube.
Ventilatory support for respiratory failure..
Cefotaxime iv plus metronidazole for infection.
Ranitidine 50mg IV 8hrly to prvent gastrointestinal beed.
Renal failure is treated with dialysis..Fresh frozen plasma if PT is more than 1.5 times normal.
Treatment of encephalopathy_
head elevation at 30degree n elective ventilation in pt with grade 3  n 4 encephalopathy.
Mannitol 20% 1g/ke body wt iv over half an hr.Dose may b repeted every 6 hr with serum osmolality kept below 310mosmol/L. Sodium thiopental bolus dose 2-4 mg/kg over 15 min is followed by iv infusion of 1_2 mg/kg/hr in resistant cases.