Encephalopathy is acute and usually evolves over a few days and progresses through stages of drowsiness, hypersomnia, unresponsiveness and eventually, coma.
2. Cerebral Edema
Cerebral edema develops in all patients with stage IV encephalopathy. Pupillary abnormalities, muscular rigidity, decerebrate posturing, focal seizures and loss of brain stem reflexes are clinical indicators.
3. Coagulopathy and Bleeding
Failure in hepatic synthesis of clotting and fibrinolytic factors; altered platelet numbers and function; and intra-vascular coagulation may be responsible for coagulopathy. Bleeding from the upper gastro-intestinal tract is most common manifestation.
Majority of children with acute liver failure will have low blood glucose levels (< 40 mg/dl) at some time during the illness. Hypoglycemia worsens encephalopathy and also contributes to dysfunction of other organs.
5. Renal Dysfunction
Functional renal failure (Hepato-renal Syndrome) occurs in a majority of children with FHF. Features include acute sodium retention (urinary spot Na < 20 mEq/L), normal urinary sediment and oliguria (< 1 ml / kg / hr). Acute tubular necrosis (ATN) may occur in some cases.
6. Electrolyte Disturbances
Hyponatremia (low sodium level in body) as well as hypokalemia (low potassium level in body) are known to occur in patients with acute liver failure.
7. Cardiovascular and Pulmonary Complications
Most children with severe FHF have significant hypotension. Many of them have decreased vascular resistance and clinical features of “Warm Shock”. Profound hypotension with metabolic acidosis indicates poor prognosis in FHF. Most such children require mechanical ventilation.
Sepsis complicates ALF in more than 50% of children. Intensive care support with invasive modalities is partly responsible. Alteration in the immune system in FHF is also an important factor. Complicating septicemia increases the risk of morbidity and mortality.