Table Of Contents
Hepatic Encephalopathy
Hepatic encephalopathy AKA portosystemic encephalopathy is neurological dysfunction caused by excessive build up of nitrogenous waste products (glutamine) ****which cause osmotic imbalance leading to cerebral oedema.
Grading of hepatic encephalopathy (West Haven)
| Grade | Description |
|---|---|
| Grade I | Altered mood or behavior, sleep disturbance (reversed sleep pattern), dyspraxia, poor arithmetic, no asterixis |
| Grade II | Increased drowsiness, confusion, slurred speech, asterixis, personality change |
| Grade II | Incoherent, restless, asterixis, stupor |
| Grade IV | Coma (unresponsive to verbal or noxious stimulus) |
- Triggers
- Constipation
- Dehydration
- Electrolyte imbalance
- Infection
- Gastrointestinal bleeding
- High-protein diet
- Medications (sedatives and opiates)
- Pathophysiology
- Ammonia is produced by intestinal bacteria and is absorbed by the intestines into the bloodstream
- Ammonia builds up in systemic circulation due to;
- Functional impairment of the liver to metabolize ammonia
- Collateral vessels between portal and systemic circulation causes ammonia to bypass the liver and enter systemic circulation
- Ammonia reaches the brain where astrocytes clear it, involving the conversion of glutamate to glutamine
- Excess glutamine produced in neurons causes fluid shift and cerebral oedema
- Differentials
- Hypoglycaemia
- Sepsis
- Trauma
- Seizure (post-ictal)
- Treatment of hepatic encephalopathy
- Lactulose (aim for 2 – 3 soft stools daily)
- Speeds transit time and reduces constipation
- Promotes bacterial uptake of ammonia
- Reduces pH killing ammonia-producing bacteria
- Antibiotics e.g. rifamixin, neomycin, metronidazole: to reduce the number of bacteria producing ammonia
- Nutritional support (including nasogastric tube feeding)
- Lactulose (aim for 2 – 3 soft stools daily)
