Hepatic encephalopathy is a medical condition that is characterized by mental disorders in patients with chronic liver diseases or portal hypertension. In hepatic encephalopathy there is buildup of toxins in the brain, which leads to neurological and psychological symptoms in patients suffering from this condition. This could be attributed to impaired liver function due to various causes such as cirrhosis, portal hypertension, liver failure, Reye’s disease, infection, hypovolemia or dehydration, constipation, electrolyte imbalance due to diuretics causing hypokalemia or hyponatremia, sedatives such as barbiturates or benzodiazepines, nitrogen overload in the gut or renal failure.
The symptoms of hepatic encephalopathy range from mild to severe depending on the above underlying causes. These include sleep disturbance, confusion, forgetfulness, mood swings, memory problems, lethargy, slurred speech, deterioration of motor skills such as writing or driving, tremors, changes in personality and behavior, irritability, apathy, disorientation, stupor, drowsiness, coma and even death if underlying disease is not managed on time.
Why Is Lactulose Used For Hepatic Encephalopathy?
The objective of hepatic encephalopathy treatment entails supportive care to the patient, identification and elimination of triggering factors, reduction of nitrogenous load from the intestines and clearance of ammonia from brain and systemic blood.
Supportive Care: It is necessary to monitor the bedside mental status of a patient with hepatic encephalopathy. Comatose patients should have endotracheal intubation and/or admitted to ICU. Dietary protein intake should be monitored by temporarily restricting protein, but should not be prolonged, as it would lead to malnutrition. Intake of food should be restored, through either mouth or nasogastric feeding, as soon as possible.
Identifying and Eliminating Triggering Factors: The triggering factors should be identified before the symptoms of hepatic encephalopathy worsen. The most commonly found precipitating factors in liver cirrhosis include gastrointestinal bleeding, infections such as pneumonia or bacterial peritonitis, medications such as sedatives, benzodiazepines, narcotics or diuretics, dehydration, renal failure, hypokalemia, constipation and transjugular intrahepatic portosystemic shunt (TIPS).
Intestinal Nitrogenous Waste Reduction: The nitrogenous waste from the intestines is reduced with either cathartics or antibiotics. Thus, lactulose plays an important role in catharsis (cleansing) of the gut. Lactulose, which is a non-absorbable disaccharide, has been used for decades. Intestinal bacteria metabolize it to lactic acid and other organic acids. The metabolism of lactulose to acids increases the acidity of the gut, thus favoring conversion of ammonium to ammonia. Gut acidification also promotes growth of good bacteria and reduces bad bacterial load. Lactulose is administered orally as 30-40 ml twice daily and the patients with severe hepatic encephalopathy can be given high doses (as high as 30 ml every 2-4 hours), either orally or through nasal tube.
In comatose patients, it can be given as enema (300 ml lactulose and 700 ml water) every 4 hours as needed. There might be some side-effects of lactulose such as diarrhea, abdominal cramping or bloating. In cases of overdose, patient might have symptoms of severe diarrhea, hypovolemia and electrolyte imbalance, which might flare up symptoms of encephalopathy, thus overdosing should be prevented. Antibiotics such as rifaximin at a dose of 400 mg thrice a day and 550 mg twice a day, metronidazole at a dose of 250 mg thrice a day and 500 mg thrice a day and neomycin at a dose of 250 mg 2-4 times daily. The combination of lactulose and rifaximin has proved to improve the quality of life of hepatic encephalopathy patients as compared to using lactulose alone.
Clearance of Ammonia from Systemic Circulation: Most of the patients with hepatic encephalopathy have low serum levels of zinc. Zinc therapy has been shown to decrease blood ammonia levels along with hepatic encephalopathy symptoms as compared to standard therapy. Further studies are needed for substantiation of zinc use. Prebiotics, probiotics and synbiotics have also been used for stimulation and balance of microflora of the gut.
Patients with cirrhosis are at a risk of developing new and recurrent episodes of hepatic encephalopathy, so their diet and nutrition should be monitored long term to avoid developing any precipitating factors. Liver transplantation is considered in cases of liver failure.
- Hepatic Encephalopathy: Causes, Symptoms, Treatment, Prognosis, Prevention, Diagnosis
- Is Hepatic Encephalopathy Life Threatening?