Hepatic Encephalopathy Experiment PDF

# Hepatic Encephalopathy Experiment ## Background This experiment focuses on ammonia intoxication hypothesis, which states that liver injury caused by rising blood ammonia leads to ammonia toxicity causing hepatic encephalopathy. ## Methods This experiment consists of two operations: - **Ligati...

# Hepatic Encephalopathy Experiment ## Background This experiment focuses on ammonia intoxication hypothesis, which states that liver injury caused by rising blood ammonia leads to ammonia toxicity causing hepatic encephalopathy. ## Methods This experiment consists of two operations: - **Ligation of the liver:** simulating liver injury. - **Injections of ammonia salt into the intestinal tract:** simulating ammonia increase. ### Experimental Steps 1. **Prepare the Rabbit:** - Weigh the rabbit. - Fix the rabbit in a supine position on a platform without anesthesia. - **Reason for no anesthesia:** Rabbits lose consciousness under general anesthesia, preventing observation of the transition from normal consciousness to hepatic encephalopathy. - Secure the rabbit's limbs with a rope knot and student assistance. 2. **Shear the hair of the upper abdomen.** 3. **Inject procaine local anesthesia:** - Pinch the rabbit's skin. - Insert the needle under the skin. - Push and retract the syringe, ensuring the needle reaches the intended incision site for anesthesia. 4. **Incision and Exploration:** - Make an 8 cm midline incision from the sternum xiphoid process down the abdomen. - Incise the subcutaneous muscle layer. - Identify the linea alba within the muscle layer. - Cut the abdominal muscles along the linea alba. - Open the abdominal cavity. - Locate the liver. - Cut the falciform ligament (a transparent film between the liver and diaphragm). - Visualize the right, left middle, and left lateral pages of the liver. 5. **Liver Surgery:** - Ligate blood vessels surrounding the root of the square pages (right, left middle, and left lateral). - Complete the liver surgery. 6. **Duodenum Surgery:** - Find the stomach. - Locate the duodenum to the right of the stomach. - Make a hole in the duodenum. - Insert a catheter into the duodenum, ensuring the direction of intubation is toward the intestines, not the stomach. - Secure the intubation with thread. - Avoid pulling the intestines. - Use hemostatic forceps or thread to close the abdominal incision. 7. **Observation and Physical Examination:** - Observe the rabbit's general condition. - Test corneal reflection by touching the eyes and observing the blink speed. - Monitor the respiratory rate. - Observe if the rabbit shows signs of irritability by tapping the table. 8. **Administer Injectable Drugs:** - Administer 5 ml of compound ammonium chloride every 5 minutes through the intubation. 9. **Observe the Rabbit’s Response:** - Monitor the rabbit's response for signs like corneal reflection, irritability, and reaction. - Continue observation until the rabbit exhibits spasm episodes. 10. **Decerebrate Rigidity:** - Observe decerebrate rigidity manifested by straight arms and legs and five claws. - Observe if the belly drums up. - Note the duration of this position (approximately 10 seconds). - The experiment is successful when these symptoms occur. 11. **Explanation:** - When the brain is suppressed, normal physiological reflexes disappear, including the corneal reflex. - As blood ammonia levels rise, ammonia enters the brain, stimulating the respiratory center, leading to hyperventilation. - Ammonia also affects the limbic region, causing abnormal activity and irritability in the rabbits. - This irritability is observed as twitching when the table is tapped. ## Conclusion This experiment demonstrates the effects of ammonia intoxication on the nervous system and demonstrates the stages of hepatic encephalopathy.